REMEDIAL INVESTIGATION REPORT
West Van Buren Area WQARF Registry Site
Phoenix, Arizona
Volume I

Terranext Project No. 03103154

Prepared For:
Arizona Department of Environmental Quality
1110 West Washington
Phoenix, Arizona 85007

August 2012

 REMEDIAL INVESTIGATION REPORT
West Van Buren Area WQARF Registry Site
Phoenix, Arizona

Volume I

August 2012

Reviewed By:

Arthur (I. Gord Kevin C. Snyder, 
Terranext Projectgw gel? Arizona Department of Environmental Quality

    

 

TABLE OF CONTENTS
1.0 West Van Buren Area Site Conceptual Model ...................................................................... 1-1
1.1 Introduction..................................................................................................................... 1-1
1.2 WQARF Process ............................................................................................................ 1-2
1.3 Site Background ............................................................................................................. 1-2
1.3.1 Site Description........................................................................................................ 1-2
1.3.2 Site History .............................................................................................................. 1-3
1.3.2.1 Early Regulatory Efforts .................................................................................. 1-3
1.3.2.2 WVBG ............................................................................................................. 1-4
1.3.2.3 Phoenix Terminal Group.................................................................................. 1-5
1.3.2.4 Facility Histories.............................................................................................. 1-5
1.3.2.5 Recent Regulatory Efforts.............................................................................. 1-12
1.4 Site Contaminants ........................................................................................................ 1-22
1.5 Contaminant Sources ................................................................................................... 1-22
1.6 Physiography................................................................................................................. 1-23
1.7 Meteorology ................................................................................................................. 1-24
1.8 Surface Water Features ................................................................................................. 1-24
1.8.1 Salt River ............................................................................................................. 1-24
1.8.2 RID Canal System................................................................................................ 1-24
1.8.3 SRP Lateral Canals .............................................................................................. 1-25
1.9 Hydrogeologic Setting .................................................................................................. 1-25
1.10 Ecology ....................................................................................................................... 1-26
2.0 Previous Investigations .......................................................................................................... 2-1
2.1 Facilities Not Required To Investigate Groundwater .................................................... 2-2
2.2 ADEQ Area Wide Investigations.................................................................................... 2-6
2.2.1 Activities from 1986-1998....................................................................................... 2-6
2.2.1.1 Kleinfelder Inventory....................................................................................... 2-7
2.2.1.2 Weston Inventory/Model Preparation.............................................................. 2-7
2.2.2 Activities from 1999-Current................................................................................... 2-7
2.2.2.1 Land and Water Use Study ................................................................................... 2-9

 2.2.2.2 Passive Diffusion Bag Sampler Evaluation ........................................................ 2-11
2.2.2.3 Chromium-Initiated Well Development ............................................................. 2-11
2.2.3 RID System Characterization ................................................................................... 2-12
2.3 Facility Investigational Work ....................................................................................... 2-13
2.3.1 Reynolds ................................................................................................................ 2-13
2.3.2 VW&R ................................................................................................................... 2-16
2.3.3 MCMM .................................................................................................................. 2-18
2.3.4 Dolphin .................................................................................................................. 2-21
2.3.5 ALSCo ................................................................................................................... 2-24
2.3.6 CRC........................................................................................................................ 2-27
2.3.7 U.S. DOE WAPA .................................................................................................. 2-28
2.3.8 POS ........................................................................................................................ 2-30
2.3.9 ALASG .................................................................................................................. 2-31
2.4 Remedial Activities ...................................................................................................... 2-32
2.4.1 Facility Activities................................................................................................... 2-32
2.4.1.1 Reynolds ........................................................................................................ 2-32
2.4.1.2 VW&R ........................................................................................................... 2-33
2.4.1.3 MCMM .......................................................................................................... 2-33
2.4.1.4 Dolphin .......................................................................................................... 2-33
2.4.1.5 CRC................................................................................................................ 2-34
2.4.2 ADEQ ERA ........................................................................................................... 2-35
3.0 Hydrogeology ........................................................................................................................ 3-1
3.1 Regional Geology ........................................................................................................... 3-1
3.2 WVBA Geology.............................................................................................................. 3-2
3.3 Regional Hydrogeology .................................................................................................. 3-5
3.4 WVBA Hydrogeology ................................................................................................... 3-6
3.4.1 Water Levels ....................................................................................................... 3-7
3.4.2 Hydraulic Gradients ............................................................................................ 3-8
3.4.3 Vertical Gradients ............................................................................................... 3-9
3.4.4 Aquifer Tests..................................................................................................... 3-10

 4.0 Nature and Extent of Contamination ..................................................................................... 4-1
4.1 Identification of Contaminants and Contaminant Sources ............................................ 4-1
4.2 Source Investigations ..................................................................................................... 4-3
4.2.1 Eastern Portion of WVBA ..................................................................................... 4-3
4.2.1.1 ALSCo ............................................................................................................. 4-4
4.2.1.2 MCMM ............................................................................................................ 4-5
4.2.1.3 CRC.................................................................................................................. 4-6
4.2.1.4 Operable Unit 3................................................................................................ 4-6
4.2.2 Central Portion of WVBA ..................................................................................... 4-8
4.2.2.1 Reynolds .......................................................................................................... 4-9
4.2.2.2 U.S. DOE ....................................................................................................... 4-10
4.2.2.3 ALASG .......................................................................................................... 4-10
4.2.2.4 VW&R ........................................................................................................... 4-11
4.2.2.5 West Central Phoenix Area WQARF Site ..................................................... 4-12
4.2.3 Western Portion of WVBA.................................................................................. 4-13
4.2.3.1 Dolphin .......................................................................................................... 4-14
4.2.3.2 POS ................................................................................................................ 4-16
4.3 Groundwater ................................................................................................................ 4-16
4.3.1 UAU1................................................................................................................... 4-17
4.3.1.1 1998................................................................................................................ 4-17
4.3.1.2 2003................................................................................................................ 4-18
4.3.1.3 2008................................................................................................................ 4-19
4.3.2 UAU2................................................................................................................... 4-20
4.3.2.1 1998................................................................................................................ 4-20
4.3.2.2 2003................................................................................................................ 4-20
4.3.2.3 2008................................................................................................................ 4-21
4.3.3 MAU .................................................................................................................... 4-21
4.3.3.1 1998................................................................................................................ 4-21
4.3.3.2 2003................................................................................................................ 4-22
4.3.3.3 2008................................................................................................................ 4-22
4.4 Canal Water ................................................................................................................. 4-23

 5.0 Contaminant Fate and Transport............................................................................................ 5-1
5.1 Potential Routes of Migration ........................................................................................ 5-1
5.1.1 Unsaturated Flow (Soils) ....................................................................................... 5-1
5.1.2 Saturated Flow (Groundwater) .............................................................................. 5-2
5.1.3 Canal Water ........................................................................................................... 5-3
5.1.4 Vapor Intrusion ...................................................................................................... 5-3
5.2 Contaminant Migration .................................................................................................. 5-4
5.2.1 Factors Affecting Contaminant Migration............................................................. 5-4
5.2.1.1 Naturally Occurring Factors ............................................................................ 5-4
5.2.1.2 Man-Induced Factors ....................................................................................... 5-6
5.2.2 Groundwater Modeling Methods and Results ....................................................... 5-7
6.0 Summary ................................................................................................................................ 6-1
6.1 Site Physical Characteristics ........................................................................................... 6-1
6.2 Site Hydrogeology .......................................................................................................... 6-3
6.3 Nature and Extent of Contamination .............................................................................. 6-4
6.4 Contaminant Fate and Transport .................................................................................... 6-9
7.0 References.............................................................................................................................. 7-1

TABLES
Table 2-1
Table 2-2
Table 2-3
Table 2-4
Table 2-5
Table 3-1
Table 3-2
Table 4-1
Table 4-2
Table 4-3
Table 4-4
Table 4-5
Table 5-1

Well Construction Information
June/July 2000 RID Canal Water Quality Data (µg/l)
June 2003 RID Canal Water Quality Data
September 2008 RID Well Analytical Results
Analytical Summary for Highest Detected Concentrations of Soil Gas and Soil
Samples Collected at Select Facilities within the West Van Buren Project Area
Well Construction Information and Groundwater Elevations
Vertical Hydraulic Gradients
Contaminant of Concern Analytical Data for Mid 1988
Contaminant of Concern Analytical Data for Mid 1993
Contaminant of Concern Analytical Data for January through July 1998
Contaminant of Concern Analytical Data for March through June 2003
Contaminant of Concern Analytical Data for March and April 2008
Physical Properties of PCE, TCE, and 1,1-DCE

 VOLUME II - FIGURES
Figure 1-1

Site Boundary

Figure 2-1
Figure 2-2
Figure 2-3
Figure 2-4
Figure 2-5
Figure 2-6

Facility Locations
Well Location Map
UAU1 Well Location Map
UAU2 Well Location Map
MAU Well Location Map
RID Well Location Map

Figure 3-1
Figure 3-2
Figure 3-3
Figure 3-4
Figure 3-5
Figure 3-6
Figure 3-7
Figure 3-8
Figure 3-9
Figure 3-10
Figure 3-11
Figure 3-12
Figure 3-13
Figure 3-14
Figure 3-15
Figure 3-16
Figure 3-17
Figure 3-18
Figure 3-19
Figure 3-20
Figure 3-21
Figure 3-22
Figure 3-23
Figure 3-24
Figure 3-25
Figure 3-26
Figure 3-27
Figure 3-28
Figure 3-29
Figure 3-30
Figure 3-31
Figure 3-32
Figure 3-33
Figure 3-34
Figure 3-35

Geologic Cross-Section Locations
Cross Section A – A’
Cross Section B – B’
Cross Section C – C’
Cross Section D – D’
Cross Section E – E’
Cross Section F – F’
UAU1 Groundwater Elevation Contours, Third Quarter 1993
UAU1 Groundwater Elevation Contours, Fourth Quarter 1993
UAU1 Groundwater Elevation Contours, First Quarter 1998
UAU1 Groundwater Elevation Contours, Second Quarter 1998
UAU1 Groundwater Elevation Contours, Third Quarter 1998
UAU1 Groundwater Elevation Contours, Fourth Quarter 1998
UAU1 Groundwater Elevation Contours, First Quarter 2003
UAU1 Groundwater Elevation Contours, Second Quarter 2003
UAU1 Groundwater Elevation Contours, Third Quarter 2003
UAU1 Groundwater Elevation Contours, Fourth Quarter 2003
UAU1 Groundwater Elevation Contours, First Quarter 2008
UAU2 Groundwater Elevation Contours, First Quarter 1998
UAU2 Groundwater Elevation Contours, Second Quarter 1998
UAU2 Groundwater Elevation Contours, Third Quarter 1998
UAU2 Groundwater Elevation Contours, Fourth Quarter 1998
UAU2 Groundwater Elevation Contours, First Quarter 2003
UAU2 Groundwater Elevation Contours, Second Quarter 2003
UAU2 Groundwater Elevation Contours, Third Quarter 2003
UAU2 Groundwater Elevation Contours, Fourth Quarter 2003
UAU2 Groundwater Elevation Contours, First Quarter 2008
MAU Groundwater Elevation Contours, First Quarter 1998
MAU Groundwater Elevation Contours, Second Quarter 1998
MAU Groundwater Elevation Contours, Third Quarter 1998
MAU Groundwater Elevation Contours, Fourth Quarter 1998
MAU Groundwater Elevation Contours, First Quarter 2003
MAU Groundwater Elevation Contours, Second Quarter 2003
MAU Groundwater Elevation Contours, Third Quarter 2003
MAU Groundwater Elevation Contours, Fourth Quarter 2003

 Figure 3-36
Figure 3-37
Figure 3-38
Figure 3-39
Figure 3-40

MAU Groundwater Elevation Contours, First Quarter 2008
Vertical Gradient Map, First Quarter 2003
Vertical Gradient Map, Second Quarter 2003
Vertical Gradient Map, Third Quarter 2003
Vertical Gradient Map, Fourth Quarter 2003

Figure 4-1
Figure 4-2
Figure 4-3
Figure 4-4
Figure 4-5
Figure 4-6
Figure 4-7
Figure 4-8
Figure 4-9
Figure 4-10
Figure 4-11
Figure 4-12
Figure 4-13
Figure 4-14
Figure 4-15
Figure 4-16
Figure 4-17
Figure 4-18
Figure 4-19
Figure 4-20
Figure 4-21
Figure 4-22
Figure 4-23
Figure 4-24
Figure 4-25
Figure 4-26
Figure 4-27
Figure 4-28
Figure 4-29
Figure 4-30
Figure 4-31
Figure 4-32
Figure 4-33
Figure 4-34
Figure 4-35
Figure 4-36
Figure 4-37
Figure 4-38

Contaminant Concentrations - 1988
Contaminant Concentrations - 1993
UAU1 PCE Concentrations - 1998
UAU1 PCE Concentrations - 2003
UAU1 PCE Concentrations – First Quarter 2008
UAU1 Total Cr Concentrations - 1998
UAU1 Total Cr Concentrations - 2003
UAU1 TCE Concentrations - 1998
UAU1 TCE Concentrations - 2003
UAU1 TCE Concentrations – First Quarter 2008
UAU1 1,1-DCE Concentrations - 1998
UAU1 1,1-DCE Concentrations - 2003
UAU1 1,1-DCE Concentrations – First Quarter 2008
UAU1 Total Cr Concentrations – First Quarter 2008
UAU2 PCE Concentrations – 1998
UAU2 TCE Concentrations – 1998
UAU2 1,1-DCE Concentrations – 1998
UAU2 PCE Concentrations – 2003
UAU2 TCE Concentrations – 2003
UAU2 1,1-DCE Concentrations – 2003
UAU2 Total Cr Concentrations – 2003
UAU2 PCE Concentrations – First Quarter 2008
UAU2 TCE Concentrations – First Quarter 2008
UAU2 1,1-DCE Concentrations – First Quarter 2008
UAU2 Total Cr Concentrations – First Quarter 2008
MAU PCE Concentrations – 1998
MAU TCE Concentrations – 1998
MAU 1,1-DCE Concentrations – 1998
MAU PCE Concentrations – 2003
MAU TCE Concentrations – 2003
MAU 1,1-DCE Concentrations – 2003
MAU Total Cr Concentrations – 2003
MAU PCE Concentrations – First Quarter 2008
MAU TCE Concentrations – First Quarter 2008
MAU 1,1-DCE Concentrations – First Quarter 2008
MAU Total Cr Concentrations – First Quarter 2008
RID Canal Sampling Results, July 18, 2000
RID Surface Water Contaminant Concentrations, June 2003

 APPENDICES
The following appendices are included on CD in back pocket:
Appendix A Reynolds Metal Company Facility
Appendix B Van Waters & Rogers Inc. Facility
Appendix C Maricopa County Materials Management Facility
Appendix D Dolphin, Incorporated Facility
Appendix E American Linen Supply Company Facility
Appendix F ChemResearch Company, Incorporated Facility
Appendix G Air Liquide America L.P. Facility
Appendix H Prudential Overall Supply Facility
Appendix I Department of Energy Facility
Appendix J Facilities Reviewed Within WVBA
Appendix K Land and Water Use Study
Appendix L Logs Used for Cross-Section Preparation
Appendix M Hydrographs
Appendix N RID84 Aquifer Test
Appendix O MCMM Aquifer Test
Appendix P North Sentinel Well Aquifer Test
Appendix Q 15th Ave Aquifer Test
Appendix R RID104 Aquifer Test
Appendix S ALSCO Aquifer Test
Appendix T 1988 Groundwater Sample Laboratory Reports
Appendix U 1993 Groundwater Sample Laboratory Reports
Appendix V 1998 Groundwater Sample Laboratory Reports
Appendix W 2003 Groundwater Sample Laboratory Reports
Appendix X 2008 Groundwater Sample Laboratory Reports
Appendix Y Historic Contaminant Concentration Trends
Appendix Z RI Responsiveness Summary
Appendix AA Final RO Report

 1.0

WEST VAN BUREN AREA SITE CONCEPTUAL MODEL
1.1

Introduction

Terranext was retained by the Arizona Department of Environmental Quality (ADEQ) to
perform a remedial investigation (RI) at the West Van Buren Area (WVBA) Water
Quality Assurance Revolving Fund (WQARF) Registry Site. The project is being
performed in accordance with Arizona Response Action Contract No. EV03-0073AA and
Procurement Reference No. 04-0035.
The WVBA extends from approximately 7th Avenue west to 75th Avenue and from
Buckeye Road north to Interstate 10. In addition, a finger shaped plume exists between
7th Avenue and 27th Avenue between Buckeye Road and Lower Buckeye Road. The
WVBA is the areal projection of the western portion of a large commingled plume of
contaminated groundwater in Phoenix, Arizona (Figure 1-1). Contributors to this
commingled plume include industrial facilities and contaminated groundwater from the
east, as regional groundwater flow is generally westward. The initial primary
contaminants of concern (COCs) comprising the commingled WVBA plume included the
following volatile organic compounds (VOCs): tetrachloroethene (PCE), trichloroethene
(TCE), 1,1,1-trichloroethane (TCA), cis 1,2-dichloroethene (cis 1,2-DCE), 1,1dichloroethane (1,1-DCA), and 1,1-dichloroethene (1,1-DCE). To a limited extent,
chromium is also considered a COC. The RI was performed to identify sources of
commingled COCs in groundwater and to evaluate the horizontal and vertical extent of
groundwater contamination.
Benzene, toluene, ethylbenzene, and xylenes (BTEX) were part of the original COC list
because of detections at various locations throughout the plume. BTEX was eventually
dropped from the COC list because the BTEX was limited to leaking underground
storage tank (LUST) facilities regulated by ADEQ’s Underground Storage Tank (UST)
Program, or limited in extent to beneath the above ground storage tanks at the Phoenix
Terminal. Releases from USTs at the Phoenix Terminal are regulated under the authority
of the UST Program. WQARF regulatory authority (Arizona Revised Statues [ARS]
§49-283.02) does not include petroleum or constituents of petroleum if the release is
regulated under the UST Program. Currently there is no ADEQ oversight of
aboveground storage tanks that hold petroleum products.
Pursuant to A.A.C. R18-16-406, the purpose of the RI is to:
1. Establish the nature and extent of the contamination and the sources thereof,
2. Identify current and potential impacts to public health, welfare, and the
environment,
3. Identify current and reasonably foreseeable use of land and water of the state,
and
4. Obtain and evaluate any other information necessary for identification and
comparison of alternative remedial action

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-1

8/9/2012

 1.2

WQARF Process

The WQARF process (A.R.S 49-287, A.A.C. R18-16-401 through 416) consists of
sequential steps taken to evaluate and subsequently remediate a site contaminated with
hazardous substances. A site can be any parcel(s) of land suspected to be polluted with
hazardous process chemicals, substances or wastes. After a preliminary investigation, it
may be determined that a site poses an actual hazard and/or potential risk to public health
and the environment and may qualify as a registry site under the WQARF program.
Once a site is designated as a WQARF registry site, the following activities may be
performed sequentially:
















Preparation to perform RI and Feasibility Study (FS)
Community Involvement Plan written and Community Advisory Board (CAB)
formed
RI performed
Beneficial uses of land and water gathered and future land uses identified
Draft RI report issued for public comment
Remedial Objectives (ROs) report developed in accordance with public
participation requirements
RI report finalized
FS conducted to evaluate options for clean-up
Draft FS report issued for public comment
FS report finalized
Proposed Remedial Action Plan (PRAP) outlines preferred choice of technology
for clean-up
Public notice of the PRAP issued
Record of Decision (ROD) formalizes decision on how clean-up will be
performed
Public notice of the ROD issued
Clean-up actions performed

At any time during the WQARF process, an Early Response Action (ERA) may be
deemed necessary by ADEQ and implemented per A.A.C R18-16-405.
1.3

Site Background
1.3.1

Site Description

The WVBA extends from approximately 7th Avenue west to 75th Avenue and from
Buckeye Road north to Interstate 10. This corresponds to an area approximately eight
miles in length and 1.5 miles in width (approximately 12 square miles). In addition, a
finger shaped plume exists between 7th and 27th Avenues between Buckeye and Lower
Buckeye Roads (Figure 1-1). Within the WVBA are industrial facilities that have used
VOCs in former, and in some cases, current operations. Figures, tables and copies of
laboratory reports for facilities which conducted groundwater investigations are
contained in the appendices Based on observations made during performance of RI field
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-2

8/9/2012

 activities, typical industrial businesses within the WVBA WQARF Registry Site include
automobile body repair, automobile painting operations, automobile repair, chemical
mixing and distribution, dry cleaning operations, foundry operations, manufacturing
operations, metal fabrication and plating, plastic manufacturing, printing operations, and
vulcanizing operations.
Ninety seven monitor wells have been installed by ADEQ to delineate the extent and
magnitude of groundwater contamination, and to further investigate potential source
areas. Groundwater elevation information is collected quarterly while water quality data
is collected on a semi-annual basis throughout the area. The City of Phoenix municipal
water system serves residences and businesses in the WVBA with drinking water. In
2006, ADEQ collected samples from seven domestic wells that were identified by
ADWR during a well search/inventory and results indicated that the COCs are not
present above the aquifer water quality standard (AWQS) (Terranext, 2006b)
1.3.2

Site History
1.3.2.1 Early Regulatory Efforts

Groundwater contamination was first detected in the WVBA during groundwater
sampling conducted by Chevron USA Inc. (Chevron) at their facility located in the
Phoenix Terminal south of Van Buren Street between 51st Avenue and 55th Avenue
(Dames & Moore, 1985). Because Chevron had reportedly never used the solvents
detected, the Arizona Department of Water Resources (ADWR) conducted an areawide
groundwater investigation in conjunction with the Arizona Department of Health
Services (ADWR, 1987).
The WVBA WQARF Registry Site, originally called the Van Buren Tank Farm Study
Area, was placed on the WQARF priority list in November 1987. ADEQ contracted with
Kleinfelder, Inc. (Kleinfelder) to conduct the preliminary site investigation in May 1988
(Kleinfelder, 1988). Since 1988, ADEQ and several companies within the WVBA have
conducted investigations of contaminated soil and groundwater. Initial field work
included conducting groundwater monitoring, soil sampling, examining area land uses,
reviewing past and current disposal practices of industrial operations, and analyzing the
potential health risks of identified COCs. A Phase I report was finalized for ADEQ in
July 1989 (Kleinfelder, 1989). The report concluded that five of the COCs identified
above were found to be present at levels above U.S. Environmental Protection Agency
(EPA) maximum contaminant levels (MCLs) in groundwater.
In October 1992, the Arizona Department of Health Services (ADHS) completed a health
risk assessment addressing the potential threat to City of Tolleson drinking water wells.
The study was conducted in anticipation of potential groundwater contamination of City
of Tolleson wells by westerly groundwater movement of the WVBA plume. The study
concluded there would be significant health effects from domestic consumption of
groundwater containing COCs at concentrations similar to those found in ADEQ
monitoring wells located near 67th Avenue and Van Buren Street. The City of Tolleson’s

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-3

8/9/2012

 most easterly well is located at approximately 83rd Avenue and Harrison Street.
Although the WVBA plume does not extend west of 80th Avenue, potentially affected
wells have been removed from service. In addition, the City of Tolleson currently has an
agreement with the City of Phoenix Water Services Department to provide drinking
water. Also, two groundwater monitoring wells have been installed at 79th Avenue, north
and south of the Roosevelt Irrigation District (RID) canal, between the leading edge of
the plume and the City of Tolleson municipal well field to monitor groundwater quality
in the area of concern.
Following the 1989 Phase I report, historical records were researched to identify
currently operating facilities that use COCs. Closed facilities that had previously
operated in the study area and had likely used COCs were also researched. The identified
facilities were contacted and provided with the results of the preliminary investigation.
In locations of the WVBA where potential contamination sources were identified, the
current facilities were encouraged to undertake voluntary investigations and cleanup.
ADEQ conducted a soil investigation at the Maricopa County Materials Management
(MCMM) facility in 1992 as a result of groundwater contamination detected in an ADEQ
groundwater monitor well located downgradient of the MCMM facility. ADEQ also
installed three groundwater monitor wells at the MCMM facility. Maricopa County then
conducted site characterization of their facility and installed and operated a soil vapor
extraction (SVE) system.
In November 1992, ADEQ encouraged approximately 50 parties to form a steering
committee to address groundwater contamination issues in the WVBA. Participants of
the steering committee formed the West Van Buren Group (WVBG).
1.3.2.2 WVBG
The WVBG was a key component of the steering committee. The makeup and formal
membership of the WVBG varied during the mid-1990s, originally consisting of
Reynolds Metals Co. (Reynolds), Van Waters & Rogers Inc. (VW&R), Maricopa
County, Dolphin, Incorporated (Dolphin), American Linen Supply Company (ALSCo,
formerly Maroney’s Cleaners), and ChemResearch Company, Inc (CRC). CRC, ALSCo,
and Maricopa County withdrew from the WVBG by 1995. The WVBG suspended
further negotiations with ADEQ for a site-wide consent agreement in June 1996, after
Arizona legislative changes were enacted.
Prior to suspension of the WVBG, members of the WVBG reviewed ADEQ files, results
of the Maricopa County well inventory, and contacted well owners to identify
groundwater wells which could be used for domestic purposes. After wells were
identified, owners were contacted and those that responded were visited so that
groundwater samples could be collected for VOC analyses. One well, Southwest Trail
Boss, exhibited VOC concentrations greater than AWQS. TCE was detected in this well
at a concentration of 6.9 micrograms per liter (µg/l), which exceeded its AWQS of 5 µg/l.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-4

8/9/2012

 This well was previously sampled in October 1994 and neither VOCs nor chromium were
detected at that time (West Van Buren Group, 1995).
1.3.2.3 Phoenix Terminal Group
The Phoenix Terminal is a petroleum storage and distribution facility located between
51st and 55th Avenues south of West Van Buren Street. Numerous releases of petroleum
compounds have occurred from storage tanks and piping owned by various companies
that have operated at the site (ENSR, 1988). Contamination from these releases has
extended to groundwater. Groundwater monitor wells have been installed to evaluate the
extent of contamination at the site. SVE systems have been used to remediate soil
contamination, while skimmers have been installed to remove free product.
Ten companies that owned, operated, controlled, or had interests in petroleum facilities at
the Phoenix Terminal formed the Phoenix Terminal Group in the early 1990s to work
with ADEQ in resolving issues related to the soil and groundwater contamination. The
original group consisted of Santa Fe Pacific Pipeline, Atlantic Richfield Co., Maricopa
County, Chevron, Salt River Project (SRP), Texaco, Shell, Unocal, Powerine Oil Co., and
Cal Jet Inc. The group name and membership has varied from year to year. An RI and
FS have been completed by the Phoenix Terminal Group. ADEQ no longer provides
oversight of Phoenix Terminal activities under the WQARF program.
1.3.2.4 Facility Histories
Reynolds Metals Co., a former aluminum extrusion facility, was located between 35th and
43rd Avenues, and between Van Buren and the Union Pacific Railroad tracks in Phoenix
which encompasses approximately 320 acres of land (HydroGeoLogic, 2007a) (Appendix
A). The facility was constructed at some time prior to 1946 under authority of the U.S.
Government’s Defense Plant Corporation as part of our country’s war effort. Aluminum
Corporation of America (ALCOA) operated the plant from the time of construction until
1946. Reynolds took over operational control in 1946 and remained in control through
the 1980s. On October 21, 1983, all production was stopped.
Two different degreasing processes were used in the plant: Stoddard solvent and vapor
recovery. The Stoddard solvent system operated from the construction date until the
early 1970s. The Stoddard solvent consisted of 85 percent nonane and 15 percent
trimethylbenzene. Still bottom sludge reportedly was sent to percolation ponds near the
Salt River. New solvent was received by rail and stored in one of the two 25,000 gallon
USTs near the still. The solvent recovery process used an enclosure that was partially
filled with TCA. In 1979, Reynolds purchased 75,000 gallons of TCA to use in a vapor
recovery degreasing unit. The vapor recovery degreasing unit was installed as a
replacement unit for the Stoddard solvent degreasing unit in the early 1970s and used
until closure of the plant in 1983. The difference between the volume of purchased TCA,
and that shipped off site is between 62,600 and 72,300 gallons per year due to use,
evaporation, spillage or leaking plumbing. Initial site investigations in 1988 identified
chromium, petroleum hydrocarbons, and VOCs such as TCA, TCE, and PCE in soils

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-5

8/9/2012

 beneath Reynolds Metal Company property. Structures were removed from the site
while the property was deeded to Reywest Development Company (Reywest), a
subsidiary of Reynolds, to sell the property as subdivided parcels.
VW&R, now owned by Univar, is a chemical distribution facility located at 50 South 45th
Avenue (HydroGeoLogic, 2007b) (Appendix B). The site was acquired in 1969 and in
1971 the office/warehouse was built. Prior to purchase by VW&R, the property was
undeveloped farm land. Site activities are limited to the western half of the approximate
nine acre site and include the warehousing, distributing, repackaging, and transporting of
industrial chemicals. No development or activities have occurred on the eastern portion
of the facility. Areas of operation include a waste water pretreatment system and sewer
interceptor, bulk solvent tank farm, bulk corrosive tank farm, former Resource
Conservation and Recovery Act (RCRA) interim status container storage unit, and
office/warehouse building. The RCRA unit was used from 1982 through 1988,
eventually receiving closure from ADEQ.
Maricopa County Materials Management is the current owner of the property located at
320 West Lincoln St (HydroGeoLogic, 2007c) (Appendix C). The property was formerly
leased to Southwest Solvents and was formerly owned by Union Pacific Railroad; neither
entity was part of the WVBG. The site is just over four acres and currently has two
buildings, one approximately 76,000 square feet in size used as a warehouse, printing
facility, and office space, and one building approximately 20,000 square feet used for
storing county court records. The warehouse area of the main building is used primarily
to store materials of a non-hazardous nature. The building was reportedly built in 1975.
Prior to purchase by Maricopa County, the property was divided into multiple lots.
Previous occupants of the site included Southern Pacific Transportation Company
(succeeded by Union Pacific Railroad Company), Linde Air Product Company, Arizona
Public Service Company (APS), and Southwest Solvents, a cleaning solvent recycling
company. Southwest Solvents operated in the northwest corner of the site for
approximately ten years. In 1964, Southwest Solvents located its solvent reclaiming
operation to the site and operated until its lease was terminated in 1974. Southwest
Solvents initially purchased or was given spent solvent from local industrial facilities to
be reclaimed. Upon distillation, Southwest Solvents sold the pure product. The company
operated three stills on-site and disposed of its hazardous waste at disposal sites in
California and Nevada. Spent solvent that Southwest Solvents primarily reclaimed onsite included PCE, TCE, TCA, and Freon. PCE came primarily from dry cleaning sludge
and TCE from industrial customers who used the solvent to clean metal parts. The spent
solvents were stored on-site in 55-gallon drums for short periods of time. Southwest
Solvents had two 150-gallon stainless steel stills that were used to distill spent solvents at
a rate of 55 gallons per hour. The company had a glass still that would separate solvents.
After several hundred gallons of spent solvent were recycled, still-bottom sludge was
cleaned out of the stills, placed in 55-gallon drums, solidified, and shipped out of state.
Southwest Solvents used TCA in a drum washer machine. The machine cleaned the
inside of reusable drums that were reconditioned for new solvents and redistilled
products. In the late 1960s, Southwest Solvents began to accept acetone, methyl ethyl

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-6

8/9/2012

 ketone and isopropyl alcohol. In 1974, MCMM purchased the property and constructed a
warehouse on the property, which housed a printing operation involving the use of multigraphic blankwash cleaning solution and SafetyKleen cleaning solution, both containing
PCE. The MCMM warehouse is located east of the former Southwest Solvents building.
APS, current owner of the adjacent eastern property at 501-505 S. 2nd Ave., once had a
two-story building that held a Univac mainframe computer and accounting/treasury
offices located on the eastern portion of the 320 W. Lincoln St. property. APS is
conducting work under an agreement with EPA at their facility location at the western
edge of the Operable Unit 3 (OU3) portion of the Motorola/52nd Street Federal Superfund
site bordering the WVBA WQARF Registry site at the MCMM facility (AMEC Earth
and Environmental, 2007).
Dolphin, Inc., located at 740 South 59th Avenue, is a precision metal casting facility
which produces precision aviation components and custom golf club heads
(HydroGeoLogic, 2007d) (Appendix D). Dolphin’s manufacturing operations consisted
of four main processes: wax pattern preparation, silica shell preparation, casting and
cleaning and finishing. The property was first developed in 1968 by Rueter Inc. as an
investment casting operation. Dolphin bought the property in 1972 and continued casting
operations. Additional property purchases in 1984 and 1988 expanded the facility to its
current size. The site contains eight buildings six of which were constructed specifically
for Dolphin’s operations. The facility includes approximately 13.5 acres consisting of
five areas identified as Dolphin I, Dolphin III, Dolphin IV, Dolphin VI, and Dolphin VII.
The building known as Dolphin IV was never used for manufacturing operations and was
demolished several years ago. Dolphin I, Dolphin III, Dolphin VI, and Dolphin VII
consist of manufacturing facilities, offices, warehouse, drum storage, vapor degreaser,
and sewer interceptor. The vapor degreaser was a small unit inside one of the
manufacturing buildings and was removed from the site in 1994 when Dolphin
discontinued use of chlorinated solvents at the site. Two sewer interceptors were
formerly used to remove solids from facility wastewater and were closed in the 1990's.
Chromium is present in the steel used by Dolphin to manufacture its products while PCE
and TCA were both used to degrease casting molds. PCE was among the chemicals used
at the Dolphin site and had been used since the initial portion of the site was developed in
1968. PCE was dispensed from drums for use in vapor degreasing and other cleaning
activities. Wax molds were cleaned by washing in aboveground dip tanks that contained
solvent and rinse water. Equipment, work surfaces, and metal parts were cleaned by wipe
cleaning and vapor degreasing. During 1990 and 1991, Dolphin instituted a source
reduction of PCE and TCA cleaning operations by transitioning to citrus-based solvents.
In September 1992, a release of liquid and sludge material occurred at Dolphin’s
production facility, known as Dolphin III. Analysis indicated that the release material
contained PCE, TCE, 1,1-DCE, and total recoverable petroleum hydrocarbons (TRPH).
PCE was limited to vapor degreasing and removal of seams from wax molds. PCE use
was discontinued at the facility in 1994 and replaced with a terpene-based substance for
degreasing operations. Cleaning solvents may have been present in wastewater
discharged through Dolphin I’s sanitary sewer pipes. In 1994, PCE was found
downgradient and adjacent from the closed sewer interceptor. As of 1999, Dolphin had

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-7

8/9/2012

 four drywells on the property. Between 1992 and 2002, several investigations were
conducted at the Dolphin facility to identify and characterize historical releases of
hazardous substances. Those investigations identified 4 releases/source areas of
hazardous substances - former drum storage areas at Dolphin I, former vapor degreaser at
Dolphin I, former sewer interceptor at Dolphin III, and a liquid and sludge release at
Dolphin III. Those investigations were conducted under the oversight of the hazardous
waste unit at ADEQ.
ALSCo, located at 720 West Buchanan Street, is a commercial dry-cleaning operation
(HydroGeoLogic, 2007e) (Appendix E). The facility is a dry cleaner/laundry that used
PCE from 1956 to 1984. The site is approximately 1.5 acres with a 31,000 square foot
laundry processing building and a paved parking lot. The site was operated as a
Maroney’s Cleaners & Laundry, Inc., from approximately 1969 to October 1979. No
information regarding how Maroney’s disposed of waste solvent, including any recycling
efforts exist. ALSCo purchased the facility in 1979 and currently owns and operates the
facility. ALSCo ceased dry cleaning operations at the site in 1995. ALSCo converted to
a water wash system and operated the two dry cleaners occasionally until 1992. ADEQ
has no information that ALSCo recycled its solvent at this time. ALSCo has been
involved in several environmental sampling investigations at the facility.
ChemResearch Co., Inc. (CRC) is an electroplating, metal finishing, and metal parts
plating company located at 1122 West Hilton Avenue, Phoenix (HydroGeoLogic, 2007f)
(Appendix F). The site had consisted of four separate properties located at 1101, 1122,
and 1130 West Hilton Avenue and 1120 West Watkins Street. The main plating
activities are carried out at 1122 West Hilton Avenue. A laboratory and warehouse are
also located at 1122 West Hilton Avenue. These two facilities occupy approximately 1.5
acres and were recently designated as one property by the City of Phoenix with the 1130
West Hilton Avenue address. The two facilities have had known releases. In 1989, CRC
used an average of 208,000 pounds of PCE per year and about 14,000 pounds of chromic
acid per year. CRC generated approximately 299,000 pounds of F006 sludge from the
plating shop, and 49,500 lbs of F001 spent PCE and 4,500 lbs of D002 corrosive liquid
containing 0.2 percent of chrome from the painting shop along with spent methyl ethyl
ketone and waste paint. A 1988 inspection report documents numerous waste tanks
ranging in size from 20 gallons to 10,000 gallons. According to a 1988 hazardous waste
facility inspection report, there were no drywells, septic tanks, surface impoundments or
injection wells reported at any of the four CRC facilities; however in 1995, two
unregistered drywells were reported at CRC’s leased facility located at 1120 West
Watkins Street.
1122 West Hilton Avenue – Plating Shop
The plating site was first developed in 1953 when Francis Plating Company began hard
chrome plating operations. CRC has conducted chrome plating in the building since
1959 and purchased the site in 1989. The following operations occurred at the property:
PCE vapor degreasing, electroplating, anodizing, special processes, and wastewater
treatment. Plating activities were moved from the east side of the building to the north

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-8

8/9/2012

 side in 1992 to conduct remedial activities in the east bay area. A variety of
electroplating and anodizing processes occurred, which involved the use of several types
of metals. Chrome plating is the most prevalent operation at this facility. CRC used PCE
degreasers in this facility’s operations to clean metal. Chromium and PCE have been
released into the environment from this facility. CRC has undertaken remediation efforts
to address the chromium contamination in the soil, and is investigating the extent or
degree that chromium and PCE have contaminated soil and groundwater. Significant
events at the 1122 West Hilton Ave facility included a release of 186 gallons of chromic
acid to the City of Phoenix sanitary sewer in November 1984. In 1988, an unknown
quantity of cyanide was released and reported to the ADEQ.
1120 West Watkins Street – Painting Shop
The 1120 West Watkins Street property had been operated by CRC for painting, and
storage of waste and flammable liquids. The building was built in the early 1950’s and
was used as a distribution center for pool supplies, and more recently, as a location of
various medical laboratories. CRC leased the property from 1979 through 1992. CRC
used a portion of this facility to operate its painting operations. These operations
involved the use of several paint booths and PCE degreasers. Hazardous materials and
wastes have been stored on-site. The City of Phoenix has owned the property since 1996
when CRC ceased operations. The City of Phoenix currently uses it for storage and as an
area to house homeless people. Test results indicated the presence of PCE in the soil at
depths where the potential for groundwater contamination could exist. On March 21,
1996, ADEQ provided its evaluation of a Phase II environmental site assessment of the
property. Based on the results of soil vapor and soil sampling, ADEQ determined that
PCE had been released to soil and was present at a depth in the soil that suggested the
potential for groundwater contamination. In an April 4, 1996 review of the Phase II
environmental assessment, PCE appeared to have been released to soil at two locations.
The first location was the former hazardous materials storage area and adjacent drum
storage area, and the second was the former PCE vapor degreasing area.
1130 West Hilton Avenue
The 1130 West Hilton Avenue warehouse/laboratory building was built in 1951 by
Lincoln A. and Virginia A. Pettinger. Business activities at this property have included
cabinet making, wood molding, wood fabrication, warehousing of paper and a plastic
products distribution center. In 1964, one company, ELKO, operated paint spray booths
in the building. In 1983, Metal Surfaces Holding Company, an electroplating company,
purchased the property and soon thereafter began leasing it to CRC. CRC purchased the
property in 1989. It has been used for a variety of purposes, including chemical storage,
maintenance, blasting of metal parts, and as a laboratory. As of 1988, the hazardous
chemical storage area was equipped with secondary containment. For a period of time,
waste material, such as spent PCE was transferred to this facility to await disposal by a
waste hauler. In its 1991 response to an ADEQ questionnaire, CRC identified a variety
of chemicals stored in the warehouse on the property. Chromic acid was the only
chemical identified containing COC.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-9

8/9/2012

 1101 West Hilton Avenue – Administration/Grinding Shop
The 1101 West Hilton Avenue site is currently used for office space, but past uses have
included offices, laboratory, grinding shop, painting, and drum storage. This building
was reportedly built in 1953 and originally occupied by Standard Printing Company.
CRC leased the building in 1973 and bought the site in 1983. Chemical storage occurred
at this location until this operation was moved to the 1122 West Hilton Avenue property.
Painting operations occurred in this building as well until these operations were moved to
the 1120 West Watkins Street Property in 1979. Painting operations at this building
included the use of PCE, MEK, alcohol, and paint thinner. CRC moved its laboratory
operations from this building to 1130 West Hilton Avenue in 1987.
Air Liquide America Specialty Gases LLC (ALASG) located at 301 South 45th Avenue,
Phoenix is an international industrial group specializing in industrial and medical gases
(HydroGeoLogic, 2007g) (Appendix G). The site contains three primary buildings: the
fill plant, the acetylene plant and the former air separator unit (ASU). Other structures on
the site include an office building, chemical storage enclosure, aboveground slurry tanks
and cylinder cleaning racks. Cooling towers were formerly present south and east of the
ASU. The first industrial operations at the 9.9 acre facility occurred in approximately
1963 when Dye Oxygen Company began industrial gas manufacturing. In 1973, Liquid
Air Corporation purchased the stock of Dye Oxygen Company. Industrial gas
manufacturing continued to operate under the name ALASG in 1994. The facility was
operated as an air separation plant, producing liquid oxygen and nitrogen, from 1973
through August 1985. From 1987 to 1994, the company conducted cylinder hydrotest
and internal cylinder cleaning operations. In 1987 acetylene manufacturing and gas
repackaging operations began and remain active at the site. ALASG used TCA at the
ASU to clean compressors, valves, and other equipment for oxygen service from 1973 to
1996. TCA solvent was also used as a degreaser for oxygen equipment during Dye
Oxygen’s operations. TCA and paint thinner were supplied to the site in 55-gallon
drums. Spent TCA was disposed by evaporation until 1987 when ALASG began
disposing as a hazardous waste. According to Liquid Air’s June 1991 information
request response, Freon-11 solvent was used as part of a vapor degreasing system in the
early 1980s to clean equipment in oxygen service. The Freon-11 was recycled. Solvent
which was not recycled was allowed to evaporate. Acetone was also used at the facility.
A 1999 Basin & Range Site Investigation Work Plan indicated that acetone was used to
stabilize acetylene gas in fill plant operations. Acetone was stored in a 600-gallon UST.
Methylene chloride was used from 1973 to 1974 to clean compressors, valves, and other
equipment for oxygen service. Synthetic lube oil was used from 1975 to 1985.
According to a 1996 information request response, ALASG purchased 4,125 gallons of
TCA for use in 1987 to 1996 and disposed of 2,610 lbs of waste TCA from 1987 to 1996.
In 2004, ALASG excavated and removed two grease traps and the portion of the concrete
trench that was present in the south room of the ASU.
Prudential Overall Supply (POS) located at 5102 West Roosevelt Street, Phoenix is an
industrial laundry and dry cleaning operation (HydroGeoLogic, 2007h) (Appendix H).

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-10

8/9/2012

 POS has owned the property since December 3, 1980, and the first industrial operations
at the POS facility occurred in approximately 1982 when laundry and dry cleaning
operations began. The bulk of the facility’s on-site operations have consisted of
laundering and pressing uniforms, overalls, and shop towels from 1982 through the
present. Dry cleaning operations began at the site in 1982 and were terminated in 1991.
Included in the building are a supply room, boiler room, maintenance shop, and an
automotive garage. An office is located on the south side of the building. The former
dry cleaning room now contains detergent tanks, laundering supplies, and equipment. A
canopy skirts the west and north side of the building, with a wastewater treatment area
situated behind the canopy on the north side of the building. Aboveground process tanks
are located in a containment area north of the building. A truck parking area, employee
parking area, storm water retention basin, narrow strip of landscape, and unpaved vacant
lot west of the retention basin are also situated on the property. Chemical and equipment
deliveries are routed to the west and north side of the building.
Chemical storage has always been in the area north of the building or inside the building.
PCE was used as the dry cleaning solvent during operations. The PCE was contained in a
750-gallon capacity internal tank housed in the dry cleaning machine. PCE was recycled
in the dry cleaning machine to minimize waste PCE. The reported amount of PCE used
and stored on-site varied dependant upon levels reported in industrial wastewater
discharge surveys, hazardous materials permit applications and inspections, Tier Two
emergency and hazardous chemical inventories, and hazardous waste shipping manifests.
Approximately 4,800 gallons of PCE were used per year. Drums containing lint/PCE
sludge were stored along the west wall in the dry cleaning room, north of the doorway
until disposed of off-site. Additionally, “Safety-Clean”, a solvent containing PCE, was
used in a small parts washer located in POS’s automotive garage. “Safety-Clean” was
used from 1982 until 1997 when a water-based solvent was applied. POS had no record
or knowledge of any liquid spills occurring in the dry cleaning room. POS estimates that
any spill that did occur would have been less than three gallons and sopped up with soiled
garments. POS is investigating the extent or degree that PCE has contaminated soil and
groundwater. Three dry wells were located in the truck parking areas to drain storm
water from the pavement. In 1995, the drywells were closed and converted to catch
basins and a storm water retention basin was excavated and renovated in 1999 when a
detergent spill occurred. The spill reportedly contained no solvents and was investigated
through the excavation and sampling of soils. No VOCs were detected in soil samples
collected from the retention basin.
U.S. Department of Energy (DOE) has property that consists of two separate parcels
located at 615 South 43rd Avenue, Phoenix, Arizona 85009 (HydroGeoLogic, 2007i)
(Appendix I). The parcel on the west side of 43rd Avenue is a substation that distributed
electricity to south-central Arizona but currently is used to supply electricity to the DOE
Western Area Power Administration (WAPA) Phoenix Area Office on the east side of
43rd Avenue. The parcel on the east side of 43rd Avenue is the WAPA operations and
maintenance complex.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-11

8/9/2012

 The substation has been operated by WAPA since it was constructed in 1941. The
substation utilized a septic system which reportedly included two leach wells and two
cesspools. These structures were not removed from the site when the substation
buildings were demolished. Film processing chemicals were reportedly disposed to these
structures. The complex on the east side of 43rd Avenue was originally constructed in
1951 by the Bureau of Reclamation. WAPA took over operation of the facility in 1980
with the Bureau of Reclamation still occupying the northwest corner of the property. The
complex contains several buildings for conducting various activities including
maintenance, storage, administrative duties, and a fueling system for facility vehicles.
Five drywells have been abandoned at the site. Three of the drywells were reportedly
part of a former maintenance building drainage and septic system. Six drywells are
currently located at the facility. Various wastes and solvents have been stored and used
at the facility including RCRA and Toxic Substances Control Act wastes, waste dielectric
fluids containing PCBs, petroleum solvents, chlorinated solvents, pesticides, waste
solvents, and fuels.
1.3.2.5 Recent Regulatory Efforts
As additional source information is gained through the remedial investigation efforts,
ADEQ’s WQARF program will continue to work with facilities to conduct investigation
and clean-up efforts. ADEQ’s WQARF program reviews work plans and has issued
work orders on consent orders as necessary.
Reynolds. Reynolds received a No Further Action (NFA) letter for soils within 14
specific areas by ADEQ in 2000. Reynolds entered into a Consent Decree with the State
of Arizona in September 2002. The Consent Decree resolved the alleged liability and
potential liability of Reynolds by seeking recovery of costs, recovery for natural resource
damages, injunctive relief, and declaratory judgment. Reynolds settled with ADEQ for
$1,956,474 on October 2, 2002. Reynolds finished conducting operations as outlined in
Section VIII of the Consent Decree and on January 6, 2006, received a letter of
satisfaction of monitoring requirements. ADEQ currently samples eight groundwater
monitor wells located on the Reynolds property.
VW&R. At the request of ADEQ, VW&R began conducting investigations at their
facility in 1989. In 1990, VW&R and ADEQ signed a Consent Order to resolve Part A
Hazardous Waste Permit Application (AHWPA) operating and record keeping issues.
While the AHWPA issues were resolved, VW&R continued to conduct characterization
of the facility and installed and operated SVE system. In 1996, a Consent Order for
additional site work was signed by VW&R and ADEQ and terminated the 1990 Consent
Order. The 1996 Consent Order stipulated that VW&R close the RCRA Interim Status
Storage unit; conduct an investigation in a parking lot area; investigate the unsaturated
cobble unit; continue groundwater investigation activities; and continue SVE operation.
SVE operation included the submittal of quarterly SVE operation reports; radius of
influence testing; and reporting. Upon completion of activities required by the 1996
Consent Order, VW&R submitted a work plan for confirmation soil sampling and upon
receipt of approval conducted the confirmation soil sampling. VW&R then submitted a

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-12

8/9/2012

 Certificate of Completion for Soil Remedial Action and a Certificate of Completion for
Groundwater Investigative Activities to ADEQ for review and approval. Upon reviewing
the Certificates of Completion, ADEQ issued an NFA letter for soils and the 1996
Consent Order was terminated. VW&R paid ADEQ $7,711 for oversight costs incurred
by the state. Currently ADEQ monitors and samples two groundwater monitor wells
located at the VW&R facility.
Maricopa County. Upon completion of site characterization and soil remediation,
Maricopa County and Union Pacific Railroad, one of the previous owners of the MCMM
property, negotiated a settlement with ADEQ. In October 2001, Maricopa County and
Union Pacific Railroad settled with ADEQ for $450,000 for ADEQ’s response and
oversight costs. ADEQ continues to investigate the ownership and tenant history of the
facility to evaluate whether other entities may also be responsible for contamination
detected at the MCMM facility. Currently, ADEQ monitors and samples three
groundwater monitor wells located at the MCMM facility.
Dolphin. A RCRA Consent Decree was issued by ADEQ in January 2000. Dolphin
received closure of the order in June 2006. On January 13, 2001, the WQARF Program
collected $410,000 from Dolphin to be used in remedial action on the WVBA plume’s
threat to City of Tolleson drinking water wells. Dolphin installed three SVE systems and
an air sparge system at the facility. During operation of the remediation systems,
Dolphin prepared operation and maintenance plan, quarterly status reports,
decommissioning plans and decommissioning reports. In April 2004, Dolphin completed
rebound testing and decommissioning sampling and received ADEQ authorization for
SVE shut down. On June 6, 2006, Dolphin satisfied the Consent Order and Consent
Judgment which were closed. Dolphin currently samples the wells at their facility and
submits semiannual reports to ADEQ.
ALSCo. Because of groundwater contamination detected in groundwater monitor wells
downgradient of the ALSCo facility, ADEQ requested that an investigation be conducted
at the facility to evaluate whether a release of PCE had occurred and if so to identify the
extent and nature of the release. ADEQ also investigated property ownership and tenant
history to evaluate whether other owners/tenants may have also contributed to
contamination detected at the facility. Data obtained indicated that ALSCo and
Maroney’s Cleaners & Laundry, Inc. were responsible for the releases of contaminants
that had occurred at the facility. In August 1997, a federal court approved a Consent
Decree between ADEQ and ALSCo. ALSCo settled with ADEQ in May 1997 for $2
million. ADEQ subsequently conducted an ERA at the site and currently monitors and
samples four groundwater monitor wells at the facility. No settlement agreement has
been negotiated between ADEQ and Maroney’s Cleaners & Laundry, Inc. ADEQ
granted ALSCo an NFA determination for soil on March 24, 2008 (ADEQ, 2008).
CRC. At the request of ADEQ, CRC initiated a facility investigation in 1990 to
determine if contaminants detected in groundwater within the WVBA had been released
at the facility. Data collected indicated that releases had occurred at the facility. In 1994,
CRC entered into a consent order with the RCRA division of ADEQ to address the

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-13

8/9/2012

 contamination. CRC has an ADEQ approved remedial action plan in-place to conduct
additional soils investigation and soil remediation. Currently CRC monitors and samples
groundwater monitor wells owned by CRC and ADEQ.
ALASG. Because of COCs detected in groundwater monitor wells downgradient of
ALASG, ADEQ requested that ALASG conduct investigations at their facility to evaluate
whether releases had occurred and fully characterize the releases. ALASG initiated
investigations at their facility in 1998. In September 2007, ALASG entered into a
Consent Order with ADEQ. ALASG has an approved work plan under Order of Consent
to further investigate groundwater contamination at the facility. In accordance with the
order, four additional groundwater monitor wells were installed at the facility during
December 2007. Currently ALASG monitors and samples seven groundwater monitor
wells at their facility.
DOE. During a LUST investigation at the DOE facility in 1992, COCs were detected in
soil samples. Because of the presence of COCs in the soil samples and the apparent use
of COCs at the facility, ADEQ requested that DOE conduct an investigation to identify
the extent of COC contamination. ADEQ requested a soil investigation be completed
around five disposal structures, the installation of additional groundwater monitor wells,
and continued monitoring and sampling of onsite groundwater monitor wells.
POS. Because of contamination detected in groundwater monitor wells downgradient of
the POS facility, ADEQ requested that an investigation be conducted at the facility to
evaluate whether a release of PCE had occurred and if so to identify the extent and nature
of the release, and POS entered into a Consent Order with ADEQ. POS has an approved
work plan under Order of Consent to further investigate soil and groundwater
contamination at the site. POS installed three groundwater monitor wells at their facility
and currently monitors and samples the wells.
Industrial Surveys and Facility Investigations.
ADEQ and its contractor,
HydroGeoLogic, Inc. (HGL), are conducting an ongoing Potential Responsible Party
(PRP) search. As per A.R.S. 49-287.04(C), the list of PRPs is not finalized until the
PRAP stage of the WQARF process.
Several industrial surveys and facility investigations have been completed for the WVBA
WQARF Registry site prior to and after it was added to the WQARF Registry on April
10, 1998. These investigations involved the review of records and have resulted in the
identification of numerous facilities of interest for further evaluation by ADEQ. A brief
summary of these investigations is found below, followed by more detailed descriptions.
A preliminary responsible party survey was conducted by the Arizona Department of
Health Services (ADHS) during the area wide groundwater investigation completed by
ADHS and ADWR in 1986. Results of the survey were reported in the ADWR report
dated 1987. The survey covered the area bounded by 35th Avenue to the east, the Salt
River to the south, 67th Avenue to the west, and McDowell Road to the north.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-14

8/9/2012

 Two earlier investigations were conducted by ADEQ’s contractor Kleinfelder in 1988
and 1989. The focus of the investigations was the West Van Buren Study Area, an area
larger than, but encompassing the existing WVBA.
A series of industrial surveys were conducted on properties within the current WVBA
after listing on the WQARF Registry. ADEQ’s contractor Weston provided the results of
its industrial survey in April 2001 and HGL completed two industrial surveys in June
2002 and a third in August 2002 involving other portions of the WQARF site. Appendix
J, Figure J-1 is a map of the WVBA boundary that identifies the areas that were the
subject of these investigations. Appendix J also includes two tables (Tables J-1 and J-2)
that list 1686 facilities that were identified by the six industrial surveys by address and
alphabetical order, respectively. Table J-3 identifies the 145 facilities currently under
investigation. Below is a summary of the research methodology used for each of the
investigations conducted for the WVBA and West Van Buren Study Area.
ADHS Investigation – October 1987. ADHS completed a preliminary responsible party
survey within the central portion of the WVBA. The area surveyed extended from 35th
Avenue west to 67th Avenue and from the Salt River north to McDowell Road. The
survey identified 149 businesses that could have potentially stored, used or disposed of
hazardous substances based on their Standard Identification Code (SIC). Data on the
businesses was obtained by reviewing the Contracts Influential 1983 – 84 by Contacts
Influential Corporation, a directory which listed commercial and industrial firms in
various manners including address and SIC. The businesses were then sorted by SIC to
group like businesses together. The sorting created 19 activity groups.
Kleinfelder Investigation - June 17, 1988. Kleinfelder completed a preliminary listing of
facilities, wells and well locations within the WVBA. The first list included 863 facilities
that potentially used, stored, produced, or disposed of chemicals, and was compiled from
information found in the following resources: the Arizona Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA), Arizona Comprehensive
Investigation and Data System (ACIDS) list; ADEQ list of USTs; ADEQ list of surface
impoundments; City of Phoenix list of industrial users; Maricopa County Department of
Civil Defense and Emergency Services list of facilities and agencies reporting extremely
hazardous substances; Maricopa County Health Department list of septic tank users; and
reports, records, and investigations available through ADEQ.
In addition, a field canvass was completed in late March 1988 to further identify facilities
of interest through observations of land use and chemical storage practices. Observations
such as the number of tanks, EPA identification numbers, number of employees, and
business operations were included on the first list. Of the 863 facilities listed, 136 were
considered “high priority facilities” that were located near areas of historical elevated
chemical concentrations in groundwater or found to use chemicals based on a review of
aerial photographs and field observations.
The second list identified 242 wells within the study area and was compiled from
published records and the results of a well reconnaissance performed in late March 1988.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-15

8/9/2012

 The list includes well numbers; well status such as whether the wells were active,
abandoned, inactive, etc.; general observations such as the size of the well pump, whether
the wells were used for irrigation or drinking water purposes; and, where available, the
names or descriptions of the facilities where the wells were located.
Kleinfelder Phase I Investigation - July 1989. Kleinfelder’s July 1989 “Phase I Report,
West Van Buren Area” was compiled from a literature and records search to provide
background information on geology, hydrogeology, and land use, and to identify
potential chemical manufacturers, users, and disposers within the West Van Buren Study
Area. Figure J-1 in Appendix J depicts the location of the study area.
The table below includes a list of local, state, and federal agency records that Kleinfelder
reviewed for the Phase I investigation for facilities located within the West Van Buren
Study Area.
Kleinfelder Records Review
Agency

ADEQ

ADHS
ADWR
Arizona State
Structural Pest Control

City of Phoenix

EPA

Maricopa County

Department/Type of Records
Groundwater quality analysis; available waste permit data; UST
listings; drywell listings; previous geologic and hydrogeologic
reports; compliance files; permits; list of permitted hazardous
waste transporters; and CERCLA, Superfund Amendments and
Reauthorization Act (SARA), and RCRA files
Fire department incident reports regarding information about
chemical users, disposers, and accidental spills
Disease prevention studies
Well registration, groundwater survey inventory, and well logs
List of certified pesticide applicators in the Phoenix area
City of Phoenix industrial waste discharge files and permits on
facilities disposing waste into the sewer system
City of Phoenix Planning Department regarding land use and
zoning information
Water well locations, construction details, and use
National Pollutant Discharge Elimination System permit list for
Maricopa County
Preliminary Assessment, RCRA, CERCLA, and SARA files
Maricopa County Bureau of Air Pollution Control regarding
information on facilities using volatile organic compounds; files
included information on the number of degreasing units in
operation and the types of chemicals utilized for degreasing
operations on-site

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-16

8/9/2012

 Agency

Maricopa County
Association of
Governments
RID

Salt River Project
United States
Geological Survey
United States Soil
Conservation Service

Department/Type of Records
Maricopa County Department of Civil Defense and Emergency
Services community right-to-know filings for local industries to
determine which facilities may have had activities that used the
chemicals detected in groundwater within the study area
Maricopa County Department of Public Health list of septic
tank users and registered public water companies within the
study area
Maricopa County Planning Department regarding land-use and
zoning information to identify the distribution of industrial and
commercial property within the study area
Maricopa County Tax Assessor regarding parcel information,
subdivision maps, parcel owners, and legal addresses 1
Regional information pertaining to groundwater use and 1985
census data for Maricopa County
Well construction, pumping schedules, and chemical analysis
data for wells
Well location, status, construction data, previous groundwater
quality analysis, and operational history of wells within the
study area
Geological and hydrogeologic information
Well construction, location, and water quality
Maps and publications to determine soil characteristics, such as
soil texture and infiltration rates

In addition to records review, Kleinfelder analyzed historical groundwater data, and
collected and analyzed groundwater and soil samples. Based on the results of records
and literature searches and groundwater and soil sampling conducted as part of the Phase
I investigation, Kleinfelder identified approximately 850 facilities for further study.
In July 1988, a questionnaire was mailed to the 850 facilities requesting information on
chemical use and past handling practices, and the nature of facility activities. Kleinfelder
received approximately 300 responses. The facilities were then evaluated by the
following criteria: review of available documents and literature; observation of existing
facilities and environmental practices during field reconnaissance; review of responses to
the questionnaires; and an assessment of the proximity of the facilities to observed
chemical concentrations in groundwater.
Weston Industrial Survey - April 18, 2001. Weston’s industrial survey included a review
of city directories to identify businesses located in a one-square-mile parcel within
1

Kleinfelder recorded the parcel owner and identification information in a database if, based on
observations or documented activities, the property land use was suggestive of chemical use, waste
handling, or disposal.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-17

8/9/2012

 Township 1 North, Range 2 East, Section 9 (Appendix J). The property searched was
within the WVBA. Weston did not review regulatory agency records for the facilities
listed in the industrial survey. Weston listed 219 addresses and three intersections in the
industrial survey. Approximately 584 businesses and 31 individuals found through a
review of city directories were associated with the 219 addresses and three intersections.
HGL Industrial Surveys Nos. 1, 2, and 3 - June 13, 2002 and August 27, 2002. HGL
conducted three industrial surveys to identify potential source areas for PCE, TCE, TCA,
DCE, and DCA contamination (HGL, 2002a, 2002b, and 2002c). The focus of the
industrial surveys was to locate significant users of COC for the purpose of assisting
ADEQ in its RI of the WQARF site. Although chromium is identified as a COC for the
WQARF site, it was not one of the COC under investigation for the industrial surveys.
The figure in Appendix J depicts the three industrial survey boundaries. The boundary
for Industrial Survey No. 1 is Township 1 North, Range 3 East, Section 6, Quarter C
(Southwest); and Township 1 North, Range 3 East, Section 7, Quarter B (Northwest).
The boundary for Industrial Survey No. 2 is Township 1 North, Range 3 East, Section 6,
Quarter D; and Township 1 North, Range 3 East, Section 7, Quarter A. The Industrial
Survey No. 3 boundary includes Sections 11 and 12 of Township 1 North, Range 2 East.
The industrial surveys were based on a review of Phoenix city directories from 1935 to
2000 to identify the address ranges within Industrial Survey Nos. 1 and 2 boundaries.
For Industrial Survey No. 3, Phoenix city directories from 1935 through 2001 were
reviewed. 2 Some of the properties within the designated boundaries were used for
commercial or industrial purposes prior to 1935; however, it was ascertained that the use
of the COC prior to 1935 was improbable based on the historical use of these chemicals.
For Industrial Survey No. 3, information from the City of Phoenix Planning Department
was obtained to ascertain the street ranges within the industrial survey boundary.
For Industrial Surveys Nos. 1, 2, and 3, a list of the classified business directory
categories from multiple years was compiled and evaluated for businesses with a
likelihood of usage of COC in their operations. Businesses with operations using COC
were included in the industrial surveys.
HGL’s records search consisted of reviewing ADEQ files for Industrial Surveys Nos. 1
and 2 and reviewing ADEQ, City of Phoenix, EPA, and Maricopa County files for
Industrial Survey No. 3. For Industrial Survey No. 1, HGL investigated 47 addresses and
about 62 businesses, and 143 addresses and about 182 businesses were investigated for
Industrial Survey No. 2. For Industrial Survey No. 3, 186 addresses and about 228
businesses were investigated. Specific details about these records searches are provided
below.
ADEQ Files. For Industrial Surveys Nos. 1 and 2, the following ADEQ files were
reviewed for companies located within these industrial survey boundaries that used waste
oil, COC, or unknown chemicals: preliminary assessment/site investigation (PA/SI) files,
2

City directories for 1943, 1944, and 1954 were not available for review.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-18

8/9/2012

 RCRA notification files, RCRA open and closed case files, and UST and LUST files. 3
HGL reviewed the above-mentioned ADEQ files as well as drywell files for Industrial
Survey No. 3. Also for Industrial Survey No. 3, ADEQ conducted a search of the ADEQ
State Permits List for information in the application and permits section of the water
quality database.
City of Phoenix Files. The City of Phoenix Fire Department was contacted regarding
incidents which may have occurred at addresses within the Industrial Survey No. 3 site
boundary. 4 Search parameters included a list of individual addresses identified through a
review of both the city directories and ADEQ files. HGL also reviewed files at the
Pollution Control Division of the City of Phoenix Water Services Department to find pretreatment violation reports for the years 1988 to 2000. 5
EPA Files. For Industrial Survey No. 3, a CERCLA search was conducted by querying
the EPA’s CERCLIS via the internet. HGL reviewed the list of facilities in Phoenix,
Arizona, that were included in CERCLIS to evaluate whether the listed facilities were
located within the industrial survey boundary. In addition, HGL reviewed the facilities in
Phoenix, Arizona, that were included in the EPA’s archived sites database to ascertain
which facilities were located within the industrial survey boundary. The EPA lists
facilities on the archived sites database when it has completed its assessment of the
property, and it has ascertained that no further steps will be taken to list that facility on
the National Priorities List.
Maricopa County Files. HGL provided the Environmental Services Department of
Maricopa County a list of addresses obtained through a city directory review and the
corresponding legal descriptions of properties located within the Industrial Survey No. 3
boundary to request non-residential septic tank information. To obtain the legal property
descriptions, the Maricopa County Assessor’s website was accessed. HGL also provided
the Air Quality Department of the Maricopa County Environmental Services Division a
list of facility names identified through its city directory search to request information
pertaining to air quality violations within the industrial survey boundary. Because air
quality records only date back five years, the focus of this search was on facilities known
to have operated within the past five years.
Other Searches. For Industrial Survey No. 3, HGL also queried the U.S. Department of
Labor Occupational Safety and Health Act facility inspection database by entering the
names of facilities identified through the city directory search. HGL also identified two
aerial photographs within its document collection for the WQARF site that were inclusive
of the Industrial Survey No. 3 boundary. The dates and source of the aerial photographs
are unknown. An aerial photograph analysis was conducted to evaluate the presence of

3

UST and LUST files were only reviewed for those companies that were identified as having a tank
containing waste oil, solvents, or unknown chemicals.
4
The search of City of Phoenix Fire Department records was inclusive of records dating from 1995 to
2002.
5
Information is not maintained for the years prior to 1988.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-19

8/9/2012

 commercial or industrial operations and to identify any evidence of environmental
contamination within the industrial survey boundary.
HGL RI Support for the West Van Buren Area WQARF Site - October 2003 - January
2007. The RI Support task assignment consisted of two phases of investigation. For the
initial phase, a boundary of the investigation was not established because ADEQ
specifically assigned certain facilities to be investigated based on known information
regarding the possible releases of COC at the facilities located within the WVBA
boundary. From October 2003 to July 2005, HGL investigated 59 facilities and issued 35
facility letter reports with research findings on these facilities, including a summary of
site operations and ownership. Relevant supporting documents were included in the
facility letter reports for ADEQ to review while evaluating whether further investigation
was necessary at the facilities. Research involved the review of ADEQ records to locate
information on releases of the COC with regard to the facilities. Search parameters
included company name and address, when available. Below is a list of the files and
databases that were reviewed.













Drywell Files
Former 202 Facility Files 6
Hazardous Material Incident Logbook Files
PA/SI Files
Potentially Responsible Party (PRP) Site Files 7
RCRA Compliance Files
RCRA Archived Files
RCRA Open and Closed Case Files
Records Information Management System (RIMS) 8
UST and LUST Files
Water Quality Database/State Permits List Files
West Van Buren WQARF Site Central File

From August 2005 to January 2007, HGL conducted the second phase of the
investigation. This phase represented a more expansive search to locate facilities within
the WVBA that were not previously investigated by HGL under the industrial surveys or
facility investigations mentioned above (Appendix J). HGL also re-reviewed ADEQ
records for facilities that were previously investigated under three HGL industrial surveys
to expand its search to include chromium releases. 9 In addition, HGL investigated
facilities listed in the April 18, 2001 Weston industrial survey as that industrial survey
did not include the review of regulatory agency records for the facilities listed. The final
6

The former 202 facility files consist of the West Van Buren Investigative files that were previously
located at ADEQ’s facility on 202 E. Earll Drive.
7
PRP Site files for the West Van Buren, Estes Landfill, and Broadway-Pantano Landfill WQARF Registry
sites were reviewed.
8
An ADEQ database available at the ADEQ records management center that listed different file types
available at the ADEQ. Files found through a review of RIMS included pollution prevention, air, oil,
voluntary remediation program, emergency response, and WQARF files.
9
Chromium was not a part of the original scope of HGL Industrial Surveys Nos. 1, 2, and 3.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-20

8/9/2012

 aspect of this investigation included a search for facilities located within zip codes 85003,
85004, 85007, 85009, and 85043 present within the WVBA. Search results were
compiled into facility letter reports.
The investigation consisted of a review of PRP site files, former 202 facility files, ADEQ
records collections, and EPA records for information on releases of the WVBA COC.
For facilities listed in the Weston industrial survey and HGL’s three industrial surveys,
HGL conducted a search of finding aids by facility name and address. 10 HGL then
conducted a search of ADEQ finding aids using the five zip codes associated with the
WVBA. Specifically, HGL conducted a review of finding aids for the files listed below
for facilities HGL previously investigated under its three industrial surveys, facilities
located within the Weston industrial survey boundary, and for facilities located within the
WVBA boundary that had not been previously investigated.
















Arizona Attorney General’s Office (AGO) Files 11
City of Phoenix Fire Department Hazardous Material Incident Files 12
Drywell Files
EPA CERCLIS Database
Former 202 Facility Files
Hazardous Materials Incident Logbook Files
Hazardous Waste Box Storage Files
PA/SI Files
PRP Site Files
RCRA Archived Files
RCRA Compliance Files
RCRA Open and Closed Case Files
Hummingbird (formerly RIMS) 13
UST and LUST Files
Water Quality Database Files

Once the finding aids were reviewed, online mapping systems were used to evaluate
whether the facilities were located within the WVBA. If facilities were located within
the WVBA, HGL requested and reviewed available files. Another evaluation that HGL
made prior to requesting files was using industrial research to evaluate whether a facility
would have used the COC. If, by the facility name or other research efforts, HGL could
not ascertain what chemicals a facility used, a file review was conducted.

10

Finding aids are ADEQ and HGL indexes and databases that list available files for review.
AGO files were considered secondary sources and would only be reviewed if requested by the ADEQ
after its review of facility letter reports.
12
The City of Phoenix Fire Department stated it did not have the staff to respond to a broad file request and
the ADEQ decided that those records would only be reviewed if additional information was needed for a
facility based on its review of the facility letter reports.
13
A search was conducted on Hummingbird for file information on 21 of the 58 facilities that were
investigated from February 3, 2004 to July 29, 2005 as Hummingbird was not available to HGL when
conducting the original research of the facilities.
11

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-21

8/9/2012

 HGL created a Microsoft Access database that has 1,656 entries comprised of facilities
and locations reviewed under HGL’s three industrial surveys and RI support. These data
are available in Appendix J, Tables J-1 and J-2. In addition, an assessment of relevant
records was conducted and confidential facility letter reports were drafted on a facility-by
facility basis with information regarding releases of COC. The 137 facilities assessed can
be found in Appendix J in Table J-3.
1.4

Site Contaminants

The primary COCs comprising the commingled WVBA plume include the following
VOCs: PCE, TCE, TCA, cis 1,2-DCE, 1,1-DCA, and 1,1-DCE. To a limited extent,
chromium is also considered a COC. Groundwater contamination enters the WVBA
from the east from the Motorola 52nd Street Federal Superfund Site OU3 area. Notable
COCs for OU3 are TCE, TCA, PCE, 1,1,2-TCA, vinyl chloride, chloroethane, 1,1-DCA,
1,1-DCE, 1,2-DCA, cis 1,2-DCE, trans 1,2-DCE and 1,4-dioxane. Contaminated
groundwater also appears to enter the WVBA from the north in the central portion of the
site from the West Osborn Complex (WOC) WWQARF Registry Site. The current
COCs in groundwater at the WOC include TCE, 1,1-DCE, and PCE.
1.5

Contaminant Sources

Reynolds Metals Co., TCA was the primary solvent used at this facility along with
Stoddard Solvent. TCA, TCE, PCE, chromium, and petroleum hydrocarbons have been
detected in soils beneath this facility. Areas of investigation include: anodizing area,
tanks including USTs and aboveground storage tanks (ASTs), manufacturing equipment
foundations, dip tanks, and distilling areas.
Van Waters & Rogers Inc. Numerous chemicals are stored and packaged at this
facility. PCE, TCE, TCA, and 1,1-DCE have been detected in the soils underlying this
facility. Areas of investigation include: waste water pretreatment system and sewer
interceptor, bulk solvent tank farm, bulk corrosive tank farm, drum storage areas, and
former Resource Conservation and Recovery Act (RCRA) interim status container
storage unit.
Maricopa County Materials Management Numerous cleaning solvents were stored
and recycled at this facility while the Southwest Solvents Recycling was in operation.
PCE, TCE, 1,1,1-TCA, 1,1-DCE, cis & trans-1,2-DCE, and 1,1-DCA have been detected
in soils underlying this facility. Areas of investigation include: Southwest Solvent
Recycling facility and the parking area.
Dolphin, Inc. Solvents were used at this facility during the casting process of metals.
PCE, TCE, TCA, 1,1-DCE, and 1,1-DCA have been detected in soils beneath this
facility. Area of concern include: septic system, interceptor tanks, degreasing/parts
cleaning areas, acid etching building, drum storage areas, and drywell.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-22

8/9/2012

 American Linen Supply Co. PCE was used at this facility as part of dry cleaning
operations. PCE, TCE, benzene, and TCA have been detected in soils beneath this
facility. Areas of investigation include: waste water disposal areas and dry cleaning
machine locations.
ChemResearch Co., Inc. PCE and metals processing chemicals associated with metal
plating and finishing were used at this facility.
PCE, TCE, 1,1-DCE, 1,2dichlorobenzene, cadmium, chromium, and lead have been detected in the soils
underlying this facility. Areas of investigation include: plating areas, UST, and waste
water treatment plant.
Air Liquide America Specialty Gases LLC Solvents used at this facility have included
TCA, paint thinner, acetone, and Freon-11. PCE, TCE, TCA, and 1,1-DCE have been
detected in soils beneath this facility. Area of concern includes: the grease trap and
associated piping.
Prudential Overall Supply PCE was used at this facility as part of dry cleaning
operations. The cleaning solvent Safety Clean was also used at this facility for
maintenance purposes. PCE and TCE have been detected in soils beneath the facility.
Areas of investigation include: dry cleaning area, waste water flume, and parts cleaning
area.
U.S. Department of Energy Petroleum based solvents, chlorinated based solvents, and
various types of wastes have been used/stored at this facility. PCE, TCE, 1,1-DCE, cis1,2-DCE, and 1,1-DCA have been detected in soils underlying the facility. Area of
concern includes the Craneway building.
1.6

Physiography

The WVBA extends from 7th Avenue to 75th Avenue and from Buckeye Road to
Interstate 10. This corresponds to an area approximately eight miles in length and 1.5
miles in width (approximately 12 square miles). In addition, a finger shaped plume exists
between 7th and 27th Avenues between Buckeye and Lower Buckeye Roads. The WVBA
covers portions of two U.S. Geological Survey topographic quadrangles; Fowler and
Phoenix, Arizona (Figure 1-1).
The highest elevation in the WVBA is 1,082 feet above mean sea level (msl) at 7th and
Grand Avenues, and the lowest elevation is 1024 feet above msl at 75th Avenue and
Buckeye Road. There is a gentle (10 to 15 feet per mile) southwestern topographic
gradient towards the Salt River. Two east-west and one north-south trending man-made
features break up the topography within the WVBA. The east-west trending features are
the railroad tracks located mid-way between Van Buren Street and Buckeye Road, and
the bermed RID canal which originates at 19th Avenue south of Interstate 17. The RID
canal flows westward south of Buckeye Road to 67th Avenue, and then zigzags
northwesterly to 75th Avenue north of the railroad tracks where it egresses from the

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-23

8/9/2012

 WVBA. The north-south trending feature is Interstate 17, which is depressed through the
WVBA adjacent to 23rd Avenue.
The WVBA is largely urbanized, particularly in the eastern and central portions.
Irrigated agricultural fields are located to the west, but are increasingly becoming
developed, particularly by large warehouse structures.
1.7

Meteorology

The climate of the Phoenix area is semi-arid, with hot summers and mild winters.
Daytime high temperatures in July average between 100 and 110 degrees Fahrenheit (F),
with nighttime low temperatures between 70 and 80 degrees F. Daytime high
temperatures in January average between 65 and 70 degrees F, with nighttime low
temperatures between 35 and 40 degrees F. Most of the area has an average annual frostfree period of between 210 and 280 days.
Precipitation averages between 7 and 8 inches per year; most of this occurs from
thunderstorms associated with the summer monsoon (July through September), with the
remainder generally occurring during the winter (December through March). Most of the
precipitation evaporates, with evaporation rates varying between about 65 to 75 inches
per year.
1.8

Surface Water Features
1.8.1

Salt River

The west-flowing Salt River is located south of the site along its entire length. Treated
effluent from the City of Phoenix 23rd Avenue wastewater treatment facility is discharged
into the Salt River bed under an EPA-issued National Pollution Discharge Elimination
System (NPDES) permit and into the RID canal. Additionally, during periods of heavy
regional precipitation, upstream dam releases and local runoff result in additional surface
water flow. When upstream dam releases occur, the Salt River acts as a source of
groundwater recharge, raising water levels and altering the direction of groundwater
flow. This is discussed further in Section 3.3.
1.8.2

RID Canal System

The RID canal originates at 19th Avenue south of Interstate 17. Year-round discharge of
water into the canal occurs at the COP 23rd Avenue wastewater treatment facility where
30,000 acre-feet per year of treated wastewater is discharged into the canal (BE&K/
Terranext, 2001c). Water within the canal is utilized for non-potable agricultural
purposes. The canal is also fed by a number of RID production wells located throughout
the WVBA; these wells discharge an additional 135,000 acre-feet per year of pumped
groundwater into the canal. The wells pump during the warmer months of the year, are
dormant during the winter (with the exception of a few wells which are pumped during
the entire year), and either discharge directly into the canal, or discharge into both

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-24

8/9/2012

 exposed and unexposed lateral canals that feed the main canal. When the RID wells are
pumping, they act as a source of groundwater discharge, lowering water levels and
altering the direction of groundwater flow. This is discussed further in Section 3.3.
1.8.3

SRP Lateral Canals

SRP’s Grand Canal trends east-west north of the WVBA. Oriented north-south from the
Grand Canal, at approximate 0.5 mile intervals, are open and piped lateral canals that
transport water by gravity flow southwards. These lateral canals are located from 19th
Avenue westward beyond 83rd Avenue. Water within the lateral canals is utilized for
non-potable agricultural purposes. The lateral canals are also fed by a number of SRP
production wells located in areas surrounding the WVBA; no SRP wells are located
within the WVBA.
1.9

Hydrogeologic Setting

The WVBA is located within the West Salt River Valley (SRV), an alluvial basin
consisting of basin-fill deposits of unconsolidated to semi-consolidated Late Tertiary to
Quaternary sediments (Weston, 2000). They range up to several thousand feet thick
within the center of the basin and consist of interbedded cobbles, gravel, sand, silt, clay,
and evaporites. The rocks that form the bounding mountains and valley floor of the SRV
are predominantly crystalline rocks. The basin-fill deposits are subdivided into three
hydrogeologic units that comprise the regional aquifer in the SRV. In ascending order,
they are the Lower Alluvial Unit (LAU), Middle Alluvial Unit (MAU) and the Upper
Alluvial Unit (UAU).
The LAU consists mainly of conglomerate and gravel grading into finer-grained
mudstones toward the center of the basin and locally contains volcanic rocks. The LAU
does not appear to be contaminated within the WVBA. The MAU overlies the LAU and
consists predominantly of silt and clay with interbedded sand and gravel lenses. The
UAU extends from the ground surface to the top of the MAU. The UAU consists mainly
of unconsolidated silt, sand, and gravel deposited during the final stages of SRV basin
development.
Groundwater occurs in the basin-fill deposits through out most of the SRV (Hammett and
Herther, 1995). The three major units, the UAU, MAU and LAU, contain measurable
quantities of water. However, this water is stored and moves under different regimes for
the UAU and the two deeper layers. Water in the UAU is unconfined. According to
Weston (2000), the MAU and LAU are both confined. Groundwater movement is
generally to groundwater depressions located across the SRV which are created by
extensive groundwater withdrawals (Hammett and Herther, 1995). Where groundwater
flow is not affected by excessive pumping, flow is generally to the west.
As mentioned above, the Salt River is the largest surface drainage feature in the vicinity
of the SRV. Although dry during most of the year, winter and early spring precipitation
combined with runoff from melting snow from the upper watershed can produce runoff.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-25

8/9/2012

 These events, although short in duration, contribute significant groundwater recharge. As
a result of this flow, water levels rose dramatically in wells within several hundred feet of
the river.
1.10

Ecology

The WVBA is located just west of downtown Phoenix, and thus, comprises an urban
environment. This reduces the potential for unique flora/fauna or endangered species or
their habitats in the area. Neither are there sensitive environments such as wildlife
breeding areas, wildlife refuges, or specially designated areas such as wild and scenic
rivers, or national parks. Because contamination is present at depth below ground
surface, there is little to no threat to flora/fauna, species or habitats.
The RID canal has been identified as wetlands (U.S. Fish and Wildlife Service, 1989).
Specifically, the RID canal is classified as a riverine, lower perennial, unconsolidated
bottom, permanently flooded excavation.
According to the Federal Emergency Management Agency (2005), portions of the
WVBA are located within a 100 year floodplain (floodplain). In the eastern portion of
the WVBA, Interstate 17 from approximately Roosevelt Street to Buckeye Road lies
within the floodplain due to its subgrade construction. Additionally an area bound by
approximately Interstate 17 and 17th Avenue is also located within the floodplain; this
area was the former location of Cave Creek Wash prior to urbanization.
Portions of the western end of the WVBA are also located in the floodplain. At
approximately 69th Avenue and Sherman Street, the RID canal bends 90 degrees to the
north. The bermed canal at this location has created a floodplain within an adjacent
agricultural field. Another floodplain is located within undeveloped property north of the
railroad tracks between 69th and 75th Avenues, and was created by the raised railroad
tracks. An additional floodplain is located within a storm water retention basin
constructed at the southeast corner of 75th Avenue and Van Buren Street.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 1-26

8/9/2012

 2.0

PREVIOUS INVESTIGATIONS

COCs for the WVBA are identified as PCE, TCE, TCA, cis 1,2-DCE, 1,1-DCA, 1,1-DCE, and to
a limited extent, chromium.
Contaminant sources have been investigated/documented
throughout the WVBA. COCs have been detected in soil, soil gas, and groundwater at the
following facilities: Reynolds, VW&R, MCMM, Dolphin, ALSCo, POS, DOE, CRC, and
ALASG.
Regulatory standards that these contaminants have been/are compared to include HBGLs
implemented by ADEQ in 1992, SRLs implemented by ADEQ in December 1997 and revised in
May 2007, GPLs implemented by ADEQ in September 1996, EPA MCLs promulgated in 1987,
and AWQSs implemented by ADEQ in September 1996. Regulatory standards applicable for
each facility are dependant upon when the facility was fully characterized. The most recent
version of the SRLs will be applicable to facilities which have not been fully characterized by
2007 or remediated by 2010. The following table lists the standards established for WVBA
COC:
Contaminant
of Concern

PCE
TCE
TCA
Cis 1,2-DCE
1,1-DCA
1,1-DCE
1,2-DCA
Chromium
Total
Chromium
III
Chromium
VI

MCL
(µg/l)

AWQS
(µg/l)

HBGL
(mg/kg)

GPL
(mg/kg)

Original SRLs
Residential
Non
SRL
Residential
(mg/kg)
SRL (mg/kg)

Revised SRLs
Residential SRL (mg/kg)

Non
Residential
SRL
(mg/kg)

5.0
5.0
200
70
NE
7.0
5.0
100

5.0
5.0
200
70
NE
7.0
5.0
100

27
120
3,300
1,200
NE
110
15
1,700

1.3
0.61
1.0
4.9
NE
0.81
0.21
590

53
27
1,200
31
500
0.36
2.5
2,100

170
70
4,800
100
500
0.8
5.5
4,500

10-6
Risk
0.51
3.0
NE
NE
NE
NE
0.28
NE

10-5
Risk
5.1
30
NE
NE
NE
NE
2.8
NE

Noncarcinogen
NE
17
1,200
43
510
120
NE
NE

13
65
1,200
150
1,700
410
6.0
NE

NE

NE

NE

590

77,000

1,000,000

NE

NE

120,000

1,000,000

NE

NE

NE

590

30

64

30

NA

NE

65

SRLs: Soil Remediation Levels MCL: Maximum Contaminant level AWQS: Aquifer
Water Quality Standard HBGL: Health Based Guidance Level GPL: Groundwater
Protection Level NE: Not Established µg/l: Micrograms per Liter Mg/kg: Milligrams per
kilogram
Numerous groundwater and soil investigations have been conducted within the WVBA. Initial
groundwater sampling was conducted by ADWR and ADHS personnel in May 1986 after
groundwater contamination by halogenated VOCs was detected at the Chevron fuel storage facility
at the Phoenix Terminal (Arizona Department of Water Resources, 1987). Groundwater samples
were collected from 12 wells resulting in the detection of groundwater contamination at seven of the
well locations. This prompted the initiation of numerous investigations to identify sources of the
contamination and characterize the groundwater contamination. Initial soil sampling was conducted
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-1

8/9/2012

 by ADEQ’s contractor, Kleinfelder, during September 1988 (Kleinfelder, 1989). Soil sampling was
conducted at 17 sites during this first phase of investigation which included areas where land use
could not be confirmed, aerial photographs indicated the possible presence of stained soils at
chemical storage facilities, in areas where groundwater quality data indicated contamination, and at
areas inspected during field reconnaissance. TCA and/or TCE were detected at 16 of the 17 sites.
These two compounds were also detected in the two background soil samples collected during this
phase of investigation. The TCE concentration detected in one of the background soil samples was
greater than the TCE concentrations detected at various facilities. Also, the TCA concentration
detected in one of the background soil samples was greater than all but five of the soil sample TCA
concentrations detected at various facilities. Xylenes were detected in soil samples collected from
seven of the sites and toluene was detected in two soil samples.
Based on the results of the Phase I investigation, six facilities, were recommended for physical
testing, 38 were recommended for site inspections, 99 were recommended for record searches, and
63 were recommended for additional questionnaires (Kleinfelder, 1989). As ADEQ investigated
the recommended facilities, Kleinfelder, on behalf of ADEQ, conducted four rounds of groundwater
sampling from November 1989 to May 1991 and installed four groundwater monitor wells as part
of a Phase II investigation (Kleinfelder, 1992a). Based on data obtained during this phase of
investigation, continued groundwater monitoring, characterization of the aquifer, contaminant
transport modeling, and installation of additional groundwater monitor wells were recommended.
These activities were undertaken by ADEQ and select facilities located within the WVBA.
As previously mentioned, based on the results of the Phase I soil sampling, six facilities were
recommended for additional physical testing at their individual facilities. Five of the six facilities
conducted investigations with ADEQ oversight. Of these five, three conducted soil investigations
that indicated the need to also conduct groundwater investigations and two facilities did not require
additional investigation.
Facilities of interest that conducted investigations within the WVBA were required to follow the
remedy selection rules which outline the requirements for completing an RI. As the ADEQ led RI
continues ADEQ conducts the PRP search. A PRP list will be provided once ARS 287.04 Notices
are issued after the PRAP is issued for public comment. The PRP search information remains
confidential until the allocation process at the site is completed.
2.1

Facilities Not Required To Investigate Groundwater

Additional facilities were investigated by ADEQ or were asked by ADEQ to conduct
investigational work to evaluate whether soil contamination at their facilities exacerbated sitewide groundwater contamination. Data and reports resulting from the investigations can be
found within the WVBA public file held at ADEQ. The following facilities (Figure 2-1)
conducted investigational soil and/or soil gas work as requested; however, these facilities were
not required to conduct further groundwater investigations or requested investigations were not
completed:
1. American National Can Co., 211 N. 51st Ave. – COCs detected in soils but did
not appear to reach groundwater. Aquifer Protection Permit No. P-102508

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-2

8/9/2012

 dated 10/3/94 issued a drywell clean closure for American National Can Co.
UST Section issued Case Closure letter for UST release on 4/18/95. ADEQ
letter to EPA dated Nov. 16, 1999 recommended no further action under
CERCLA.
2. Anderson Clayton/Western Cotton Services Co., 615 S 51st Ave – TCE
detected in soil sample collected during Phase I investigation but at
concentration less than background sample. Onsite industrial well sample
contained no COCs, however, no COCs were identified as used at facility.
PASI report dated 3/21/90 indicated no need for additional investigation.
3. Arizona Parts Master, 15 N. 57th Dr. – Contamination found at the facility was
from petroleum hydrocarbons. Not investigated under WQARF program.
4. Arnold Corporation, 40 S. 45th Ave – COCs detected in soils during
investigations conducted at site. Risk assessment completed following ADHS
comments. No closure letter issued by ADEQ. Letter from ADEQ dated
October 18, 1991 stated that discharges from Arnold unlikely to have resulted
in groundwater contamination.
5. AT&T, 505 N.51st Ave – COCs detected in soils during investigations.
ADEQ notified AT&T considered closed in a letter dated 6/19/1996.
6. AWECO, 3918 W. Lincoln St. – No COCs documented in release. No
closure letter issued by ADEQ.
7. BC Assemblage, 333 N. Black Canyon Highway – During a preliminary site
assessment, soils were sampled and analyzed for pesticides, herbicides, PCBs,
and petroleum hydrocarbons; ADEQ requested copies of report. Not sampled
for WVBA COCs. No letter issued.
8. Blue Circle West, 1510 W. Lincoln St. – No COCs were detected in soil
sample collected during Phase I investigation.
9. Brake Supply, 420 S. 7th Ave – PCE & TCE detected in soils but preliminary
site investigation report prepared by Roy F. Weston, Inc. on behalf of ADEQ
dated 4/15/93 recommended that further investigation was not warranted.
ADEQ Internal Memo dated 5/17/93 was in agreement.
10. Bud’s Oil, 1340 W. Lincoln St – COCs detected in soil samples but limited in
depth. No apparent affect on groundwater. ADEQ issued letter dated
10/12/89 stating that ADEQ does not intend to initiate further evaluations at
the facility.
11. Chevron, U.S.A., Inc., 3050 S. 19th Ave. – TCA and TCE detected at
concentrations slightly greater than detection limits in soil sample collected
during Phase I investigation but less than concentrations detected in
background samples.
12. CoStar Corp/Data Packaging Corp, 425 S. 67th Ave – Investigated soil release
at oil separator and at drywell where contaminated soil was excavated to 25
feet below ground surface (bgs). Soil remediation confirmed and groundwater
monitor wells requested by ADEQ in letter dated 9/9/93 but were never
completed.
13. Grow Group, Inc. 4940 W. Jefferson St. – During a preliminary site
assessment, soils were sampled and analyzed for pesticides, herbicides, PCBs,

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-3

8/9/2012

 and petroleum hydrocarbons, ADEQ requested copies of report. Not sampled
for WVBA COCs.
14. Hi-Tech Plating, Inc., 4313 W. Van Buren St. – PCE & TCE detected in
drywell. Investigated area adjacent to and below the drywell but found no
VOCs in soil or groundwater. No letter issued by ADEQ.
15. Jacquay’s Equipment Co., 1219 S. 19th Ave. – Recommended for physical
testing in Kleinfelder Phase I report but no record of testing in file. No letter
from ADEQ.
16. Joe’s Diesel Repair, 6316 W. Van Buren St. – TCA and TCE detected at
concentrations slightly greater than the detection limits in soil sample
collected during Phase I investigation but less than concentrations detected in
background samples.
17. LaSalle Draperies, 710 W. Buchanan St. – PCE and TCE detected in soil gas
but not soil samples. Tom Curry, former ADEQ project manager for WVBA,
telephone record dated 7/30/92 indicated that additional sampling could result
in issuing a no action letter.
18. Research Chemicals, 8220 W. Harrison St., Tolleson – TCA and TCE
detected at concentrations slightly greater than the detection limits in soil
sample collected during Phase I investigation but less than concentrations
detected in background samples. Investigated/operated under RCRA
according to facility permit.
19. Owens-Corning Fiberglass Corp., 1880 W. Fillmore St. – Submitted
preliminary site assessment report as part of questionnaire request response to
ADEQ. ADEQ letter dated February 9, 1990 stated that the facility was not
considered for further evaluations.
20. Penn Athletic, 306 S. 45th Ave – Conducted soil investigations associated with
UST release which indicated that no COCs released. Preliminary assessment
report by ADEQ 6/18/90 recommended no further action under CERCLA.
ADEQ Voluntary Remediation Program issued a NFA letter dated 6/4/02.
21. Petco, Inc., W. Side of 67th Ave. N. of railroad – TCA and TCE detected at
concentrations slightly greater than the detection limits in soil sample
collected during Phase I investigation but less than concentrations detected in
background samples.
22. Unocal, 10 S. 51st Ave. – PCE detected in soil samples collected from
property leased from Santa Fe Pacific Pipeline Partners, L.P. Soil data
collected by Brown and Caldwell (1990a & b) and Levine Fricke (1994), and
groundwater data collected from groundwater monitor wells upgradient and
downgradient of the area indicate that COC concentrations are similar,
possibly indicating that the release did not affect groundwater quality.
23. Ray & Bob’s Truck Salvage, 101 S. 35th Ave. – TCA and TCE detected at
concentrations slightly greater than the detection limits in soil sample
collected during Phase I investigation but less than concentrations detected in
background samples.
24. Revlon, 4301 W Buckeye Rd – Conducted soil sampling and soil remediation
for releases of contaminants other than WVBA COCs. ADEQ Preliminary
Assessment dated 2/28/90 recommended no further action under CERCLA.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-4

8/9/2012

 Following additional investigations, ADEQ issued a letter dated 2/21/01; no
further testing will be required if Revlon provided a revised report addendum.
25. Roadway Express, 2021 S. 51st Ave. – TCE detected at concentration slightly
greater than the detection limit in soil sample collected during Phase I
investigation but less than concentration detected in background samples.
26. Salesco Systems/Turken Industrial Properties, 5736 W. Jefferson St. – COCs
detected in drywell sludge. ADEQ requested that full extent of drywell
contamination be investigated in a letter dated 2/19/92 but no information in
the file indicating that it was completed.
27. Santa Fe Railroad Yard, W. of 19th Ave. between McDowell Rd. and Fillmore
St. – TCA and TCE detected at concentrations slightly greater than the
detection limits in soil sample collected during Phase I investigation but less
than concentrations detected in background samples.
28. Schuff Steel, 4420 S. 19th Ave. – TCA and TCE detected at concentrations
slightly greater than the detection limits in soil sample collected during Phase
I investigation but less than concentrations detected in background samples.
29. Seaport Petroleum, 57 N. 57th Ave. – Contamination found at the facility was
from petroleum hydrocarbons. Not under WQARF jurisdiction.
30. Smithey Recycling Co., 3640 S. 35th Ave. – TCA and TCE detected at
concentrations slightly greater than the detection limits in soil sample
collected during Phase I investigation but less than concentrations detected in
background samples.
31. Southwest Feed & Seed, 350 S. 75th Ave. – TCA and TCE detected at
concentrations slightly greater than the detection limits in soil sample
collected during Phase I investigation but less than concentrations detected in
background samples.
32. Sta-Rite Industries, Inc., 1146 W. Hilton St. – Had a release of PCE to soil.
Excavated contaminated soil. No response by ADEQ.
33. Sun State Builders, 43rd Ave/Gibson Lane – Soil sampling did not detect
COCs. ADEQ issued letter stating not considered PRP dated 6/24/88.
34. Transco Lines, 3839 W. Buckeye Rd. – TCA and TCE detected at
concentrations slightly greater than the detection limits in soil sample
collected during Phase I investigation but less than concentrations detected in
background samples.
35. Triple E Properties, 1909 W. Fillmore St. – Investigated release of petroleum
hydrocarbons from aboveground storage tank. ADEQ letter dated October 21,
1991 stated that the facility was not considered for further evaluation.
36. Tritech Manufacturing, Inc./Tri-Star Quality Metal Finishing, Inc., 5144 W
McKinley St – Sampling around drywell indicated no COCs present in
subsurface. ADEQ installed well upgradient on site is higher in VOCs than
downgradient wells.
37. Western States Petroleum, Inc., 450 S. 15th Ave. – Facility submitted a
workplan to do soil sampling but no sampling data are contained in file. Two
USTs were removed from the facility and ADEQ issued a letter dated
12/29/93 stating that the case was closed because no release of regulated
substances had occurred from the USTs.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-5

8/9/2012

 38. Phoenix Vegetable Distribution, S. Side of Buckeye Rd. E. of 83rd Ave. –
TCE detected at concentration slightly greater than the detection limit in soil
sample collected during Phase I investigation but less than concentrations
detected in background samples.
39. World Resources Co., 8113 W. Sherman St. – TCA and TCE detected at
concentrations slightly greater than the detection limits in soil sample
collected during Phase I investigation but less than concentrations detected in
background samples. Investigated/operated under RCRA according to facility
permit.
2.2 ADEQ Area Wide Investigations
2.2.1

Activities from 1986-1998

Initial groundwater sampling was conducted by ADWR and ADHS personnel in May 1986
(Arizona Department of Water Resources, 1987). After the creation of the WVBA WQARF site in
1987, ADEQ retained Kleinfelder as their contractor to perform site investigations. A Phase I
investigation was conducted in 1988 and reported in July 1989 (Kleinfelder, 1989). The Phase I
included an assessment of existing information from record reviews, questionnaires, field
reconnaissance (including historical water data) and sampling. This was followed by a 1991 Phase
II groundwater investigation and sampling report (Kleinfelder, 1992a).
During 1991 through 1998, ADEQ continued site characterization activities, and its contractors
installed and sampled monitor wells within the WVBA. The following lists ADEQ contractor, year
monitor wells were installed, and monitor well designation from 1991 - 1998:
Kleinfelder (8 wells)

1991: AVB10-01 through AVB10-04, AVB12-01, AVB14-01, AVB18-01, and
AVB22-01
Weston (14 wells)

1992: AVB34-01, AVB35-01 and AVB38-01 through AVB38-04

1993: AVB42-01 through AVB42-03, AVB46-01, AVB47-01, and AVB57-01

1994: AVB60-01 and AVB61-01
Fluor Daniel GTI (6 wells)

1997-98: AVB69-01 and 02, and AVB77-01 through AVB77-04
GEC (7 wells)

1998: AVB70-01, AVB71-01, AVB72-01, AVB73-01, AVB74-01, AVB75-01 and
AVB76-01
ADEQ also gained access to several current and former LUST site, private, and industrial monitor
wells throughout the project timeframe. ADEQ currently utilizes the “AVB” designation followed
by the facility identification number (location-specific) and site identification number (wellspecific) to identify monitoring well and groundwater samples.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-6

8/9/2012

 Two well inventories were conducted during this time frame in an attempt to identify groundwater
wells located within and adjacent to the WVBA. These surveys were conducted by ADEQ
contractors Kleinfelder and Weston. Information obtained from the surveys was used to identify
wells for collecting groundwater samples and for lithologic interpretation.
2.2.1.1 Kleinfelder Inventory
ADEQ’s former contractor, Kleinfelder, Inc., conducted a review of groundwater wells located
within and adjacent to the WVBA as part of the original WVBA investigation (Kleinfelder, 1992b).
The inventory contained well information obtained from ADWR, RID, reports submitted to ADEQ
by various consultants, and from information Kleinfelder personnel obtained in the field. The
report identified 510 wells potentially existing within and adjacent to the WVBA. Of these, 295
were verified by Kleinfelder personnel.
2.2.1.2 Weston Inventory/Model Preparation
Roy F. Weston, Inc. reviewed records at ADWR, files at ADEQ, and data from consultants to
identify groundwater wells in the vicinity of the WVBA as part of the development of a transient
groundwater flow model for the Central Phoenix area (Weston, 2000). Information obtained from
this well inventory was used to identify lithologic characteristics, well completions, and pumping
information. This inventory included wells a considerable distance from the WVBA because the
model covered a much larger portion of Phoenix.
Concurrent with the well inventory, Weston developed a Phase I database followed by a conceptual
model. Weston developed a five-layer model with seasonal stress periods as a final end product.
Modeling activities are described in further detail in Section 5.2.2 of this report and in the June 9,
2000 Weston report “Central Phoenix Groundwater Model”.
2.2.2

Activities from 1999-Current

ADEQ retained Terranext (then BE&K/Terranext) in 1999 to perform RI activities. Terranext
developed project plans (BE&K/Terranext, 2000a, b, and c) and initiated the following ongoing site
characterization activities:


Well inventory - BE&K/Terranext performed a well inventory to identify existing wells
registered with ADWR. The well inventory assists ADEQ in complying with ARS § 49282.06(B)(4)(b), which indicates that selected remedial actions must address any well that
would produce water that is not fit for its current or reasonably foreseeable use.
BE&K/Terranext identified locations and uses of wells in the WVBA by reviewing
ADWR’s well registry database (BE&K/Terranext 2000d). The boundaries of the inventory
were 7th and 91st Avenues on the east and west, respectively, and McDowell and Lower
Buckeye Roads on the north and south, respectively. This information was used to identify
groundwater wells which may be located in the WVBA whose uses could be affected by the
degradation of water quality. This inventory identified 971 wells between 7th and 91st
Avenues, and McDowell and Lower Buckeye Roads. Of these, over 160 wells were

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-7

8/9/2012

 identified as production wells. Based on current WVBA boundaries, slightly less than half
of the wells are located within the WVBA which could be affected by groundwater quality
degradation. Half of these wells had a water use listed as irrigation. The remainder had
water uses listed as domestic, municipal, or industrial, however, no municipal wells are
currently operable in the WVBA.
 Monitor well installation - Since early 2001, ADEQ initiated eight rounds of monitor well
installation by Terranext within the WVBA:
- Early 2001 (9 wells): AVB81-01 through AVB88-01 (BE&K/Terranext, 2001a)
- December 2001 and March 2002 (14 wells): AVB91-01 through AVB100-01
(BE&K/Terranext, 2002a)
- Spring 2003 (9 Wells): AVB115-01 through AVB122-02 (BE&K/Terranext 2003a)
- Spring 2004 (10 Wells): AVB116-02 and AVB122-03 through AVB125-01 and
AVB127-01 through AVB130-01 (Terranext, 2004a)
- May 2005 and October 2005 (5 wells): AVB124-02, AVB131-01, AVB133-01,
AVB132-01 and 02 (Terranext, 2005a)
- Spring 2006 (7 Wells): AVB126-01 and –02, AVB134-01 and –02, and AVB13501 through 137-01 (Terranext, 2006a)
- Spring 2007 (6 wells): AVB82-02, AVB91-03, AVB121-02, AVB126-03,
AVB139-01, and AVB141-01 (Terranext, 2007)
- Spring 2008 (2 wells): AVB140-01 And AVB142-01 (Terranext, 2008a)


Water-level measurements – water levels have been measured on a monthly, quarterly, or
semi-annually basis since 2000. Monitor wells, either newly constructed by ADEQ or
constructed by other parties which ADEQ has gained access, have been added to the WVBA
monitor well network over time. Water-level monitoring reports (up to first quarter 2002)
and semi-annual water quality reports (post first quarter 2002) contain the collected water
level data.



Groundwater sampling – groundwater sample collection occurs semi-annually within the
WVBA monitor well network. BE&K/Terranext’s initial sampling event occurred during
second quarter 2000 followed by another event during first quarter 2001. Currently,
collection of groundwater samples occurs during the first and third quarters of each calendar
year. Along with the results of the sampling, water quality reports contain water level data
and maps, sampling procedures, laboratory analyses and quality assurance/quality control
verification.

 Map preparation - BE&K/Terranext prepared water level and COC concentration contour
maps covering the period 1993 through 1999 utilizing data collected from ADEQ wells and
wells installed during site investigations by facilities identified in Section 1.3.2
(BE&K/Terranext, 2000e). Specific contaminant concentrations mapped consisted of PCE,
TCE, 1,1-DCE, and chromium. These maps were prepared for two aquifers identified as the
upper alluvial aquifer (UAU) and the middle alluvial aquifer (MAU). A primary objective
of the preparation of these maps was to aid in site characterization of the groundwater
plume. Terranext continued with contouring efforts for the 2000 through 2003 time period
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-8

8/9/2012

 (Terranext, 2005b). Prepared maps include contours for the contaminants PCE, TCE, 1,1DCE, and total chromium. These maps were prepared for aquifers identified as the upper
portion of the UAU (UAU1), lower portion of the UAU (UAU2), and the upper portion of
the MAU. Section 4.1 of this report further discusses this effort.
As new wells were installed, some existing wells required abandonment due to changes by
landowners who made changes to the land use. Abandonment was performed in accordance with
ADWR requirements, and included monitor wells AVB10-03 and –04, AVB22-01, AVB38-01,
AVB38-02, AVB38-03, AVB46-01, and AVB78-01. Figures 2-2 through 2-5 show locations of
wells within the WVBA. Table 2-1 details construction information and wellhead elevations of
currently and previously monitored wells.
In addition to the above activities performed by Terranext, ADWR conducted a review of their
database, ADEQ files, and conducted field surveys to identify groundwater wells within and
adjacent to the WVBA (ADWR 2005). Information from this survey was used to identify
duplicates in the ADEQ database and identify private wells for sampling. The data were
submitted to ADEQ in database format for incorporation into the ADEQ database in September
2005. Twenty-nine domestic wells were identified in or near the WVBA; of these, five are
located within the WVBA and provide groundwater for domestic use. In order to gain access to
domestic wells, ADEQ attempted to contact domestic well owners through certified letters and
residential visits. ADEQ was able to gain access to four domestic wells for sampling; ADEQ
was not able to obtain access to the fifth well. No VOCs (EPA Method 8260B) were detected in
any of the groundwater samples collected from the four domestic wells; results and detection
limits ranged from <0.50 µg/l to <20 µg/l and are provided in Terranext, 2006b.
2.2.2.1 Land and Water Use Study
Pursuant to A.A.C. R18-16-406(D) a Land and Water Use Study was prepared for the WVBA.
The report was issued in draft form on October 31, 2001. Terranext gathered information on
current and foreseeable land and water usage through interviews, City of Phoenix General Plan
maps, ADWR well database, aerial photographs, facility reports submitted to ADEQ and zoning
maps from the City of Phoenix, City of Tolleson, and Maricopa County.
Land use within the WVBA is predominantly zoned industrial with smaller tracts of residential
and commercial. Water uses for production wells located in the WVBA include domestic,
industrial, irrigation, utility, commercial, stock, test and municipal. Canal and surface water can
be found within the RID and SRP canal systems, respectively. RID and SRP currently provide
their members with water for agricultural irrigation.
Updates since 2001 were obtained through researching current information and issuing a
questionnaire to stakeholders within the WQARF site. Two different questionnaires were
developed for stakeholders. One focused on property owners within the WVBA and one focused
on Municipalities/Utilities. A final Land and Water Use Study can be found in Appendix K
along with sample questionnaires. A total of 57 questionnaires were mailed and of these, 25
were completed and returned. Following lists the company/facility name or address of those
whom returned the questionnaire :

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-9

8/9/2012

 

























710 W. Buchanan
5727 W. Van Buren
6510 W. Buckeye Road
7300 W. Van Buren
Action Fabricating of Arizona
ALASG
Americold Logistics
Arizona Public Service
BP West Coast Products/ARCO
Caljet Monroe I
City of Phoenix
CRC
DOE
Dolphin.
HEAD/Penn Racquet Sports
LA/Yuma Freight Lines
MCMM
POS
RID
Salt River Project (SRP) Tank Farm Substation
Specialty Textile Services
SRV Water User’s Association
Straight Arrow Enterprises
Trail Boss
Univar USA Inc.

The questionnaires requested specific information in the following areas:





Property information
On-site wells
Water use
Waste streams
2.2.2.2 Passive Diffusion Bag Sampler Evaluation

A three-week deployment of passive diffusion bags (PDBs) in eight wells within and around the
WVBA was performed during third quarter 2001 to assist in comparing the results of this
sampling method with the traditional purge and sample method (BE&K/Terranext, 2001b).
PDBs are capsules approximately 16 inches in length which are constructed of flexible four-mil
polyethylene membrane and filled with distilled water. PDBs are suspended in the saturated
portion of the well and allowed to equalize for a period of at least two weeks. While suspended
in groundwater, dissolved VOCs in groundwater equilibrate with the distilled water contained
within the PDB. This method of sampling is less expensive then the typical purge and sample
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-10

8/9/2012

 technique used to collect groundwater samples. Good correlation between the traditional and
PDB samples was observed; the approximate average variation for detected compounds was 20
percent. Data indicated good correlation (correlation coefficient of 0.9968) between PDB and
traditional sampling methods. Concentrations ranged from not detected (detection limits
provided in referenced report) to 120 µg/l for PCE. In general, larger variations were observed
in samples with low concentrations, because higher relative differences would occur with smaller
absolute differences.
The three-week deployment of PDBs was followed by a six-month deployment of PDBs in nine
wells (BE&K/Terranext, 2002b). Again, review of the results suggested good correlation
between the traditional and PDB sampling methods. The relative percent difference of detected
compounds averaged approximately 14 percent. Data indicated good correlation (correlation
coefficient of 0.8992) between PDB and traditional sampling methods. Currently, ADEQ
deploys over 50 passive diffusion bags in select monitor wells for semiannual groundwater
sample collection.
2.2.2.3 Chromium-Initiated Well Development
Sampling of the WVBA monitor well network detected elevated total chromium concentrations
(up to 63 mg/l) in selected wells in September and November 2002, and March and September
2003 (BE&K/Terranext, 2002c, 2003d). However, analytical results for dissolved chromium
analyses were less than or only slightly greater than the laboratory reporting limit of 0.01 mg/l.
As a result, ADEQ redeveloped wells exhibiting elevated chromium concentrations in
February/March 2003 and in February 2004. The objective of well redevelopment was to
remove fine-grained sediment within and immediately adjacent to the wells. It was hypothesized
that the sediment may be the origin of the elevated chromium concentrations (BE&K/Terranext
2003b, Terranext 2004b). Chromium concentrations in groundwater samples declined
substantially after redevelopment of the monitor wells. Detected total chromium concentrations
ranged from 12 µg/l to 529 µg/l. Based on this information, ADEQ believes that the detected
chromium in most of the wells (AVB10-01, AVB57-01, AVB69-02, AVB70-01, AVB72-01,
AVB73-01, AVB74-01, AVB75-01, and AVB76-01) may be due to deterioration of the stainless
steel well casing, where present, or naturally occurring in subsurface soils.
2.2.3

RID System Characterization

ADEQ contracted BE&K/Terranext to conduct two investigations to evaluate the effect of
pumping groundwater from the WVBA into the RID canal (BE&K/Terranext, 2001c, 2003c).
Locations of RID pumping wells and canals within the WVBA are shown on Figure 2-6. The
objectives of the canal characterization were to:



Assess concentrations of VOCs in RID wells within the WVBA.
Evaluate VOC concentrations within RID canal water downstream of discharging RID wells.

The investigation’s approach was as follows:


Sample RID wells in the WVBA;

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-11

8/9/2012

 



Evaluate resulting groundwater quality data to select specific well/canal locations for further
investigation;
Perform a temperature survey to assess the mixing of the well discharge into the canal. Use
survey results to identify downgradient canal locations for water quality sampling;
Perform water quality sampling at selected locations to assess the mixing of VOCs from well
discharges into the canal.

BE&K/Terranext sampled 17 RID wells in April 2000. Well RID-84 contained the highest
concentration of PCE of the sampled RID wells (76 µg/l) and was subsequently selected for
further investigation. The groundwater sample collected from well RID-92 contained the highest
TCE concentration of the sampled RID wells (70 µg/l) and was also subsequently selected for
further investigation.
Subsequently, BE&K/Terranext conducted a survey of physical parameters of the canal water
including surface water flow, temperature, and conductivity at locations up and down stream of
RID-84 (BE&K/Terranext, 2001c). Based on the results of the survey, BE&K/Terranext
collected eight samples from the canal in the vicinity of RID-84.
Analytical results for the samples collected from well RID-84 and the adjacent canal indicate that
elevated concentrations of VOCs are present in groundwater at well RID-84; however, VOC
concentrations in the canal are substantially lower than the well water (BE&K/Terranext, 2001c)
(Table 2-2). Analytical results for the samples collected from well RID-92 and the adjacent
canal indicate that elevated concentrations of VOCs are present in groundwater and in the canal.
VOC concentrations do not decrease substantially with distance from RID-92 as with RID-84.
Based upon the results of the RID canal sampling in 2000, it appears that contaminant
concentrations at well RID-84 decrease rapidly in the canal within approximately 125 feet of the
well as a result of dilution and/or volatilization. VOC concentrations in the canal adjacent to
well RID-92 dropped slightly within 200 feet of the well discharge but then remained steady for
at least 1,000 feet from the well discharge. The discrepancy in the change in VOC
concentrations at the two canals is probably due of the increased volume of water that passes
through the canal adjacent to well RID-84.
Select RID wells and related canals were again sampled in 2003 (BE&K/Terranext, 2003c)
(Table 2-3). The objective of this sampling event differed as it was to evaluate the nature and
extent of contamination in groundwater in the area of RID wells and in the adjacent canals within
the WVBA. ADEQ identified 26 RID wells within the WVBA and seven canal locations
including two lateral canals, the south main canal, and north canal for sampling. The canal
samples were collected approximately ¼ to ½ mile downstream of sampled RID wells with the
exception of the sample collected downstream of well RID-103 which was approximately 43 feet
downstream of the well.
PCE was the most prevalent VOC detected in the RID wells, exceeding the AWQS of 5 µg/l in
18 of the 26 sampled wells. Of these 18 wells, 14 exceeded the AWQS of 5 µg/l for TCE, and
four of these 14 wells exceeded the AWQS of 7 µg/l for 1,1-DCE. The majority of contaminant
concentrations in the samples collected from the canals had not decreased substantially when

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-12

8/9/2012

 compared to the well samples. Contaminants detected during both rounds of canal sampling do
not have applicable surface water quality standards for crop irrigation for livestock consumption.
Select RID wells have been sampled throughout the history of the WVBA investigation with the
permission of the RID. In 1986, six RID wells were sampled during the groundwater
investigation conducted by ADWR and ADHS (Arizona Department of Water Resources, 1987).
COCs were detected in five of the RID wells at concentrations greater than their respective
AWQS. Sporadic sampling of the RID wells occurred until 2003 when ADEQ began sampling
the RID wells on a more regular basis. Between June 2003 and March 2008, eight sampling
rounds of select RID wells occurred. Additional detail regarding the regular sampling and
analysis of the RID wells can be reviewed in the sampling reports (BE&K/Terranext 2003c,
Terranext 2004c, 2004d, 2005c, 2005d, 2006b, 2006c, and 2008b). RID wells are screened over
multiple aquifers, and data collected from the RID wells are presented on UAU1 and UAU2
figures and discussed further in Section 4.3. The most recent round of RID well sampling
occurred in September 2008 and data are presented in Table 2-4.
2.3 Facility Investigational Work
2.3.1

Reynolds

In 1988, Reynolds conducted initial site investigations including soil and soil gas sampling, and
detected chromium, petroleum hydrocarbons, and chlorinated hydrocarbons such as TCA and
PCE in soils beneath the Reynolds property (Dames & Moore, 1988) (Table 2-5) (Appendix A).
Additional soil sampling, soil gas extraction well installation, and soil gas sampling were
conducted in 1989 and 1990 (Dames & Moore, 1991a). Soils encountered at the Reynolds
facility consisted of clayey sand/sandy clay to approximately 40 feet bgs; sand, gravel, and
cobbles were encountered below 40 feet. TCE and TCA were detected in soil samples along
with ethylbenzene, xylenes, toluene, and Stoddard solvent. PCE, TCE, and TCA were detected
in soil gas samples along with petroleum hydrocarbons and Stoddard solvent. Additional soil
gas sampling was conducted in 1994, 1995, 1996, and 1999 (Geotechnical and Environmental
Consultants, Inc. [GEC], 1995b, 1995c, 1996a, & 1999a & b). TCA was the most commonly
detected COC.
The highest TCA soil gas concentrations detected at the Reynolds facility were 4,000 µg/l and
1,600 µg/l (Table 2-5). The 4,000 µg/l sample was collected at a depth of approximately 20 to
40 feet bgs from a soil vapor probe. This probe was located in the vicinity of the former east
Stoddard solvent dip tank. This screened interval is completed in the lower portion of the finegrained soil underlying the facility. The depth of the other sample was not reported but was also
collected from the same area.
Based on the results of initial soil gas sampling, soil investigations were conducted in 1991,
1992, 1994, 1995, 1997, 1998, and 1999 (GEC, 1991, 1995a, 1996b, 1997a, 1997b, 1998a,
1999a) (Sergent, Hauskins & Beckwith, 1991). As was identified during the soil gas sampling,
TCA was the most commonly detected COC during the soil investigations. The highest TCA
concentration detected in the soil was 510 milligrams per kilogram (mg/kg) (Table 2-5). This
soil sample was collected at the former location of the east Stoddard solvent degreasing tank

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-13

8/9/2012

 from a depth of approximately three feet bgs. This concentration is less than the nonresidential
soil remediation level (SRL) and residential SRL for TCA of 4,800 mg/kg and 1,200 mg/kg,
respectively, but greater than the minimum groundwater protection level (GPL) which is 1.0
mg/kg (Table 2-5). TCE was not detected in soil samples collected at the Reynolds facility at
concentrations greater than the nonresidential SRL of 70 mg/kg. One soil sample collected at the
Reynolds facility contained TCE at a concentration greater than the residential SRL of 27 mg/kg
(Table 2-5). The sample contained TCE at a concentration of 27.9 mg/kg and was collected at a
depth of approximately 15 feet bgs from the vicinity of the east Stoddard dip tank and east
Stoddard UST. This soil sample and 15 other soil samples collected at the Reynolds facility
contained TCE at concentrations greater than the minimum GPL for TCE of 0.61 mg/kg. Two
soil samples collected from the Reynolds facility exceeded the minimum GPL for PCE of 1.3
mg/kg. PCE concentrations of 2.0 mg/kg and 1.5 mg/kg were detected at depths of
approximately 15 feet bgs and 25 feet bgs, respectively. These two soil samples were collected
in the vicinity of former plant manufacturing equipment. 1,1-DCE was detected at a
concentration of 1.1 mg/kg in a soil sample collected at a depth of approximately ten feet bgs in
the vicinity of the east Stoddard solvent dip tank (Table 2-5). This concentration exceeded the
nonresidential SRL, residential SRL, and minimum GPL for 1,1-DCE of 0.8 mg/kg, 0.36 mg/kg,
and 0.81 mg/kg, respectively. No other soil samples collected at the Reynolds facility contained
VOCs at concentrations greater than SRLs.
TCA, TCE, and PCE are not believed to be constituents of Stoddard solvent so their origin is
unclear unless Stoddard solvent wasn’t the only solvent used in this area. Petroleum
hydrocarbons, Stoddard solvent, and PCBs were also detected during the soil and soil gas
investigations. Chromium was detected in shallow soils while conducting excavating activities
near the western end of the former main plant building. The highest chromium concentration
was 938 mg/kg at a depth of approximately two feet bgs which is less than the Human Health
Based Guidance Level (HBGL) of 1,700 mg/kg. (Dames & Moore, 1992) (Table 2-5). In 1992,
the HBGL was the soil cleanup guidance standard.
Concurrent with the soil investigations, groundwater was investigated through the installation,
monitoring, and sampling of groundwater monitor wells (Appendix A). Initially five
groundwater monitor wells were installed at the Reynolds facility in 1990 (Dames & Moore,
1990). Limited aquifer testing was conducted at each of the five wells to estimate aquifer
parameters in the vicinity of the wells. Results of the aquifer testing indicated that aquifer
characteristics beneath the Reynolds facility were similar to aquifer characteristics documented
in previously conducted regional investigations. Groundwater monitoring indicated that
groundwater elevations fluctuated with seasonal groundwater withdrawals as did horizontal flow
directions and gradients which were in general similar to regional groundwater data. Depths to
groundwater fluctuate seasonally due to regional groundwater pumping by more than 20 feet.
The horizontal groundwater flow direction is westerly fluctuating from north-northwesterly to
southerly and the gradient ranged from approximately 0.0004 feet per feet (ft/ft) to 0.0025 ft/ft.
The deepest groundwater levels are typically at the end of the summer just before regional
irrigation pumps are turned off and shallowest in the spring prior to the startup of the pumping
season. PCE, TCE, TCA, and 1,1-DCE were detected in groundwater samples collected from
the monitor wells. The highest concentrations of TCA (39.6 µg/l and 130 µg/l) and 1,1-DCE
(14.2 µg/l and 62.5 µg/l) were detected in groundwater samples collected from wells PS-1 and

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-14

8/9/2012

 PS-2, respectively, which are located adjacent to the solvent still area and the east Stoddard dip
tank, respectively (Appendix A). PCE (19.1 µg/l) and TCE (43.3 µg/l) concentrations in
groundwater samples collected from upgradient well PS-4 were higher than groundwater
samples collected from the other four monitor wells (PCE – 4.0 µg/l to 12.3 µg/l, TCE – 2.9 µg/l
to 32.5 µg/l). A sixth groundwater monitor well was installed at the facility in 1991 (Dames &
Moore, 1991b). In 1994 three additional groundwater monitor wells were installed at the
Reynolds facility (GEC, 1995a).
Numerous rounds of groundwater monitoring and sampling have been conducted at the facility
since the well installations. COCs including PCE, TCE, TCA, 1,1-DCA, 1,1-DCE, and cis 1,2DCE have been detected in groundwater samples collected from the wells. PCE, TCE, TCA, and
1,1-DCE are the only COCs that have been detected at concentrations greater than the AWQS.
The highest COC concentrations detected in the groundwater samples included PCE at 55 µg/l,
TCE at 363 µg/l, TCA at 228 µg/l, 1,1-DCA at 208µg/l, 1,1-DCE at 65.9 µg/l, and cis 1,2-DCE
at 7 µg/l. The highest PCE and TCE concentrations detected in groundwater samples varied
from the upgradient well to wells in the vicinity of the former solvent still area and the east
Stoddard dip tank The highest concentrations of the other COCs were detected in groundwater
samples collected from the vicinity of the former solvent still area and the east Stoddard dip tank.
Continued groundwater monitoring and sampling indicated that groundwater elevations
continued to fluctuate seasonally along with flow directions. Contaminant concentrations
declined with time but continued to remain greater than AWQSs for PCE, TCE, and occasionally
1,1-DCE. Currently, ADEQ collects samples from select wells previously installed by Reynolds.
During site characterization, remedial activities including vapor extraction and soil excavation
were conducted to mitigate contaminant concentrations. Site specific remediation standards
were calculated for petroleum hydrocarbons, which was the only contaminant to exceed nonresidential HBGLs, and for TCA, which was the only contaminant to exceed site-specific GPLs
calculated using site-specific parameter input values for the ADEQ GPL model to evaluate the
effectiveness of remediation (Reynolds Metals Company, 1996). Following site activities, risk
analyses were conducted for areas which still contained contaminants exceeding residential and
non-residential SRLs (Reynolds Metals Company, 1998 & 1999). These were eventually
approved by ADEQ and an NFA was issued on February 29, 2000 for 14 locations where
releases had occurred (ADEQ, 2000). The following lists the areas of releases, area description,
contaminants detected, and corrective actions taken:





Right-of-Way (ROW) Area I – Former Anodizing Area – Chromium in soils –
Excavated – NFA location
ROW Area IIId – Large Manufacturing Equipment – Petroleum Hydrocarbons –
Excavated – NFA location
ROW Area IIIf – Large Manufacturing Equipment – Petroleum Hydrocarbons –
Excavated – NFA location
Former Manufacturing Equipment Foundations (Trenches 1 through 8) –
Polynuclear Aromatic Hydrocarbons (PAHs) and VOCs – Excavation/Risk
Analysis/Voluntary Environmental Mitigation Use Restriction (VEMUR) – NFA
location

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-15

8/9/2012

 











Northwest Stoddard Dip Tank – Solvent Use/Storage – Stoddard Solvent and
TCA – Soil Vapor Extraction/Excavation/Risk Analysis/VEMUR – NFA location
East Stoddard UST – Solvent Use/Storage – Stoddard Solvent and TCA – Soil
Vapor Extraction/Excavation/Risk Analysis/VEMUR – NFA location
Stoddard Solvent Distilling Operations at Building #150 – Solvent Use/Storage –
Stoddard Solvent and TCA – Soil Vapor Extraction/Excavation/Risk Analysis/
VEMUR – NFA location
Southwest Stoddard Dip Tank – Solvent Use/Storage – Stoddard Solvent and
TCA – Soil Vapor Extraction/Excavation/Risk Analysis/VEMUR – NFA location
West Stoddard USTs – Solvent Use/Storage – Stoddard Solvent and TCA – Soil
Vapor Extraction/Excavation/Risk Analysis/VEMUR – NFA location
Building #150 USTs – Solvent Use/Storage – Stoddard Solvent and TCA – Soil
Vapor Extraction/Excavation/Risk Analysis/VEMUR – NFA location
East Aboveground Storage Tank (AST) – Solvent Storage – Stoddard Solvent –
Excavation/Risk Analysis – NFA location
Former Oil Pump Pit Area – Solvent Storage – No Contaminants Present – No
Action Required – NFA location
Drywell South of Building #150 – Drainage – No Contaminants Present – No
Action Required – NFA location
East Soil Gas Area – Solvent Use/Storage – Stoddard Solvent and TCA – Soil
Vapor Extraction/Excavation/Risk Analysis/VEMUR – NFA location
East Stoddard Tank – Solvent Use/Storage – Stoddard Solvent and TCA – Soil
Vapor Extraction/Excavation/Risk Analysis/VEMUR
2.3.2 VW&R

VW&R conducted a property assessment including the collection of numerous soil and soil gas
samples, and installation and monitoring of 11 groundwater monitor wells (Appendix B). Initial
site activities were conducted in 1989 with the completion of a soil gas survey and soil sampling
by Harding Lawson Associates (HLA) (1990a). PCE, TCE, TCA, and 1,1-DCE were detected in
soil vapors at several locations across the facility with PCE detected at the highest concentration
of 1,330 µg/l near the southern end of the solvent tank farm (Table 2-5). The highest TCE soil
gas concentration detected at the VW&R facility was 484 µg/l from a depth of approximately 15
feet bgs (Table 2-5). This soil gas sample was also collected from the south end of the solvent
tank farm. The highest TCA concentration detected in the soil gas was 1,200 µg/l from a depth
of approximately ten feet bgs (Table 2-5). This sample was also collected from the area adjacent
to the south end of the solvent tank farm. 1,1-DCE was detected at a maximum concentration of
323 µg/l (Table 2-5). This soil gas sample was collected at a depth of approximately five feet
bgs from the northwestern portion of the VW&R facility. These data were used to identify areas
where soil samples should be collected. Additional soil gas samples were collected in 1997 in
the vicinity of a former laboratory waste storage drum (HLA, 1997a). Soil sampling
investigations were conducted in 1990, 1991, and 1997 (HLA, 1990b, 1991, 1997a & b).
Contaminants of concern detected during the soil investigations included PCE, TCE, TCA, 1,1DCE, and 1,1-DCA. Soils encountered consisted primarily of clay, silt, and sand to
approximately 40 to 50 feet bgs, underlain by gravel with varying amounts of sand, cobbles, and
fine-grained materials. PCE was detected at the highest concentration of 4.250 mg/kg near the
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-16

8/9/2012

 west edge of the corrosive tank farm (Table 2-5). This concentration exceeded the minimum
GPL of 1.3 mg/kg for PCE. No other VOCs were detected in soil samples at concentrations
greater than applicable soil standards at the time. Following soil characterization, an SVE
system was installed in November 1992 and operated in the area north of the solvent tank farm,
the area south of the solvent tank farm and the areas north and west of the corrosive tank farm
(Ensolutions, Inc., 1998).
Following the soil investigations, eight groundwater monitor wells were installed at the VW&R
facility (HLA, 1992) (Appendix B). Groundwater monitoring indicated that groundwater
elevations fluctuated with seasonal groundwater withdrawals by as much as 20 feet annually.
Horizontal flow directions and gradients were similar to regional groundwater flow directions
and gradients with flow directions varying from northwesterly to southwesterly and gradients
were in the range of approximately 0.0006 ft/ft to 0.0013 ft/ft. PCE, TCE, TCA, 1,1-DCE, and
1,2-DCE were detected in groundwater samples collected from the monitor wells. PCE, TCE,
TCA, and 1,1-DCE were detected at concentrations that exceeded the AWQS. The highest
concentrations of PCE were detected in groundwater samples collected from the wells located
adjacent to the facility’s western boundary. The highest PCE concentration detected at the
facility was 1,400 µg/l. TCE concentrations were typically highest in groundwater samples
collected from the upgradient monitor wells. However, the highest TCE concentration detected
was 200 µg/l detected in a groundwater sample collected from well MW-7 located along the
western boundary of the facility. TCA and 1,1-DCE were typically highest in concentration in
the groundwater samples collected from the monitor wells adjacent to the facility’s western
boundary. The highest TCA concentration detected was 220 µg/l. The highest 1,1-DCE
concentration detected was 110 µg/l. Vertical profiling was conducted at select wells at the
facility in February and August 1994 to investigate the possibility of a vertical gradient within
the aquifer beneath the VW&R facility using down-hole geophysical tools including a
temperature gage and a spinner tool and the collection of depth specific groundwater samples
(HLA, 1994a & 1994b). Results of profiling indicated that downward vertical movement was
present within the wells investigated. In June and July 1997, three additional groundwater
monitor wells were installed at the facility to collect groundwater data from deeper within the
UAU (HLA, 1997c). Data collected from the deeper wells indicated that groundwater
contamination was limited in depth to the shallow zone investigated by the original eight monitor
wells. Following remediation of the vadose zone by SVE, contaminant concentrations in
groundwater declined and VW&R ceased groundwater monitoring and sampling with ADEQ
concurrence. Currently ADEQ collects groundwater samples from two groundwater monitor
wells at the facility and the other wells were abandoned by VW&R.
The SVE system was operated periodically until 1998 (Ensoultions, Inc., 2000) (Appendix B).
In July 2001, confirmation soil sampling was conducted at the VW&R facility to evaluate
whether soil contamination concentrations had declined to levels less than SRLs and minimum
GPLs (Geotrans, Inc., 2001). Analytical results of the soil samples indicated that none of the
COC were present at concentrations greater than the applicable regulatory standards. Based on
these data, ADEQ issued a NFA determination for the facility soils in 2002 (ADEQ, 2002).
Several areas have been investigated at the VW&R facility. Four of these areas, the area north of
the solvent tank farm, south of the solvent tank farm and areas north and west of the corrosive

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-17

8/9/2012

 tank farm were identified as source areas. The following lists the areas investigated, area
description, contaminants detected, and corrective actions taken:












Corrosive Tank Farm – Chemical Storage/Mixing – VOCs – Soil Vapor
Extraction
Solvent Tank Farm – Chemical Storage/Mixing – VOCs – Soil Vapor Extraction
Freon Handling Area – Chemical Storage – No Contaminants Present – No
Action Required
RCRA Drum Storage Area – Chemical Storage – No Contaminants Present – No
Action Required
Waste Water Pretreatment System and Associated Piping – Waste Water
Neutralization – VOCs – No Action Required
Sewer Interceptor – Waste Water Disposal – VOCs – No Action Required
North Central Area of Facility – Drum Storage – VOCs – No Action Required
Northwest Area of Facility – Drum Storage – VOCs – No Action Required
Area Adjacent to Neighboring Drywell – VOCs – No Action Required
Former Laboratory Drum Storage Area – VOCs – No Action Required
Unimproved East Area – No Activities – VOCs – No Action Required
2.3.3

MCMM

Maricopa County conducted soil gas and soil sampling on-site and installed/operated an SVE
system for approximately six months (Appendix C). To investigate groundwater contamination,
several groundwater monitor wells were also installed and periodically sampled. MCMM
facility investigations were initiated by ADEQ in 1992 in response to groundwater contamination
detected in a monitoring well downgradient of the facility. Soils observed at the MCMM facility
in the vadose zone included clay and silt with variable amounts of sand to approximately 20 feet
bgs. Below approximately 20 feet, sand and gravel were encountered with varying amounts of
clay, silt, and cobbles. A soil gas survey conducted in June 1992 at the facility detected PCE,
TCE, 1,1,1-TCA, 1,1-DCE, cis & trans-1,2-DCE, and 1,1-DCA in the soil vapor collected from
beneath the western portion of the facility (Weston, 1992a) (HydroGeoChem, Inc.
[HGC],1992a). PCE and TCE were the most commonly detected VOCs with PCE at a
concentration in excess of 1,000 µg/l and TCE at a concentration in excess of 800 µg/l (Table 25). These soil vapor concentrations were detected in the vicinity of the former Southwest
Solvent Reclamation facility at a depth of approximately five feet bgs.
Based on the 1992 soil gas survey, soil sampling was conducted at the MCMM facility and
adjacent properties of US WEST Communications and Southern Pacific Transportation
Company in conjunction with the installation of three groundwater monitor wells at the MCMM
facility in February 1993 (Weston, 1993b) (Appendix C). PCE and TCE were the only VOCs
detected in the soil samples analyzed during this investigation. PCE was detected at a maximum
concentration of 0.7 mg/kg and TCE was detected at a maximum concentration of 4.2 mg/kg
(Table 2-5). These concentrations were detected in soil samples collected during the drilling and
installation of groundwater monitor well MC-02 located in the north central portion of the
facility. The TCE concentration exceeded the minimum GPL for TCE of 0.61 mg/kg. No other
VOCs were detected in soil samples collected at the MCMM facility at concentrations greater
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-18

8/9/2012

 than SRLs. Groundwater concentrations of PCE detected at the MCMM facility were 33µg/l at
monitoring well MC-02, 63 µg/L in monitoring well MC-01 and 900 µg/L in monitoring well
MC-03. TCE concentrations detected in groundwater at MCMM ranged from 82 µg/L at MC-02
to 290 µg/L at MC-03. PCE and TCE contamination were also detected in soil samples collected
from borings drilled at the US WEST Communications property west of the MCMM facility.
Based on the distribution of PCE and TCE, this contamination was believed to be related to the
soil contamination discovered at MCMM. No VOC soil contamination was detected in
boreholes drilled at Southern Pacific Transportation Company north of the MCMM facility.
During March 1995, a Gore Sorber Screening Survey was conducted to augment soil gas data
gathered in June 1992. The results of the survey indicated a low-level presence of PCE and TCE
across the site with an area of relatively higher vapor-phase PCE, TCE and 1,1-DCA in the
northwest portion of the property (Flour Daniel GTI, 1996b). According to the Gore Sorber
Screening Survey, the highest mass of TCE was noted at the southeast corner of the property.
This was consistent with groundwater quality data collected from well MC-01, also located near
the southeast corner of the property. A geophysical survey utilizing ground penetrating radar
was conducted at the site in the northwest portion of the facility to investigate the possible
presence of a well. Two anomalies were detected but further investigation uncovered rebar
reinforced concrete in one anomaly and nothing in the other anomaly. Soil samples collected at
the anomalies did not contain detectable VOCs. Soil samples were also collected during this
investigation along with the installation of a vapor extraction well, groundwater extraction well,
two groundwater monitor wells, three nested groundwater piezometers with screened intervals in
the upper portion of the UAU1, the lower portion of the UAU1, and the UAU2, and a
groundwater piezometer. PCE and TCE were the only VOCs detected in soil samples with the
exception of 1,1-DCE which was detected in one soil sample. The highest PCE concentration
detected was 0.15 mg/kg which was collected from the northwest corner of the facility. The
highest TCE concentration detected was 0.21 mg/kg which was collected from the northeast
corner of the facility.
An additional soil gas survey was conducted in the southeast portion of the MCMM facility in
1997 to confirm the presence of PCE and TCE in soil vapors in this area (Fluor Daniel GTI,
1997). Samples were only analyzed for PCE and TCE. Analytical results indicated the presence
of both VOCs with PCE detected at a highest concentration of 62 µg/l and TCE detected at a
highest concentration of 98 µg/l.
In November 1995, an SVE pilot test was conducted at the facility in the vicinity of the former
Southwest Solvents Reclamation facility to investigate the suitability of the facility for
remediation by SVE (Fluor Daniel GTI, 1996c). Data collected during the pilot test indicated
that the area was suitable for remediation via SVE. VOCs detected in the soil vapors during the
pilot test included PCE, TCE, 1,1,1-TCA, 1,1-DCE, 1,1-DCA, chloroform, and Freon 113. PCE
was detected at the highest concentration of 2,238 µg/L (Table 2-5). The highest TCE
concentration detected was 462 µg/l. SVE was conducted from mid August to early September
and mid October to late November 1997 (Fluor Daniel GTI, 1998a & b). The system was shut
down after soil vapor concentrations had reached asymptotic levels as was agreed by ADEQ
personnel. The highest PCE and TCE concentrations detected were PCE at a concentration of
531.8 µg/l, TCE at a concentration of 524.5 µg/l.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-19

8/9/2012

 As mentioned above, three rounds of groundwater monitor well installations were conducted at
the MCMM facility (Appendix C). Numerous rounds of groundwater monitoring and sampling
have been conducted at the facility since the well installations. COCs including PCE, TCE,
TCA, 1,1-DCE, 1,1-DCA, and cis 1,2-DCE have been detected in groundwater samples collected
from the wells. PCE, TCE, 1,1-DCE and cis 1,2-DCE were detected at concentrations greater
than the AWQS. 1,2-Dichloroethane (1,2-DCA) was also detected at concentrations greater than
the AWQS. PCE and TCE were the most commonly detected COCs with PCE detected at a
highest concentration of 3,800 µg/l and TCE with a highest concentration of 1,800 µg/l. The
highest 1,1-DCE concentration detected was 35 µg/l. The highest cis 1,2-DCE concentration
detected was 2,500 µg/l. The highest 1,2-DCA concentration detected was 500 µg/l. The
highest PCE concentrations were detected in groundwater samples collected from the vicinity of
the former Southwest Solvent recycling facility in the northwest portion of the MCMM property.
The highest TCE concentrations have been detected in groundwater samples collected from the
vicinity of the former Southwest Solvent recycling facility and the middle of the southeast
parking lot. COCs were also detected at concentrations greater than AWQS in the deeper nested
piezometers. Groundwater monitoring indicates that groundwater elevations fluctuate with
seasonal groundwater withdrawals as do horizontal flow directions and gradients. Depths to
groundwater fluctuate by ten feet or more; the horizontal flow direction ranges from northwest to
west-southwest, and gradients fluctuate from approximately 0.0007 ft/ft to 0.008 ft/ft. An
aquifer test was conducted at the groundwater extraction well in July 1995 (Groundwater
Technology, Inc. [GTI], 1995). Results of the aquifer testing indicated that the coarse-grained
aquifer beneath the MCMM facility is similar to aquifer characteristics documented in previously
conducted regional investigations. ADEQ currently monitors/samples wells MC-05 (AVB10601, MC-N06 #2 (AVB106-02), and MC-N06 #3 (AVB106-03) at the facility.
Maricopa County personnel reviewed the Kleinfelder well survey results and ADWR well
database, and conducted field surveys to identify wells which could be used for human
consumption or other domestic use (Maricopa County Division of Water and Waste
Management, 1994). This survey identified 82 wells that could potentially be used for domestic
purposes. Further investigation, however, ascertained that of these, only 14 were actually used
for domestic purposes. Maricopa County personnel were able to sample 12 of the wells for
analyses of VOCs. One of the two wells not sampled was discovered to be regularly sampled by
ADEQ and the other well was not sampled because the well owner would not allow the county
personnel to sample the well. The samples were analyzed using EPA Test Methods 601 and 602.
No VOCs were detected. The detection limits ranged from 0.5 µg/l to 5.0 µg/l.
Several areas have been investigated at the MCMM facility. Two of these areas, the former
Southwest Solvent Recycling facility and southeast parking lot, were identified to be source
areas. Active remediation by SVE was completed at the facility in the vicinity of the former
Southwest Solvent Recycling facility. The following lists areas investigated, area description,
contaminants detected, and corrective actions taken:



Former Southwest Solvent Recycling Facility – Chemical Recycling –VOCs –
Soil Vapor Extraction
Southeast Parking Lot – Vehicle Parking – VOCs – No Action Taken

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-20

8/9/2012

 


Anomaly #1 – Unknown – No Contaminants – No Action Required
Anomaly #2 – Unknown – No Contaminants – No Action Required
2.3.4 Dolphin

Dolphin initiated subsurface investigations at their 740 South 59th Avenue facility in June 1988
to investigate soil contamination at a discharge pipe and drainage area (Scott, Allard &
Bohannan, Inc. [SAB], 1988) (Appendix D). Analytical results of soil samples collected during
this investigation detected TCA, 1,1-DCE, and 1,1-DCA. In September 1992, a release of liquid
and sludge material occurred at Dolphin’s production facility, known as Dolphin III. Analysis
indicated that the release material contained PCE ranging in concentration from 2,300 mg/kg to
77,000 mg/kg (Basin & Range Hydrogeologists, Inc. [BRH], 1993a). TCE and 1,1-DCE were
also detected in extracts of the release liquid and sludge samples at concentrations that exceeded
regulatory levels for the hazardous waste characteristic of toxicity. The highest PCE
concentration detected in soil at the Dolphin facility was 8,040 mg/kg (Table 2-5). This
concentration exceeds the nonresidential SRL of 170 mg/kg, residential SRL of 53 mg/kg, and
minimum GPL of 1.3 mg/kg. This was a sample of soil excavated from a release area north of
the Dolphin III building. The highest TCE soil concentration detected at the Dolphin facility was
30 mg/kg (Table 2-5). This TCE concentration was detected in the same soil sample which
contained the highest PCE concentration. Additionally, TRPH were detected in one release area
sample at a concentration of 25,000 mg/kg.
Since 1992, several investigations of soil, soil vapor, and groundwater have been conducted at
the site (Appendix D). Shallow soils encountered at the Dolphin, Inc. facility consisted of sand
with varying amounts of silt and gravel to approximately 20 to 25 feet bgs. A fine grained unit
of silt and clay was then encountered for approximately 10 to 35 feet. The fine-grained unit is
underlain by gravel with varying amounts of sand, cobbles, and to a lesser extent silt and clay.
Soil samples collected to depths of approximately 63 feet bgs from the vicinity of the former
drum storage areas and a PCE degreaser area contained concentrations of PCE in soil greater
than the minimum GPL of 1.3 mg/kg. Soil gas sampling was conducted at the site in September
and November 1994 (Tracer Research Corporation, 1994). PCE, TCE 1,1,1-TCA, 1,1-DCE and
1,2-DCE were detected at the facility. The highest soil gas PCE concentration detected at the
Dolphin facility was at a concentration of 33,000 µg/l, near the center of the western edge of the
Dolphin I building near former drum storage areas and a PCE degreaser. Other VOCs detected
in soil gas samples were at concentrations of 2 to 3 orders of magnitude less than the highest
PCE concentration. In 1995 and 1996, soil investigations including the collection of soil samples
and the installation of 12 SVE wells were conducted (BRH, 1996b). PCE and 1,1,1-TCA were
the only COCs detected in the soil samples. PCE was the most commonly detected contaminant.
The highest PCE concentration was detected at 42 mg/kg. This concentration exceeded the
minimum GPL for PCE of 1.3 mg/kg. PCE was also detected at concentrations greater than the
minimum GPL in the vicinity of the former drum storage area and PCE degreaser. No other
VOCs were detected.
An SVE pilot test was conducted at the facility in 1996. Data from this pilot test ascertained that
SVE would be a cost effective method for site remediation, and were used to help design an SVE
system. In 1996, Dolphin closed a drywell (#1) which was located west of the Dolphin I
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-21

8/9/2012

 building in the area of former drum storage and near a PCE degreaser (Dolphin, Inc., 1996). A
sediment sample collected from the upper chamber of the drywell contained detectable
concentrations of PCE, TCE, cis-1,2-DCE, and 1,1,1-TCA. The highest PCE concentration
detected in the drywell sediment was at 220 mg/kg. In 1997, a bermed retention area was
investigated for metals and VOCs (Dolphin, Inc., 1997). Chromium was detected in concrete
core samples and soil samples at concentrations less than the ADEQ HBGL. PCE was detected
in two soil samples collected from the retention area at concentrations of 1.5 mg/kg and 0.450
mg/kg. In 1998, two additional drywells (#2 and #3) were sampled prior to abandonment
(Brown and Caldwell, 1999a). No VOCs were detected in sediment samples collected from the
drywell chambers.
In 2000 and 2001, additional soil vapor and soil samples were collected at the site (Brown &
Caldwell, 2001 & 2002a). The 2000 investigation was conducted at the property north of the
main plant known as the Dolphin II/V facility. PCE, TCE, and 1,1-DCE were detected in soil
vapor samples at this facility. The highest PCE concentration was detected at 110 µg/l. VOCs
were not detected in soil samples collected at the Dolphin II/V facility. Metals including
chromium and lead were detected in soil samples, but were less than or equal to background
concentrations for these compounds. Results of the investigation conducted at the main facility
in 2001 indicated that PCE was the only VOC detected during the soil gas survey with the
exception of dichlorodifluoromethane which was detected in one soil gas sample. The highest
PCE concentration was 19 µg/l which was collected between the Dolphin I building and the
southwest building. PCE was also the only VOC detected in soil samples collected during the
investigation conducted at the main plant. The highest PCE concentration detected was 0.76
mg/kg which was collected near the closed Dolphin I interceptor. Soil samples were also
analyzed for metals. Hexavalent chromium, arsenic, and beryllium, were detected at
concentrations which exceeded regulatory standards. However, a site specific risk analysis was
conducted which ascertained that the concentrations did not pose a risk to human health or the
environment.
Groundwater investigations were conducted concurrent with the soil investigations at the
Dolphin facility. Three groundwater monitor wells with Westbay MP Systems (Westbay) were
installed at the site in June 1993 and October 1994 (BRH, 1996a). Sampling ports were installed
across the UAU1 and UAU2 and into the top of the MAU1. PCE, TCE, 1,1-DCE, cis-1,2-DCE,
1,1,1-TCA, and 1,1-DCA, are COCs which have been detected in groundwater samples collected
from the monitor wells. PCE, TCE, 1,1-DCE and cis 1,2-DCE are the only COCs which have
been detected at concentrations greater than their respective AWQSs. PCE has been the most
commonly detected contaminant and has been detected at the highest concentration of 95,000
µg/l (Basin & Range Hydrogeologists, Inc., 1998). COCs have also been detected in
groundwater samples collected from the upgradient wells at the facility with TCE and 1,1-DCE
at concentrations similar to the source area well. However, the highest TCE concentration
detected at the facility was 340 µg/l which was detected in a groundwater sample collected from
the well located in the release area. The highest 1,1-DCE concentration detected at the facility
was 68 µg/l. The highest cis 1,2-DCE concentration detected at the facility was 4,000 µg/l.
Groundwater monitor well analytical results have detected groundwater contamination to
approximately 400 feet bgs. Additional groundwater monitor wells were installed at the facility
in 2000 (Brown and Caldwell, 2000a). Four groundwater monitor wells were completed in the

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-22

8/9/2012

 UAU1 and two were completed in the MAU. The monitor wells were installed downgradient of
the previously installed groundwater monitor wells. Analytical results of groundwater samples
collected from the UAU1 monitor wells indicated that COC were present in groundwater
downgradient of the source area well at lower concentrations but still greater than the AWQS.
No VOCs were detected in the groundwater samples collected from the MAU monitor wells.
Groundwater monitoring has indicated that groundwater elevations fluctuate with seasonal
groundwater withdrawals as do horizontal flow directions and gradients. However, the
groundwater data were, in general, similar to regional groundwater characteristics, i.e., depths to
groundwater fluctuated by 15 feet or more; westerly flow direction ranged from northwest to
southwest; and gradients fluctuated from approximately 0.0003 ft/ft to 0.0021 ft/ft. Dolphin
currently conducts quarterly monitoring and semiannual sampling of its groundwater monitor
well network.
During site characterization, Dolphin installed three SVE systems and an air sparge (AS) system
at their facility (Brown and Caldwell, 1999b) (Appendix D). Two SVE systems were installed in
the vicinity of the former PCE degreaser and former drum storage areas near the Dolphin I
building. These systems were designed to separately extract soil vapors from the coarse-grained
soil zone (high-flow [HF] system) and the fine-grained soil zone (low-flow [LF] system). The
third SVE system was installed in the vicinity of the closed sewer interceptor at the Dolphin III
building. The AS wells were installed in vicinity of the former PCE degreaser and former drum
storage area near the Dolphin I building. The Dolphin I HF and LF systems operated from
October 1998 until April 2002 (Brown and Caldwell, 2004a). Decommissioning sampling of the
SVE systems indicated that soils had been remediated to below SRLs. The Dolphin III SVE
system was operated from November 1998 to November 2001 (Brown and Caldwell, 2002b).
Decommissioning sampling of this SVE system indicated that soils had also been remediated to
levels below SRLs. During the operation of the remediation systems, COC concentrations in the
groundwater beneath the facility dropped substantially. Currently COC concentrations detected
in groundwater samples collected from the groundwater monitor wells located at and
downgradient of the release areas are similar in concentration to COC concentrations detected in
groundwater samples collected from the upgradient groundwater monitor wells.
Several areas have been investigated at the Dolphin facility. Three of these areas, former drum
storage near Dolphin I building, former PCE degreaser at Dolphin I building and closed sewer
interceptor at Dolphin III building were identified to be source areas (Brown and Caldwell,
2004a). Active remediation including soil excavation, SVE, and AS have been completed at the
facility. The following lists areas investigated, area description, contaminants detected, and
corrective actions taken:




Alden Leeds Building Septic and Interceptor Tanks – Waste Water Disposal –
VOCs – No Action Required
Former Acid Etch Building – Metal Parts Cleaning With Acid – Chromium and
PCE – Concrete Removal & Soil Vapor Extraction
Former Drum Storage Areas – Chemical Storage – VOCs – Soil Vapor Extraction
& Air Sparging

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-23

8/9/2012

 















Former PCE Degreaser – Metal Parts Cleaning – VOCs – Soil Vapor Extraction
& Air Sparging
Former Satellite PCE Drum Storage Area – Chemical Storage – VOCs – No
Action Required
Closed Dolphin I Interceptor – Waste Water Disposal – VOCs – No Action
Required
Closed Dolphin III Interceptor – Waste Water Treatment – VOCs – Soil Vapor
Extraction
Discharge Pipe and Drainage Area – – VOCs – No Action Required
Liquid and Sludge Material Spill Area – No Operations Area – VOCs – Soil
Excavation
Former Flammable Materials Storage Areas – Chemical Storage Area – VOCs –
No Action Required.
Drainage Basin – Facility Storm Water Holding – No Contaminants – No Action
Required
Former Saw Shed – Cutoff and De-gate – No Contaminants – No Action
Required
Parking Areas – Employee Parking – No Contaminants – No Action Required
Unused Areas – No Activities – No Contaminants – No Action Required
Dolphin II/V Facility – Parts Testing and Machining – VOCs – No Action
Required
Drywell # 1 – Storm Water Discharge – VOCs – Soil Vapor Extraction & Air
Sparging
Drywell #2 – Storm Water Discharge – No Contaminants – No Action Required
Drywell # 3 – Storm Water Discharge – No Contaminants – No Action Required
2.3.5 ALSCo

At the request of ADEQ, several subsurface investigations were conducted at the ALSCo
facility. An initial soil gas survey was conducted in June 1992 (Environmental Geosciences
Engineering, 1992) (Appendix E). Analytical results of soil gas samples indicated the presence
of PCE, TCE, benzene, and to a lesser extent TCA. The highest PCE concentration was detected
at 4,796 µg/l in the vicinity of the former sump adjacent to the center of the western edge of the
building (Table 2-5). TCE was detected in the same soil gas sample at a concentration of 336
µg/l. The highest TCA concentration was detected at a concentration of 170 µg/l. This soil gas
sample was collected from the southwest corner of the facility building. Based on data collected
during the soil gas survey, soil sampling was conducted at the facility. Soil sampling was
conducted in July, August, October, and November 1992 (Jennings, Strouss & Salmon, 1992).
Vadose zone soils encountered at the ALSCo facility included mostly sand with varying amounts
of clay, silt, and gravel. Gravel content increases after approximately 30 feet bgs to become the
dominant component with cobbles. A layer of silt and clay approximately ten feet thick was
encountered at approximately 50 feet bgs. PCE was the most prevalent contaminant detected
with detections of TCE and total 1,2-DCE to a lesser degree. The highest PCE concentration
detected was in a split soil sample collected by ADEQ representatives at a concentration of 3.2
mg/kg (Analytical Technologies, Inc., 1992) (Table 2-5). This concentration exceeds the
minimum GPL for PCE of 1.3 mg/kg. This split sample was also reported as having a PCE
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-24

8/9/2012

 concentration of 160 µg/kg in a table included in a split sampling report by Weston (1993a) but
the report contained no laboratory reports for backup. This sample was collected during the
installation of monitor well MW-2 (AVB40-07) at a depth of approximately 60 feet bgs adjacent
to the center of the west property boundary. One other soil sample collected at the ALSCo
facility contained PCE at a concentration greater than the minimum GPL. This soil sample
contained PCE at a concentration of 1.57 mg/kg (Table 2-5). It was collected at a depth of
approximately five feet bgs in the southwest corner of the facility building. The highest TCE
concentration detected was 0.4 mg/kg. The highest total 1,2-DCE concentration detected was
0.08 mg/kg. No other COCs were detected in the soil samples. Soil samples analyzed by
ALSCo contractors prior to November 1993 were not adequately extracted for VOC analysis and
therefore are suspected to be reported at concentrations lower than what may have been actually
present in soil samples (CEC/WRA, 1994).
Soil vapor monitor wells were installed at the site in 1998 (Fluor Daniel GTI, 1998c & IT Corp,
1999) (Appendix E). Soil gas samples collected from the vapor wells included detectable
concentrations of PCE, TCE, cis-1,2-DCE, and benzene. The highest PCE concentration of
26,929 µg/l was detected west of the northwest corner of the building (Table 2-5). This sample
was collected from a depth of approximately 65 feet to 68 feet bgs. The highest TCE
concentration detected was 336 µg/l. The highest cis 1,2-DCE concentration detected was 61
µg/l. Benzene was detected in two samples at concentrations of 1.9 µg/l and 2.2 µg/l. ADEQ
(HGC 1999b) conducted an SVE pilot test at the ALSCo facility in February 1999 using
previously installed SVE and monitoring wells. Data from this pilot test indicated that
conditions at the facility were favorable for remediation by SVE. As part of an ERA, a SVE,
AS, and groundwater extraction and treatment remediation system was installed and operated at
the facility.
Based on analytical data, four groundwater monitor wells were installed at the facility and at the
neighboring property upgradient of the facility (CEC/WRA, 1993) (Appendix E). Additional
groundwater monitor wells were installed during vadose zone characterization (Fluor Daniel
GTI, 1998c). These included three nested wells in the central portion of the parking lot which
were screened in the upper and lower zone of the UAU. COCs detected in groundwater samples
collected at the facility include PCE, TCE, 1,1-DCE, 1,1-DCA, cis 1,2-DCE and chromium.
Contaminants detected at concentrations greater then their AWQS included PCE, TCE, 1,1-DCE,
and cis 1,2-DCE,. The highest PCE concentration was detected at 42,000 µg/l from groundwater
monitor well MW-2 (AVB40-07). As mentioned above, this well is adjacent to the center of the
west property boundary. The highest TCE concentration detected was 670 µg/l. This
concentration was also detected in a groundwater sample collected from monitor well MW-2.
The highest 1,1-DCE concentration detected was 18 µg/l. The highest cis 1,2-DCE
concentration detected was 400 µg/l. These were both also detected in groundwater samples
collected from monitor well MW-2. Data collected from the nested wells indicate that
groundwater in deeper zones within UAU1 and UAU2 is not contaminated. A well was installed
by ADEQ in the north portion of the parking lot near a drywell in December 1998 to assess the
northern extent of groundwater contamination at the facility (IT Corp, 1999). Contaminants
detected in the groundwater samples collected from this well were greater than their respective
AWQS.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-25

8/9/2012

 Groundwater monitoring indicated that groundwater elevations fluctuated with seasonal
groundwater withdrawals as did horizontal flow directions and gradients. These data were, in
general, similar to regional groundwater data, i.e., depths to groundwater fluctuated by ten feet or
more; westerly flow direction ranged from northwest to southwest; and gradients fluctuated from
approximately 0.0017 ft/ft to 0.0034 ft/ft.
The remediation system was operated periodically from 2001 to 2003. Testing after system shut
down indicated that the ERA remedial action objectives (RAOs) were accomplished. The ending
soil gas PCE and TCE concentrations indicated that the vadose zone RAOs of 20µg/L for PCE
and 14 µg/L for TCE were met, and VOC concentrations detected in downgradient wells were
similar to those in upgradient wells. Following groundwater and soil remediation, select
groundwater monitor wells were abandoned by ADEQ. Currently ADEQ monitors two
downgradient and one upgradient groundwater monitor wells and the three onsite nested monitor
wells. ADEQ granted ALSCo an NFA determination for soil on March 24, 2008. Soil gas
concentrations when converted to total soil concentrations equal 0.03 mg/kg PCE and 0.04
mg/kg TCE. Both of these values are below the current residential SRLs and minimum GPLs for
PCE and TCE.
Several areas have been investigated at the ALSCo facility. Five of these areas, former sump,
area of south door, area of north door, northwest corner of the old building, and northwest corner
of the building addition, were identified to be source areas (HGC, 1996). The following lists the
areas investigated, area description, contaminants detected, and corrective actions taken:












Former Sump – Waste Water Disposal – VOCs – Soil Vapor Extraction
Area of South Door – Surface Disposal of Waste Water – VOCs – Soil Vapor
Extraction
Area of North Door – Surface Disposal of Waste Water – VOCs – Soil Vapor
Extraction
Northwest Corner of the Old Building – Surface Disposal of Waste Water –
VOCs – Soil Vapor Extraction
Northwest Corner of the Building Addition – Surface Disposal of Waste Water –
VOCs – No Action Taken
Southwest Area of Parking Lot– Disposal of Waste Water – VOCs – Soil Vapor
Extraction
Central Area of Parking Lot– Disposal of Waste Water – VOCs – Soil Vapor
Extraction
North Area of Parking Lot – Disposal of Waste Water – VOCs – Soil Vapor
Extraction
Maroney’s Cleaners #1 Machine – Dry Cleaning – VOCs – Soil Vapor Extraction
Maroney’s Cleaners #2 Machine – Dry Cleaning – VOCs – Soil Vapor Extraction
Historical Solvent Use Area – Dry Cleaning – VOCs – No Action Taken
2.3.6 CRC

Site investigation activities conducted at the CRC facility were initiated in April 1990 (PeglerWelch, Inc., 1990) (Appendix F). Analytical results of soil samples collected during initial
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-26

8/9/2012

 sampling indicated the presence of PCE, 1,2-dichlorobenzene, cadmium, chromium, and lead.
The highest PCE concentration detected was 53.8 parts per billion (ppb) and was located in the
west bay area near the anodize area. The highest chromium concentration was 1,100 parts per
million (ppm) and was located in the chrome plating area. Soils encountered in the vadose zone
at the CRC facility included silt and sand with varying amounts of gravel to approximately ten
feet bgs. Gravel with varying amounts of silt, sand, and cobbles were encountered below
approximately ten feet bgs. A soil vapor survey was conducted at the facility and adjacent
properties in October 1992 (Weston, 1992b) (HGC, 1992b). Data collected during this
investigation indicated that PCE, TCE and 1,1-DCE were present in the soil vapor beneath the
facility. The most commonly detected COC was PCE. The highest PCE concentration was
detected at 1,100 µg/l (Table 2-5). This was detected in the vicinity of the former PCE UST at a
depth of approximately five feet bgs. The highest TCE concentration detected was 13.2 µg/l.
1,1-DCE was detected at concentrations of 0.17 µg/l and 0.21 µg/l. Additional soil sampling
was conducted at the site in the area of the chrome plating operations in 1994 and the anodizing
area in 1996 (Hargis + Associates, Inc. [HAI], 1995a and 1997). Chromium was detected at a
maximum concentration of 223 mg/kg in two soil samples collected at ten feet bgs and 14 feet
bgs of the chrome plating area, which is greater than the nonresidential and residential SRLs of
65 mg/kg and 30 mg/kg, respectively, for chromium assuming that the chromium concentration
is in the form of hexavalent chromium. VOCs were not analyzed for in chrome plating area soil
samples.
Chromium was detected at concentrations of up to 663 mg/kg in soil samples collected from the
anodizing area and PCE was detected at concentrations of up to 3,500 mg/kg (Table 2-5). The
chromium concentration exceeds the minimum GPL of 590 mg/kg.
This chromium
concentration also exceeds the current SRLs for chromium in the form of hexavalent chromium.
The PCE concentration exceeds the nonresidential and residential SRLs of 13 mg/kg and 0.51
mg/kg, respectively, and the minimum GPL of 1.3 mg/kg. In 2005, soil samples were collected
from the area of the waste water treatment plant (HAI, 2006). Chromium and other metals were
detected in the soil samples with chromium exceeding the residential SRL in one sample.
In 1995, soil beneath the chrome plating east bay area was excavated and transported offsite for
disposal (HAI, 1995b) (Appendix F). Chromium concentrations of up to 32,000 mg/kg were
detected in soil during excavation (Table 2-5). Soil was excavated to approximately 10.5 feet
bgs. Remaining concentrations of chromium detected in confirmation soil samples were as high
as 1,760 mg/kg which exceeds the nonresidential and residential SRLs of 65 mg/kg and 30
mg/kg, respectively, for chromium in the form of hexavalent chromium and the minimum GPL
of 590 mg/kg, and PCE was detected at a concentration of 1.10 mg/kg. The only other COC
detected in soil samples collected at the facility was 1,1-DCE, which was detected in one soil
sample at a concentration of 0.05 mg/kg.
Concurrent with excavation activities, two groundwater monitor wells were installed at the
facility (Appendix F). PCE and hexavalent chromium were detected in the groundwater samples
collected from the groundwater monitor well located downgradient of the chrome plating area at
concentrations greater than AWQSs. A groundwater monitor well was installed downgradient of
the CRC facility in 1997 (HAI, 1997). Chromium was not detected in the initial groundwater
samples collected from the downgradient well but PCE was detected at concentrations greater

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-27

8/9/2012

 than the AWQS. In 1998, two groundwater monitor wells were installed downgradient of the
facility and a deep well was installed at the facility into the UAU2 (HAI, 1999). Data collected
from the deep well indicated that groundwater in the UAU2 is not contaminated. Groundwater
samples collected from the downgradient wells have contained chromium at concentrations
greater than the AWQS on occasion and have consistently contained PCE at concentrations
greater than the AWQS. TCE, 1,1-DCE, and cis 1,2-DCE have also been detected in
groundwater samples collected from monitor wells associated with this facility but the
concentrations have been less than the AWQS. The highest chromium and PCE concentrations
detected at the facility are 25 mg/L and 1,800 µg/L, respectively. Groundwater monitoring
indicates that groundwater elevations fluctuate with seasonal groundwater withdrawals as do
horizontal flow directions and gradients. Depths to groundwater fluctuate by ten feet or more;
the horizontal flow direction ranges from northwest to west-northwest; and gradients fluctuate
from approximately 0.003 ft/ft to 0.009 ft/ft. CRC continues to collect groundwater samples
from the groundwater monitor wells on a quarterly basis.
CRC currently has an approved remedial action plan in place to excavate contaminated soil in
the vicinity of the anodizing area. Several areas have been investigated at the CRC facility.
Three of these areas, former chrome plating area, anodizing area, and the former PCE UST have
had releases of contaminants. The following lists the areas investigated, area description,
contaminants detected, and corrective actions taken:





Former Chrome Plating Area – Metal Plating – Metals/VOCs – Soil Excavation
Anodizing Area – Metal Plating – Metals/VOCs – No Actions Taken
Former PCE UST – Chemical Storage – Metals/VOCs – No Actions taken
Waste Water Treatment Plant – Waste Water Treatment – Metals – No Action
Taken
2.3.7 U.S. DOE WAPA

In June 1992, during UST release investigations, PCE and TCA were detected in six soil samples
but at concentrations less than HBGLs (Woodward-Clyde Consultants, 1994) (Appendix I). PCE
concentrations ranged from 0.011 mg/kg to 0.23 mg/kg. TCA was detected in one soil sample at
a concentration of 0.032 mg/kg. Soils encountered in the vadose zone consisted of clay and silt
to approximately 30 feet bgs with an occasional thin sand lens at approximately 15 feet bgs.
Gravel with sand and cobbles underlie the fine-grained soils. Three groundwater monitor wells
were installed during the UST investigation. Detected COCs included PCE, TCE, 1,1-DCE, cis1,2-DCE, and 1,1-DCA. Groundwater samples collected from the wells contained PCE and TCE
at concentrations that exceeded the AWQS of 5 µg/l for both VOCs. The highest PCE
concentration detected was 62 µg/l. The highest TCE concentration detected in groundwater
samples collected at the facility was 77 µg/l.
In 2001, ADEQ began sampling of three on-site groundwater monitor wells and a production
well used for irrigation (Appendix I). In May 2003, U.S. DOE sampled two drywells at the site,
DW-1 (the southern drywell) and DW-2 (the northern drywell) (SCS Engineers, 2003). Both
drywells contained wet sediment and DW-2 contained liquid. Sample DW-2 did not contain
detectable VOCs, however, sample DW-1 contained 1,1-DCE at 0.32 mg/kg.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-28

8/9/2012

 A soil vapor survey was conducted in the operations area of the DOE complex in April 2005
(SCS Engineers, 2005) (Appendix I). The site was divided into six investigation areas and
sampling was performed in each of the areas judged to contain potential sources of VOCs. A
total of 103 samples were collected at the six areas. The highest PCE concentration was detected
in two of the samples at 0.72 µg/L. TCE was detected in five soil vapor samples collected by
DOE’s consultant and in three split soil vapor samples collected by ADEQ. SCS Engineers
analyzed the samples using EPA Method 624 Modified and ADEQ analyzed the samples using
EPA Method TO-15 Modified. The concentrations were less than 1 µg/L in all but one ADEQ
sample which contained PCE (0.92 µg/L) TCE (1.6 µg/L), 1,1-DCE (0.1 µg/L), and cis 1,2-DCE
(0.011 µg/L) in sample PAO-SV-A4-8-18. Trichlorofluoromethane was detected in one soil
vapor sample at 2,900 µg/L in PAO-SV-A6-5.
ADEQ has met with WAPA personnel and requested that DOE conduct a soils investigation at
the substation to evaluate whether releases to the environment have occurred at this facility, and
have requested additional groundwater investigation at the operations and maintenance complex.
Several areas have been investigated at the DOE facility. One of these areas, the craneway
building, experienced a release of contaminants. The following lists the areas investigated, area
description, contaminants detected, and corrective actions taken:









Craneway Building – Equipment Maintenance –VOCs – No Action Taken
Drywells – Storm Water Runoff – No Contaminants – No Action Required
Heavy Equipment Storage Area – Equipment Storage – No Contaminants – No
Action Required
Warehouse Storage Area – Storage – No Contaminants – No Action Required
Service Station – Vehicle Fueling – No Contaminants – No Action Required
Vehicle Repair Shop – Vehicle Repair – No Contaminants – No Action Required
Paint Shop – Painting – No Contaminants – No Actions Required
Shop Building – Maintenance – No Contaminants – No Action Required

2.3.8 POS
POS has conducted three soil investigations including characterization of a UST release and two
laundry area investigations (Appendix H). Soils within the vadose zone beneath the POS facility
consist of interfingered layers of sand, silt, and clay to 107 feet bgs, the maximum depth
explored. In December 2004, a soil and soil gas investigation was conducted at the facility
(Miller Brooks, 2005). Soil samples were collected from six locations (SG-1, SG-5, SG-6, SG-7,
SG-8, and SG-9) and soil gas samples were collected from nine locations (SG-1 through SG-9).
Soil samples were collected at depths of 5 to 6 ft bgs and 7 to 8 ft bgs. Laboratory analysis did
not detect COC above the minimum laboratory reporting limits in the soil samples. Laboratory
analysis of each of the soil gas samples detected PCE concentrations in each soil gas sample.
The PCE concentrations ranged from a minimum of 15.6 µg/l to a maximum of 950 µg/l. The
highest PCE concentration, 950 µg/l, was detected in sample SG-8 at a depth of 11 feet bgs,
adjacent to the wastewater flume and the wastewater discharge line. In addition to PCE, TCE
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-29

8/9/2012

 was also detected in the three soil gas samples that had the highest PCE concentrations. The
highest TCE concentration detected was 5.37 µg/l. TCE was not detected above minimum
laboratory limits in the other six soil gas samples, possibly because of elevated detection limits
due to dilution of the samples by the laboratory because of high PCE concentrations.
Based on the results of the initial investigation, a soil and soil gas investigation was conducted at
two locations on the POS property on October 16 though 19, 2006 (Miller Brooks, 2007)
(Appendix H). Soil samples and soil gas samples were collected from the northwest corner of
the former dry-cleaning room and under the canopy, adjacent to the reclaim equipment. The
highest PCE concentration detected in soil beneath the former dry-cleaning room was 1.7 mg/kg
collected at 95 ft bgs. The highest PCE concentration detected in soil beneath the reclaim
equipment was 1.9 mg/kg collected at 85 ft bgs. Both concentrations exceed the residential SRL
of 0.51 mg/kg and the minimum GPL of 1.3 mg/kg. Two other soil samples collected in the
former dry-cleaning room and three other soil samples collected near the reclaim equipment
contained PCE at concentrations greater than the residential SRL but less than the minimum
GPL. No other VOCs were detected. Laboratory analysis of each of the soil gas samples
detected PCE concentrations. The highest PCE concentration detected was 2,985 µg/l from a
depth of 105 ft bgs. This soil gas sample was collected from beneath the former dry-cleaning
room. PCE was also detected beneath the reclaim equipment at a maximum concentration of
2,900 µg/l at 85 ft bgs. TCE was detected in soil gas samples collected from beneath the former
dry-cleaning room but not in soil gas samples collected from beneath the reclaim equipment.
The highest TCE concentration detected in soil gas was 27.4 µg/l. collected from a depth of 105
feet bgs. Although not detected, the method reporting limits for additional COC were elevated
due to the high PCE concentrations.
Several areas have been investigated at the POS facility. Three of these areas, former dry
cleaning area, waste water flume, and parts washer area have had releases of contaminants. The
following lists the areas investigated, area description, contaminants detected, and corrective
actions taken:





Former Dry-Cleaning Area – Cleaning and PCE Storage –VOCs – No Actions
Taken
Former Dry Wells – Storm Water Runoff – VOCs – No Action Required
Waste Water Flume – Waste Water Disposal – VOCs – No Action Taken
Parts Washer – Parts Cleaning – VOCs – No Action Taken
2.3.9 ALASG

ALASG has investigated soil at their facility through the collection of soil gas and soil samples.
Soils encountered beneath the site include sand with gravel to approximately 19 feet bgs.
Underlying the surficial unit is clayey silt to approximately 39 feet bgs. Gravel, cobbles, and
sand underlie the clayey silt. A soil gas survey was initially conducted at ALASG in July 1998
(ENSR, 1998) (Appendix G). VOCs detected during the investigation included PCE, TCE,
TCA, and 1,1-DCE. The highest concentrations were detected in the building which contained
the former ASU located adjacent to the eastern boundary of the facility. TCA was detected at the
highest concentration of the VOCs analyzed for at a concentration of 440 µg/l. This sample was
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-30

8/9/2012

 collected from a depth of approximately 18 feet bgs in the south end of the ASU building. The
highest PCE concentration detected was 150 µg/l. This soil gas sample was collected at a depth
of 16.5 feet bgs located near the center of the facility between the acetylene plant and the fill
plant. One soil gas sample, SG 2-6’, yielded liquid containing TCA and PCE. This sample was
collected at a depth of approximately six feet bgs near the west grease trap in the ASU building.
Additional soil sampling, soil gas extraction well installation, and soil gas sampling were
conducted at the ALASG facility in 2000, 2003, and 2004 (BRH, 2001a, 2004, 2005) (Appendix
G). VOCs were detected during these investigations including PCE, TCE, TCA, 1,1-DCE, 1,1DCA, and 1,2-DCA. TCA was detected at the highest soil gas concentration of the VOCs
analyzed at a concentration of 55,000 µg/l (Table 2-5). This soil gas sample was collected at a
depth of five feet bgs at the west grease trap in the ASU building. 1,1-DCA was detected at a
concentration of 1,700 ug/l in the same soil gas sample. The highest 1,1-DCE concentration
detected was 440 µg/l in the same sample. The highest soil gas concentration detected for PCE
during this phase of investigation was 90 µg/l. This concentration was detected at two locations,
in the northwest corner of the facility at a depth of approximately 55 feet bgs and in the north
central portion of the facility at a depth of approximately 55 feet bgs. The highest VOC
concentration detected in soil samples was TCA detected at a concentration of 6,300 mg/kg.
This sample was collected at a depth of approximately four feet bgs in the vicinity of the west
grease trap in the air separation unit building. This concentration exceeds the residential and
nonresidential SRL of 1,200 mg/kg and the minimum GPL of 1 mg/kg. TCA was also detected
at a concentration of 1,100 mg/kg from the same depth in another area of the west grease trap.
1,1-DCE was detected at a maximum concentration of 100 mg/kg in soil samples collected at the
ALASG facility. This concentration is greater than the minimum GPL for 1,1-DCE of 0.81
mg/kg. This soil sample was collected from a depth of approximately four feet bgs in the
vicinity of the west grease trap. Two soil samples collected from the area of the west grease trap
contained TCE at concentrations greater than the minimum GPL for TCE of 0.61 mg/kg. 1,2DCA was also detected in a soil sample from this area with a concentration greater than the
nonresidential SRL, residential SRL, and minimum GPL of 5.5 mg/kg, 2.5 mg/kg, and 0.21
mg/kg, respectively. PCE was not detected at concentrations greater than the SRLs or minimum
GPL in soil samples collected at the ALASG facility. Chromium was detected in three soil
samples collected at the grease trap at concentrations less than the regulatory standards for
chromium.
Three groundwater monitor wells were installed at the ALASG facility in November 2000 (BRH,
2001b) (Appendix G). The wells were located in the vicinity of the ASU building. COCs
detected in groundwater samples collected at the facility include PCE, TCE, 1,1-DCA, 1,1-DCE,
TCA and cis 1,2-DCE. PCE and TCE were detected at concentrations greater than the AWQS in
groundwater samples collected from the monitor wells (BRH, 2001b, 2001c, 2001d, 2003). The
highest PCE concentration detected was 22µg/l. The highest TCE concentration detected was 18
µg/l. PCE and TCE concentrations were slightly higher in groundwater samples collected from
the downgradient monitor well as opposed to the upgradient and cross-gradient monitor wells.
Four additional groundwater monitor wells have been installed at the facility under a consent
order; however, no reports have been submitted to ADEQ to date.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-31

8/9/2012

 Several areas have been investigated at the ALASG facility. One of these areas, grease trap and
associated conduits within the former air separation unit, has had a release of contaminants. The
following lists the areas investigated, area description, contaminants detected, and corrective
actions taken:







Grease Trap and Associated Conduits – Water Disposal –VOCs – No Actions
Taken
Acetylene Plant – Acetylene Gas Production/Packaging – VOCs – No Action
Required
Plant and Former Truck Maintenance Area – Gas Mixing/Packaging & Vehicle
Repair – VOCs – No Action Required
Northwest Parking Area – Vehicle Parking – No Contaminants – No Action
Required
Chemical Storage Area – Chemical Storage – No Contaminants – No Action
required
Cylinder Cleaning Racks – Cylinder Cleaning – No Contaminants – No Action
Required

2.4 Remedial Activities
2.4.1

Facility Activities
2.4.1.1 Reynolds

Reynolds operated an SVE system installed at the site in 1989 and operated it periodically until
1991 (Reynolds Metals Co., 1994). Operation was discontinued because of air permit
limitations. The mass of contaminants removed by the SVE system is not available. The SVE
system was to be restarted following modifications to the system and permit but Reynolds
completed risk analyses instead of operating the SVE system. Trenching and excavation
activities were also conducted at several areas across the Reynolds facility to remove
contaminated soils, mostly contaminated with petroleum hydrocarbons. Reynolds excavated and
removed approximately 3,100 tons of contaminated soil from the site. Risk assessments were
conducted for the release areas where residual soil contamination was present. ADEQ
subsequently issued NFAs for 14 release areas at the facility (ADEQ, 2000).
2.4.1.2 VW&R
In an effort to remediate soil at the site, VW&R installed an SVE system at the site and began
operating the system in November 1992 under Maricopa County Division of Air Pollution
Control Permit No. 9301590 (Ensolutions, Inc., 1998) (Appendix B). Installation and operation
of the SVE system was a voluntary remedial action to remove soil vapors containing VOCs from
the subsurface. The system consisted of a positive displacement blower to create a vacuum at
seven vapor extraction wells located in the area north of the solvent tank farm, the area south of
the solvent tank farm, and the area north and west of the corrosive tank farm. Extracted vapors
were routed through an air water separator, inlet filter, and two granular-activated carbon (GAC)
canisters connected in series. Radius of influence testing was conducted at the facility to
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-32

8/9/2012

 demonstrate the effectiveness of the remediation system on November 1, 1997 (Ensolutions, Inc.,
1998). Results of the radius of influence testing indicated that the SVE system was designed and
operated to effectively remediate the source areas targeted by the remediation system. The
system ran periodically until October 25, 1998 when it was shut down (Van Waters & Rogers
Inc., 1999). After the system was shut down, a calculation of the amount of VOCs removed was
completed resulting in an estimation of 580 pounds to 870 pounds of VOCs removed from the
subsurface (Ensolutions, Inc., 2000). After the system was shut down, soil samples were
collected from the source areas to evaluate contaminant concentrations (Geotrans, Inc., 2001).
Confirmation soil samples indicated that soil contamination had been remediated and ADEQ
issued an NFA letter to VW&R for the remediated soil contamination (ADEQ, 2002).
2.4.1.3 MCMM
MCMM installed/operated an SVE system from mid August to early September and mid October
to late November 1997 (Appendix C). Subsequent soil vapor testing indicated that PCE and
TCE levels were asymptotic and were calculated to have been reduced below minimum GPLs
(Fluor Daniel GTI, 1998b). Final PCE and TCE concentrations were measured at 532 µg/l and
525 µg/l, respectively. The minimum GPLs calculated for the facility were 2,707 µg/l for PCE
and 1,403 µg/l for TCE. An estimated 145 pounds of VOCs were removed from the subsurface
via the SVE system (Fluor Daniel GTI, 1998a). In October 2001, Maricopa County and Union
Pacific Railroad settled with ADEQ.
2.4.1.4 Dolphin
As previously mentioned, three SVE systems and an AS system were operated at the Dolphin
facility under a RCRA consent order. (Brown and Caldwell, 1999b) (Appendix D). The two
SVE systems installed in the vicinity of the former PCE degreaser and former drum storage areas
near the Dolphin I building included six nested well clusters (Brown and Caldwell, 2000b). The
well clusters included a well screened in the shallow coarse-grained unit which extends to a
depth of approximately 18 to 20 feet bgs, the fine-grained deeper unit which extend to
approximately 50 feet bgs, and the deeper coarse-grained unit which extends to the groundwater
table. The Dolphin I HF SVE system extracted soil vapors from the two coarse-grained units.
The Dolphin I LF SVE system extracted soil vapors from the fine-grained unit. The third SVE
system was installed in the vicinity of the closed sewer interceptor at the Dolphin III building.
This system utilized one SVE well screened in the lower coarse-grained unit. The SVE
extraction systems each consisted of a positive displacement blower, air and water separator, and
two 2000-pound GAC canisters connected in series. A radius of influence study was conducted
at the facility during the pilot test in 1996 and determined that the systems would be a viable
method of remediation.
The AS system included three wells installed adjacent to SVE extraction wells in vicinity of the
former PCE degreaser and former drum storage area near the Dolphin I building (Brown and
Caldwell, 2000b) (Appendix D). The wells were screened at 120 to 130 feet bgs. The AS
system was operated concurrent to the Dolphin I SVE system. Although there is no method to
measure the amount of VOCs removed from the groundwater by the AS system, concentrations
of COCs contained in the groundwater samples dropped substantially including PCE from a high

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-33

8/9/2012

 concentration of 95,000 µg/l to as low as 5.2 µg/l. Currently, COC concentrations contained in
groundwater samples collected from upgradient wells are similar to concentrations detected in
groundwater samples collected from source wells.
The Dolphin I HF and LF systems operated from October 1998 until April 2002 when soil vapor
concentrations had reached asymptotic concentrations (Brown and Caldwell, 2004a). Final PCE
concentrations contained in soil vapor samples ranged from less than the detection limit of 0.50
µg/l to 1,500 µg/l. TCE concentrations contained in soil vapor samples ranged from less than the
detection limit of 0.50 µg/l to 2.7 µg/l. 1,1-DCE concentrations contained in soil vapor samples
ranged from less than the detection limit of 1.0 µg/l to 5.6 µg/l. The remediation criteria for
PCE, TCE, and 1,1-DCE were 2,120 µg/l, 976 µg/l, and 1,389 µg/l, respectively. GAC sampling
indicated that approximately 5,290 pounds of VOCs were removed from the two coarse-grained
units in the vicinity of the Dolphin I building and approximately 5,168 pounds of VOCs from the
fine-grained unit in the vicinity of the Dolphin I building. Decommissioning sampling of the
SVE systems indicated that VOCs in soil vapors had been reduced to concentrations indicative
that the soil concentrations are less than the residential SRLs and minimum GPLs. The Dolphin
III SVE system was operated from November 1998 to November 2001 when soil vapor
concentrations had reached asymptotic concentrations (Brown and Caldwell, 2002b). Final PCE
concentrations contained in soil vapor samples ranged from 4.0 µ/l to 9.5 µg/l. TCE and 1,1DCE soil vapor concentrations were all less than the detection limit of 0.50 UG/l and 1.0 µg/l,
respectively. The remediation criteria for PCE, TCE, and 1,1-DCE were 2,120 µg/l, 976 µg/l,
and 1,389 µg/l, respectively. GAC sampling indicated that approximately 1,200 pounds of
VOCs were removed from the lower coarse-grained unit in the vicinity of the Dolphin III sewer
interceptor.
2.4.1.5 CRC
In 1995, soil beneath the chrome plating east bay area was excavated and transported offsite for
disposal (HAI, 1995b) (Appendix F). Chromium concentrations of up to 32,000 mg/kg were
detected in soil during excavation (Table 2-5). Soil was excavated to approximately 10.5 feet
bgs. Logistics and the coarse-grained nature of the soils encountered prevented the excavation of
additional soil. Remaining concentrations of chromium detected in confirmation soil samples
exceeded the nonresidential and residential SRLs and the minimum GPL for chromium. PCE
was also detected in confirmation soil samples but at concentrations less than soil standards.
Additional remediation activities are proposed for the west bay area of the facility for chromium
and PCE if present.
2.4.2

ADEQ ERA

An ERA is a remedial action performed at the site prior to the final remedy, and often prior to the
completion of the RI. Pursuant to A.A.C. R18-16-405, an ERA is conducted to address current
risks to public health, welfare, and the environment; protect or provide a supply of water;
addresses sources of contamination; or controls or contains contamination where such actions are
expected to reduce the scope or cost of the final remedy at the WQARF site. The purpose of the
ERA at this facility was to remove the source so as not to exacerbate the soil and groundwater
contamination.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-34

8/9/2012

 An ERA was conducted for the WVBA WQARF site at the ALSCo facility at 722 W. Buchanan
Street in Phoenix, Arizona (Appendix E). As described in Section 1.3.2.4, the facility has
provided industrial laundry and linen supply services to the Phoenix area for many years.
ALSCo had settled liability with the State on May 15, 1997. The ERA was initiated to control
the migration of COC plume and reduce VOC concentrations, particularly PCE, in soils at the
site to concentrations that would not cause additional groundwater contamination. Groundwater
extraction and treatment, SVE, and AS were employed to complete the ERA.
The initial ERA evaluation was conducted by ADEQ’s contractor HydroGeoChem, Inc. As
previously mentioned in Section 2.3.5, HGC (1999b) conducted an SVE pilot test at the ALSCo
facility in February 1999. The data obtained from the pilot test were used to design the SVE
system. In July 1999, HGC recommended a remedial design. Further refinements to the design
and specifications were developed following an aquifer test conducted by HGC (2000).
Following approval, ADEQ retained BE&K/Terranext to serve as the oversight contractor and to
install the groundwater extraction well and injection well, the six AS wells, and five of the seven
SVE wells.
ADEQ ascertained that RAOs for groundwater at ALSCo were to reduce PCE and TCE
concentrations in groundwater beneath the site to levels that were relatively the same as
upgradient water quality, and the treatment system was no longer efficiently removing
groundwater contamination. The RAOs for PCE and TCE in soil gas concentrations within the
vadose zone soil were calculated by HGC to be 20 µg/l and 14 µg/l, respectively.
The SVE system was designed to extract soil gas from seven soil vapor extraction wells at a total
flow rate of up to 400 cubic feet per minute (cfm). The SVE system was operated in conjunction
with the AS system to capture VOCs liberated from groundwater as a results of AS. The SVE
system could also be operated as a stand-alone system for remediation of PCE from the
unsaturated zone. The AS system was designed to operate in conjunction with the SVE system
only. The groundwater extraction system was designed to operate independent of the SVE/AS
systems. Extracted groundwater was routed through the heat exchanger to cool the extracted
vapor stream prior to entry into the GAC canisters. Therefore, the SVE system was not operated
without the groundwater extraction system operating.
The groundwater extraction well was installed along the central area of the west property
boundary and the injection well was installed near the southeast corner of the property in
November 1999 (BE&K/Terranext, 2000f) (Appendix E). The extraction well was completed to
a depth of 122 feet bgs with a screened interval of 67 feet bgs to 122 feet bgs. The injection well
was completed to a depth of 123 feet bgs with a screened interval of 68 feet bgs to 123 feet bgs.
During September through November 2000, a submersible pump with 150 gallons per minute
(gpm) capacity at 185 feet total head was installed in the extraction well and the groundwater
extraction well and the injection wells were piped to the groundwater treatment system
(BE&K/Terranext, 2001d). The groundwater treatment system consisted of two bag filters to
remove suspended solids and two 5,000-pound liquid phase GAC containing canisters to remove
VOCs. In August 2001, the extraction well was removed from service because of sand intrusion.
This well was replaced in November with an adjacent similarly designed well. The

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-35

8/9/2012

 extraction/injection wells were operated in compliance with ADWR Poor Quality Groundwater
Withdrawal Permit 59-582827.
Five AS/SVE well clusters and one AS well were installed in July 2000 in the area of the facility
west of the building (BE&K/Terranext, 2001d). Two vapor extraction wells had been previously
installed at the facility in December 1998 in the area of the former grease trap adjacent to the
west end of the facility building (IT Corp, 1999). One of these two extraction wells was
completed with a screened interval of 35 feet bgs to 55 feet bgs and one with a screened interval
of 65 feet bgs to 95 feet bgs. The AS wells were completed with screened intervals of 105 feet
bgs to 115 feet bgs. The SVE wells were installed with screened intervals of 45 feet bgs to 70
feet bgs. During September through November, the remediation wells were piped to the
treatment compound. The SVE system consisted of a moisture knockout tank, condensate
storage tank, heat exchanger, two 5,000-pound vapor phase GAC containing canisters, and an
SVE blower with a design capacity of 370 standard cfm at five inches mercury inlet vacuum
pressure and 1.5 inches mercury outlet pressure. The AS system consisted of a receiver tank and
oil-cooled rotary screw air compressor with a capacity of 40 cfm at 125 pounds per square inch
(psi). The remediation systems were connected to a telecommunications system for remote
monitoring and notification of system failure.
Following remediation system installation, the system was prepared for startup (URS, 2001).
Initial startup involved the testing of the SVE system in January 2001. The optimal air flow was
set to 310 to 350 standard cfm with initial PCE concentrations measured at the well heads
ranging from 86,000 to 660,000 parts per billion volume (ppbv). The PCE concentration
upstream of the GAC was 280,000 ppbv and at the exhaust stack at 3,600 ppbv. The SVE
system was operated in accordance with Maricopa County Environmental Services Air Quality
Division Air Quality Permit No. 000164. The AS system was designed to volatize VOCs
contained in the groundwater beneath the facility. Initial testing was conducted in February
2001. Based on AS testing, the system was set to operate at wellhead pressures of 12.5 to 30 psi.
Start-up of the entire remedial system was on March 7, 2001. Sampling of the waste streams
was conducted following startup with the following results:

Vapor In
Compound
Concentration
ppbv
PCE
260,000
TCE
6,000
Cis-1,2-DCE
2,800
Groundwater In
Compound
Concentration
µg/l
PCE
39
TCE
6.4

West Van Buren WQARF Registry Site
Remedial Investigation Report

Vapor Out – Canister 1
Compound
Concentration
ppbv
PCE
11,000
TCE
140
Cis-1,2-DCE
33
Groundwater Out – Canister 1
Compound
Concentration
µg/l
PCE
<2
TCE
<2

Page 2-36

Vapor Out – Canister 2
Compound
Concentration
ppbv
PCE
<5
TCE
<5
Cis-1,2-DCE
<5
Groundwater Out – Canister 2
Compound
Concentration
µg/l
PCE
<2
TCE
<2

8/9/2012

 The groundwater extraction and treatment system was operated from March 2001 to September
2003. As mentioned above, problems developed with the extraction well in August 2001 and the
groundwater extraction system was shut down while a replacement well was completed.
Groundwater levels were measured at onsite and offsite groundwater monitor wells monthly by
BE&K/Terranext to calculate the capture zone. Data indicated that the capture zone covered the
ALSCo facility. Groundwater samples were collected from onsite groundwater monitor wells
and the groundwater treatment system quarterly. Analytical data for the groundwater samples
indicated a decrease in concentrations with time and no breakthrough occurred at the
groundwater treatment system. As of September 2003, an estimated 24 pounds of VOCs had
been removed from groundwater and over 118 million gallons of water had been treated
(BE&K/Terranext, 2003d, URS, 2003, ADEQ, 2004). Groundwater influent concentrations for
March 2003 were PCE at <2.0 µg/l and TCE at 2.5 µg/l. Groundwater data collected from
downgradient wells were similar in concentration to upgradient wells. Based on these data, it
was ascertained that the RAOs for groundwater had been met.
The SVE system was operated to maximize contaminant mass removal within air permit
operating limits (URS, 2001). This required regular monitoring and adjustment of the SVE
system by URS to maintain the highest flow rate and concentration of contamination from the
extraction wells while insuring compliance with the air quality permit. Prior to system startup,
the highest soil concentrations detected at the facility were PCE at 3,969,400 ppbv, TCE at
14,590 ppbv, and 1,2-DCE at 15,510 ppbv (IT Corp, 1999). During SVE system operation, soil
vapor concentrations rapidly dropped until reaching asymptotic levels by the end of the first year
of operation. To augment the recovery of contaminants from the vadose zone, air injection was
conducted at select SVE wells starting in December 2001 (BE&K/Terranext, 2003d). This
process increased the recovery of VOCs from the vadose zone but operational problems with the
SVE equipment limited the effectiveness of the process. By October 2002, soil vapor
concentrations had dropped to levels less than the RAOs.
The groundwater extraction and treatment system ceased operation in September 2003 after
treating approximately 118 million gallons of groundwater and removing approximately 17.8 lbs
of PCE, 6.0 lbs of TCE and 0.1 lbs of DCE (BE&K/Terranext, 2003d, URS, 2003, ADEQ,
2004). The system was temporarily shut down to allow for any “rebound” in the presence of
dissolved halogenated organic compounds in groundwater within the former source area. During
the “rebound” period, groundwater sampling and groundwater elevation measurement events
were conducted. Data could not be collected in September 2003 because of declining
groundwater levels. One year of groundwater rebound testing did not support re-starting the
remedial system. Since shutdown of the groundwater extraction system, PCE concentrations in
groundwater samples collected from the downgradient well, AVB40-7, have been only slightly
greater than concentrations detected in the upgradient well AVB40-08. TCE concentrations in
groundwater samples collected from the downgradient well have been less than the
concentrations in the upgradient well. PCE and TCE concentrations in groundwater samples
collected from the crossgradient well, AVB77-04, have been less than the concentrations in
groundwater samples collected from the upgradient well.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-37

8/9/2012

 The SVE system ceased operation in October 2002 after the removal of over 900 pounds of
VOCs from the vadose zone (BE&K/Terranext, 2003d). ADEQ then evaluated if the SVE
system had accomplished its goal of remediating the soil. Rebound sampling was performed by
sampling the SVE vapor stream on a monthly basis until January 2003 and then again in four
months. These data were evaluated to evaluate whether significant concentrations of
contaminants were still present in the vadose zone. Results of a mass balance analysis of
remaining VOCs in soils and the operation optimization study mentioned above indicated that
soil contamination concentrations were less than minimum GPLs. Given the results of the
vadose zone investigation relative to the remaining presence of PCE and TCE in soil (under
equilibrium conditions) as of May 22, 2003, the vadose zone soil within the source area had been
substantially remediated within the depth interval of 13.5 feet bgs to 68 feet bgs. Further, the
RAOs for soil within this interval were initially achieved by May 22, 2003. As a result, further
soil remediation and soil gas sampling for analysis within the depth interval of 13.5 to 68 feet
bgs were no longer necessary. Beneath 68 feet bgs to the water table surface, vadose zone soil
within the source area had been substantially remediated relative to ADEQ minimum GPLs and
the RAOs. Further soil remediation beneath 68 feet bgs was no longer recommended.
During the first quarter of 2005, Terranext performed field tasks in several phases, regarding the
closure of the ERA remediation systems. The field tasks consisted of well abandonments,
remediation compound closure, and restoration of the asphalt parking lot within the former
remediation compound and at the abandoned wells. On March 24, 2008, ADEQ granted ALSCo
an NFA determination for soil (ADEQ, 2008).

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 2-38

8/9/2012

 3.0

HYDROGEOLOGY
3.1

Regional Geology

As previously mentioned, The WVBA is located within the West SRV, an alluvial basin
characteristic of Basin and Range physiography. The rocks that form the bounding
mountains and valley floor of the SRV are predominantly crystalline rocks.
The SRV alluvial basin consists of basin-fill deposits of unconsolidated to semiconsolidated Late Tertiary to Quaternary sediments (Weston, 2000). They range up to
several thousand feet thick within the center of the basin and consist of interbedded cobbles,
gravel, sand, silt, clay, and evaporites. The lithologic relationships appear to represent
alluvial fan and playa deposits formed in a closed basin during the early and middle stages
of basin development followed by fluvial and alluvial fan deposits formed during the late
stages of basin development after the establishment of through-flowing drainages (Corkhill
and others, 1993). These deposits are subdivided into three hydrogeologic units that
comprise the regional aquifer in the SRV:




Lower Alluvial Unit (LAU)
Middle Alluvial Unit (MAU)
Upper Alluvial Unit (UAU)

The LAU consists mainly of conglomerate and gravel grading into finer-grained
mudstones toward the center of the basin and locally contains volcanic rocks. The LAU
reaches thicknesses of up to 10,000 feet in the center of the basin. The LAU was
deposited during the early stages of basin development. The increasing thickness and
decreasing particle size of the LAU with increasing distance from the surrounding
mountains suggest that the alluvial basin was closed during deposition of the LAU
(Laney and Hahn, 1986). Few wells penetrate the LAU due to its depth and low yield.
The LAU does not appear to be contaminated within the WVBA.
The MAU overlies the LAU and consists predominantly of silt and clay with interbedded
sand and gravel lenses. Many of the fine-grained deposits in the MAU can be associated
with ancient playa environments based on the extensive evaporite deposits encountered
(Brown and Pool, 1989). As more through-flowing streams developed, the lithologic
sequence grades into fluvial sands and gravels interspersed with clays associated with
backwater areas. Although minor in thickness when compared to the silt and clay, the
sand and gravel lenses can yield large quantities of water to wells. Near the basin
margin, the MAU consists mainly of sand and gravel, and is difficult to distinguish from
the UAU. The MAU reaches thicknesses of 1,600 feet in the SRV.
The UAU extends from the ground surface to the top of the MAU. The UAU consists
mainly of unconsolidated silt, sand, and gravel deposited during the final stages of SRV
basin development. The association of coarse-grained deposits within the vicinity of the
Salt River suggests that the UAU was deposited by the ancestral Salt River. The UAU
grades from predominantly gravel and cobbles near the Salt River to finer floodplain
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-1

8/9/2012

 deposits in adjacent areas (Brown and Pool, 1989). The UAU ranges between 200 and
500 feet in thickness, and most water production wells extract a large portion of their
water from the UAU (Weston, 2000).
3.2

WVBA Geology

Terranext (2006d) prepared geologic cross-sections across the WVBA and used these
cross sections to evaluate alluvial unit stratigraphy. Numerous geologic logs of varying
quality are available for the WVBA. The logs were first reviewed for quality and those
with minimal lithologic descriptions (exclusively ADWR well logs) or of shallow (less
than 200 feet bgs) wells were excluded; logs of shallow wells were excluded because, in
most instances, these wells did not penetrate the base of UAU1 as described below.
Locations of the remaining logs were then plotted. Based upon the spatial distribution of
available well logs, six cross-section locations were identified. These include two eastwest sections and four north-south sections spread out across the WVBA (Figure 3-1).
Boring and geophysical logs used in cross-section preparation are included as Appendix
L.
Each of the cross-sections was then created by an Arizona registered geologist. The
cross-sections were scaled horizontally and vertically, and the vertical exaggeration
calculated. Wellhead elevations were then obtained for each well. The geology of each
individual log was first plotted using a minimum ten-foot thickness interval. Depending
on the detail of each log, sometimes a predominant lithology was plotted, ignoring thin
interbeds. It should also be noted that lithologies and depths identified on each log were
assumed accurate; in most cases, these logs were developed from drill cuttings as
opposed to depth-specific sample collection.
After the geology of each log was plotted, correlations were performed utilizing the units
identified in Weston (2000). These units as identified by Weston are described below.
Weston (2000) found that enough gradation exists within the UAU to allow separation
into two sublayers. The uppermost layer is comprised of loose surface soils grading
downward into interfingered sand and gravel lenses. Clay lenses, when present, are thin
and usually characterized as clayey sands. Termed UAU1 for purposes of identification,
the breakpoint between this and the lower UAU (termed UAU2) is the point where clay
lenses within the unit increase in number until clays dominate the lithologic horizons.
Weston (2000) identified the transition between the UAU and MAU as that area within
the lithologic sequence characterized by at least 40 feet of material often referred to as
hard brown clay or sticky brown clay. Below this point, the lithology usually shows a
marked increase in the amount of fine-grained material present.
Cross-section A-A’ (Figure 3-2) is an east-west cross-section across the WVBA, and
extends from monitor well OU3-11C in downtown Phoenix west to monitor well
AVB60-01 (79th Avenue south of Van Buren). UAU1 is present from the ground surface
to depths ranging from approximately 180 feet to 310 feet bgs. In the western portion of
the cross-section (AVB60-01 and 98-01), UAU1 appears to become finer grained. The
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-2

8/9/2012

 MAU appears to have been penetrated by the deeper wells comprising this cross-section,
thus the thickness of UAU2 along this cross-section ranges from approximately 30 feet to
200 feet or greater. UAU2 also appears to become finer-grained to the west (beginning at
monitor well DIMW-8D).
Cross-section B-B’ (Figure 3-3) is an east-west cross-section across the northern portion
of the WVBA, and extends from monitor well AVB129-02 in the northwest portion of
the WVBA east to COP production well AVB95-02. COP no longer uses this well
located at 35th Avenue south of I-10 for groundwater withdrawal. UAU1 is present from
the ground surface to depths ranging from approximately 245 feet to 300 feet bgs. As
with cross-section A-A’, UAU1 appears to become finer-grained to the west (AVB12902 and 91-02) within cross-section B-B’. The MAU does not appear to have been
penetrated by the wells comprising this cross-section, thus the thickness of UAU2 along
this cross-section is unknown. As with UAU1, UAU2 also appears to become more finegrained west of AVB96-02.
Cross-section C-C’ (Figure 3-4) is the westernmost of the north-south cross-sections, and
extends from piezometer P-1 (near 83rd Avenue and Thomas) south to privately owned
production well Viss-2 (Broadway and 75th Avenue). UAU1 is present from the ground
surface to depths ranging from approximately 210 feet to 265 feet bgs. The southern
portion of UAU1 approaching the Salt River (BTE-2 and Viss-2) appears to coarsen
considerably. The MAU appears to have been penetrated by the deeper wells comprising
this cross-section, thus the thickness of UAU2 along this cross-section ranges from
approximately 200 feet to 260 feet or greater. Conversely to UAU1, UAU2 and the
MAU appear to coarsen northwards.
Cross-section D-D’ (Figure 3-5) extends from SRP production well SRP-067 (67th
Avenue and Encanto) south to privately owned production well King-2 (Elwood and 59th
Avenue). UAU1 is present from the ground surface to depths ranging from
approximately 220 feet to 320 feet bgs, generally thickening to the north. The MAU
appears to have been penetrated by the deeper wells comprising this cross-section, thus
the thickness of UAU2 along this cross-section ranges from approximately 65 feet to 100
feet or greater. It should be noted that the UAU2/MAU contact in monitor well DIMW8D was selected based upon the geophysical log of this well. As with cross-section C-C’,
UAU1 appears to coarsen southwards and UAU2 appears to coarsen northwards; the
lithology of the MAU appears constant within this cross-section.
Cross-section E-E’ (Figure 3-6) is the central-most of the north-south cross-sections, and
extends from monitor well AVB94-02 (43rd Avenue and I-10) south to production well
RID-90 (RID canal and 47th Avenue). UAU1 is present from the ground surface to
approximately 295 feet bgs across the entire cross-section, and thus the UAU1/UAU2
contact slopes gently southward paralleling the surficial topography. UAU1 is generally
coarse throughout, perhaps becoming slightly more fine-grained in the northernmost well
(AVB94-02). The MAU appears to have been penetrated by the deeper wells comprising
this cross-section; the thickness of UAU2 in the wells comprising the cross-section

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-3

8/9/2012

 ranges from approximately 30 feet to 85 feet or greater. As with the other north-south
cross-sections, UAU2 appears to coarsen northwards.
Cross-section F-F’ (Figure 3-7) is the easternmost of the north-south cross-sections, and
extends from monitor well AVB131-01 (18th Avenue and I-10) south to monitor well
DM-3-D (the 19th Avenue Landfill on the north bank of the Salt River). UAU1 is present
from the ground surface to depths ranging from 170 feet to 240 feet bgs, generally
thickening to the south. The MAU appears to have been penetrated by the deeper wells
comprising this cross-section, thus the thickness of UAU2 along this cross-section ranges
from approximately 30 feet to 165 feet or greater. UAU1 is coarse throughout the crosssection; UAU2 appears to coarsen southwards.
Based upon the prepared cross-sections (Figures 3-2 through 3-7), the following
generalized observations regarding the alluvial unit stratigraphy of the WVBA have been
developed.
UAU1 This uppermost layer is comprised of loose surface soils grading downward into
interfingered sand and gravel lenses; clay lenses, when present, are thin and usually
characterized as clayey sands (Weston, 2000). UAU1 ranges in thickness from
approximately 170 feet to 310 feet bgs. Based upon the east-west cross-sections, UAU1
appears to become finer-grained west of about 75th Avenue. Except in the eastern portion
of the WVBA (cross-section F-F’), UAU1 also appears to become finer-grained
northwards, particularly in the northwest portion of the WVBA (cross-sections C-C’ and
D-D’). Currently, 100 groundwater wells screened within UAU1 are monitored.
UAU2 This intermediate layer occurs where clay lenses increase in number until clays
dominate the lithologic horizons (Weston, 2000). UAU2 is encountered at depths
ranging from approximately 170 feet to 310 feet bgs, and exhibits a considerable range in
thickness, from approximately 30 feet to 260 feet or greater. UAU2 appears thickest in
the western portion of the WVBA (cross-section C-C’). Based upon the east-west crosssections, UAU2 appears to become more fine-grained west of about 67th Avenue.
Conversely to UAU1, except in the eastern portion of the WVBA (cross-section F-F’),
UAU2 appears to become finer-grained southwards; UAU2 appears to become coarser in
the southern portion of cross-section F-F’ where the cross-section terminates at the Salt
River. Currently, 45 groundwater wells screened within UAU2 are monitored.
MAU Weston (2000) identified the transition between the UAU and MAU as that area
within the lithologic sequence characterized by at least 40 feet of material often referred
to as hard brown clay or sticky brown clay. Below this point, the lithology usually shows
a marked increase in the amount of fine-grained material present. The MAU is
encountered at depths ranging from approximately 260 feet to 500 feet bgs. The
shallowest depth to the MAU is in the east (cross-section F-F’), deepening in the west
(cross-section C-C’). Currently, eight groundwater wells screened within the MAU are
monitored.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-4

8/9/2012

 3.3

Regional Hydrogeology

As previously mentioned, groundwater occurs in the basin-fill deposits through out most
of the SRV (Hammett and Herther, 1995). The aquifer system consists of the
hydrostratigraphy identified in Sections 1.7 and 3.1. The three major units, the UAU,
MAU and LAU, contain measurable quantities of water. However, this water is stored
and moves under different regimes for the UAU and the two deeper layers. Water in the
UAU is unconfined. According to Weston (2000), the MAU and LAU are both confined.
However, it is apparent from pumping data and water level responses in nearby wells that
the three units are hydraulically interconnected. Whether water in the MAU and LAU is
always confined is not clear because of the heterogeneous nature of the sediments and the
limited data (Weston, 2000).
Groundwater movement is generally to groundwater depressions located across the SRV
which are created by extensive groundwater withdrawals (Hammett and Herther, 1995).
Where groundwater flow is not affected by excessive pumping, flow is generally to the
west. Groundwater levels have fluctuated across the SRV with time dependant on
groundwater pumpage and surface water infiltration. From the 1920s through the 1960s
groundwater levels dropped primarily due to groundwater pumpage (Reeter and Remick,
1986). Groundwater production was reduced in the 1970s and early 1980s across the
SRV and groundwater levels in general rose. Groundwater levels in the early 1990s
continued to rise because of periods of flow in the Salt River due to increased
precipitation and reduced groundwater pumpage. In the mid to late 1990s and early
2000s, water levels in areas of former excessive groundwater pumpage in the east SRV
continued to rise while groundwater levels in the remainder of the east SRV and most of
the west SRV declined (ADWR, 2004) (Rascona, 2005).
Hydraulic properties across the SRV vary among the aquifer units and within the units
due to the heterogeneity of the units. Calculations have been made for the individual
units based on aquifer testing and lithologic makeup. However, available data are limited
in part because numerous wells are screened across multiple units. Hydraulic
conductivities (K) in the LAU range from approximately 0.001 feet per day (ft/d) to 24
ft/d (Brown and Pool, 1989) (Laney and Hahn, 1986). Hydraulic conductivities in the
MAU range from approximately 4 ft/d to 100 ft/d with the higher hydraulic
conductivities occurring in the eastern portion of the SRV. Hydraulic conductivities in
the UAU are the highest ranging from approximately 50 ft/d to 1,700 ft/d.
Transmissivities for the LAU can range from approximately 1,000 square feet per day
(ft2/d) to greater than 15,000 ft2/d. Transmissivities are estimated for the MAU and the
UAU with the MAU ranging up to 60,000 ft2/d and the UAU ranging from approximately
2,500 ft2/d to 150,000 ft2/d. Storage coefficient/specific yields for the SRV were
estimated by Corell and Corkhill (1994) as part of modeling efforts conducted for the
ADWR. A storage coefficient of 0.005 was given to the MAU for confined conditions.
Specific yield values for the MAU were estimated to range from 0.03 to 0.10. Specific
yields for the UAU were estimated to range from 0.08 to 0.20.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-5

8/9/2012

 The Salt River is the largest surface drainage feature in the vicinity of the SRV.
Although dry during most of the year, winter and early spring precipitation combined
with runoff from melting snow from the upper watershed can produce runoff. These
events, although short in duration, contribute significant groundwater recharge. In 1966,
infiltration rates in the Salt River were calculated to average 1.1 ft/d (Briggs and Werho,
1966). As a result of this flow, water levels rose dramatically in wells within several
hundred feet of the river.
Mann and Rohne (1983) examined flood events of February 1978 to June 1980, which
totaled 5.45 million acre-feet (AF). They concluded that the total stream flow loss in the
74-mile reach between Granite Reef Dam and Gillespie Dam was at least 474,000 AF.
During that same time period, groundwater pumpage in the area was reduced by about 35
percent (1.9 million AF). Water levels were measured in 169 shallow wells along the
Salt River. Water level increases ranged from 1 to 45 feet in 157 wells and declines
ranged from 1 to 43 ft in 11 wells with the greatest rise occurring near the Salt River.
The average 35-foot rise in water levels was attributed to both recharge from the Salt
River and reduction in groundwater pumpage. The average infiltration rate was
calculated at 0.45 ft/d.
3.4

WVBA Hydrogeology

Information on hydraulic properties within the WVBA was compiled by Weston (2000).
Production wells used for aquifer testing were screened across multiple aquifer units.
Therefore, available production well aquifer tests provided average data for multiple
aquifer units. Transmissivity values in the vicinity of the WVBA were found to range
from 4,000 to 160,000 gallons per day per foot (gpd/ft). Transmissivity values were
converted to hydraulic conductivity values by Weston, who found the hydraulic
conductivity of the UAU ranges from 5 to 700 ft/d, the range for the MAU is 7 to 30 ft/d,
and the range for the LAU is 3 to 20 ft/d.
Weston (2000) developed storage coefficient/specific yield values for the WVBA. The
specific yield ranges from 0.08 to 0.20 in the shallow UAU. Deeper UAU storage
coefficients/specific yields range from 0.009 to 0.02. MAU storage coefficients range
from 0.0003 to 0.0005. LAU storage coefficients range from 0.001 to 0.0009.
Groundwater pumpage represents the major outflow from the groundwater system within
the WVBA. The primary production wells within the WVBA are those operated by RID.
Groundwater pumpage within the WVBA is discussed further in Appendix K.
Groundwater recharge in the WVBA occurs when water at the land surface infiltrates and
reaches the groundwater table. Sources of recharge include the infiltration of excess
irrigation water, leakage from irrigation canals and lateral canals, and effluent discharge
and naturally occurring recharge from flood flows within the Salt River. While the Salt
River itself is not located within the WVBA, its proximity makes the riverbed a
significant source of groundwater recharge within the WVBA.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-6

8/9/2012

 Much of the western portion of the WVBA consists of irrigated agriculture. Fields are
irrigated using flood application, and excess irrigation water historically applied to these
fields characteristically reached the local water table as recharge. As agricultural fields are
converted to urban uses, groundwater recharge from excess irrigation is lessened. One of
the more comprehensive attempts to quantify recharge from agricultural fields was
performed by ADWR (Corell and Corkhill, 1994). An appropriate travel time had to be
established between the land surface and the aquifer. This travel time, based upon the
thickness of the unsaturated zone beneath the field, was termed the lag time for agricultural
recharge and averaged ten years. Thus, once the WVBA is fully urbanized, it will take
approximately ten years for groundwater recharge from excess irrigation to cease. Weston
(2000) calculated the recharge rate from irrigated agriculture at 1.82 feet/year/acre of
irrigated agriculture.
Canals also constitute a source of groundwater recharge. Unlined (earthen) canals,
contribute substantially more water than lined channels. Concrete lining does not entirely
eliminate seepage from these systems. The RID canal was relined in 1986 (Corkhill and
others, 1993). Prior to 1986, the recharge rate was calculated at 0.21 AF per year per
lineal foot. After relining in 1986, this appears to have been reduced by approximately
90 percent.
At the COP 23rd Avenue wastewater treatment facility, treated sewage effluent is
discharged to the Salt River. Flow continues in the Salt River to about 67th Avenue, and
100 percent of the discharge is assumed to recharge the groundwater table (Corkhill and
others, 1993).
Corkhill and others (1993) estimated that the average annual recharge along the Salt
River from Tempe Butte to the 91st Avenue wastewater treatment facility was
approximately 12 percent of the annual Granite Reef Dam discharge. Weston (2000)
concluded that recharge from Salt River runoff is highly localized and of little
consequence from a volumetric standpoint, but runoff is important in changing the
direction of groundwater movement that may be experienced as a result of sudden rise in
the water table.
In addition to discharge and recharge, groundwater flows through the WVBA. Within
UAU1, groundwater generally flows into the WVBA from the east and north, and out of
the WVBA to the west and south. Within UAU2 and the MAU, groundwater generally
flows into the WVBA from the east and out of the WVBA to the west. Further details on
hydraulic gradients within the WVBA are presented in Section 3.5.2.2.
3.4.1

Water Levels

Water level monitoring has been performed regularly in the WVBA since 1993. The
frequency of groundwater monitoring was reduced from monthly to semiannual at the
beginning of 2002. However, due to lowering water levels in the WVBA, quarterly water
level monitoring of the water quality network was implemented beginning December
2002. The hydrographs in Appendix M document an overall decrease in water levels since

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-7

8/9/2012

 monitoring was initiated in 1993. Since 1993, water levels in both shallow and deeper
wells have declined approximately 35 feet, an average of approximately two and 1/3 feet
per year for the 15-year time frame. The decline in water levels appears to have stopped
within the past two years and was most likely due to the drought which has extended the
pumping season for irrigation wells in the WVBA and reduced surface water quantities
available for infiltration.
As demonstrated by the hydrographs in Appendix M, water levels fluctuate in most of the
wells on a semi-annual basis, with water levels lower in the summer and higher in the
winter. This is likely due to a cyclical combination of rebound within the aquifer following
production well pump shutdown and to a lesser degree local area precipitation during the
winter months, and seasonal pumpage of area irrigation wells during the summer months.
The largest semi-annual water level changes are observed in monitor wells AVB69-01 and
–02 (Appendix M). These wells are located close to production irrigation well RID-104.
The large semi-annual water level changes observed in these wells are likely due to the
operation of this RID well during the summer months.
3.4.2

Hydraulic Gradients

The static depth to groundwater was measured to the nearest 0.01 foot with an electronic
water level indicator. The water levels were measured from a known surveyed measuring
point at each well; groundwater elevations were then calculated from the surveyed
measuring point.
Depth to groundwater measurements and groundwater elevations for the periods 1993,
1998, 2003, and First Quarter 2008 are presented in Table 3-1. Five year intervals for
presenting groundwater elevation data were selected to reduce the volume of data
contained in this report. Data for other years are contained in monitoring reports at
ADEQ. Locations of wells completed within UAU1, UAU2, and the MAU are presented
on Figures 2-2 through 2-5. Contouring software (SURFER) was used to generate
contours within UAU1, UAU2, and the MAU over the time period covered by Tables 31a through 31q.
Groundwater contours for the upper portion of the UAU (UAU1) are shown on Figures 3-8
through 3-18. In the eastern portion of the WVBA (east of approximately 35th Avenue),
groundwater flow is in a general westerly direction at quarterly gradients ranging from
about 9 to 20 feet per mile. The central portion and part of the western portion of the
WVBA (between approximately 35th and 63rd Avenues) is characterized by a flattening of
the water table, with southerly groundwater flow in the north-central portion of the WVBA.
In the western portion of the WVBA (west of approximately 63rd Avenue), an apparent
depression/trough of the surface of the groundwater table is located in the northwestern
portion of the WVBA centered at approximately Roosevelt Street and 75th Avenue.
Because of this apparent depression/trough, groundwater flow south of Van Buren Street
and west of 75th Avenue is northward. The change in direction is possible caused by
surface water leaking from the RID cannel and irrigation of fields south and west of the

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-8

8/9/2012

 cannel. It should be noted that the wellhead of AVB74-01 was resurveyed to confirm the
accuracy of groundwater elevations collected from this well.
Groundwater contours for the lower portion of the UAU (UAU2) are shown on Figures 319 through 3-27. Based upon these contours, groundwater flow in UAU2 is westerly,
with deviations ranging from southwesterly to northwesterly. Quarterly gradients across
the entire WVBA were observed at approximately nine feet per mile with some flattening
of the gradient in the central portions during 2003 and the first quarter 2008. In the eastern
end of the WVBA during 2nd and 3rd Quarters 2003, the difference in groundwater
elevations between the southeastern most well AVB69-01 and the nearest well, AVB77-02
is greater than 40 feet. This high gradient is likely due to the high drawdown experienced
at well AVB69-01 due to its proximity to production well RID-104.
Groundwater contours for the MAU are shown on Figures 3-28 to 3-36. Based upon these
contours, groundwater flow in the MAU varies by season as a result of the pumping of
RID wells during the summer months. During non-pumping conditions (first and fourth
quarters), groundwater flow is westerly at approximately eight feet per mile. However,
during pumping conditions (second and third quarters), groundwater flow in the eastern
portion of the WVBA is southwesterly towards RID-104 at a gradient of about 38 to 40
feet per mile. Groundwater flow in the western portion of the WVBA during pumping
conditions is westerly at a gradient of approximately five feet per mile.
3.4.3

Vertical Gradients

There are a number of paired wells in the WVBA where adjacent wells were installed to
different depths. Water level data from these paired wells have been used to quantify
vertical gradients within the WVBA. Tables 3-2a through 3-2d contain calculated
vertical hydraulic gradients over four consecutive quarters of water level monitoring. To
calculate vertical gradients, it was first necessary to calculate the vertical distance
between the midpoints of the perforated intervals (dl) of the paired wells. Then, the
difference in potentiometric elevations (dh) of the paired wells was obtained, and the
vertical gradient (dh/dl) calculated. Downward vertical gradients are demonstrated by
negative gradient values.
The calculated vertical hydraulic gradients over four consecutive quarters of water level
monitoring for each of the paired wells were plotted (Figures 3-37 to 3-40). Several
conclusions can be drawn from the data:




Six paired wells consistently exhibited downward vertical flow [AVB10, AVB96,
AVB106, AVB116, AVB124 (monitored for two consecutive quarters), and
AVB129].
Paired wells AVB77, 91, and 94 consistently exhibited upward vertical flow.
The eight remaining paired wells exhibited both upward and downward vertical flow
through four consecutive quarters of water level monitoring (AVB68, AVB69,
AVB81, AVB92, AVB95, AVB108, AVB120, and AVB 122).

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-9

8/9/2012

 



Upward vertical flow was most prevalent during fourth quarter 2004 and first quarter
2005, diminishing during the second and third quarters of 2005. This trend
corresponds to the seasonal pumping of the RID wells, which were pumping when
water levels were measured during the second and third quarters of 2005.
The presence of partially confined conditions at depth at those locations where
upward vertical flow was consistently observed.
3.4.4

Aquifer Tests

Water levels and aquifer tests are used to confirm the groundwater flow direction and the
flow characteristics. To better understand the characteristics of the aquifers underlying
the WVBA, a number of aquifer tests have been performed across the WVBA by ADEQ
and others. ADEQ conducted five aquifer tests across the WVBA. Aquifer tests were
also conducted at the MCMM and Reynolds facilities. The following are brief
summaries of the aquifer tests performed within the WVBA.
Reynolds In March 1990, five short-term aquifer tests were conducted at newly installed
groundwater monitor wells (Dames & Moore, 1990). The wells were pumped at a rate of
5.5 gpm for approximately one hour. Water-level measurements were collected at the
wells using a steel tape and chalk. Data were analyzed using the Cooper-Jacob method
and an estimated 20 percent specific yield. Calculated transmissivities ranged from
40,000 gpd/ft to more than 500,000 gpd/ft and calculated hydraulic conductivities ranged
from 150 ft/d to 1,700 ft/d.
RID Well 84 In October 1992, ADEQ conducted an aquifer pump test on RID Well 84
(Weston, 1993c) (Appendix N). RID Well 84 was chosen as the pumping well because
of its high pumping rate, location in front of the plume, and easy access for piezometers
in the nearby area. The RID well is completed across UAU1 and UAU2 aquifers. In
May and September 1992, four piezometers (PZ-1 through PZ-4) were installed at
different distances and bearings from the pumping well. The piezometers were drilled
and installed to a maximum depth of 150 feet based on the assumption that the aquifer
would respond as a continuous unconfined aquifer without excessive drawdown and only
partial penetration would be required. In addition to the piezometers, previously installed
groundwater monitor wells AVB10-01 through AVB10-04 at the Estrella Business Park
were also monitored during the aquifer test. Discharge was monitored with a flow meter.
From the first week of September 1992 through the start of the aquifer test on October
13, 1992, water levels were monitored with hand-held water level indicators in the
piezometers and four monitor wells at the Estrella Business Park (AVB10-01 through 04). Review of water level measurements indicates a slow rebound caused from the
cessation of regional pumping.
The aquifer test commenced on October 13, 1992, and ran continuously at an average
pumping rate of 3,000 gpm for approximately 48 hours. The aquifer test was ended
prematurely because SRP crews working in the area disrupted power to the pump. After
shutting the pump off, personnel immediately monitored the piezometers and wells for
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-10

8/9/2012

 early time recovery data; however, some initial data were not obtained. Recovery was
monitored for approximately 24 hours. During this 24-hour period, more than 90 percent
of the recovery was recorded on the wells and piezometers.
During the pumping and recovery portion of the test, periodic visual observations in the
surrounding area showed that none of the large-capacity production/irrigation wells were
pumping within an approximate one mile radius of the site. This confirmed that outside
influences on the test were kept at a minimum.
The aquifer test revealed that there are two aquifers that respond differently to pumping
of the RID well. The upper unconfined aquifer had a saturated thickness of
approximately 140 ft with a depth to the base of the aquifer at 225 ft. Beneath the aquifer
is a 25 ft thick leaky aquitard. The semi-confined aquifer beneath the aquitard is
approximately 70 ft thick and underlain by a thick clay sequence. The unconfined
aquifer exhibited a delayed response. For purposes of analysis, half of the 3,000 gpm
pumping rate was also applied to each aquifer.
Data collected from the lower semi-confined aquifer were analyzed using the Hantush
method. The data collected from the unconfined aquifer were analyzed using the
Neuman method. The transmissivity for the semi-confined aquifer was calculated to
range from 258,250 gpd/ft for the 1,500 gpm pumping rate to 508,956 gpd/ft. for the
3,000 gpm pumping rate. Using the estimated saturated thickness of 70 feet for the semiconfined aquifer, the hydraulic conductivity for the 1,500 and 3,000 gpm rates were 490
ft/d and 970 ft/d, respectively. The storativity of the semi-confined aquifer was
calculated at 0.00034. The transmissivity of the unconfined aquifer is approximately
221,170 to 1,457,240 gpd/ft. Using the estimated aquifer saturated thickness of 140 feet,
the hydraulic conductivity was calculated to range from 210 to 1,390 ft/d. The specific
yield was calculated to range from 0.044 to 0.134
MCMM In July 1995, MCMM conducted an aquifer pump test at their facility (GTI,
1995) (Appendix O). The aquifer test was designed and implemented to evaluate aquifer
characteristics under the site to estimate groundwater and VOC migration rates. Site
lithology and regional information indicate a permeable aquifer and a review of onsite
lithologic logs indicates variations in sediment grain size, resulting in varying hydraulic
conductivities, and locally heterogeneous soil conditions. Four wells at the site were
used during the aquifer test: one extraction well (EW-01) and three observation wells
(PZ-01, MC-03 and MC-04) located 41, 50 and 156 ft from the extraction well,
respectively. The wells were screened in the same interval in the saturated zone, with
about 37 ft of screen from the groundwater level to the bottom of the well. To assure
extraction of groundwater, a submersible pump used for groundwater extraction was set
at the depth of the gravel layer (about 80 ft bgs). Groundwater levels in the extraction
and observation wells were recorded using data loggers equipped with pressure
transducers.
After evaluating background variations in groundwater levels, a step-drawdown test was
performed on extraction well EW-01 in July 1995 to identify appropriate pumping rates.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-11

8/9/2012

 A 15-hour constant-rate extraction test was then conducted at a pumping rate of 50 gpm.
Groundwater levels were recorded in the extraction well and three observation wells.
Under the constant 50-gpm groundwater extraction, the rate increase of groundwater
drawdown was stable. No aquifer boundary conditions were observed, with a relatively
homogeneous aquifer response. The groundwater elevation data were corrected for an
assumed linear background decrease in groundwater level of about 0.07 ft/d. The
drawdown data was interpreted using the Theis equation, through approximation by the
Cooper/Jacob method and through the use of the computer software curve matching
program, Groundwater Well Analysis Program.
The results of the aquifer test indicate that the upper zone of the aquifer has a high
transmissivity, ranging from 100,000 to 264,000 gpd/ft. Hydraulic conductivities were
calculated based on the transmissivities and an aquifer thickness of 37 feet which was
equal to the screened interval of the extraction well. The resulting hydraulic conductivity
was estimated to range from 350 ft/d to 930 ft/d. The storage coefficient was calculated
to range from 0.001 to 0.008.
During the groundwater extraction test, samples of extracted groundwater were collected
for analysis of contaminants. Groundwater samples were collected after extraction of
1,000, 15,000, and 56,000 gallons of groundwater from well EW-01. The analytical
results confirm the presence of VOCs in groundwater at the site, indicating VOC
concentrations decreased slightly and are within the same order of magnitude as the
average dissolved VOC concentrations for PCE/TCE in up and cross-gradient wells MC01, MC-02, and MC-05. During the pump test, PCE and TCE concentrations in extracted
water averaged 160 and 140 µg/l, respectively, while 1,2-DCA averaged 21.7 µg/l.
North Sentinel Well In March 1997, ADEQ conducted an aquifer pump test at the North
Sentinel Well (NSW) located near 79th Avenue and West Van Buren Street (Weston,
1997a) (Appendix P). The NSW aquifer test was conducted to evaluate aquifer
properties of the MAU. Drawdown was measured at RID irrigation well RID-83 which
had been pumping prior to the test and remained pumping during the test. The RID well
is approximately 500 feet south of the NSW. A step draw-down aquifer test was first
conducted to identify a suitable pump rate. The submersible pump was set at a depth of
approximately 220 ft bgs or about 130 ft below the water level. Flow rates were
monitored with a flow meter equipped with a totalizer. Time and drawdown data were
collected using a water level indicator with numerous early-time readings, with increased
intervals between readings as the test progressed. The constant rate extraction test was
run at an average flow rate of 61 gpm. Approximately 29,300 gallons of water were
pumped over the eight-hour testing period. Recovery was monitored for 50 minutes. At
that time, 98 percent of the drawdown had been recovered and the test was completed.
Drawdown data obtained during the aquifer test were analyzed using the Theis curve
matching method, Jacob-Cooper straight-line method, Moench Solution, and
Papadopulos-Cooper solution for confined aquifers. Recovery data were analyzed using
the Theis recovery method.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-12

8/9/2012

 In this area, the MAU appears to be a leaky confined aquifer. Transmissivities ranged
from 3,717 gpd/ft to 8,889 gpd/ft. However, the value derived from the use of the
Moench solution (3,916 gpd/ft) was ascertained to be the most representative
transmissivity estimate. Based on a saturated thickness of 60 feet and using the
transmissivity calculated using the Moench solution (3,916 gpd/ft), the hydraulic
conductivity was calculated to be 8.726 ft/d.
Water quality samples were collected during the test to evaluate water quality changes
with time. Samples were collected in the first and last hour of the test. PCE was the only
constituent detected in the samples at concentrations of 1.4 and 1.1 µg/l in the first and
last sample, respectively.
Madison Street Well In June 1997, ADEQ conducted an aquifer pump test at the
Madison Street well located between 13th and 15th Avenues in Phoenix (Weston, 1997b)
(Appendix Q). The purpose of this aquifer test was to evaluate aquifer properties of the
MAU and to monitor drawdown in the UAU while pumping from the MAU. The project
involved installing one six-inch diameter production well (AVB68-01) screened in the
MAU, an observation well (AVB68-04, four-inch diameter) screened in the MAU, and a
nested piezometer pair (AVB 68-02 and AVB68-03, two-inch diameter) screened in the
UAU and MAU. The pretest water level was measured in the wells and indicated a
downward vertical hydraulic gradient between the UAU (as represented by the water
level in piezometer AVB68-02) and MAU (as represented by the water levels in the other
three wells) at this location. A step drawdown test was conducted on June 3, 1997. A
submersible pump was installed at a depth of approximately 225 ft bgs or about 140 ft
below the water level. Discharge was monitored with a flow meter equipped with a
totalizer. Pressure transducers equipped with a data logger were lowered into AVB68-02
and AVB68-03. Water level data were collected in the pumping well by using a water
level indicator. Numerous early-time readings were collected and the intervals between
readings were increased as the test progressed. Based on results of the step drawdown
test, a pumping rate of 100 gpm was selected. A 48-hour constant rate test was
completed with a flow rate that average 86.7 gpm. Approximately 127,700 gallons of
water was pumped over the first 24-hour testing period. After 24 hours of pumping, data
were sufficient to evaluate the transmissivity and storativity of the MAU. During this
period, the water level in the UAU piezometer (AVB68-02) did not fluctuate appreciably.
For the last portion of the test, the flow rate was increased to 120 gpm. Recovery was
monitored for six hours and 98 percent of the drawdown had been recovered, and the test
was completed. At the completion of the 48-hour constant rate test, 293,790 gallons had
been pumped, bringing the total, including the step test, to 312,220 gallons of
groundwater pumped. Drawdown data obtained during the aquifer test were analyzed
using the Theis curve matching method, Jacob-Cooper straight-line method, Moench
Solution, and Papadopulos-Cooper solution for confined aquifers. Recovery data were
analyzed using the Theis recovery method.
The upper portion of the MAU, at a depth of 240 to 254 ft bgs, appears to be the
producing zone. Transmissivity was calculated at 1,522 gpd/ft. Storativity was
calculated to range from 0.000021 to 0.00012. Hydraulic conductivity was calculated

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-13

8/9/2012

 using the transmissivity and a saturated thickness of 14 feet. The resulting hydraulic
conductivities ranged from 14.54 ft/d to 84.39 ft/d. The range of calculated storativity
values indicates confined, rather than leaky confined conditions in the producing interval
at this location. This is supported by the lack of drawdown in the observation well
completed in the overlying UAU. Additionally, the calculated transmissivity value and
relatively high pumping rate indicate that aquifer materials, rather than aquitard
materials, are tapped by well AVB68-01.
Groundwater samples were collected in the first and last hour of the test to evaluate water
quality changes with time. The analytical results indicated some presence of aromatic
and halogenated hydrocarbons. The highest concentrations of PCE/TCE were 4.37 and
22.8 µg/l, respectively.
RID Well 104 In September 1997, ADEQ installed transducers in two wells adjacent to
RID Well 104 near 19th Avenue and Pima Street in Phoenix (Weston, 1999) (Appendix
R). Instead of running a short-term (less than 72 hours) aquifer test, ADEQ opted to
collect water level measurements during normal pumping of RID Well 104. The
observation wells, AVB-69-01 and AVB69-02, were constructed in the UAU2/MAU and
UAU1, respectively. Continuous water level recorders were installed in each observation
well and water levels were collected through the 1998 pumping season (approximately
six months). Because Well 104 is an integral part of the RID irrigation system, it was not
possible to install a flow meter on the well’s discharge line. RID was able, however, to
provide continuous discharge records based upon the daily electrical consumption logs of
the pump. According to these records, the well pumps an average of 17.36 AF per day.
Because RID could not take the well out of service long enough for water levels in the
aquifer to return to static conditions, the water level measurement program was begun
while the well was pumping. Data sets were selected which corresponded with periods
when the well had shut down and water levels had recovered for at least 24 hours. Data
from AVB69-01 and AVB69-02 provided the long-term drawdown information required
to evaluate the overall utility of short-term aquifer tests in the development of a model
spanning decades of intense pumping.
During the first few hours of pumping, it appears that most of the water withdrawn is
extracted from the most conductive layers within the aquifer system. The resulting
calculated transmissivities were high, ranging from 166,000 to 196,000 gpd/ft, and
implied that the entire penetrated section of the aquifer exhibited a conductivity that
represented only a few lenses within the system. As pumping continued, however,
drawdown increased geometrically with time and the corresponding calculated
transmissivity decreased to less than 50,000 gpd/ft. This indicates that with continued
pumping the more conductive layers within the system are dewatered and only the less
conductive layers become available to deliver water to the well. Interestingly, the
calculated transmissivities for both pumping durations were nearly identical for both the
UAU and MAU within the specified time period implying a high degree of connection
between the systems. This aquifer test demonstrated that aquifer tests conducted for a
shorter duration may not stress the system sufficiently to provide good results and should

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-14

8/9/2012

 not be utilized within the context of long-term model development.
samples were not collected during this aquifer test.

Groundwater

ALSCo In December 1999, aquifer tests were conducted at ALSCo in UAU1 to collect
data pertinent to the design of the groundwater remediation system to be installed at the
facility (HGC, 2000) (Appendix S). A constant pumping rate aquifer test was conducted
at the extraction well (EX1) utilizing three groundwater monitor wells (MW-2, MW-5S,
and MW-5M) as observation wells. A step drawdown test was conducted at the injection
well (INJ1) utilizing groundwater monitor well MW-3 as an observation well.
Transducers were used to obtain water-level measurements and a flow meter was used to
measure flow rates. The extraction well was pumped at an average of 148.4 gpm for five
hours. Rebound was monitored for two hours.
Data collected during the constant rate test were analyzed using the Cooper-Jacob
method. Transmissivities were calculated to range from 24,000 ft2/d to 36,000 ft2/d.
Using a saturated thickness of 140 feet, the hydraulic conductivity was calculated to
range from 170 ft/d to 260 ft/d. The vertical hydraulic conductivity was calculated using
the software program WHIP. This resulted in a calculated vertical hydraulic conductivity
of 19 ft/d. These data were then used to calculate the pumping rate that would create an
appropriate capture zone for the ALSCo ERA.
Data collected during the step-drawdown test were evaluated using the Bierschenk
graphical method to estimate specific capacity and potential drawdown. The results
indicated that injecting 300 gpm through the injection well would create a ten-foot
groundwater mound.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 3-15

8/9/2012

 4.0

NATURE AND EXTENT OF CONTAMINATION

As indicated in Section 1.0, the WVBA WQARF site extends across a large area of
southwestern Phoenix. Overlying the groundwater contaminant plume that comprises the
WVBA WQARF registry site is a mixture of industrial, commercial, and residential
properties. Groundwater contamination in the WVBA was first discovered in 1984
during routine groundwater sampling at the Phoenix Terminal (Dames & Moore, 1985).
Since then, data have been collected in an attempt to characterize the contaminant plume,
identify sources of the plume, and remediate the plume to reduce the risk to human health
and the environment. The extent and concentrations of COCs detected in the
groundwater plume suggest that multiple sources have contributed to the plume over
time.
Soils that comprise the vadose zone across the WVBA consist of unconsolidated mixtures
of clay, silt, sand, gravel, and cobbles. Typically the uppermost portion of the vadose
zone consists of clay, silt, and sand with minor amounts of gravel. The lower portion of
the vadose zone consists of gravels and cobbles with varying amounts of sand, clay, and
silt. The coarse lower portion of the vadose zone is encountered at greater depths from
east to west, and south to north within the WVBA. For instance, gravel/cobble soils have
been encountered at a depth of approximately ten feet bgs in the vicinity of CRC
Company, Inc. (1130 West Hilton Avenue), and at a depth of approximately 50 feet bgs
at the Dolphin facility (740 South 59th Avenue).
The overall coarse-grained nature of the vadose zone is not conducive to the retention of
contaminants which may be released to the subsurface. Also, the heterogeneous nature of
the vadose zone prevents contaminants from migrating uniformly through the vadose
zone. Therefore, it is sometimes difficult to collect soil and soil gas samples from the
vadose zone which may be ideally located for the detection and characterization of
contaminants in the vadose zone. However, COCs have been identified and characterized
to the best extent possible. The following is a summation of the highest concentrations of
COCs that have been detected within the WVBA in the vadose zone, and in ground and
surface water.
4.1

Identification of Contaminants and Contaminant Sources

COCs at concentrations greater than minimum GPLs, SRLs, and/or HBGLs have been
detected at the following facilities: ALSCo (PCE), CRC (PCE and Cr), Dolphin (PCE,
TCE and Cr), MCMM (TCE), Reynolds (PCE, TCE, TCA, 1,1-DCE, and Cr), VW&R
(PCE), ALASG (TCE, 1,1-DCE, TCA, and 1,2-DCA), and POS (PCE) (Table 2-5).
Detection limits for some of the COCs exceed regulatory standards as indicated in Table
2-5 because of dilution of the samples by the laboratory during analysis due to higher
concentrations of other COCs.
COCs have been detected at concentrations greater than AWQSs in groundwater samples
collected from the following facilities: ALSCo (PCE, TCE, cis 1,2-DCE, and 1,1-DCE),
CRC (PCE and Cr), Dolphin (PCE, TCE, cis 1,2-DCE, and 1,1-DCE), MCMM (PCE,
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-1

8/9/2012

 TCE, cis 1,2-DCE, and 1,1-DCE), Reynolds (PCE, TCE, 1,1-DCE, and TCA), VW&R
(PCE, TCE, 1,1-DCE, and TCA), ALASG (PCE, TCE, and 1,1-DCE), and DOE (PCE
and TCE) (Tables 4-1 through 4-5) (Appendices T through Y). Other COCs may have
been present at concentrations greater than regulatory standards but cannot be ascertained
because the laboratory diluted samples during analyses thus increasing detection limits to
levels greater than regulatory standards.
The highest concentration of PCE detected in soil gas was 33,000 µg/l, collected in 1994
at the Dolphin, Inc. facility (Tracer Research Corp., 1994) (Table 2-5). TCE was
detected in soil gas at a concentration of greater than 800 µg/l in 1992 at the MCMM
facility (HGC, 1992a). In a sample collected from the ALASG facility in 2003, 1,1-DCE
was detected at a concentration of 440 µg/l and TCA was detected at a concentration of
5,500 µg/l (Basin & Range Hydrogeologists, Inc., 2004).
The highest concentrations of PCE and TCE detected in a soil sample were 8,040 and 30
mg/kg, respectively, in 1992 at the Dolphin, Inc. facility (Basin & Range
Hydrogeologists, Inc., 1993a) (Table 2-5). The highest 1,1-DCE and TCA concentrations
were detected in a soil sample collected at the ALASG facility in 2004 at concentrations
of 100 and 6,300 mg/kg, respectively (Basin & Range Hydrogeologists, Inc., 2005). The
highest detected concentration of chromium in soil was 32,000 mg/kg, collected at the
CRC facility in 1995 (Hargis + Associates, 1995b).
The highest concentration of PCE detected in groundwater was 95,000 µg/l, collected in
1998 from well DIMW-1 at the Dolphin Inc. facility (Basin & Range Hydrogeologists,
Inc., 1998). TCE was detected at its highest concentration of 1,800 µg/l in 1996 from
MCMM facility well PZ-01 (Fluor Daniel GTI, 1996a). The highest concentration of
1,1-DCE detected was 290 µg/l in a sample collected from well CT-W-03 in 1987 at the
Chevron terminal in the Phoenix tank farm (Groundwater Technology, Inc., 1988). The
highest detected concentration of chromium was 40,500 µg/l from ADEQ well AVB7201 in September 2003 (BE&K/Terranext, 2004).
PCE and TCE were detected at concentrations greater than the AWQS in canal water
samples collected from the RID canals in 2000 and 2003 (Tables 2-2 and 2-3)
(BE&K/Terranext, 2001c, 2003c). However, because water in the RID canals is
designated for use as agricultural irrigation, PCE and TCE have not been assigned surface
water standards. The highest PCE and TCE concentrations were 21 and 70 µg/L,
respectively, and were collected from the lateral canal adjacent to well RID-92. Based on
the data collected, it was concluded that VOC concentrations in the main RID canal are
primarily reduced by dilution due to significant base flow from the 23rd Avenue
Wastewater Treatment Plant and from RID wells pumping uncontaminated groundwater.
However, VOC concentrations in the smaller lateral RID canals do not appear to
significantly drop in concentration with distance from the RID wells.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-2

8/9/2012

 4.2

Source Investigations

As previously discussed, PCE is the predominant COC for the WVBA. However, in
certain areas of the WVBA other COCs have been detected. The following is a
discussion of COC contamination concentrations segregated into different portions of the
WVBA; the “Eastern Portion” extending from 7th to 35th Avenues, “Central Portion”
extending from 35th to 51st Avenues, and “Western Portion” extending from 51st to 75th
Avenues. It should be noted that ADEQ is continuing to conduct a PRP search for the
WVBA and may identify other contaminant sources beyond those identified below.
4.2.1 Eastern Portion of WVBA
Sixteen facilities were investigated by ADEQ or were requested by ADEQ to conduct
investigations in the eastern portion of the WVBA. The eastern portion of the WVBA
extends from 35th Avenue to the eastern site boundary. The following facilities
conducted investigations or had investigations conducted at their facilities; facility
locations are shown on Figures 1-1 and 2-1:
1. ALSCo, 720 West Buchanan St. – Investigated soil and
groundwater, conducted remediation, settled with ADEQ, ADEQ
completed remediation.
2. CRC, 1122 West Hilton Ave. – Investigated soil and groundwater,
conducted remediation, work plan approved by ADEQ Hazardous
Waste Unit to continue investigation and conduct remediation.
3. MCMM, 320 West Lincoln St – Investigated soil and groundwater,
conducted remediation, settled with ADEQ.
4. BC Assembledge, 333 N. Black Canyon Highway – Petroleum
hydrocarbon release.
5. Blue Circle West, 1510 W. Lincoln St. – Phase I soil sample
collected but contained no detectable COC.
6. Brake Supply, 420 S. 7th Ave. – ADEQ conducted soil gas and soil
sampling, recommended no further action.
7. Bud’s Oil, 1340 W. Lincoln St – Investigated soil but not
groundwater.
8. Chevron, U.S.A., Inc., 3050 S. 19th Ave. – Phase I soil sample
collected but not recommended for additional investigation.
9. LaSalle Draperies, 710 W. Buchanan St. – ADEQ conducted soil
gas and soil sampling, recommended no further action.
10. Owens-Corning Fiberglass Corp., 1880 W. Fillmore St. –
Conducted their own preliminary site assessment, not requested to
conduct additional investigation.
11. Ray & Bob’s Truck Salavage, 101 S. 35th Ave. – Phase I soil
sample collected but not recommended for additional investigation.
12. Santa Fe Railroad Yard, W. of 19th Ave. between McDowell Rd.
and Fillmore St. – Phase I soil sample collected but not
recommended for additional investigation.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-3

8/9/2012

 13. Schuff Steel, 4420 S. 19th Ave. – Phase I soil sample collected but
not recommended for additional investigation.
14. Sta-Rite Industries, Inc., 1146 W. Hilton St. – Investigated soil,
remediated PCE contaminated soil by excavation, no groundwater
investigation.
15. Triple E Properties, 1909 W. Fillmore St. – Investigated soil and
identified to be petroleum hydrocarbon release.
16. Western States Petroleum, Inc., 450 S. 15th Ave. – Conducted UST
removal investigation under ADEQ UST Section but no record of
completing investigation requested under ADEQ WQARF program.
Of these, three facilities, ALSCo and MCMM in the east-central area and CRC in the
southeastern area, were asked to conduct groundwater investigations because of COC
detected in the vadose zone. COC detected at concentrations greater than regulatory
standards in the vadose zone in the eastern portion of the WVBA have included PCE,
TCE, and chromium.
4.2.1.1 ALSCo
PCE was the most prevalent COC detected in the vadose zone in both soil and soil gas
samples in the eastern portion of the WVBA. The highest PCE concentrations detected
in soil gas samples collected in the eastern portion of the WVBA were from the ALSCo
facility. PCE was detected in soil gas and soil samples across the site with the highest
concentrations in the west-central section of the ALSCo facility. Groundwater data
presented on Figures 4-1, 4-2, 4-3, 4-7, and 4-11, along with data presented in Section
2.1, indicate that releases of PCE at the ALSCo facility extended vertically to
groundwater. However, data indicate that PCE did not migrate vertically into UAU2 and
the MAU. An ERA conducted at the ALSCo facility remediated soil to concentrations
less than SRLs and minimum GPLs. The ERA also reduced PCE concentrations in
groundwater beneath the facility to concentrations similar to upgradient concentrations.
First Quarter 2008 PCE concentrations in groundwater beneath the ALSCo facility
ranged from less than 0.50 to 19 µg/l. The detected concentrations are similar to
concentrations detected in upgradient groundwater monitor wells.
TCE was detected in soil gas samples at concentrations an order of magnitude less than
PCE at the ALSCo facility and was not detected in soil samples at concentrations greater
than SRLs or the minimum GPL. TCE was detected in soil gas samples across the site
but only detected in soil samples collected from the western section of the facility. The
presence of TCE in soils beneath the ALSCo facility may be due to the degradation of
PCE or the release of the contaminant. Groundwater data obtained from beneath the
facility indicate that TCE present in soils beneath the ALSCo facility migrated vertically
to groundwater. However, TCE did not migrate vertically into UAU2 and the MAU.
First quarter 2008 TCE concentrations in groundwater beneath the ALSCo facility ranged
from 1.3 to 6.4 µg/l. The detected concentrations are similar to concentrations detected
in upgradient groundwater monitor wells.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-4

8/9/2012

 Cis/total 1,2-DCE were detected in soil gas samples at concentrations similar to TCE soil
gas concentrations at the ALSCo facility. Total 1,2-DCE was detected in a few soil
samples at concentrations slightly greater than the method detection limit. Cis 1,2-DCE
detection may be the result of a release of this COC or a result of the degradation of PCE
and TCE. Based on these data and groundwater data for the eastern portion of the
WVBA, cis 1,2-DCE detected in the vadose zone may have migrated vertically to
groundwater at the ALSCo facility but not into UAU2 and the MAU. Cis 1,2-DCE was
not detected in groundwater samples collected beneath ALSCo during First Quarter 2008.
None of the other COCs were detected in soil samples collected at the ALSCo facility.
TCA was detected in soil gas across the site but at low concentrations. Therefore, none
of these COCs are believed to have been released at the facility. None of these COCs
were detected in groundwater samples collected from the ALSCo facility during First
Quarter 2008.
4.2.1.2 MCMM
PCE was detected in soil gas and soil samples collected from the MCMM facility but at
concentrations less than SRLs and the minimum GPL. The focus of characterization at
the MCMM facility was the northwest corner, where the former Southwest Solvent
reclamation operations occurred. However, a passive soil gas survey was conducted
across the facility which detected PCE in soil gas across the facility. Groundwater data
presented on Figures 4-1, 4-2, 4-3, 4-7, and 4-11, along with data presented in Section
2.1, indicate that the releases of PCE which occurred at the MCMM facility affected
groundwater quality in UAU1 but not UAU2 and the MAU. First Quarter 2008 PCE
concentrations in groundwater beneath the MCMM facility ranged from less than 0.50 to
5.9 µg/l. The detected concentrations are similar to concentrations detected in upgradient
groundwater monitor wells.
TCE was detected in soil gas at concentrations similar to PCE concentrations detected at
the MCMM facility. TCE was only detected in one soil sample collected from the
MCMM facility at a concentration greater than regulatory standards. Groundwater and
soil data collected from the MCMM facility indicate that a TCE release to the vadose
zone and UAU1 occurred at the MCMM facility, but not to UAU2 and the MAU. First
Quarter 2008 TCE concentrations in groundwater beneath the MCMM facility ranged
from less than 0.50 to 20 µg/l. The detected concentrations are similar to concentrations
detected in upgradient groundwater monitor wells.
Each of the other COCs was detected in soil gas samples collected at the MCMM facility
but 1,2-DCA was the only other COC detected in soil samples. 1,2-DCA was detected in
one soil sample collected from the northwest corner of the MCMM facility. 1,2-DCA is
also the only other COC detected in groundwater samples collected from beneath the
MCMM facility at a concentration greater than the AWQS. Based on these data, it
appears that a release of 1,2-DCA from the MCMM facility affected groundwater quality
beneath the facility. No COC other than PCE and TCE were detected in groundwater
samples collected during First Quarter 2008 beneath the MCMM facility.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-5

8/9/2012

 4.2.1.3 CRC
PCE was detected in soil gas and soil samples collected at the CRC facility. PCE was
detected in soil samples at concentrations greater than SRLs and the minimum GPL.
Groundwater data presented on Figures 4-1, 4-2, 4-3, 4-7, and 4-11, along with data
presented in Section 2.1, indicate that releases of PCE occurred in the east and west bays
of the CRC facility and migrated vertically to UAU1. PCE releases did not affect UAU2
and the MAU. PCE was detected in groundwater samples collected during First Quarter
2008 beneath the facility at concentrations up to 390 µg/l.
TCE was detected in soil gas samples at the CRC facility but not in soil samples. Based
on this and groundwater data collected from beneath the CRC facility, it does not appear
that a release of TCE occurred at the CRC facility. TCE was not detected in groundwater
samples collected at the CRC facility during First Quarter 2008.
1,1-DCE was the only other VOC COC that was detected in soil gas and/or soil samples
at the CRC facility. These data coupled with groundwater data collected from beneath
the facility indicate that 1,1-DCE and the other COCs were not released from the facility.
These COCs for First Quarter 2008 were not detected beneath the CRC facility.
Chromium was only investigated in the eastern portion of the WVBA at the CRC facility.
Chromium was detected at concentrations greater than regulatory standards as total
chromium, but no data are available to evaluate the percentage of hexavalent chromium.
Hexavalent chromium is suspected to be present in soils in this area because it is present
in underlying groundwater. Limited remediation of chromium in the vadose zone at the
CRC facility was conducted; logistics prevented the complete removal of the contaminant
from the vadose zone. Data included in Section 2.1 and groundwater data for chromium
presented on Figures 4-6 and 4-10 suggest sources of chromium at the CRC facility.
Total chromium concentrations in groundwater for First Quarter 2008 beneath the CRC
facility ranged up to 18 mg/l.
4.2.1.4 Operable Unit 3
Groundwater contaminated with chlorinated solvents has been identified at the Motorola
52nd Street Federal Superfund Site OU3 area directly east of the WVBA. OU3 is
bordered roughly on the north by McDowell Road, on the east by 20th Street, on the south
by Buckeye Road, and on the west by 7th Avenue.
EPA is the lead agency for OU3, and has directed PRPs to conduct facility specific
RI/FS’s. In addition, a group of OU3 PRPs has formed the OU3 working group, and will
conduct an OU3 site-wide RI. The OU3 site-wide RI will take place concurrently with
facility specific investigations. The scope of work and administrative order of consent
between the OU3 working group and EPA is under negotiation. The site-wide RI is
expected to start in early 2009. Notable COCs for OU3 are TCE, TCA, PCE, 1,1,2-TCA,

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-6

8/9/2012

 vinyl chloride, chloroethane, 1,1-DCA, 1,1-DCE, 1,2-DCA, cis 1,2-DCE, trans 1,2-DCE
and 1,4-dioxane.
Federal Superfund sites are governed under CERCLA, commonly known as Superfund.
EPA identifies PRPs and collects evidence of COC use by sending CERCLA Section
104(e) information request letters to identified parties, reviewing documents, conducting
interviews, and performing research as a PRP search. The following parties have been
identified as PRPs at OU3:
1. APS, 502 South 2nd Avenue – Investigated soil gas, soil and
groundwater
2. Arvin Meritor, et. al., 500 South 15th Street – Investigated soil gas,
soil and groundwater
3. Former Baker Metals Facility, 1601 East Madison Street –
Investigated soil gas, soil and groundwater
4. Capitol Engineering, 724 East Southern Pacific Drive – Have not yet
conducted investigations
5. McCoy’s, 1624 East Washington Street – Will not be conducting any
soil or groundwater sampling. Facility has settled with U.S. EPA
based on ability to pay.
6. Phoenix Newspapers, Inc., 120 East Van Buren Street – Investigated
soil gas, soil and groundwater
7. SRP, 1616 East Lincoln Street – Investigated soil gas, soil and
groundwater
8. Walker Power/Tiernay Turbines, 1301 East Jackson Street – In process
of investigating soil gas, soil and groundwater
9. Union Pacific Railroad, 1301 Harrison Street – Have not yet
conducted investigations
10. Wabash/Fruehauf, 902 South 7th Street – Have not yet conducted
investigations
11. Westinghouse, 1824 East Jefferson Street – Have not yet conducted
investigations
12. Milum Textile Services Company, 333 North 7th Avenue – Have not
yet conducted investigations
WVBA groundwater data indicate that TCE and 1,1-DCE (and to a lesser extent, PCE)
groundwater contamination originates from the OU3 area east of Seventh Avenue and
flows into the WVBA WQARF site from the east. First Quarter 2008 TCE
concentrations in groundwater in the eastern portion of the WVBA ranged from less than
0.50 µg/l to 160 µg/l. First Quarter 2008 1,1-DCE concentrations in groundwater in the
eastern portion of the WVBA ranged from less than 0.50 µg/l to 23 µg/l. First Quarter
2008 PCE concentrations in groundwater in the eastern portion of the WVBA ranged
from less than 0.50 µg/l to 76 µg/l.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-7

8/9/2012

 4.2.2

Central Portion of WVBA

Vadose zone contamination investigations have been conducted in the central portion of
the WVBA at 18 facilities. The central portion of the WVBA is located between 35th and
51st Avenues. The following facilities conducted investigations or had investigations
conducted at their facilities; facility locations are shown on Figures 1-1 and 2-1:
1. ALASG, 301 S. 45th Ave. – Investigated soil and currently
investigating groundwater.
2. Reynolds, located between 35th and 43rd Avenues, and between Van
Buren and the Union Pacific Railroad tracks – Investigated soil and
groundwater, conducted remediation, settled with ADEQ.
3. U.S. DOE, 615 S. 43rd Ave. – Investigated soil and currently
investigating groundwater.
4. VW&R, 50 S. 45th Ave. – Investigated soil and groundwater,
conducted remediation, received NFA for soil contamination.
5. American National Can Co., 211 N. 51st Ave. – COC detected in soils
but were not requested to investigate groundwater.
6. Anderson Clayton/Western Cotton Services Co., 615 S 51st Ave –
ADEQ sampled soil and groundwater and did not require additional
investigation.
7. Arnold Corporation, 40 S. 45th Ave – Investigated soil and conducted
risk assessment.
8. AT&T, 505 N.51st Ave – Conducted soil investigation, not required to
investigate groundwater.
9. AWECO, 3918 W. Lincoln St. – Conducted soil investigation, not
required to investigate groundwater.
10. Grow Group, Inc. 4940 W. Jefferson St. – Conducted soil
investigation, not required to investigate groundwater.
11. Hi-Tech Plating, Inc., 4313 W. Van Buren St. – Conducted soil
investigation, not required to investigate groundwater.
12. Penn Athletic, 306 S. 45th Ave – Investigated soil and groundwater,
closed site under ADEQ Voluntary Remediation Program (VRP).
13. Revlon, 4301 W Buckeye Rd – Conducted soil investigation and
remediation but not requested to investigate groundwater.
14. Roadway Express, 2021 S. 51st Ave. – Phase I soil sample collected
but not recommended for additional investigation.
15. Smithey Recycling Co., 3640 S. 35th Ave. – Phase I soil sample
collected but not recommended for additional investigation.
16. Sun State Builders, 43rd Ave/Gibson Lane – Conducted soil
investigation, not requested to investigate groundwater.
17. Transco Lines, 3839 W. Buckeye Rd. – Phase I soil sample collected
but not recommended for additional investigation.
Of these, five facilities, Reynolds, U.S. DOE, ALASG, Penn Athletic, and VW&R were
requested to conduct groundwater investigations. Because the contaminants at Penn
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-8

8/9/2012

 Athletic were not COCs for WVBA, they were not required to conduct additional
investigations after groundwater monitor wells were installed and sampled. The primary
COCs at the Penn Athletic facility were normal hexane and naphthenic distillates
suspected to have leaked from USTs. Upon completing their investigation, Penn Athletic
was issued an NFA by ADEQ’s VRP. COCs detected at concentrations greater than
regulatory standards in the vadose zone in the central portion of the WVBA have
included TCA, PCE, TCE, 1,1-DCE, 1,2-DCA, and chromium (Table 2-5).
4.2.2.1 Reynolds
PCE was detected at low concentrations in several soil gas samples collected at the
Reynolds facility. Two soil samples collected from the Trench 6 area east of the East
Stoddard Solvent dip tank at the Reynolds facility exhibited PCE at concentrations
greater than the minimum GPL. Soil and groundwater data collected from the Reynolds
facility indicate that releases of PCE may have affected groundwater quality; however,
upgradient groundwater data are similar in concentration to data collected from beneath
the facility so the impact on groundwater may have been minimal when compared to
upgradient facilities. First Quarter 2008 PCE concentrations in groundwater samples
collected from the Reynolds facility ranged from 2.4 to 6.4 µg/l. The detected
concentrations are similar to concentrations detected in upgradient groundwater monitor
wells.
TCE was detected in soil gas samples collected across the Reynolds facility but at low
concentrations. Several soil samples collected at the Reynolds facility exhibited TCE at
concentrations greater than the minimum GPL. Most of these were collected in the
vicinity of the former Stoddard Solvent dip tanks. Soil and groundwater data indicate
that TCE source areas at the Reynolds facility may have also affected groundwater
quality, but upgradient groundwater data are slightly greater in concentrations then the
groundwater collected at the facility. First Quarter 2008 TCE concentrations in
groundwater beneath the Reynolds facility ranged from 1.8 to 16 µg/l. The detected
concentrations are similar to concentrations detected in upgradient groundwater monitor
wells.
TCA was detected in numerous soil gas samples collected across the Reynolds facility
and at the highest concentrations of any of the COC detected at the facility. Soil samples
collected in the vicinity of the East Stoddard Solvent dip tank exhibited TCA at
concentrations greater than the minimum GPL. Soil and groundwater data indicated that
TCA releases at the Reynolds facility migrated vertically to UAU1. However, TCA does
not appear to have migrated vertically to the deeper aquifers. TCA was detected in one
groundwater sample collected during First Quarter 2008 at the Reynolds facility at a
concentration of 0.96 µg/l. The detected concentration is similar to concentrations
detected in upgradient groundwater monitor wells.
1,1-DCE was detected in one soil sample at the Reynolds facility at a concentration
which exceeded the SRLs and the minimum GPL. 1,1-DCE was also detected in soil gas
samples collected from the Reynolds facility. The presence of 1,1-DCE detected in the
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-9

8/9/2012

 vadose zone may indicate that its presence is due to use and release and/or degradation of
TCA and/or PCE and TCE. The presence of 1,1-DCE in groundwater beneath the
Reynolds facility is believed to be caused by the degradation of TCA and possibly
PCE/TCE. First Quarter 2008 1,1-DCE concentrations in groundwater beneath the
Reynolds facility ranged from less than 0.50 to 1.6 µg/l. The detected concentrations are
similar to concentrations detected in upgradient groundwater monitor wells.
Chromium was only detected in one soil sample at a concentration greater than regulatory
standards in the central portion of the WVBA; this was at the Reynolds facility. In First
Quarter 2008, chromium was detected in groundwater samples collected at the Reynolds
facility at concentrations ranging from less than 0.010 to 0.063 mg/l. The detected
concentrations are similar to concentrations detected in upgradient groundwater monitor
wells.
1,1-DCA was the only other COC detected in soil gas or soil samples collected from the
Reynolds facility, however, at concentrations less than regulatory standards. The
presence of 1,1-DCA may be due to a release of the COC to the vadose zone or more
likely a result of degradation of TCA. Based on soil and groundwater data for the central
WVBA, it does not appear that releases of 1,1-DCA to the vadose zone in the central
portion of the WVBA migrated to groundwater.
4.2.2.2 U.S. DOE
PCE and TCE were detected in soil gas samples collected at the DOE facility at low
concentrations primarily in the area of the facility’s maintenance buildings. PCE was
also detected in soil samples collected in the vicinity of the former craneway building but
at concentrations less than SRLs and the minimum GPL. TCA was detected in one soil
sample collected at the DOE facility at a concentration less than SRLs and the minimum
GPL. No other COCs were detected in soil samples collected at the DOE facility.
Groundwater investigations are ongoing by the U.S. DOE.
4.2.2.3 ALASG
PCE along with TCA were detected at the ALASG facility in liquid collected from
shallow soil during a soil gas investigation. The liquid was detected at the grease trap in
the ASU building. PCE was not detected in soil samples at concentrations greater than
SRLs or the minimum GPL. Soil and groundwater data may indicate that releases of
PCE at the ALASG facility affected groundwater quality. Groundwater investigations are
ongoing by ALASG under consent order with ADEQ.
TCE was detected in soil gas samples collected at the ALASG facility but at
concentrations lower than concentrations of PCE, typically by an order of magnitude.
Two soil samples collected from the ALASG facility exceeded the minimum GPL for
TCE. These soil samples were collected from the area of the former grease trap in the
ASU building. Because TCE is not reported to have been used at the ALASG facility the
presence of TCE in the soil may be due to the degradation of PCE or may have been in
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-10

8/9/2012

 use without the knowledge of ALASG personnel. Groundwater data collection is not
complete at the facility to evaluate whether TCE detected in the soil has migrated to
groundwater.
1,1-DCE was detected soil gas samples collected across the ALASG facility. The highest
concentrations were detected at the grease trap in the ASU building. Several soil samples
collected from the grease trap area within the ASU of the ALASG facility exhibited 1,1DCE at concentrations greater than the minimum GPL for 1,1-DCE. The presence of
1,1-DCE may be due to the degradation of PCE, TCE, and/or TCA. Data are not
conclusive at this time if 1,1-DCE present in the soil beneath the ALASG facility has
affected groundwater.
TCA was detected in soil gas samples collected across the ALASG facility with the
highest concentrations detected in the area of the grease trap in the ASU building.
Several soil samples collected at the ALASG facility exhibited TCA at concentrations
greater than the minimum GPL. One soil sample also exceeded the SRLs for TCA.
These soil samples were collected in the vicinity of the grease trap in the ASU building.
Groundwater data collection is not complete at the facility to evaluate whether TCA
detected in the soil has migrated to groundwater.
1,2-DCA was not detected in soil gas samples collected at the ALASG facility and was
only detected in one soil sample collected from the ALASG facility. The soil sample
exceeded the SRLs and the minimum GPL for 1,2-DCA and was collected in the vicinity
of the grease trap in the ASU building. Data do not indicate that 1,2-DCA migrated
vertically to groundwater.
Cis 1,2-DCE was detected at low concentrations in four soil gas samples collected from
the ALASG facility and was not detected in any soil samples. Soil gas samples exhibited
low concentrations of 1,1-DCA at the ALASG facility. 1,1-DCA was detected in soil
samples collected from the ALASG facility but at concentrations less than regulatory
standards. The presence of 1,1-DCA may be due to the degradation of TCA in the soil.
4.2.2.4 VW&R
PCE was the most commonly detected COC at the VW&R facility. PCE was most
commonly detected in soil gas samples collected in the vicinity of the two tank farms in
the west portion of the VW&R facility. One soil sample collected from this facility
exhibited PCE at a concentration greater than the minimum GPL for PCE. This soil
sample was collected from the west side of the corrosive tank farm. Groundwater data
presented on Figures 4-1, 4-2, 4-3, 4-7, and 4-11 along with data included in Section 2.1
indicate that the release of PCE at the VW&R facility contaminated groundwater beneath
the facility and migrated downgradient of the facility. PCE was detected at a
concentration of 12 µg/l in the groundwater sample collected from beneath the VW&R
facility during First Quarter 2008. The detected concentration is similar to concentrations
detected in upgradient groundwater monitor wells.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-11

8/9/2012

 TCE was detected in soil gas samples collected from the VW&R facility but at
concentrations typically an order of magnitude less than the PCE concentrations. TCE
was also detected in soil samples collected from the VW&R facility but at concentrations
less than regulatory standards. The presence of TCE in the soil may be due to releases of
TCE or the degradation of PCE. Based on a review of soil and groundwater data beneath
the VW&R facility, it does not appear that TCE has migrated vertically to groundwater.
TCE was detected at a concentration of 13 µg/l in the groundwater sample collected from
beneath the VW&R facility during First Quarter 2008. The detected concentration is
similar to concentrations detected in upgradient groundwater monitor wells.
1,1-DCE was detected in soil gas samples collected from the VW&R facility but at
concentrations typically an order of magnitude less than the PCE concentrations.
However, the 1,1-DCE concentrations were typically greater than the TCE soil gas
concentrations. 1,1-DCE was also detected in soil samples collected from the VW&R
facility but at concentrations less than regulatory standards. The presence of 1,1-DCE in
the soil may be due to releases of 1,1-DCE or the degradation of PCE, TCE, and/or TCA.
Based on a review of soil and groundwater data beneath the VW&R facility, it does not
appear that 1,1-DCE has migrated vertically to groundwater. 1,1-DCE was detected at a
concentration of 1.5 µg/l in the groundwater sample collected from beneath the VW&R
facility during First Quarter 2008. The detected concentration is similar to concentrations
detected in upgradient groundwater monitor wells.
TCA was detected in soil gas samples collected at the VW&R facility at concentrations
similar to TCE concentrations. TCA was also detected in soil samples collected from the
VW&R facility but not at concentrations greater than SRLs and the minimum GPL. Soil
and groundwater data indicate that the TCA release at the VW&R facility may have
affected groundwater quality. TCA was not detected in the groundwater sample collected
from beneath the VW&R facility during First Quarter 2008.
Cis 1,2-DCE, 1,1-DCA, and 1,2-DCA were not analyzed for in soil gas samples collected
at the VW&R facility. Cis 1,2-DCE was also not analyzed for in soil samples but trans
1,2-DCE was analyzed for in soil samples. These COC were detected in soil samples at
low concentrations at the VW&R facility. However, none of these COC were detected at
concentrations greater than SRLs or minimum GPLs. These COC are not believed to
have contaminated groundwater at the VW&R facility. Cis 1,2-DCE, 1,1-DCA, and 1,2DCA were not detected in the groundwater sample collected from beneath the VW&R
facility during First Quarter 2008.
4.2.2.5 West Central Phoenix Area WQARF Site
TCE and other VOCs appear to be entering the central portion of the WVBA from the
north. Investigations have been conducted within the West Central Phoenix (WCP)
WQARF Registry Site, north of the central portion of the WVBA and hydraulically
upgradient. In the summer of 1998, the WCP was split into five separate plumes. The
West Osborn Complex (WOC) site is the southernmost of five plumes in the WCP and is
closest to the WVBA. The WOC is bounded approximately by the Grand Canal to the
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-12

8/9/2012

 north, 31st Avenue to the east, McDowell Road to the south, and 55th Avenue to the west.
VOC contamination in the area was first detected in groundwater in July 1982.
Three facilities have been identified as likely sources of groundwater contamination in
the WOC:
1. United Industrial Corporation (UIC), Investigated soil and groundwater,
conducted SVE soil remediation, entered into a consent decree, settled with
ADEQ, preparing two FS’s, groundwater investigation is ongoing.
2. Corning Inc./Components Incorporated, Investigated soil and groundwater,
settled with ADEQ.
3. NUCOR Corporation, settled with ADEQ.
ADEQ, in conjunction with UIC, agreed that the deep aquifer and the shallow aquifer
should be further characterized and are to be remediated separately. The current
COCs in groundwater at the WOC include TCE, 1,1-DCE, and PCE. TCE presents
the highest contaminant concentration in the WOC. Currently, ADEQ is evaluating
the FS for the deep aquifer and is awaiting the submittal of the FS for the shallow
aquifer. ADEQ issued the final remedial objectives report in May 2005.
4.2.3 Western Portion of WVBA
Vadose zone contamination investigations have been conducted in the western portion
of the WVBA at 15 facilities. The western portion of the WVBA extends from 51st
Avenue to the western site boundary.
The following facilities conducted
investigations or had investigations conducted at their facilities; facility locations are
shown on Figures 1-1 and 2-1:
1. Dolphin, 740 S. 59th Ave. – Investigated soil and groundwater,
conducted remediation, received RCRA closure of consent order for
soils.
2. POS, 5102 W. Roosevelt St. – Currently investigating soil and
groundwater.
3. CoStar Corp/Data Packaging Corp, 425 S. 67th Ave – Conducted
soil investigation, requested to investigate groundwater but never
completed.
4. Arizona Parts Master, 15 N. 57th Dr. – Conducted soil investigation
ascertained release was limited to petroleum hydrocarbons, not
investigated further under WQARF.
5. Joe’s Diesel Repair, 6316 W. Van Buren St. – Phase I soil sample
collected but not recommended for additional investigation.
6. Petco, Inc., W. Side of 67th Ave. N. of railroad – Phase I soil
sample collected but not recommended for additional investigation.
7. Phoenix Vegetable Distribution, S. Side of Buckeye Rd. E. of 83rd
Ave. – Phase I soil sample collected but not recommended for
additional investigation.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-13

8/9/2012

 8. Phoenix Tank Farm, 51st Ave/Van Buren St. – Petroleum
contaminants, not a COC of WVBA.
9. Unocal, 10 S. 51st Ave. – Conducted soil investigation, not required
to investigate groundwater.
10. Research Chemicals, 8220 W. Harrison St., Tolleson – Phase I soil
sample collected but not recommended for additional investigation.
11. Salesco Systems/Turken Industrial Properties, 5736 W. Jefferson
St. – Conducted soil investigation, requested to do additional
investigation but no record of being conducted.
12. Seaport Petroleum, 57 N. 57th Ave. – Conducted soil investigation
determined release was limited to petroleum hydrocarbons, not
investigated further under WQARF.
13. Southwest Feed & Seed, 350 S. 75th Ave. – Phase I soil sample
collected but not recommended for additional investigation.
14. Tritech Manufacturing, Inc./Tri-Star Quality Metal Finishing, Inc.,
5144 W McKinley St – Conducted soil investigation, not requested
to investigate groundwater.
15. World Resources Co., 8113 W. Sherman St. – Phase I soil sample
collected but not recommended for additional investigation.
Three facilities, Dolphin, POS, and CoStar Corp/Data Packaging Corp were requested to
conduct groundwater investigations. CoStar Corp/Data Packaging Corp went bankrupt
before any wells were installed at this facility. Groundwater data collected from
surrounding groundwater monitor wells indicate that COC concentrations are higher in
monitor wells upgradient of CoStar Corp/Data Packaging Corp than in monitor wells
downgradient of the facility. COC detected at concentrations greater than regulatory
standards in the vadose zone in the western portion of the WVBA have included PCE,
TCE, 1,2-DCE, and chromium.
4.2.3.1 Dolphin
PCE was detected in the vadose zone in both soil and soil gas samples collected at the
Dolphin facility. The highest soil gas concentrations were detected in the vicinity of
drum storage, PCE degreaser, drain pipes and a leach field. Several soil samples
collected from the Dolphin facility exhibited PCE at concentrations greater than the
residential SRL and the minimum GPL. Groundwater data shown on Figures 4-3, 4-7,
and 4-11 along with data presented in Section 2.1 indicate that the release of PCE
occurring at the Dolphin facility contaminated groundwater beneath the facility and
migrated downgradient of the facility. In First Quarter 2008, PCE concentrations in
groundwater samples collected from Dolphin wells ranged from less than 0.50 to 51
µg/l.
TCE was only detected in soil gas samples collected from the Dolphin facility in the
areas of the drum storage, PCE degreaser, and the southwest building but at
concentrations of up to three orders of magnitude less than PCE soil gas
concentrations. TCE was only detected in one soil sample, collected from soil
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-14

8/9/2012

 excavated from a spill area, at a concentration greater than the residential SRL and the
minimum GPL. The presence of TCE in the vadose zone at the Dolphin facility is
likely due to the degradation of PCE but may have also been due to an unknown
release of TCE even though the owner/operator does not have documented use of TCE
at the facility. Data presented in Section 2.1 and shown on Figures 4-4, 4-8, and 4-12
indicate that TCE at the Dolphin facility has not migrated to groundwater. First
Quarter 2008 TCE concentrations in groundwater beneath the Dolphin facility ranged
from less than 0.50 to 7.7 µg/l.
1,1-DCE was detected in soil gas samples collected from the Dolphin facility in the areas
of drum storage, PCE degreaser, and the southwest building but again at concentrations
of up to three orders of magnitude less than PCE soil gas concentrations. 1,1-DCE was
only detected in soil samples collected from a drainage area at the Dolphin facility, but
not at concentrations which exceeded regulatory standards. The use of 1,1-DCE is not
documented, so 1,1-DCE detected in the vadose zone may indicate that its presence is
due to use/release without the knowledge of the owner/operator or due to the degradation
of PCE and/or TCA. Data presented in Section 2.1 and shown on Figures 4-5, 4-9, and 413 for 1,1-DCE indicate that the presence of 1,1-DCE in the vadose zone at the Dolphin
facility has not affected groundwater quality. First Quarter 2008 1,1-DCE concentrations
in groundwater beneath the Dolphin facility ranged from less than 0.50 to 1.7 µg/l.
Chromium was only detected in one soil sample at a concentration greater than regulatory
standards at the Dolphin facility. Based on soil and groundwater data, a release of this
COC has occurred but does not appear to have migrated to groundwater. In First Quarter
2008, chromium was not analyzed for in groundwater samples collected at the Dolphin
facility.
Cis 1,2-DCE was only detected in one soil sample collected from the western portion of
the WVBA at a concentration greater than regulatory standards. This sample was
collected from soil excavated from the same spill area where PCE and TCE were detected
at the Dolphin facility. Cis 1,2-DCE was detected in soil gas samples collected from the
Dolphin facility at locations and concentrations similar to TCE soil gas concentrations.
Cis 1,2-DCE detection is probably a result of the degradation of PCE. Based on these
data and groundwater data for the western portion of the WVBA, cis 1,2-DCE detected in
the vadose zone at the Dolphin facility has not migrated to groundwater. First Quarter
2008 cis 1,2-DCE concentrations in groundwater beneath the Dolphin facility ranged
from less than 0.50 to 5 µg/l.
TCA was detected in the vadose zone at the Dolphin facility, but at concentrations less
than regulatory standards; TCA was also detected in soil gas samples. The presence of
TCA in the vadose zone indicates that a release of this COC occurred but when soil data
are reviewed with groundwater data, no resulting groundwater contamination is evident.
TCA was not detected in groundwater samples collected during First Quarter 2008
beneath the Dolphin facility.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-15

8/9/2012

 1,1-DCA was detected in soil at the Dolphin facility but at concentrations less than
regulatory standards. Based on soil and groundwater data for the Dolphin facility, it does
not appear that releases of 1,1-DCA at the Dolphin facility migrated to groundwater.
First quarter 2008 1,1-DCA concentrations in groundwater beneath the Dolphin facility
were less than the practical quantification limit.
4.2.3.2 POS
The POS facility has been requested to conduct a groundwater investigation under the
WQARF program and signed a consent order in May 2008, but has not completed a
groundwater investigation at this time. PCE was detected in the vadose zone in both soil
gas and soil samples collected at the POS facility. Soil samples collected from the POS
facility exhibited PCE at concentrations greater than regulatory standards. Groundwater
data shown on Figures 4-1, 4-2, 4-3, 4-7, and 4-11 along with data presented in Section
2.1 indicate that the releases of PCE occurring at the POS facility contaminated
groundwater beneath the facility and migrated downgradient of the facility.
TCE and cis 1,2-DCE were detected in soil gas samples collected from the POS facility
but at concentrations of up to three orders of magnitude less than PCE soil gas
concentrations. Locations where TCE and cis 1,2-DCE were detected in soil gas samples
do not have documented uses of these COCs. The presence of TCE and cis 1,2-DCE in
the vadose zone at the POS facility may be a result of degradation of PCE or it could be a
release of these COCs without the owner’s knowledge of its use.
1,1-DCE was not detected in soil gas or soil samples collected at the POS facility. TCA,
1,1-DCA, and 1,2-DCA were not analyzed for in samples collected at the facility.
4.3

Groundwater

As discussed in Section 3.4.2, the alluvial units of interest in the WVBA are as follows:
 UAU1 – The uppermost alluvial unit, UAU1 ranges in thickness from
approximately 170 to 310 feet bgs.
 UAU2 - This intermediate layer occurs where clay lenses increase in number until
clays dominate the lithologic horizons. UAU2 exhibits a considerable range in
thickness, from approximately 30 to 260 feet or greater. UAU2 appears thickest in
the western portion of the WVBA.
 MAU - The MAU is encountered at depths ranging from approximately 260 to
500 feet bgs. The shallowest depth to the MAU is in the east, deepening in the west.
Initial sampling activities in the WVBA did not differentiate between alluvial units, since
there were fewer monitor wells in which to sample. Tables 4-1 and 4-2 contain water
quality data for wells sampled in 1988 and 1993, and these data are plotted on Figures 41 and 4-2, respectively. Copies of the laboratory reports are contained in Appendices T
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-16

8/9/2012

 and U, respectively. In 1988, several wells in the central and eastern portions of the
WVBA exhibited contaminant concentrations exceeding AWQSs, prompting further
groundwater investigation. By 1993, the groundwater monitor well network had been
expanded, providing further detail into the extent and magnitude of groundwater
contamination within the WVBA. COC were detected at concentrations greater than
AWQS in wells from the eastern boundary to 67th Avenue. Areas of elevated PCE and
TCE concentrations are present in the east at the ALSCo facility, in the center at the
VW&R facility, and in the west downgradient of the Dolphin facility. ADEQ has
continued the expansion of the WVBA monitor well network through the incorporation
of existing monitor wells and installation of new monitor wells, and semiannual
monitoring of these wells has been and continues to be performed by ADEQ contractors.
Historic contaminant concentration trends are presented in Appendix Y.
4.3.1 UAU1
4.3.1.1 1998
Water quality data (PCE, TCE, 1,1-DCE, and total chromium) for groundwater samples
collected January through July 1998 are presented in Table 4-3. Copies of the laboratory
reports are contained in Appendix V. Figures 4-3 through 4-6 show UAU1 contaminant
concentrations for data collected in 1998. In general, COC concentrations are lower in
the east and center of the WVBA when compared to concentrations detected in 1993, and
are higher in the west. The decline in concentrations may be due to remedial activities
and declining groundwater levels. The apparent increase in concentrations may be due to
the expansion of the groundwater monitoring program.
 PCE concentrations are contoured on Figure 4-3. Based upon the contours, PCE
contamination exceeding the AWQS of 5 µg/l extends from the eastern boundary of
the WVBA to approximately 69th Avenue, and north of the RID canal; the northern
extent of PCE contamination was not delineated. Areas of elevated PCE
concentrations are present in the east in the vicinity of the ALSCo facility, in the
southeast in the vicinity of the CRC facility, in the center in the vicinity of the
VW&R facility, and in the west at the Dolphin facility.
 TCE concentrations are contoured on Figure 4-4. Based upon the contours, TCE
contamination exceeding the AWQS of 5 µg/l also extends from the eastern boundary
of the WVBA to approximately 69th Avenue, and north of the RID canal. The
northern extent of TCE contamination exceeding the AWQS appears to be limited to
south of Roosevelt Street. Areas of elevated TCE concentrations are present in the
east in the vicinity of the MCMM facility, north of the MCMM facility extending
from the OU3 site to just east of the Reynolds facility, and in the west downgradient
of the Dolphin facility.
 1,1-DCE concentrations are contoured on Figure 4-5. Based upon the contours,
1,1-DCE contamination exceeding the AWQS of 7 µg/l is present in three discrete
areas. In the eastern WVBA, a 1,1-DCE plume extends from the eastern boundary of
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-17

8/9/2012

 the WVBA to 27th Avenue. In the north-central WVBA, a 1,1-DCE plume trends
northwest from 43rd Avenue to between 51st and 55th Avenues. In the western
WVBA, a 1,1-DCE plume extends from 59th Avenue north of Buckeye to RID-84.
Elevated 1,1-DCE concentrations occur at well AVB14-01 in the east, well AVB3701 in the center, and well AVB10-04 in the west.
 Total chromium concentrations are presented on Figure 4-6. Five wells were
sampled and analyzed for total chromium; four of them exceed the AWQS of 0.1
mg/l. These are located in the vicinity of the CRC facility.
4.3.1.2 2003
Water quality data for groundwater samples collected March through June 2003 are
presented in Table 4-4. Copies of the laboratory reports are contained in Appendix V.
Figures 4-7 through 4-10 show UAU1 contaminant concentrations for data collected in
2003. COC concentrations are lower when compared to concentrations detected in 1993
and 1998. The decline in concentrations may be due to remedial activities conducted
within the WVBA and declining groundwater levels.
 PCE concentrations are contoured on Figure 4-7. Based upon the contours, PCE
contamination exceeding the AWQS extends from the eastern boundary of the
WVBA to at least 75th Avenue, and north of the RID canal except between 67th and
71st Avenues. The northern extent of PCE contamination exceeding the AWQS
appears to be limited to south of Roosevelt Street except between 51st and 59th
Avenues. Areas of elevated PCE concentrations are present in the east in the vicinity
of the ALSCo facility, in the southeast in the vicinity of the CRC facility, in the
north-center in the vicinity of the POS facility, and in the west downgradient of the
Dolphin facility.
 TCE concentrations are contoured on Figure 4-8. Based upon the contours, TCE
contamination exceeding the AWQS extends from the eastern boundary of the
WVBA to approximately 71st Avenue, and north of the RID canal except in the
vicinity of RID-84. The northern extent of TCE contamination exceeding the AWQS
appears to be limited to south of Roosevelt Street except between 39th and 47th
Avenues. Areas of elevated TCE concentrations are present in the east downgradient
of the MCMM facility, north of the MCMM facility extending from the OU3 site to
the DOE facility, at well AVB94-01 in the north-center, and in the west at well
AVB122-02.
 1,1-DCE concentrations are contoured on Figure 4-9. Based upon the contours,
1,1-DCE contamination exceeding the AWQS is again present in three discrete areas.
In the eastern WVBA, a 1,1-DCE plume extends from the eastern boundary of the
WVBA to 27th Avenue. In the north-central WVBA, a 1,1-DCE plume trends south in
the vicinity of 43rd Avenue in a triangular pattern from 37th to 51st Avenues. In the
western WVBA, a 1,1-DCE plume extends from 59th Avenue and Van Buren to RID84.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-18

8/9/2012

  Total chromium concentrations are presented on Figure 4-10. Ten wells exceed
the AWQS of 100 µg/l. Areas of elevated chromium concentrations are present in the
southeast in the vicinity of the CRC facility, in the east at well AVB72-01, and in the
west at wells AVB73-01, AVB75-01, and AVB76-01.
4.3.1.3 2008
Water quality data for groundwater samples collected during First Quarter 2008 are
presented in Table 4-5. Copies of the laboratory reports are contained in Appendix X.
Figures 4-11 through 4-14 show UAU1 contaminant concentrations for data collected in
First Quarter 2008. COC concentrations appear to have continued to decline with the
exception of chromium, PCE in the southeast and north-center, and TCE in the east.
 PCE concentrations are contoured on Figure 4-11. Based upon the contours, PCE
contamination exceeding the AWQS extends from the eastern boundary of the
WVBA to approximately 69th Avenue, and north of the RID canal except between
67th and 71st Avenues. The northern extent of PCE contamination exceeding the
AWQS appears to be limited to south of Roosevelt Street, except between 47th and
55th Avenues where it extends to approximately Interstate 10. Areas of elevated PCE
concentrations continue to be present downgradient of the ALSCo facility, in the
southeast at the CRC facility, and in the north-center at the POS facility.
 TCE concentrations are contoured on Figure 4-12. Based upon the contours, TCE
contamination exceeding the AWQS extends from the eastern boundary of the
WVBA to approximately 59th Avenue, and north of the RID canal. The northern
extent of TCE contamination exceeding the AWQS appears to be limited to south of
Roosevelt Street except between 41st and 55th Avenues. Areas of elevated TCE
concentrations are present in the east extending from the eastern site boundary to the
DOE facility, and at well AVB94-01.
 1,1-DCE concentrations are contoured on Figure 4-13. Based upon the contours,
1,1-DCE contamination exceeding the AWQS is present primarily in the eastern
WVBA, a 1,1-DCE plume extends from the eastern boundary of the WVBA to
approximately 35th Avenue. Additionally, the 1,1-DCE concentration of RID-106,
located in the western portion of the WVBA, also exceeded the AWQS.
 Total chromium concentrations are presented on Figure 4-14. Ten samples
exceed the total chromium AWQS of 0.10 mg/l. Areas of elevated chromium
concentrations are present in the southeast in the vicinity of the CRC facility, in the
east at well AVB72-01, and in the west at wells AVB73-01, AVB75-01, and AVB7601.
4.3.2 UAU2
4.3.2.1 1998
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-19

8/9/2012

 Groundwater data collected from UAU2 in January through July 1998 were limited to the
western portion of the site. Figures 4-15 through 4-17 show UAU2 contaminant
concentrations for data collected in 1998. Data are also included in Table 4-3 and copies
of the laboratory reports are contained in Appendix V.
 PCE concentrations are presented on Figure 4-15, and exceed the AWQS in
groundwater samples collected from AVB10-02 (94 µg/l), AVB69-01 (26 µg/l), RID109 (13 µg/l), and DIMW-1 (61 µg/l).
 TCE concentrations are presented on Figure 4-16. TCE concentrations exceeding
the AWQS were detected in groundwater samples collected from AVB10-02 (18
µg/l) and RID-109 (5.9 µg/l).
 1,1-DCE concentrations are presented on Figure 4-17. 1,1-DCE concentrations
exceeding the AWQS were detected in the groundwater sample collected from
AVB10-02 (26 µg/l).
4.3.2.2 2003
Figures 4-18 through 4-21 show UAU2 contaminant concentrations for data collected
March through June 2003. Data are also included in Table 4-4 and copies of the
laboratory reports are contained in Appendix W.
 PCE concentrations are contoured on Figure 4-18. Based upon the contours, PCE
contamination exceeding the AWQS extends from 19th Avenue to at least 75th
Avenue, and north of the RID canal except between 67th and 71st Avenues. The
northern extent of PCE contamination exceeding the AWQS appears to coincide with
Van Buren Street in the area of 51st Avenue but is undefined in the east and west.
 TCE concentrations are contoured on Figure 4-19. Based upon the contours, TCE
contamination exceeding the AWQS extends from the eastern boundary of the
WVBA to approximately 71st Avenue, and north of the RID canal except in the
vicinity of RID-84. The northern extent of TCE contamination exceeding the AWQS
is undefined in the east and appears to be limited to south of Roosevelt Street west of
approximately 59th Avenue.
 1,1-DCE concentrations are contoured on Figure 4-20. Based upon the contours,
1,1-DCE contamination exceeding the AWQS is present in two discrete areas. In the
eastern WVBA, 1,1-DCE exceeding the AWQS was detected in the groundwater
sample collected from RID-100. In the western WVBA, a 1,1-DCE plume extends
from approximately 59th Avenue and Van Buren to RID-84 and RID-106.
 Total chromium concentrations are presented on Figure 4-21.
sampled wells analyzed for total chromium exceeded the AWQS.
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-20

None of the

8/9/2012

 4.3.2.3 2008
Figures 4-22 through 4-25 show UAU2 contaminant concentrations for data collected in
First Quarter 2008. Data are also presented in Table 4-5 and copies of the laboratory
reports are contained in Appendix X.
 PCE concentrations are contoured on Figure 4-22. Based upon the contours, PCE
contamination exceeding the AWQS discontinuously extends from approximately the
eastern boundary to 75th Avenue north of the RID canal. The northern extent of PCE
contamination exceeding the AWQS appears to be limited to north of Van Buren
Street in the eastern WVBA and Interstate 10 in the western WVBA.
 TCE concentrations are contoured on Figure 4-23. Based upon the contours, TCE
contamination exceeding the AWQS extends from the eastern boundary of the
WVBA to approximately 51st Avenue north of the RID canal. The northern extent of
TCE contamination exceeding the AWQS appears to be limited to south of Roosevelt
Street except in the eastern edge of the WVBA.
 1,1-DCE concentrations are contoured on Figure 4-24. Based upon the contours,
1,1-DCE contamination exceeding the AWQS is limited to the eastern WVBA. A
westerly-trending 1,1-DCE plume exceeding the AWQS extends from approximately
the eastern boundary to 35th Avenue.
 Total chromium concentrations are presented on Figure 4-25. One groundwater
sample, collected from well AVB134-02, exceeded the total chromium AWQS of 100
µg/l.
4.3.3 MAU
4.3.3.1 1998
Figures 4-26 through 4-28 show MAU contaminant concentrations for data collected
January through July 1998. Data are also presented in Table 4-3 and copies of the
laboratory reports are contained in Appendix V.
 PCE concentrations are presented on Figure 4-26. PCE concentrations exceeding
the AWQS were detected in groundwater samples collected from AVB69-01 (26
µg/l) and DIMW-1 (18 µg/l).
 TCE concentrations are presented on Figure 4-27. The only detectable TCE
concentration was from the groundwater sample collected from DIMW-1 (0.9 µg/l).
 1,1-DCE concentrations are presented on Figure 4-28. None of the analyzed
groundwater samples exhibited detectable 1,1-DCE concentrations.
4.3.3.2 2003
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-21

8/9/2012

 Figures 4-29 through 4-32 show MAU contaminant concentrations for data collected
March through June 2003. Data are also presented in Table 4-4 and copies of the
laboratory reports are contained in Appendix W.
 PCE concentrations are presented on Figure 4-29. The only PCE concentration
exceeding the AWQS was detected in the groundwater sample collected from
AVB82-01 (30 µg/l).
 TCE concentrations are presented on Figure 4-30. The only detectable TCE
concentration was from the groundwater sample collected from AVB82-01 (2.5 µg/l).
 1,1-DCE concentrations are presented on Figure 4-31. The only 1,1-DCE
concentration exceeding the AWQS was detected in the groundwater sample
collected from AVB82-01 (8.9 µg/l).
 Total chromium concentrations are presented on Figure 4-32. Of the five wells
analyzed for total chromium, one (AVB61-01) exceeded the AWQS.
4.3.3.3 2008
Figures 4-33 through 4-36 show MAU contaminant concentrations for data collected in
First Quarter 2008. Data are also presented in Table 4-5 and copies of the laboratory
reports are contained in Appendix X.


PCE concentrations are presented on Figure 4-33. The only PCE concentration
exceeding the AWQS was detected in the groundwater sample collected from
AVB82-01 (60 µg/l).



TCE concentrations are presented on Figure 4-34. The only TCE concentration
exceeding the AWQS was detected in the groundwater sample collected from
AVB82-01 (16 µg/l).



1,1-DCE concentrations are presented on Figure 4-35. The only 1,1-DCE
concentration exceeding the AWQS was detected in the groundwater sample
collected from AVB82-01 (22 µg/l).



Total chromium concentrations are presented on Figure 4-36. Of the four wells
analyzed for total chromium, none exceeded the AWQS.

4.4 Canal Water

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-22

8/9/2012

 The RID wells and canal system were first sampled by Terranext in 2000, followed by
additional sampling in 2003 (BE&K/Terranext, 2001c, 2003c). The RID canal system
within the WVBA is presented on Figure 2-6.
BE&K/Terranext sampled 17 RID wells in April 2000 to identify where canal water
sampling would take place. Well RID-84 exhibited the highest concentration of PCE and
well RID-92 exhibited the highest TCE concentration, and therefore the canal system at
these locations was selected for canal water sampling.
In June 2000, the RID lateral canal downgradient of RID-92 was sampled at the well
discharge and at downgradient distances of 200, 500, and 1,000 feet. These data are
summarized in Table 2-2, and demonstrate a stabilization of VOC concentrations within
200 feet of the well discharge point into the lateral canal.
Upstream and downstream of RID-84, BE&K/Terranext conducted a survey of physical
parameters of the canal water including flow, temperature, and conductivity. Based on
the results of the survey, BE&K/Terranext collected eight samples from the canal in the
vicinity of RID-84 in July 2000. Table 2-2 and Figure 4-37 identify the sample locations
relative to RID-84 with corresponding VOC concentrations. Based on the data collected,
it was concluded that VOC concentrations in the RID canal are primarily controlled by
dilution. Due to the significant base flow from the 23rd Avenue Wastewater Treatment
Plant and from RID wells pumping uncontaminated groundwater, the effect of RID well
discharge of groundwater containing VOCs into the canal is not appreciable; VOC
concentrations are diluted to below AWQSs within 125 feet of the point of discharge.
Beyond 125 feet of the point of discharge, the diluted/reduced VOC concentrations
stabilized, and remained persistent a minimum of two miles downstream of the discharge
point.
Sampling of RID canal water at seven locations was performed in June 2003. Canal
water sampling procedures first consisted of a measurement of each location’s physical
structure followed by a measurement of canal water field parameters. Physical
measurements included the following:





Canal/lateral bottom width (feet)
Water depth (feet)
Canal/lateral width at water surface (feet)
Water velocity (counts per second converted to centimeters per second)

Canal water field parameters were measured using a Horiba multiple meter sensor. The
instrument probe was submerged directly into each lateral; a five-gallon bucket was used
to collect a sample from the RID canal. The following parameters were measured at each
sample location:




Temperature
pH
electrical conductivity (EC)

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-23

8/9/2012

 



turbidity
dissolved oxygen (DO)
oxidation reduction potential (ORP)

Using the channel and velocity measurements, water flow in cubic feet per second was
estimated for each location.
Halogenated contaminants of concern in the RID canal system are displayed below with
their highest detected concentration and corresponding canal location; results are
summarized in Table 2-3.
Contaminant Sample ID/location Concentration (µg/l)
RID-92 Ditch
21
PCE
RID-92 Ditch
70
TCE
RID-89 Ditch
3.1
1,1-DCE
RID-92 Ditch
3.0
cis-1,2-DCE
RID-89 Ditch
0.69
1,1-DCA
None Detected
TCA
Figure 4-38 depicts concentrations of 1,1-DCE, PCE, and TCE at canal sample locations.
PCE exceeded the AWQS (for comparison only) of 5 µg/l in 6 of 7 canal water samples.
TCE exceeded the AWQS of 5 µg/l in 5 of 7 canal water samples. Contaminants
detected during both rounds of canal sampling do not have applicable surface water
standards.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 4-24

8/9/2012

 5.0

CONTAMINANT FATE AND TRANSPORT
5.1

Potential Routes of Migration

The following four potential routes of migration have been identified for VOCs released
into the vadose zone in the WVBA:





Unsaturated flow
Saturated flow (groundwater)
Surface water
Vapor intrusion
5.1.1

Unsaturated Flow (Soils)

Once released to the vadose zone, depending on the VOC release rate, unsaturated VOC
transport occurs either as a dissolved component of vadose zone moisture (low release
rate) or as a non-aqueous phase liquid (high release rate). Either way, unsaturated flow is
primarily vertically downward until either a change in lithology or the groundwater table
are encountered. As a result of this primarily vertically downward migration, unsaturated
flow occurs at or near the source area. As vadose zone soils within the WVBA are
generally permeable, unsaturated flow in the WVBA typically continues to the
groundwater table.
The rate of unsaturated VOC flow is dependent upon vadose zone soil physical properties
including permeability, moisture content, and total organic carbon (TOC) content, and
specific VOC physical properties including specific gravity, Henry’s Law constant,
solubility, octanol-water partition coefficient (K ow ), and organic carbon partition
coefficient (K oc ). With respect to VOC physical properties, the rate of unsaturated VOC
flow will increase as solubility and Henry’s Law constant increase, and K oc decreases.
Table 5-1 lists some physical properties for PCE, TCE, and 1,1-DCE. Based on their K oc
values, the COC in general will migrate through the vadose zone at a greater rate than
water.
Few site-specific measured vadose zone soil physical properties for the WVBA are
available. Physical properties were analyzed at the MCMM facility located on the
eastern edge of the WVBA during well installation and soil sampling in 1995 (Fluor
Daniel GTI, Inc., 1996b). Physical property analyses were conducted on soil samples
from 10 to 220 feet bgs. Analyses consisted of moisture content, density, effective
porosity, pore fluid saturation, native state effective permeability to air, native state
effective air conductivity, and TOC. Soil physical parameters were analyzed on six soil
samples collected at depths of 10 to 30 feet bgs at the Reynolds Metals Company facility
in 1996 (Geotechnical and Environmental Consultants, Inc., 1996a). The samples were
analyzed for TOC, bulk density, moisture content, and total porosity. Physical properties
were analyzed on soil samples collected at depths from 10 to 120 feet bgs at the ALASG
facility located near the center of the WVBA (Basin & Range Hydrogeologists, 2001a).
Analyses consisted of dry bulk density, specific gravity, moisture content, TOC, and
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-1

8/9/2012

 grain size distribution. Based on dry bulk density and specific gravity, porosities were
estimated. Physical properties were also analyzed on soil samples collected at the
Dolphin, Inc. facility located in the west- central portion of the WVBA (Basin & Range
Hydrogeologists, 1996b). Physical properties (moisture content, dry density, TOC, and
grain size analysis) were also analyzed on soil samples collected at the VW&R facility
located in the central portion of the WVBA (Harding Lawson Associates, 1997b).
The following generalizations can be made using existing data, and field observations of
drill cuttings and soil samples continuously collected during rotosonic drilling:


The vadose zone is comprised of unsaturated UAU1 soils. As described in
Section 3.4.2, UAU1 is comprised of loose surface soils grading downward into
interfingered sand and gravel lenses; clay lenses, when present, are typically thin
and usually characterized as clayey sands. Based upon the east-west crosssections, UAU1 appears to become finer-grained west of about 75th Avenue.
Except in the eastern portion of the WVBA, UAU1 also appears to become finergrained northwards, particularly in the northwest portion of the WVBA.



Depth to groundwater within the WVBA currently ranges from approximately 75
to 140 feet bgs depending on location and season; thus, this is the range in
thickness of the vadose zone. In general, depth to groundwater is greatest in the
north-central portion of the WVBA and shallowest along the eastern boundary of
the WVBA.



Based upon the observed generalizations of UAU1 lithology, except in the eastern
portion of the WVBA, the permeability of vadose zone soils decreases northward
within the WVBA, and is likely lowest west of about 75th Avenue. .



The moisture content of vadose zone soils has been measured, ranging from 2.6
percent (dry) to moist at 22 percent (Fluor Daniel GTI, Inc., 1996b, Geotechnical
and Environmental Consultants, Inc., 1996, Harding Lawson Associates, 1997b,
and Basin & Range Hydrogeologists, 1996b and 2001a). Dry bulk densities
ranged from 1.15 grams per cubic centimeter (g/cc) to 1.92 g/cc. Porosities were
calculated to range from 22 to 45 percent. TOC ranged from 74 to 3,650 mg/kg.
5.1.2

Saturated Flow (Groundwater)

Upon reaching the groundwater table as unsaturated flow in the WVBA, VOCs dissolve
into the uppermost UAU1 aquifer. The presence of dense non-aqueous phase liquids in
the WVBA has not been identified. Once dissolved, VOCs have migrated both vertically
and horizontally within UAU1.
As described in Section 3.5.2.3, downward vertical flow within the WVBA has been
quantified. Thus, dissolved VOCs in UAU1 have been transported downwards into
UAU2, as presented in Section 4.3.2. Figures 4-15 through 4-24 document the current
extent of VOC contamination in UAU2. VOC contamination within UAU2 has also been
West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-2

8/9/2012

 transported downwards into the MAU, as described in Section 4.3.3. VOC contamination
within the MAU appears limited to the western portion of the MAU; since 2003, PCE,
TCE, and/or 1,1-DCE concentrations near or above corresponding AWQSs have been
detected in groundwater samples collected from MAU monitor wells DIMW-1 and/or
AVB82-01 (Figures 4-26 through 4-35).
As described in Section 3.5.2.2, horizontal flow within the WVBA has also been
quantified. Thus, dissolved VOCs in the UAU1, UAU2, and MAU are transported
horizontally within the existing hydraulic gradients.
5.1.3

Canal Water

As discussed in Section 3.3.2, the RID canal originates at 19th Avenue south of Interstate
17, continuing on to the 23rd Avenue wastewater treatment facility where 30,000 acre-feet
per year (AFY) of treated wastewater is discharged into the canal. The canal is also fed
by a number of RID production wells located throughout the WVBA; these wells
discharge an additional 135,000 acre-feet per year of pumped groundwater into the canal.
Some of these wells extract VOC-contaminated groundwater which has been detected in
canal water. Concentrations of VOCs in canal water in the vicinity of select wells exceed
the AWQSs but because the end use of the RID canal water is agricultural there are no
applicable surface water standards.
As discussed in Section 4.4, BE&K/Terranext collected eight samples from the RID canal
in July 2000 upstream and downstream of well RID-84. Based on the data collected, it
was concluded that VOC concentrations in the RID canal are primarily controlled by
dilution. Due to the significant base flow from the 23rd Avenue wastewater treatment
facility and from RID wells pumping uncontaminated groundwater, the effect of RID
well discharge of groundwater containing VOCs into the canal is not appreciable; VOC
concentrations are diluted to below AWQSs within 125 feet of the point of discharge to
4.0 µg/L or less. Beyond 125 feet of the point of discharge, however, the diluted/reduced
VOC concentrations stabilized, and remained persistent a minimum of two miles
downstream from the discharge point.
5.1.4

Vapor Intrusion

Once released to the vadose zone, VOCs can volatilize into soil gas which can migrate
upwards to the ground surface. Depending on the land use/surface cover, soil gas can
either be released directly to the atmosphere, become trapped beneath impermeable
structures, or migrate into structures either beneath or at the ground surface. Typically,
vapor intrusion will occur at or near the contaminant (in this case VOC) source area, but
can also occur via off-gassing from the groundwater. The likelihood of vapor intrusion
via this pathway decreases with increasing depth to groundwater.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-3

8/9/2012

 5.2

Contaminant Migration
5.2.1

Factors Affecting Contaminant Migration

As VOCs are dissolved in groundwater within UAU1, UAU2, and the MAU, the factors
affecting contaminant migration are the same as those affecting groundwater flow, both
vertically and horizontally. As indicated in Section 3.5.1, groundwater flow in the
WVBA is dominated by seasonal pumping of the RID wells, with recharge occurring
from flood events in the Salt River supplemented with excess agricultural irrigation,
canal leakage, and inflow from the east.
5.2.1.1 Naturally Occurring Factors
One naturally occurring factor affecting contaminant migration is the variability in
aquifer characteristics. Transmissivity values in the vicinity of the WVBA were found to
range from 4,000 to 160,000 gallons per day per foot. Transmissivity values were
converted to hydraulic conductivity values by Weston (2000), who found the hydraulic
conductivity of the UAU ranges from 5 to 700 ft/d and the range for the MAU is 7 to 30
ft/d. In accordance with Darcy’s law, the rate of VOC migration increases with increased
hydraulic conductivity and gradient.
Groundwater recharge in the WVBA occurs when water at the land surface infiltrates and
reaches the groundwater table. Sources of recharge include the infiltration of excess
irrigation water, leakage from irrigation canals and laterals, and effluent discharge and
naturally occurring recharge from precipitation-created flood flows within the Salt River.
While the Salt River itself is not located within the WVBA, its proximity makes the
riverbed a significant naturally occurring source of groundwater recharge within the
WVBA. Additionally, as regional groundwater flow in UAU1 is from the east and north,
groundwater enters the WVBA from these directions.
The Salt River is the largest surface drainage feature in the vicinity of the WVBA.
Although dry during most of the year, winter and early spring precipitation combined
with runoff from melting snow from the upper watershed can produce runoff. These
events, although short in duration, contribute significant groundwater recharge. In 1965,
infiltration rates in the Salt River were calculated to average 1.1 ft/d (Briggs and Werho,
1966). As a result of this flow, water levels rose dramatically in wells within several
hundred feet of the river.
Mann and Rohne (1983) examined flood events of February 1978 to June 1980, which
totaled 5.45 million AF. They concluded that the total streamflow loss in the 74-mile
reach between Granite Reef and Gillespie Dams was at least 474,000 AF. During that
same time period, groundwater pumpage in the area was reduced by about 35 percent (1.9
million AF). Water levels were measured in 169 shallow wells along the Salt River.
Water levels rose from 1 to 45 feet in 157 wells and declined 1 to 43 ft in 11 wells with
the greatest rise occurring near the Salt River. The average 35-foot rise in water levels

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-4

8/9/2012

 was attributed to both recharge from the Salt River and reduction in groundwater
pumpage. The average infiltration rate was calculated at 0.45 ft/d.
Corkhill and others (1993) estimated that the average annual recharge along the Salt
River from Tempe Butte to the 91st Avenue wastewater treatment facility was
approximately 12 percent of the annual Granite Reef Dam discharge. Weston (2000)
concluded that recharge from Salt River runoff is highly localized and of little
consequence from a volumetric standpoint, but runoff is important in changing the
direction of groundwater movement that may be experienced as a result of sudden rise in
the water table.
Another process affecting VOC transport in groundwater is retardation, the process of
adsorption/desorption. The affinity of a VOC for organic carbon in soil is expressed by
the solid-water partition (distribution) coefficient identified as K d , which relates to the
dissolved contaminant mass in groundwater to the mass sorbed to soil, and calculated as
follows:
K d = K oc (f oc ), where
K d = distribution coefficient [milliliter (ml) water /g soil ]
K oc = organic carbon partition coefficient (ml water /g oc )
f oc = organic carbon fraction (g oc /g soil )
The retardation factor of a VOC in soil can be calculated as follows:
R d = 1 + [p b (K d ) / n e ], where
R d = retardation factor (unitless)
p b = bulk density (g/cm3)
n e = effective porosity (ml water / cm3 soil )
As indicated in Section 5.1.1, TOC was found to range from 74 to 3,650 mg/kg, average
bulk density values ranged from 1.15 to 1.92 g/cm3, and effective porosity ranged from
22 to 45 percent. Using the mean of these values and ADEQ-supplied values for K oc , the
following average retardation factors for the WVBA were calculated:




PCE - R d = 4.1
TCE - R d = 2.1
1,1-DCE - R d =1.6

Based upon the above values, 1,1-DCE will exhibit the highest contaminant velocity of
the three identified VOCs.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-5

8/9/2012

 5.2.1.2 Man-Induced Factors
Groundwater pumpage represents the major outflow from the groundwater system within
the WVBA. The primary production wells within the WVBA are those operated by RID,
which are operated seasonally during the hotter months of the year. RID provides its
members with water for agricultural irrigation. The total number of RID production wells is
approximately 104. Of these wells, 31 (30 operational) are located within or adjacent to the
WVBA. The RID wells are pumped from approximately March into September.
There are two sources of RID water. Approximately 30,000 AFY is obtained as effluent
from the 23rd Avenue wastewater treatment facility and approximately 135,000 AFY is
obtained from pumped groundwater. According to Mr. Stan Ashby (2001), no wells have
been shut down due to contamination.
As farmland currently being served by RID becomes developed, less water will be
needed (Ashby, 2001). As addressed in the Land and Water Use Study (Appendix K),
RID’s prediction is that for at least the next ten years, delivery rates will remain similar to
those of today. RID does not generate written documents addressing future water use
projections.
Much of the western portion of the WVBA consists of irrigated agriculture. Fields are
irrigated using flood application, and excess irrigation water historically applied to these
fields characteristically reached the local water table as recharge. As agricultural fields are
converted to urban uses, groundwater recharge from excess irrigation is lessened. One of
the more comprehensive attempts to quantify recharge from agricultural fields was
performed by ADWR (Corell and Corkhill, 1994). An appropriate travel time had to be
established between the land surface and the aquifer. This travel time, based upon the
thickness of the unsaturated zone beneath the field, was termed the lag time for agricultural
recharge and averaged ten years. Thus, once the WVBA is fully urbanized, it will take
approximately ten years for groundwater recharge from excess irrigation to cease. Weston
(2000) calculated the recharge rate from irrigated agriculture at 1.82 feet/year/acre of
irrigated agriculture.
Canals also constitute a source of groundwater recharge. Unlined (earthen) canals,
contribute substantially more water than lined channels. Concrete lining does not entirely
eliminate seepage from these systems. The RID canal was relined in 1986 (Corkhill and
others, 1993). Prior to 1986, the recharge rate was calculated at 0.21 AF per year per
lineal foot. After relining in 1986, this appears to have been reduced by approximately
90 percent.
At the COP 23rd Avenue wastewater treatment facility, treated sewage effluent not
pumped to the RID canal is discharged to the Salt River. Flow continues in the Salt River
to about 67th Avenue, and 100 percent of the discharge is assumed to recharge the
groundwater table (Corkhill and others, 1993).

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-6

8/9/2012

 5.2.2 Groundwater Modeling Methods and Results
ADEQ and its former contractor, Weston, developed a five-layer, transient, groundwater
flow model for the Central Phoenix Area (Weston, 2000). The Central Phoenix Plume
Model (CPM) was designed to model aquifer conditions and groundwater movement
including the effects of existing groundwater pumping. The CPM was constructed using
Groundwater Vistas, MODFLOW, and MODFLOW-SURFACT to simulate the
groundwater flow. Its purpose is to assist in the evaluation of remedial strategies and
their effects on groundwater movement and the contaminant plume. Specific fate and
transport modeling was not conducted because the scale of the model was too large and
the data requirements too extensive. The CPM has the potential to be modified to
develop fate and transport models for specific areas.
Prior to the CPM, four models were developed in the study area. These included the
ADWR/ADEQ Central Phoenix Target Model (Corell, 1992), ADWR Salt River Valley
(SRV) model (Corell and Corkhill, 1994), Motorola 52nd Street Facility (M52) Model
(Dames & Moore, 1995) and the VW&R model for the WVBA (Harding Lawson
Associates, 1997d). The SRV model covered the entire Salt River Valley while the M52
model partially covered the east portion of the CPM, extending from McDowell Road to
Air Lane, and 52nd Street to Seventh Avenue. The VW&R model partially covered the
western portion of the CPM extending from Camelback to Elliot Roads, and from
Seventh Street to 99th Avenue. The models are three-dimensional using MODFLOW to
simulate groundwater flow. Information and data from these models were used in the
development of the CPM; however, none of the models alone were sufficient to meet the
requirements of the CPM.
The CPM was developed by first creating a conceptual model to identify and summarize
the major flow components of the aquifer system. Flow components include outflow in
the form of pumping and groundwater movement, inflow from canals, agricultural
irrigation, Salt River recharge, and groundwater movement; and changes in storage. The
time period covered by the model was selected to be 1972 to 1996 based on the pumping
history of the area, water level data, and the model purpose.
The conceptual model was developed by the collection of available data including well
records, annual pumping volumes, water levels, water use, river discharge, land use, and
recharge, followed by the preparation of a database to contain the data. The CPM was
originally scoped as a three layer model but was eventually changed to a five layer model
as a result of Technical Exchange Meetings. Development of the three-layer transient
model was conducted using the UAU, MAU, and LAU as model layers. The five-layer
seasonal transient model is the final version of the CPM. The five-layer seasonal
transient model was completed by separating the UAU and the MAU into two layers
each, modifying aquifer parameters to reflect changes in layer thicknesses and
compositions, converting transient data arrays into seasonal rates, conversion of head
boundaries to transient conditions from steady-state conditions, and three stress periods
per year were added instead of a single annual stress period.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-7

8/9/2012

 The division of the UAU is based on the content of fine-grained material while the MAU
is subdivided based on thickness because a definitive marker horizon could not be
established. As described in Section 3.4.2, the upper portion of the UAU (UAU1) is
comprised of interfingered sand and gravel lenses with minimal clay lenses. The lower
portion of the UAU (UAU2) begins where clay lenses increase in number until clays
dominate the lithology. The transition between the UAU and MAU is interpreted to
begin where at least 40 feet of hard brown clay or sticky brown clay is encountered.
Below this point, the lithology usually shows a marked increase in the amount of finegrained material present.
The UAU is considered to be under unconfined conditions while the other aquifers are
considered to be confined, but become unconfined as groundwater is withdrawn. Aquifer
parameters used in the model were collected from available reports presenting aquifer test
results for the model area. Hydraulic conductivities were calculated from existing
transmissivity data and lithologic information. Hydraulic conductivities used for the
UAU ranged from 5 to 700 ft/d. Hydraulic conductivities used for the MAU ranged from
7 to 30 ft/d, and for the LAU ranged from 3 to 20 ft/d. Vertical hydraulic conductivities
were not available for the CPM area so they were set at ten percent of the horizontal
hydraulic conductivity. Storage coefficient/specific yield for UAU1 was taken from
Corell and Corkhill (1994) at 0.08 to 0.20. Discussions during Technical Exchange
Meetings ascertained that the storage coefficient/specific yield for UAU2 should range
from 0.009 to 0.02; the MAU should range from 0.0003 to 0.0005; and the LAU should
range from 0.001 to 0.0009. Values used for the aquifer parameters varied across the site
within each aquifer and between different aquifers. Specific values used for different
areas of the model are shown in Weston (2000) on Figures 38 through 44.
Outflow in the CPM area includes groundwater pumping and underflow across the
boundaries. Groundwater pumping volumes were obtained from well owners including
municipalities and agencies. Private wells were not included because of the limited data
available and the minimal volume of groundwater pumped by these wells. After annual
pumping volumes were identified, the volume pumped from each model layer was
calculated based on the screened interval of the pumping well and the hydrologic
properties of the screened zone. Because of the variation in pumping volumes during the
year, pumping volumes were also divided to reflect this variation. Outflow in the CPM
by underflow across the boundaries could not be calculated due to the lack of data and
uncertainties involved, and therefore was not used for the conceptual model. However,
even though no outflow was used in the conceptual model, during model calibration and
validation outflow in the CPM by underflow across the boundaries was estimated at an
order of magnitude less than pumping.
Inflow to the CPM area includes canals, agricultural irrigation, Salt River recharge, and
underflow across the boundaries. The annual volume of water for the model time frame
from the various possible recharge sources was calculated using available sources, and
totaled for the CPM area. If information indicated that a possible source was not
providing water to the CPM area for a given time frame (i.e., no flow in the Salt River),
then this source was given a value of zero for that time period. As in identifying outflow,

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-8

8/9/2012

 underflow as an inflow component into the CPM was not used in the conceptual model
because of the uncertainties making it impossible to calculate. During calibration and
validation of the CPM, underflow as an inflow component into the CPM was estimated
using water levels at adjacent wells. Once inflow and outflow volumes were calculated,
the annual water budget was calculated and then divided into the three annual stress
periods.
Because model boundaries could not be set at physical features which control flow, the
boundaries were set by an artificial mechanism that simulates underflow with time across
the boundaries. Three types of flow conditions were set for the boundaries; zones of no
flow across the boundaries, zones with time variant flow and heads, and zones with
constant flow and head.
The CPM is constructed with a uniform grid of 80 rows and 144 columns. Nodal spacing
is 660 feet. The model units are days and feet and Ks are feet per day per model mode.
As mentioned above, the CPM covers a 25 year period from 1972 through 1996. Each
year is divided into three stress periods based on the VW&R model and verified by
pumping data provided by RID for 1992 through 1998. The stress periods were divided
into periods of January and February for a total of 59 days, March through September for
a total of 214 days, and October through December for a total of 92 days.
Data arrays selected for the CPM included those that stay constant with time and that
change with time. The constant arrays included K, storage coefficient/specific yield and
bottom elevations for all five layers; locations of boundary conditions; no flow locations;
constant flow rates and locations; river node locations; starting water level data;
calibration target data; and vertical conductance. Data arrays that change with time
included pumping, recharge, water levels at time-variant flow boundaries, and stress
periods when there is river flow.
Following model construction, model calibration was conducted. The CPM was run 59
times as a three layer model and 57 times as a five layer model. Adjustments were made
to the data arrays as appropriate depending on the mass balance error and how calculated
data and observed data matched at the calibration targets; 156 calibration targets were
used to evaluate the model’s accuracy.
Model calibration was considered complete when the mass balance error was 0.17
percent, the residual mean was one foot, the residual standard deviation was 9.3, the
residual standard deviation divided by the range was four percent, and the absolute
residual mean (ARM) was 7.2 feet. These statistics are considered good, meeting the
criteria originally established for the CPM including an ARM of less than ten feet and
residual standard deviation of less than ten percent.
Following model calibration, a sensitivity analysis was conducted. Parameters examined
to test the CPM sensitivity included agricultural recharge rates; canal recharge rates;
storage coefficient/specific yield; river conductance, discharge volume for COP 23rd Ave

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-9

8/9/2012

 wastewater treatment facility; horizontal and vertical K; pumping rates; and general head
boundary conductance. Results indicated that the CPM is most sensitive to agricultural
recharge and river conductance. The least sensitive parameters were storage coefficient
or specific yield.
Because of the groundwater pumping history for the area, the CPM starts in transient
conditions. The sensitivity analysis and calibration completed on the model ensure that
the model meets the purpose of the CPM. Specifics regarding input data, model
simulations, calibration procedures and sensitivity analysis, can be obtained from Weston
(2000).
Following model calibration, validation of the model was completed for the time frame
1996 through 1998 (Weston, 2001). Validation indicated that CPM calibration meets the
purpose of the model using the newer data set. The mass balance remained the same as
the original data set at 0.17 percent. The residual mean was 2.62 feet as compared to one
foot for the earlier data set. The residual standard deviation divided by the range in target
values was three percent which is slightly more accurate than the original four percent.
The ARM was 7.12 feet which is slightly more accurate than the calibration ARM of 7.2
feet.
Measured water levels and simulated water levels are, in general, less than ten feet in
difference. The gradients and water-level contour maps for the simulated and observed
data are similar in direction of flow and shape. Overall modeling results indicate that the
simulated results match well with observed data. There are areas, however, that need
more data to improve model calibration. Based on model calibration and validation, the
CPM meets its intended purpose to evaluate remedial alternatives and contaminant
movement in the CPM area.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 5-10

8/9/2012

 6.0

SUMMARY
6.1

Site Physical Characteristics



The WVBA is the areal projection of the western portion of a large commingled
plume of contaminated groundwater in Phoenix, Arizona. Contributors to this
plume include both industrial facilities and contaminated groundwater from the
east and north, as regional groundwater flow is generally west and southwesterly.
The initial primary COC for the WVBA include the following VOCs: PCE, TCE,
TCA, cis 1,2-DCE, 1,1-DCA, and 1,1-DCE. To a limited extent, chromium is
also being considered a COC. The RI was performed to evaluate the horizontal
and vertical extent of groundwater contamination in the WVBA.



The WVBA extends from 7th to 75th Avenues and from Buckeye Road to
Interstate 10. This corresponds to an area approximately eight miles in length and
1.5 miles in width (approximately 12 square miles). In addition, a finger shaped
plume exists between 7th and 27th Avenues between Buckeye and Lower Buckeye
Roads. Within the WVBA are industrial facilities that have used VOCs in former,
and in some cases, current operations. Typical industrial businesses within the
WVBA WQARF Registry Site include automobile body repair, automobile
painting operations, automobile repair, chemical mixing and distribution, dry
cleaning operations, foundry operations, manufacturing operations, metal
fabrication and plating, plastic manufacturing, printing operations, and
vulcanizing operations.



The west-flowing Salt River is located south of the site along the entire length of
the WVBA. Treated effluent from the 23rd Avenue wastewater treatment facility
is discharged into the Salt River bed under an EPA-issued NPDES permit.
Additionally, during periods of heavy regional precipitation, upstream dam
releases and local runoff result in additional surface water flow. When upstream
dam releases occur, the Salt River acts as a source of groundwater recharge,
raising water levels and altering the direction of groundwater flow to a more
northward direction.



The RID main canal originates at 19th Avenue south of Interstate 17. Year-round
discharge of water into the canal occurs at the 23rd Avenue wastewater treatment
facility where 30,000 acre-feet per year of treated wastewater is discharged into
the canal. Water within the canal is utilized for non-potable agricultural purposes.
The canal is also fed by a number of RID production wells located throughout the
WVBA; these wells discharge an additional 135,000 acre-feet per year of pumped
groundwater into the canal. The wells pump during the warmer months of the
year, are dormant during the winter (with the exception of a few wells which are
pumped during the entire year), and either discharge directly into the canal, or
discharge into both exposed and unexposed lateral canals that feed the canal.
When the RID wells are pumping, they act as a source of groundwater discharge,

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-1

8/10/2012

 lowering water levels and altering the direction of groundwater flow in the eastern
portion of the WVBA from westerly to southwesterly.


The WVBA is located within the SRV, an alluvial basin characteristic of Basin and
Range physiography. The SRV alluvial basin consists of basin-fill deposits of
unconsolidated to semi-consolidated late Tertiary to Quaternary sediments ranging
up to several thousand feet thick within the center of the basin and consisting of
interbedded cobbles, gravel, sand, silt, clay, and evaporites. The basin-fill deposits
are subdivided into three hydrogeologic units that comprise the regional aquifer in
the SRV:
-

Lower Alluvial Unit (LAU)
Middle Alluvial Unit (MAU)
Upper Alluvial Unit (UAU)

Few wells penetrate the LAU due to its depth and low yield. The LAU does not
appear to be contaminated within the WVBA. The MAU overlies the LAU and
consists predominantly of silt and clay with interbedded sand and gravel lenses.
The MAU reaches thicknesses of 1,600 feet in the SRV. The UAU extends from
the ground surface to the top of the MAU. The UAU consists mainly of
unconsolidated silt, sand, and gravel deposited during the final stages of SRV
basin development. The association of coarse-grained deposits within the vicinity
of the Salt River suggests that the UAU was deposited by the ancestral Salt River.
The UAU ranges between 200 and 500 feet in thickness.


Based upon site-specific WVBA cross-sections, the following generalized
observations regarding the alluvial unit stratigraphy of the WVBA have been
developed.
UAU1 This uppermost layer is comprised of loose surface soils grading
downward into interfingered sand and gravel lenses; clay lenses, when present,
are thin and usually characterized as clayey sands. UAU1 ranges in thickness
from approximately 170 feet to 310 feet. Based upon the east-west cross-sections,
UAU1 appears to become finer-grained west of about 75th Avenue. Except in the
eastern portion of the WVBA, UAU1 also appears to become finer-grained
northwards, particularly in the northwest portion of the WVBA.
UAU2 This intermediate layer occurs where clay lenses increase in number until
clays dominate the lithologic horizons. UAU2 is encountered at depths ranging
from approximately 170 feet to 310 feet bgs, and exhibits a considerable range in
thickness, from approximately 30 feet to 260 feet or greater. UAU2 appears
thickest in the western portion of the WVBA. Based upon the east-west crosssections, UAU2 appears to become more fine-grained west of about 67th Avenue.
Conversely to UAU1, except in the eastern portion of the WVBA, UAU2 appears
to become finer-grained southwards.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-2

8/10/2012

 MAU The transition between the UAU and MAU is that area within the
lithologic sequence characterized by at least 40 feet of material often referred to
as hard brown clay or sticky brown clay. Below this point, the lithology usually
shows a marked increase in the amount of fine-grained material present. The
MAU is encountered at depths ranging from approximately 260 feet to 500 feet
bgs. The shallowest depth to the MAU is in the east, deepening in the west.
6.2

Site Hydrogeology



Groundwater flow in the WVBA is dominated by regional pumping centers (RID
wells) with recharge occurring from flood events in the Salt River supplemented
with excess agricultural irrigation and canal leakage. Groundwater movement
within the region is predominantly controlled by the aerial distribution of Salt
River recharge and RID well pumping. The aquifer system consists of the
hydrostratigraphic units identified above. It is apparent from pumping data and
water level responses in nearby wells that the three units are hydraulically
interconnected. The Salt River is the largest surface drainage feature in the
vicinity of the SRV. Although dry during most of the year, winter and early
spring precipitation combined with runoff from melting snow from the upper
watershed can produce runoff. These events, although short in duration,
contribute significant groundwater recharge.



Water level monitoring has been performed regularly in the WVBA since 1993.
Hydrographs document an overall decrease in water levels since monitoring was
initiated in 1993. Since 1993, water levels in both shallow and deeper wells have
declined approximately 35 feet, an average of approximately three feet per year.
Water levels fluctuate in most of the wells on a semi-annual basis, with water levels
lower in the summer and higher in the winter. This is likely due to a cyclical
combination of rebound within the aquifer following production well pump
shutdown and to a lesser degree local area precipitation during the winter months,
and seasonal pumpage of area irrigation wells during the summer months.



In the eastern portion of the WVBA (east of approximately 35th Avenue),
groundwater flow within UAU1 is in a general westerly direction at quarterly
gradients ranging from about 9 to 20 feet per mile. The central portion of the
WVBA (between approximately 35th and 63rd Avenues) is characterized by a
flattening of the water table, with southerly groundwater flow in the north-central
portion of the WVBA. In the western portion of the WVBA (west of
approximately 63rd Avenue), a depression of the surface of the groundwater table is
located in the northwestern portion of the WVBA centered at approximately
Roosevelt Street and 75th Avenue. Because of this depression, groundwater flow
south of Van Buren Street and west of 75th Avenue is northward.



Groundwater contours for the lower portion of the UAU (UAU2) indicate that
groundwater flow in UAU2 is westerly, with deviations ranging from

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-3

8/10/2012

 southwesterly to northwesterly. Quarterly gradients across the entire WVBA were
observed at approximately nine feet per mile.


Groundwater flow in the MAU varies by season as a result of the pumping of RID
wells during the summer months. During non-pumping conditions (first and
fourth quarters), groundwater flow is westerly at approximately eight feet per
mile. However, during pumping conditions (second and third quarters),
groundwater flow in the eastern portion of the WVBA is southwesterly towards
RID-104 at a gradient of about 38 to 40 feet per mile. Groundwater flow in the
western portion of the WVBA during pumping conditions is westerly at a gradient
of approximately five feet per mile.
6.3

Nature and Extent of Contamination



Contaminant sources have been investigated/ documented throughout the WVBA.
The COCs have been detected in soil gas, soil, canal water, and groundwater
samples. The highest PCE and TCE concentrations detected in a soil sample
collected in the WVBA were 8,040 and 30 mg/kg in 1992 at the Dolphin, Inc.
facility. The highest 1,1-DCE and TCA concentrations detected in soil were 100
and 6,300 mg/kg, collected in 2004 from the ALASG facility. The highest
detected concentration of chromium in soil was 32,000 mg/kg, collected at the
CRC, Inc. facility in 1995. The highest concentration of PCE detected in
groundwater was 95,000 µg/l, collected in 1998 from well DIMW-1 at the
Dolphin Inc. facility. TCE was detected at its highest concentration of 1,800 µg/l
in 1996 from MCMM facility well PZ-01. The highest concentration of 1,1-DCE
detected was 290 µg/l in a sample collected from well CT-W-03 in 1987 at the
Chevron terminal in the Phoenix tank farm. The highest detected concentration of
chromium was 40.5 mg/l from ADEQ well AVB72-01 in September 2003.



Water quality data (PCE, TCE, 1,1-DCE, and total chromium) for 55 UAU1 wells
from groundwater samples collected January through July 1998 are as follows:
- PCE contamination exceeding the AWQS of 5 µg/l extended from the eastern
boundary of the WVBA to approximately 69th Avenue, and north of the RID
canal; the northern extent of PCE contamination was not delineated.
- TCE contamination exceeding the AWQS of 5 µg/l also extended from the
eastern boundary of the WVBA to approximately 69th Avenue, and north of the
RID canal. The northern extent of TCE contamination exceeding the AWQS
appears to be limited to south of Roosevelt Street.
- 1,1-DCE contamination exceeding the AWQS of 7 µg/l is present in three
discrete areas. In the eastern WVBA, a 1,1-DCE plume extends from the eastern
boundary of the WVBA to 27th Avenue. In the north-central WVBA, a 1,1-DCE
plume trends northwest from 43rd Avenue to between 51st and 55th Avenues. In

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-4

8/10/2012

 the western WVBA, a 1,1-DCE plume extends from 59th Avenue north of
Buckeye to RID-84.
- Total chromium was analyzed for in five wells completed in the UAU1 during
this period. Each of the groundwater samples contained detectable concentrations
of total chromium with four of them exceeding the AWQS of 0.1 mg/l.


Water quality data for 90 UAU1 wells from groundwater samples collected
March through June 2003 are as follows:
- PCE contamination exceeding the AWQS extends from the eastern boundary of
the WVBA to at least 75th Avenue, and north of the RID canal except between
67th and 71st Avenues. The northern extent of PCE contamination exceeding the
AWQS appears to be limited to south of Roosevelt Street except between 51st and
59th Avenues. As a result of elevated PCE concentrations in this area, a PRP
(POS) initiated site characterization, under a consent order, to evaluate the
possible source of PCE north of Roosevelt Street.
- TCE contamination exceeding the AWQS extends from the eastern boundary of
the WVBA to approximately 71st Avenue, and north of the RID canal except in
the vicinity of RID-84. The northern extent of TCE contamination exceeding the
AWQS appears to be limited to south of Roosevelt Street except between 39th and
47th Avenues. The possible source of this contamination north of Roosevelt Street
is currently under investigation by a PRP located in the WCP WQARF Registry
Site.
- 1,1-DCE contamination exceeding the AWQS is present in three discrete areas.
In the eastern WVBA, a 1,1-DCE plume extends from the eastern boundary of the
WVBA to 27th Avenue. In the north-central WVBA, a 1,1-DCE plume trends
south in the vicinity of 43rd Avenue in a triangular pattern from 37th to 51st
Avenues. In the western WVBA, a 1,1-DCE plume extends from 59th Avenue
and Van Buren to RID-84.
- Total chromium was analyzed in groundwater samples collected from 81 wells
with screened intervals in the UAU1. Total chromium was detected in 40 of these
samples with ten samples exceeding the total chromium AWQS of 0.1 mg/l. With
the exception of the southeast corner of the site, these wells are spread across the
entire WVBA without a distinct pattern to identify a manmade source. Therefore,
data interpretation suggests that the chromium in the wells not located in the
southeast corner of the WVBA is possibly from deterioration of stainless steel
well casing, or naturally occurring within native soils.



Water quality data for 100 UAU1 wells from groundwater samples collected in
2008 are as follows:

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-5

8/10/2012

 - PCE contamination exceeding the AWQS extends from the eastern boundary of
the WVBA to approximately 71st Avenue, and north of the RID canal except
between 67th and 71st Avenues. The northern extent of PCE contamination
exceeding the AWQS appears to be limited to south of Roosevelt Street except
between 47th and 55th Avenues, where POS investigative activities continue.
- TCE contamination exceeding the AWQS extends from the eastern boundary of
the WVBA to approximately 67th Avenue, and north of the RID canal. The
northern extent of TCE contamination exceeding the AWQS appears to be limited
to south of Roosevelt Street except between 41st and 55th Avenues.
- 1,1-DCE contamination exceeding the AWQS extends from the eastern
boundary of the WVBA to approximately 35th Avenue, north of the RID canal
and south of Van Buren Street. Additionally, well RID-106 in the western portion
of the WVBA also exceeds the AWQS for 1,1-DCE.
- Total chromium was analyzed for in groundwater samples collected from 57
wells with screened intervals in the UAU1. Total chromium was detected in 33 of
these samples with ten samples exceeding the total chromium AWQS of 0.10
mg/l. With the exception of the southeast corner of the site, these wells are spread
across the entire WVBA without a distinct pattern to identify a manmade source.
Therefore, data interpretation suggests that the chromium in the wells not located
in the southeast corner of the WVBA is possibly from deterioration of stainless
steel well casing, or naturally occurring within native soils.


Groundwater data were collected from seven UAU2 wells in 1998 in the western
and southeastern portions of the site. Water quality data for UAU2 wells for data
collected January through July 1998 are as follows:
- PCE concentrations exceeding the AWQS were detected in groundwater
samples collected from wells AVB10-02, AVB69-01, RID-109, and DIMW-1.
- TCE concentrations exceeding the AWQS were detected in groundwater
samples collected from AVB10-02 and RID-109.
- 1,1-DCE concentrations exceeding the AWQS were detected in the groundwater
sample collected from AVB10-02.



Water quality data for 38 UAU2 wells from samples collected March through
June 2003 are as follows:
- PCE contamination exceeding the AWQS extends from 19th Avenue to at least
75th Avenue, and north of the RID canal except between 67th and 71st Avenues.
The northern extent of PCE contamination exceeding the AWQS appears to
coincide with Van Buren Street in the area of 51st Avenue but is undefined in the
east and west.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-6

8/10/2012

 - TCE contamination exceeding the AWQS extends from the eastern boundary of
the WVBA to approximately 55th Avenue and from approximately 59th Avenue to
east of 75th Avenue, and north of the RID canal except in the vicinity of RID-84.
The northern extent of TCE contamination exceeding the AWQS is undefined in
the east and appears to be limited to south of Roosevelt Street west of
approximately 59th Avenue.
- 1,1-DCE contamination exceeding the AWQS is present in two discrete areas.
In the eastern WVBA, 1,1-DCE exceeding the AWQS was detected in the
groundwater sample collected from RID-100. In the western WVBA, a 1,1-DCE
plume extends from approximately 59th Avenue and Van Buren to RID-84 and
RID-106.
- Total chromium was analyzed in eighteen wells completed in the UAU2. Eight
of the samples contained detectable concentrations of total chromium; however,
none of the concentrations exceeded the AWQS.


Water quality data for 45 UAU2 wells from groundwater samples collected in
2008 are as follows:
- PCE contamination exceeding the AWQS discontinuously extends from the
eastern boundary of the WVBA to approximately 75th Avenue, and north of the
RID canal. The northern extent of PCE contamination exceeding the AWQS
appears to be limited to north of Van Buren Street in the eastern WVBA and
Interstate 10 in the western WVBA.
- TCE contamination exceeding the AWQS extends from the eastern boundary of
the WVBA to approximately 55th Avenue, and north of the RID canal. TCE was
also detected at a concentration exceeding the AWQS at well RID-106. The
northern extent of TCE contamination exceeding the AWQS appears to be limited
to south of Van Buren Street except in the eastern edge of the WVBA.
- 1,1-DCE contamination exceeding the AWQS extends from the eastern
boundary of the WVBA to approximately 35th Avenue. 1,1-DCE was also
detected at a concentration exceeding the AWQS at well RID-106. The northern
extent of TCE contamination exceeding the AWQS appears to be limited to south
of Roosevelt Street.
- Total chromium was analyzed in 32 of the 45 UAU2 wells. Nine samples
contained detectable concentrations of total chromium with one groundwater
sample, collected from well AVB134-02, exceeding the total chromium AWQS of
100 µg/l.



Water quality data for seven MAU wells from groundwater samples collected in
1998 are as follows:

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-7

8/10/2012

 - PCE concentrations exceeding the AWQS were detected in groundwater
samples collected from AVB69-01 (26 µg/l) and DIMW-1 (18 µg/l).
- The only detectable TCE concentration was from the groundwater sample
collected from DIMW-1 (0.9 µg/l).
- 1,1-DCE was not detected in any of the groundwater samples collected during
this round of sampling at the MAU wells.


Water quality data for ten MAU wells from groundwater samples collected in
2003 are as follows:
- The only PCE concentration exceeding the AWQS was detected in the
groundwater sample collected from AVB82-01 (30 µg/l).
- The only detectable TCE concentration was from the groundwater sample
collected from AVB82-01 (2.5 µg/l).
- 1,1-DCE was only detected in one sample collected from the MAU wells. This
groundwater sample was collected from monitor well AVB82-01 and exceeded
the AWQS at a concentration of 8.9 µg/l.
- Total chromium was analyzed in five of the ten MAU wells. The groundwater
sample collected from well AVB61-01 contained total chromium at a
concentration which exceeded the AWQS.



Water quality data for eight MAU wells from groundwater samples collected in
2008 are as follows:
- The only PCE concentration exceeding the AWQS was detected in the
groundwater sample collected from AVB82-01 (60 µg/l). AVB82-02 exhibited a
concentration of 4.9 µg/l of PCE.
- The only TCE concentration exceeding the AWQS was detected in the
groundwater sample collected from AVB82-01 (16 µg/l).
- The only 1,1-DCE concentration exceeding the AWQS was detected in the
groundwater sample collected from AVB82-01 (22 µg/l).
- Total chromium was analyzed in four of the eight MAU wells sampled. Total
chromium was detected in each of the samples but at concentrations less than the
AWQS.



Sampling of RID canal water at seven locations was performed in June 2003.
PCE exceeded the AWQS (for comparison only) of 5 µg/l in 6 of 7 canal water

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-8

8/10/2012

 samples. TCE exceeded the AWQS of 5 µg/l in 5 of 7 canal water samples. The
end use of RID canal water is for irrigation; no surface water quality standards are
established for PCE and TCE.
6.4

Contaminant Fate and Transport



The following four potential routes of migration have been identified for VOCs
released into the vadose zone in the WVBA: unsaturated flow (soils), saturated
flow (groundwater), canal water and vapor intrusion.



The following generalizations can be made using existing data, and field
observations of drill cuttings and soil samples continuously collected during
rotosonic drilling:



-

The vadose zone is comprised of unsaturated UAU1 soils, consisting of
loose surface soils grading into interfingered sand and gravel lenses; clay
lenses, when present, are thin and usually characterized as clayey sands.
Based upon the east-west cross-sections, UAU1 appears to become finergrained west of about 75th Avenue. Except in the eastern portion of the
WVBA, UAU1 also appears to become finer-grained northwards,
particularly in the northwest portion of the WVBA.

-

Depth to groundwater within the WVBA currently ranges from
approximately 75 to 140 feet bgs depending on location and season; thus,
this is the range in thickness of the vadose zone. In general, depth to
groundwater is greatest in the north-central portion of the WVBA and
shallowest along the eastern boundary of the WVBA.

-

Based upon the observed generalizations of UAU1 lithology, the
permeability of vadose zone soils within the WVBA is likely lowest west
of about 75th Avenue and except in the eastern portion of the WVBA,
decreases northward.

-

The moisture content of vadose zone soils has been measured, ranging
from 2.6 percent (dry) to moist at 19 percent. Dry bulk densities ranged
from 1.15 to 1.92 g/cc. Porosities were calculated to range from 22 to 45
percent. TOC ranged from 74 to 3,650 mg/kg.

One naturally occurring factor affecting contaminant migration is variability in
aquifer characteristics. Transmissivity values in the vicinity of the WVBA were
found to range from 4,000 to 160,000 gallons per day per foot. Transmissivity
values converted to hydraulic conductivity values indicate that the hydraulic
conductivity of the UAU ranges from 5 to 700 ft/d and the range for the MAU is 7
to 30 ft/d. In accordance with Darcy’s law, the rate of VOC migration increases
with increased hydraulic conductivity and gradient.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-9

8/10/2012

 

Another process affecting VOC transport in groundwater is retardation, the
process of adsorption/desorption. The affinity of a VOC for soil is expressed by
the solid-water partition (distribution) coefficient which relates to the dissolved
contaminant mass in groundwater to the mass sorbed to soil. Based upon
calculated values, 1,1-DCE will exhibit the highest contaminant velocity of the
three identified VOCs.

Groundwater pumpage represents the major outflow from the groundwater system
within the WVBA. The primary production wells within the WVBA are those operated
by RID, which are operated seasonally during the hotter months of the year. Thirty
operable RID wells are located within or adjacent to the WVBA, and are pumped from
approximately March to September.
There are two sources of RID water.
Approximately 30,000 AFY is obtained as effluent from the COP 23rd Avenue
wastewater treatment facility and approximately 135,000 AFY is obtained from pumped
groundwater. The RID was formed in 1928 after securing an agreement with SRP to
pump and deliver water in 1923.
 Much of the western portion of the WVBA consists of irrigated agriculture. Fields
are irrigated using flood application, and excess irrigation water historically applied
to these fields characteristically reached the local water table as recharge. As
agricultural fields are converted to urban uses, groundwater recharge from excess
irrigation is lessened. Once the WVBA is fully urbanized, it will take approximately
ten years for groundwater recharge from excess irrigation to cease.


The CPM was designed to model aquifer conditions and groundwater movement
including the effects of existing groundwater pumping. Its purpose is to assist in
the evaluation of remedial strategies and their effects on groundwater movement
and the contaminant plume. The CPM has the potential to be modified to develop
fate and transport models for specific areas. The time period covered by the
model was selected to be 1972 to 1996 based on the pumping history of the area,
water level data, and the model purpose. Each year is divided into three stress
periods and verified by pumping data provided by RID for 1992 through 1998.
The stress periods were divided into periods of January and February for a total of
59 days, March through September for a total of 214 days, and October through
December for a total of 92 days. Measured water levels and simulated water
levels are, in general, less than ten feet in difference. The gradients and waterlevel contour maps for the simulated and observed data are similar in direction of
flow and shape. Overall modeling results indicate that the simulated results
match well with observed data. There are areas, however, that need more data to
improve model calibration. Based on model calibration and validation, the CPM
meets its intended purpose to evaluate remedial alternatives and contaminant
movement in the CPM area.



The RID canal originates at 19th Avenue south of Interstate 17 continuing on to
the 23rd Avenue wastewater treatment facility where 30,000 AFY of treated
wastewater is discharged into the canal. The canal is also fed by a number of RID
production wells located throughout the WVBA; these wells discharge an

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-10

8/10/2012

 additional 135,000 AFY of pumped groundwater into the canal. Some of these
wells extract VOC-contaminated groundwater which is discharged into the canal.
Concentrations of VOCs in canal water do not exceed surface water standards.
Due to the significant base flow from the 23rd Avenue wastewater treatment
facility and from RID wells pumping uncontaminated groundwater, the effect of
RID well discharge of groundwater containing VOCs into the canal is not
appreciable; VOC concentrations are diluted to below AWQSs within 125 feet of
the point of discharge. Beyond 125 feet of the point of discharge, however, the
diluted/ reduced VOC concentrations stabilize, and remained consistent at 4.0
µg/l and less a minimum of two miles downstream from the discharge point.


Once released to the vadose zone, VOCs can volatilize into soil gas which can
migrate upwards to the ground surface. Depending on the land use/surface cover,
soil gas can either be released directly to the atmosphere, become trapped beneath
impermeable structures, or migrate into structures either beneath or at the ground
surface. Typically, vapor intrusion will occur at or near the contaminant (in this
case VOC) source area, but can also occur via off-gassing from the groundwater.
The likelihood of vapor intrusion via this pathway decreases with increasing
depth to groundwater.

West Van Buren WQARF Registry Site
Remedial Investigation Report

Page 6-11

8/10/2012

 SECTION 7.0

REFERENCES

Allen Stephenson Associates, 2003, Quarterly Groundwater Monitoring Letter Report,
American Linen Supply Company (ALSCo), LUST File #0291.01; Facility ID #0-004699
AMEC Earth and Environmental, 2007, Technical Memorandum, Western Boundary
Investigation, Motorola 52nd Street Superfund Project, Operable Unit 3, Arizona Public
Service Co., USEPA Docket No. 2004-25.
Analytical Technologies, Inc., 1992, Faxed laboratory reports to Tom Curry of ADEQ.
Arcadis Geraghty & Miller, 1999, 1998 Annual Groundwater Monitoring Report, Mobest
Railroad, 707 North 20th Avenue, Phoenix, Arizona
Arizona Department of Environmental Quality, 2000, West Van Buren Reynolds Metals
Company No Further Action under ARS 49-287.01F
Arizona Department of Environmental Quality, 2002, No Further Action Determination
for Soils at the Vopak USA Facility, 50 South 45th Avenue, Phoenix, AZ
Arizona Department of Environmental Quality, 2004, Annual Water Withdrawal and Use
Report
Arizona Department of Environmental Quality, 2008, No Further Action Determination
for Soil at American Linen Supply Company Facility Site Located at 720 West
Buchanan, Phoenix, Arizona
Arizona Department of Water Resources, 1987, Fowler Industrial Area/Van Buren Tank
Farm Site Inspection Report
Arizona Department of Water Resources, 2004, Phoenix AMA Comprehensive
Hydrologic Monitoring Plan, Second Annual Status Report
Arizona Department of Water Resources, 2005, ADEQ WVBA Submittal, prepared for
ADEQ
Ashby, Stan, 2001, Meeting between Mr. Stan Ashby of RID and ADEQ personnel on
April 30, 2001
ASL Hydrologic & Environmental Services, 1998, Site Characterization Report, Western
States Petroleum Fuelco #105, 3202 West Van Buren, Phoenix, Arizona, LUST File
#2972.01 and 2972.02
ASL Hydrologic & Environmental Services, 1999, Groundwater Monitoring Letter
Report-December 1998 Through February 1999, Western States Petroleum Fuelco #105,

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-1

8/10/2012

 3202 West Van Buren Avenue, Phoenix, Arizona, LUST File #2972.01; ASL Project
#23601
ATC Associates inc., 2005, Groundwater Monitoring Report (2005), Former Circle K
Store No. 01992, 1201 North 59th Avenue, Phoenix, Arizona 85043, ADEQ Facility ID
No. 0-004554, ADEQ LUST File Nos. 2462.01 and 2464.04
Basin & Range Hydrogeologists, Inc., 1993a, Results of Soil Excavation Activities
Conducted in Response to a Release of Liquids and Sludge at Dolphin III
Basin & Range Hydrogeologists, Inc., 1993b, Revised Work Plan, Phase I Hydrological
Investigation at Dolphin I
Basin & Range Hydrogeologists, Inc., 1996a, Results of the Phase I Hydrogeological
Investigation at Dolphin, Inc., 740 South 59th Avenue, Phoenix, Arizona, March 6.
Basin & Range Hydrogeologists, Inc., 1996b, Results of Soil Investigations at Dolphin,
Inc., 740 S. 59th Ave., Phoenix, AZ
Basin & Range Hydrogeologists, Inc., 1998, Groundwater Monitoring Data Collected at
Dolphin Wells DIMW-1, DIMW-2, and DIMW-3
Basin & Range Hydrogeologists, Inc., 2001a, Report on Vadose Zone Investigation, Air
Liquide America Corp., 301 S. 45th Ave., Phoenix, AZ
Basin & Range Hydrogeologists, Inc., 2001b, Initial Groundwater Monitoring Report –
Fourth Quarter 2000 (Revised), Air Liquide America Corporation, 301 South 45th
Avenue, Phoenix, Arizona
Basin & Range Hydrogeologists, Inc., 2001c, Groundwater Monitoring Report – First
Quarter 2001, Air Liquide America Corporation, 301 South 45th Avenue, Phoenix,
Arizona
Basin & Range Hydrogeologists, Inc., 2001d, Groundwater Monitoring Report – Second
Quarter 2001, Air Liquide America Corporation, 301 South 45th Avenue, Phoenix,
Arizona
Basin & Range Hydrogeologists, Inc., 2003, Groundwater Monitoring Report –Third
Quarter 2001, Air Liquide America, Phoenix, AZ
Basin & Range Hydrogeologists, Inc., 2004, Vadose Zone Investigation Report
Addendum, Air Liquide America Limited Partnership, 301 South 45th Avenue, Phoenix,
AZ

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-2

8/10/2012

 Basin & Range Hydrogeologists, Inc., 2005, Soil Assessment Report for October December 2004 Investigations, Air Liquide Phoenix Plant, 301 South 45th Avenue,
Phoenix, AZ
BE&K/Terranext, 1998, Site Characterization Report, Department of Economic Security,
1720 West Madison Street, Phoenix, Arizona, ADEQ LUST File #2789.01, ADEQ
Facility ID 0-008114
BE&K/Terranext, 2000a, Site-Specific Health and Safety Plan, West Van Buren
WQARF Registry Site, Phoenix, AZ, prepared for ADEQ
BE&K/Terranext, 2000b, Quality Assurance Project Plan, West Van Buren WQARF
Registry Site, Phoenix, AZ, prepared for ADEQ
BE&K/Terranext, 2000c, Field Sampling and Analysis Plan, West Van Buren WQARF
Registry Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2000d, Well Inventory Report, West Van Buren WQARF Registry
Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2000e, Technical Memorandum, Water Level and Chemical
Concentration Contour Map Development, West Van Buren WQARF Registry Site,
Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2000f, Well Installation Report, Wells EX-1 and IN-1, ALSCo
Facility, 720 West Van Buren, Phoenix, Arizona
BE&K/Terranext, 2001a, Well Installation Report, West Van Buren WQARF Registry
Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2001b, Passive Diffusion Bag Sample Water Quality Report, West
Van Buren WQARF Registry Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2001c, Roosevelt Irrigation District Canal Characterization Report,
West Van Buren WQARF Registry Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2001d, Construction Certification Report, ALSCo Early Response
Action, West Van Buren, WQARF Registry Site, Phoenix, Arizona
BE&K/Terranext, 2002a, Well Installation Report, West Van Buren WQARF Registry
Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2002b, Passive Diffusion Bag Sample Water Quality Report, West
Van Buren WQARF Registry Site, Phoenix, AZ prepared for ADEQ

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-3

8/10/2012

 BE&K/Terranext, 2003a, Well Installation Report, West Van Buren WQARF Registry
Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2003b, Well Development Report, West Van Buren WQARF Registry
Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2003c, Roosevelt Irrigation District Water Quality Report, West Van
Buren WQARF Registry Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2003d, Second Half 2002 and First Half 2003 Groundwater and
Remedial Performance Monitoring Report, ALSCo Early Response Action, West Van
Buren WQARF Registry Site, Phoenix, AZ prepared for ADEQ
BE&K/Terranext, 2004, Third Quarter 2003 Water-Quality Report, West Van Buren
WQARF Registry Site, Phoenix, AZ, prepared for ADEQ
Blaes Environmental Management, Inc., 1999, Fourth Quarter 1998, Vapor Extraction
Remediation Status for Circle K Store #00608, Located at 6440 West Van Buren in
Phoenix, Arizona
Blaes Environmental Management, Inc., 2003, Groundwater Monitoring and Sampling
Report - June 2003 Event, Former Circle K Store #1992, 1201 North 59th Avenue,
Phoenix, Arizona, Blaes Environmental Project #007-1992-08
Briggs, P.C. and L.L. Werho, 1966, Infiltration and Recharge from the Flow of April
1965 in the Salt River near Phoenix, AZ, Arizona State Land Department WaterResources Report No. 29
Brown and Caldwell, 1990a, Final Site Assessment, Unocal Property, Van Buren Tank
Farm, Phoenix, Arizona
Brown and Caldwell, 1990b, Subsurface Investigation Report, UNOCAL Phoenix
Terminal, Leased Parcel
Brown & Caldwell, 1999a, Dry Well Sampling at Dolphin I and VI Loading Docks
Brown & Caldwell, 1999b, Performance Status Report For Soil Vapor Extraction
Systems at Dolphin, Inc., March 12
Brown & Caldwell, 2000a, Dolphin, Inc. Phase II Hydrogeological Investigation Report
Brown & Caldwell, 2000b, Soil Vapor Extraction operation plan, Dolphin, Incorporated
740 South 59th Avenue, Phoenix, Arizona 85043
Brown & Caldwell, 2001, Dolphin II/V Site Assessment Report, Phoenix, AZ

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-4

8/10/2012

 Brown & Caldwell, 2002a, Dolphin Main Plant Site Assessment Report
Brown & Caldwell, 2002b, Dolphin III Soil Vapor Extraction System Decommissioning
Report
Brown and Caldwell, 2003, Groundwater Monitoring Data Collected at Dolphin Wells
DIMW-1 through DIMW-9D, January through June 2003.
Brown & Caldwell, 2004a, Dolphin I Soil Vapor Extraction System Decommissioning
Report
Brown and Caldwell, 2004b, Groundwater Monitoring Report, January through
December 2003, Dolphin Incorporated
Brown and Caldwell, 2008, Groundwater Monitoring Data Collected at Dolphin Wells
DIMW-1 through DIMW-9D, January through June 2008.
Brown, J.G. and D.R. Pool, 1989, Hydrogeology of the Western Part of the Salt River
Valley Area, Maricopa County, AZ, U.S. Geological Survey Water-Resources
Investigations Report 88-4202
Burge & Associates, 1993a, Underground Storage Tanks Site Assessment, Basha's
Warehouse, 3435 West Buckeye Road, Phoenix, Arizona
Burge & Associates, 1993b, Underground Storage Tank Site Assessment, Valley Truck,
2320 South 15th Avenue, Phoenix, Arizona
CEC/WRA, 1993, Revised Plan to Remediate the Vadose Zone beneath ALSCo
CEC/WRA, 1994, Draft Remedial Action Plan, Phase III (Remedial Testing) at ALSCo
Corell, S. W., 1992, Groundwater Flow and Contaminant Transport Model, Central
Phoenix, Maricopa County, Arizona, Arizona Department of Water Resources, Modeling
Report No. 3
Corell, S.W. and E.F. Corkhill, 1994, A Regional Groundwater Flow Model of the Salt
River Valley – Phase II, Phoenix Active Management Area Numerical Model,
Calibration, and Recommendations, ADWR Modeling Report No. 8
Corkhill and others, 1993, A Regional Groundwater Flow Model for the Salt River
Valley – Phase I, Phoenix Active Management Area, Hydrogeologic Framework and
Basic Data Report, ADWR Modeling Report No. 6
Dames & Moore, 1985, Final Report, Groundwater Monitoring Well Installation and
Testing, Phoenix Terminal, prepared for Chevron USA, Inc.

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-5

8/10/2012

 Dames & Moore, 1988, Soils Investigation Report, Former Phoenix Extrusion Plant,
Phoenix, AZ
Dames & Moore, 1990, Final Report, Groundwater Investigation, Former Phoenix
Extrusion Plant, Phoenix, AZ
Dames & Moore, 1991a, Reynolds Metals Company, Former Phoenix Extrusion Plant,
35th Avenue & Van Buren, Southwest Corner, Phoenix, AZ, Installation Permit No.
8900461
Dames & Moore, 1991b, Transmittal Water Quality Data, July 1991, Former Phoenix
Extrusion Plant, Phoenix, Arizona, for Reynolds Metals Company
Dames & Moore, 1992, Results of Right-of-Way Soil Investigation, Area 1, Former
Extrusion Plant, Phoenix, AZ
Dames & Moore, 1993, Letter of Transmittal, Water Quality and Water Level Data,
Second Quarter 1993, Former Extrusion Plant, Phoenix
Dames & Moore, 1995, Technical Memorandum, Bedrock Ridge Models for Motorola
Delta Environmental Consultants, Inc. 1993, System Monitoring report, April - June
1993, Black canyon Shell, Phoenix, Arizona, Delta No. 31-89-021, ADEQ No.
4336/4715.0297
Dolphin, Inc., 1996, Closure Report for Drywell #1; ADEQ Registration # 07-3140;
Dolphin, Inc.
Dolphin, Inc., 1997, Letter to Ms. Lupe Buys, ADEQ, September 12, 1997
Ensolutions, Inc. 1998, Van Waters & Rogers Inc., Phoenix, AZ
Ensolutions, Inc. 2000, Soil Vapor Extraction System Evaluation, Van Waters & Rogers
Inc., Phoenix, AZ
ENSR, 1988, Summary Site Assessment Report for the Van Buren Tank Farm, Phoenix,
Arizona
ENSR, 1998, Soil Gas Survey Results, Air Liquide America Corporation, Phoenix, AZ
Environmental Geosciences Engineering, 1992, Report of Soil-Vapor Survey Conducted
at Maryatt Industries to Evaluate Potential Soil Contamination
Environmental Science & Engineering, Inc., 1993, Results of the August 1993 Quarterly
Groundwater Monitoring Program For Circle K Truxtop #01992, 1201 N 59th Ave.,
Phoenix, Arizona
WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-6

8/10/2012

 Environmental Science & Engineering, Inc., 1994, Results of the November 1993
Quarterly Groundwater Monitoring Program For Circle K Truxtop #01992, 1201 N 59th
Ave., Phoenix, Arizona, (LUST #4715.2464)
Environmental Technology, Inc., 1998, Quarterly Groundwater Monitoring Report, First
Quarter, 1998, State Tractor & Equipment Company, 407 South 17th Avenue, Phoenix,
Arizona
Environmental Technology, Inc., 1999, Site Characterization Report, Former Caljet
Truck Stop #11, 1851 South 19th Avenue, Phoenix, Arizona 85009
Environmental Technology, Inc., 2003, Corrective Action Plan, Part One of Two,
Western States Petroleum Fuelco #105, 3202 West Van Buren, Phoenix, Arizona 86009
Federal Emergency Management Agency, 2005, Flood Insurance Rate Maps for Portions
of Maricopa County, AZ
Fluor Daniel GTI, 1995, Ground Penetrating Radar and Soil Sampling Report, MCMM
Facility, 320 West Lincoln Street, Phoenix, AZ
Fluor Daniel GTI, 1996a, Second Quarter 1996 Groundwater Monitoring and Sampling
at the 320 West Lincoln Street Property in Phoenix, AZ
Fluor Daniel GTI, 1996b, Well Installation and Soil Sampling Report, 320 West Lincoln
Street, Phoenix, AZ
Fluor Daniel GTI, 1996c, Vapor Extraction Test Results, 320 West Lincoln Street,
Phoenix, AZ
Fluor Daniel GTI, 1997, Soil Gas Sampling Report, 320 West Lincoln Street, Phoenix
Fluor Daniel GTI, 1998a, SVE Extraction Termination Letter to Richard Olm, March 11,
1998
Fluor Daniel GTI, 1998b, SVE Termination Letter, April 16, 1998
Fluor Daniel GTI, 1998c, Groundwater and Soil Vapor Well Installation Report, Former
ALSCo, Phoenix, AZ
Fluor Daniel GTI, 1998d, Second Quarter, 1998 Groundwater Monitoring and Sampling
at the 320 West Lincoln Street Property in Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1991, Yellow Soil Found in Sewer
Trench, Reywest Commerce Center, Phoenix, Arizona

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-7

8/10/2012

 Geotechnical and Environmental Consultants, Inc., 1993, Monitoring Well Installation,
Sampling and Testing, Kachina Steel Facility, LUST File No. 4715.1835, 642 North 17th
Avenue, Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1995a, Summary of Vadose Zone
Investigations, June 1994 through June 1995, Former Phoenix Extrusion Plant, Phoenix
Geotechnical and Environmental Consultants, Inc., 1995b, Soil Gas Survey and Site
Reconnaissance, Building 27, Reywest Commerce Center, 3780 W. Adams, Phoenix, AZ
Geotechnical and Environmental Consultants, Inc., 1995c, Fourth Quarter Groundwater
Monitoring, Former Phoenix Extrusion Plant, Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1996a, Deep Soil Vapor Monitoring
at Area C and Response to ADEQ's Review Comments, Former Phoenix Extrusion Plant,
Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1996b, Summary Report of Right-ofWay Soil Studies, Reywest Commerce Center, Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1997a, Right-of-Way Excavation
Report, Reywest Commerce Center, Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1997b, Additional Subsurface
Investigation, Reywest Commerce Center, Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1998a, Additional Subsurface
Investigation in Trench Areas, Reywest Commerce Center, Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1998b, Laboratory Test Results,
Groundwater Monitoring Project, Former Phoenix Extrusion Plant
Geotechnical and Environmental Consultants, Inc., 1999a, Soil/Soil Gas Sampling and
Analysis, Former Phoenix Extrusion Plant, Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 1999b, Results of Additional Soil Gas
Sampling and Analysis, Former Phoenix Extrusion Plant, Phoenix, Arizona
Geotechnical and Environmental Consultants, Inc., 2003, Groundwater Monitoring Data
(March 2003), Former Phoenix Extrusion Plant, SW of 35th Avenue and Van Buren
Street, Phoenix, Arizona,
Geotrans, Inc., 2001, Confirmatory Soil Investigation, Vopak USA, 50 South 45th
Avenue, Phoenix, Arizona

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-8

8/10/2012

 Geraghty & Miller, Inc., 1988, Final Draft, Arizona Public Service, West Phoenix Power
Plant, Diesel Release Impact Report
Greene, D. Ken, 1997, Fax forwarding laboratory data from soil vapor extraction system
to Hugh Larkin/Rita Neill
Groundwater Technology, Inc., 1988, Summary of Activities for the Chevron Phoenix
Terminal Located at 5110 W. Madison Street, Phoenix, Arizona
Groundwater Technology, Inc., 1995a, Air Permit Application for SVE
Groundwater Technology, Inc., 1995b, Aquifer Pump Test Report, Maricopa County
Materials Management Facility, 320 West Lincoln Street, Phoenix, Arizona
Hammett, B.A. and R.L. Herther, 1995, Maps Showing Groundwater Conditions in the
Phoenix AMA, Arizona, ADWR Hydrologic Map Series Report No. 27
Harding Lawson Associates, 1990a, Soil Gas Investigation, Van Waters & Rogers Inc.,
Phoenix, Arizona
Harding Lawson Associates, 1990b, Subsurface Soil Investigation, Van Waters & Rogers
Inc., Phoenix, Arizona
Harding Lawson Associates, 1991, Draft Phase III Subsurface Soil Investigation, Van
Waters & Rogers Inc., Phoenix, Arizona
Harding Lawson Associates, 1992, Groundwater Investigation, Van Waters & Rogers
Inc., Phoenix, Arizona
Harding Lawson Associates, 1993a, Groundwater Monitoring and Sampling Report,
April through July 1993, Van Waters & Rogers Inc., Phoenix, Arizona
Harding Lawson Associates, 1993b, Second Quarter 1993 Report, Groundwater
Monitoring and Sampling, Unocal Service Station No. 3870, Phoenix, Arizona, UST File
No. 4715.1213
Harding Lawson Associates, 1994a, Vertical Profiling Under Static Conditions, Van
Waters & Rogers Inc., Phoenix, Arizona
Harding Lawson Associates, 1994b, Vertical Profiling Under Dynamic Conditions, Van
Waters & Rogers Inc., Phoenix, Arizona
Harding Lawson Associates, 1997a, Parking Lot Area Investigation, Van Waters &
Rogers Inc., Phoenix, Arizona

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-9

8/10/2012

 Harding Lawson Associates, 1997b, Unsaturated Cobble Zone Investigation, Van Waters
& Rogers Inc., Phoenix, Arizona
Harding Lawson Associates, 1997c, Groundwater Monitoring and Sampling Report, July
through September 1997, Van Waters & Rogers Inc., Phoenix, Arizona
Harding Lawson Associates, 1997d, Groundwater Flow Modeling, West Van Buren
WQARF Study Area
Harding Lawson Associates, 1998a, Groundwater Monitoring and Sampling Report,
April through June 1998, Van Waters & Rogers Inc., 50 South 45th Avenue, Phoenix,
Arizona
Harding Lawson Associates, 1998b, Groundwater Monitoring and Sampling Report, July
through September 1998, Van Waters & Rogers Inc., 50 South 45th Avenue, Phoenix,
Arizona
Harding Lawson Associates, 1999, Groundwater Monitoring and Sampling Report,
October through December 1998, Van Waters & Rogers Inc., 50 South 45th Avenue,
Phoenix, Arizona
Hargis + Associates, 1995a, Remedial Action Plan, ChemResearch Company, Inc.,
Phoenix, Arizona
Hargis + Associates, 1995b, Summary Report, Remedial Action Plan RAP-1,
Chemresearch Co., Phoenix, Arizona
Hargis + Associates, 1997, Summary Report, Site Assessment Plan SAP-2,
ChemResearch Co., Phoenix, Arizona
Hargis + Associates, Inc., 1998a, Status Report, Second Quarter 1998, ChemResearch
Company, Inc., Phoenix, Arizona
Hargis + Associates, Inc., 1998b, Status Report, Third Quarter 1998, ChemResearch
Company, Inc., Phoenix, Arizona
Hargis + Associates, 1999a, Supplemental SAP-2 Summary Report, ChemResearch Co.,
Phoenix, Arizona
Hargis + Associates, Inc., 1999b, Status Report, First Quarter 1999, ChemResearch
Company, Inc., Phoenix, Arizona
Hargis + Associates, 2003a, Status Report, Results of First Quarter 2003 Groundwater
Monitoring Summary of Results, Groundwater Monitoring Program 2002,
ChemResearch Company, Inc., Phoenix, Arizona

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-10

8/10/2012

 Hargis + Associates, 2003b, Status Report, Results of Second Quarter 2003 Groundwater
Monitoring Summary of Results, Groundwater Monitoring Program 2003,
ChemResearch Company, Inc., Phoenix, Arizona
Hargis + Associates, 2004, Status Report, Results of Fourth Quarter 2003 Groundwater
Monitoring Annual Status Report, Groundwater Monitoring Program 2003,
ChemResearch Co., Inc., Phoenix, Arizona
Hargis + Associates, 2006, Soils Data From ChemResearch Co., Inc., Letter to Ms.
Nicole Coronado, Arizona Department of Environmental Quality, March 9, 2006
Hargis + Associates, 2008, Status Report, Results of First Quarter 2008 Groundwater
Monitoring, Groundwater Monitoring Program, Chemresearch Co., Inc., Phoenix,
Arizona
HSI Geotrans, Inc., 1998a, March 1998 Monthly Water-Level Report, Groundwater
Elevation Network, West Van Buren and East Washington WQARF Areas, Phoenix,
Arizona
HSI Geotrans, Inc., 1998b, Groundwater Monitoring Report, Second Quarter 1998, East
Washington and West Van Buren WQARF Areas, Phoenix, Arizona
HSI Geotrans, Inc., 1998c, August 1998 Monthly Water-Level Report, Groundwater
Elevation Network, West Van Buren and East Washington WQARF Areas, Phoenix,
Arizona
HSI Geotrans, Inc., 1999, Groundwater Monitoring Report, Fourth Quarter 1998, East
Washington and West Van Buren WQARF Areas, Phoenix, Arizona
HTS Risk Management Services, Inc., 1993, Phase II Environmental Assessment,
Monitoring Well Installation, and Preliminary Contamination Assessment, Aztec
Construction Property, 4022 West Lincoln Street, Phoenix, AZ, HTS Project # 9332584
HydroGeoChem, Inc., 1992a, Soil Gas Survey of 320 W. Lincoln, Phoenix, AZ
HydroGeoChem, Inc., 1992b, Soil Gas Survey of Hilton Avenue, Phoenix, AZ
HydroGeoChem, Inc., 1996, Technical Assessment of the ALSCo De Minimus
Settlement
HydroGeoChem, Inc., 1999a, Letter to Mr. Richard Olm, ADEQ, March 8, 1999
HydroGeoChem, Inc., 1999b, Early Response Action Evaluation at the American Linen
Supply Company Site, 720 W. Buchanan Phoenix, Arizona

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-11

8/10/2012

 HydroGeoChem, Inc., 2000, Results of Well Development and Aquifer Pumping Test at
the American Linen Services Company Site, 720 W. Buchanan, Phoenix, Arizona
HydroGeoLogic, Inc., 2002a, Final Industrial Survey No. 1, For the West Van Buren
WQARF Registry Site, prepared for ADEQ
HydroGeoLogic, Inc., 2002b, Final Industrial Survey No. 2, For the West Van Buren
WQARF Registry Site, prepared for ADEQ
HydroGeoLogic, Inc., 2002c, Final Industrial Survey No. 3, For the West Van Buren
WQARF Registry Site, prepared for ADEQ
HydroGeoLogic, Inc., 2007a, Letter Report – Operational History of Reynolds Metals
Company Facility, Phoenix, AZ, prepared for ADEQ
HydroGeoLogic, Inc., 2007b, Letter Report – Operational History of Van Waters &
Rogers Facility, Phoenix, AZ, prepared for ADEQ
HydroGeoLogic, Inc., 2007c, Letter Report – Operational History of Maricopa County
Materials Management, Phoenix, AZ, prepared for ADEQ
HydroGeoLogic, Inc., 2007d, Letter Report – Operational History of Dolphin, Inc.
Facility, Phoenix, AZ, prepared for ADEQ
HydroGeoLogic, Inc., 2007e, Letter Report – Operational History of American Linen
Supply Company Facility, Phoenix, AZ, prepared for ADEQ
HydroGeoLogic, Inc., 2007f, Letter Report – Operational History of ChemResearch
Company Facility, Phoenix, AZ, prepared for ADEQ
HydroGeoLogic, Inc., 2007g, Letter Report – Operational History of Air Liquide
America Corporation Facility, Phoenix, AZ, prepared for ADEQ
HydroGeoLogic, Inc., 2007h, Letter Report – Operational History of Prudential Overall
Supply, Inc. Facility, Phoenix, AZ, prepared for ADEQ
HydroGeoLogic, Inc., 2007i, Letter Report – Operational History of Department of
Energy Facility, Phoenix, AZ, prepared for ADEQ
IT Corp, 1999, Draft Groundwater and Soil Vapor Well Installation Report, Former
American Linen Supply Co. 720 W. Buchanan St, Phoenix, AZ
Jennings, Strauss, and Salmon, 1992, Maryatt Industries De Minimis Settlement Proposal
Kleinfelder, 1988, Summary Report, Task Assignment K-2, West Van Buren Area,
Phoenix, AZ, prepared for ADEQ
WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-12

8/10/2012

 Kleinfelder, 1989, Phase I Report, West Van Buren Area, Phoenix, AZ, Task Assignment
K-2, prepared for ADEQ
Kleinfelder, 1992a, Technical Memorandum, Monitoring Well Installation and
Groundwater Sampling, Task Assignment K-2, Phase II, West Van Buren Area, Phoenix,
AZ, prepared for ADEQ
Kleinfelder, 1992b, ADEQ Water Quality Assurance Revolving Fund, West Van Buren
Area, Well Information, prepared for ADEQ
Kleinfelder, 1993, Quarterly Groundwater Water Monitoring Report, Weyerhaeuser
Facility, 1431 South 43rd Avenue, Phoenix, Arizona
Laney, R.L. and M.E. Hahn, 1986, Hydrogeology of the Eastern Part of the Salt River
Valley Area, Maricopa and Pinal Counties, AZ, U.S. Geological Survey Water-Resources
Investigations Report 86-4147
Levine Fricke, 1994, Further Subsurface Assessment and Closure Report, UNOCAL
Lease Property, Santa Fe Pacific Pipeline Partners, L.P., Phoenix Terminal, Phoenix,
Arizona
LFR Levine Fricke email correspondence.
LFR, 2006, Draft Remedial Investigation Report, West Central Phoenix North Plume
Site, prepared for ADEQ
Mann, L.J. and P.B. Rohne, Jr., 1983, Streamflow Losses and Changes in Groundwater
Levels along the Salt and Gila Rivers near Phoenix, AZ – February 1978 to June 1980,
U.S. Geological Survey Water Resources Investigations Report 83-4043
Maricopa County Division of Water and Waste Management, 1994, West Van Buren
Area WQARF Domestic Well Survey and Sampling Project, April 27, 1994
memorandum from Ron Ramsey to John Power
Miller Brooks Environmental, Inc., 1998a, Preapproval Work Plan for Site
Characterization Activities, for Former Texaco Station #60-349-0309, 1837 West Van
Buren Street, Phoenix, Arizona 85007
Miller Brooks Environmental, Inc., 1998b, Circle K Store #0608, June 1998 Groundwater
Monitoring Report, LUST #2586.01, Facility ID #0-001271, MTBE Project #154-060827
Miller Brooks Environmental, Inc., 2005, Direct-Push Soil Gas Sampling and Soil
Sampling at Prudential Overall Supply, 5102 West Roosevelt Street, Phoenix, Arizona

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-13

8/10/2012

 Miller Brooks Environmental, Inc., 2007, Soil and Soil Gas Sampling at Prudential
Overall Supply
Miller Brooks Environmental Inc/Blaes Environmental Management Inc., 1998b, Soil
and Groundwater Remediation Quarterly Monitoring Report - 1st Qtr 1998, December
18, 1997 Through March 31, 1998 for Circle K Store # 0608 6440 West Van Buren,
Phoenix, AZ, April 30, 1998, ADEQ Lust #2586.01, ADEQ Facility ID # 0-001217
Ogden Environmental and Energy Services Co., Inc., 1998, LUST Ground Water
Monitoring Report, Fry's Food Stores Distribution Center, 435 South 59th Avenue,
Phoenix, Arizona, (LUST ID No. 3371.02)
Patrick Welch, Inc., 1990, July Report, ChemResearch Company Site Investigation, 1122
W. Hilton Avenue, Phoenix, Arizona Letter to ADEQ
Pegler-Welch, Inc., 1992, Letter dated April 22, 1992 to Mr. Richard Burge,
ChemResearch Co., Concerning the Installation of Groundwater Monitor Wells
QST Environmental, 1998, Results of the Annual Groundwater Monitoring, Period
Ending January 30, 1998, Consolidated Freightways, 830 South 25th Avenue, Phoenix,
Arizona
Rascona, S.J., 2005, Maps Showing Groundwater Conditions in the Phoenix AMA,
Arizona, ADWR Hydrologic Map Series Report No. 35
Reeter, R.W. and W.H. Remick, 1986, Maps Showing Groundwater Conditions in the
Phoenix AMA, Arizona, ADWR Hydrologic Map Series Report No. 12
Reynolds Metals Co., 1994, Letter dated March 3, 1994 to Mr. Richard C. Olm, ADEQ,
concerning proposed investigations and the operation of a soil vapor extraction (SVE)
system
Reynolds Metals Co., 1996, Determination of Appropriate Soil Remediation Standards
for Contaminated Soils at Reynolds Metals Company’s Former Phoenix Extrusion Plant
Reynolds Metals Co., 1998, Right-of-Way Risk Assessment, Reynolds Metals
Company’s Former Phoenix Extrusion Plant, Phoenix, Arizona
Reynolds Metals Co., 1999, Site Wide Assessment, Reynolds Metals Company’s Former
Phoenix Extrusion Plant, Phoenix, Arizona
Science & Engineering Analysis Corporation, 1993, Phase II Subsurface Assessment,
Circle K Store No., 0608, 6440 West Van Buren Street
Scott, Allard & Bohannan. Inc., 1988, Subsurface Soil Investigation, Dolphin, Inc.,
Phoenix, Arizona
WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-14

8/10/2012

 SCS Engineers, 2003, Drywell Sampling, Operations and Maintenance Area, 615 South
43rd Avenue, Phoenix, Arizona
SCS Engineers, 2005, Soil Vapor Survey Report, Western Area Power Administration,
Phoenix Area Office
Sergent, Hauskins & Beckwith, 1991, Soil Sampling and Chemical Analyses, 39th
Avenue and Washington Street Alignment, Phoenix, Arizona
Southwest Environmental Consultants, Inc., 1998, Site Characterization Report, Christy
Signs, 1825 South Black Canyon Highway, Phoenix, Arizona 85009, ADEQ LUST File
#2059.01, ADEQ Facility #0186
Southwest Environmental Consultants, Inc., 1999, Quarterly Monitoring Report, Christy
Signs, 1825 South Black Canyon Highway, Phoenix, Arizona 85009, ADEQ LUST File
#2059.01, ADEQ Facility #0186
Terranext, 2004a, Well Installation Report, West Van Buren WQARF Registry Site,
Phoenix, AZ prepared for ADEQ
Terranext, 2004b, Well Development Report, West Van Buren WQARF Registry Site,
Phoenix, AZ prepared for ADEQ
Terranext, 2004c, First Quarter 2004 Water Quality Report, West Van Buren WQARF
Registry Site, Phoenix, AZ prepared for ADEQ
Terranext, 2004d, Third Quarter 2004 Water Quality Report, West Van Buren WQARF
Registry Site, Phoenix, AZ prepared for ADEQ
Terranext, 2005a, Well Installation Report, West Van Buren WQARF Registry Site,
Phoenix, AZ prepared for ADEQ
Terranext, 2005b, Water Level and Contaminant Concentration Contour Map
Development, West Van Buren WQARF Site, Phoenix, AZ prepared for ADEQ
Terranext, 2005c, First Quarter 2005 Water Quality Report, West Van Buren WQARF
Registry Site, Phoenix, AZ prepared for ADEQ
Terranext, 2005d, Third Quarter 2005 Water Quality Report, West Van Buren WQARF
Registry Site, Phoenix, AZ prepared for ADEQ
Terranext, 2006a, Well Installation Report, West Van Buren WQARF Registry Site,
Phoenix, AZ prepared for ADEQ

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-15

8/10/2012

 Terranext, 2006b, First Quarter 2006 Water Quality Report, West Van Buren WQARF
Registry Site, Phoenix, AZ prepared for ADEQ
Terranext, 2006c, Third Quarter 2006 Water Quality Report, West Van Buren WQARF
Registry Site, Phoenix, AZ prepared for ADEQ
Terranext, 2006d, Geologic Cross-Sections for West Van Buren WQARF Registry Site,
Phoenix, AZ prepared for ADEQ
Terranext, 2007, Well Installation Report, West Van Buren Area (WVBA), Water
Quality Assurance Revolving Fund (WQARF) Registry Site, Phoenix, AZ prepared for
ADEQ
Terranext, 2008a, Well Installation Report, West Van Buren Area (WVBA) Water
Quality Assurance Revolving Fund (WQARF) Registry Site, Phoenix, AZ prepared for
ADEQ
Terranext, 2008b, First Quarter 2008 Water-Quality Report, West Van Buren Area
(WVBA) Water Quality Assurance Revolving Fund (WQARF) Registry Site, Phoenix,
AZ prepared for ADEQ
Tracer Research Corp., 1994, Vapor Trace Shallow Soil Gas Investigation, Dolphin I and
Dolphin III Sites, Phoenix, Arizona
URS, 2001, ALSCo WQARF Site Monthly Report
URS, 2003, December 2002 ALSCo WQARF Site Monthly Report
U.S. Fish and Wildlife Service, 1989, National Wetlands Inventory, Fowler and Phoenix
7.5-Minute Topographic Quadrangles, AZ
Van Waters and Rogers Inc., 1999, Soil Vapor Extraction System Fourth Quarter 1998
Operations Summary, 50 South 45th Avenue, Phoenix, Arizona
West Van Buren Group, 1995, Private Well Survey Report, West Van Buren WQARF
Study Area, Phoenix, Arizona.
Weston, 1992a, Draft Technical Memorandum: Soil Gas Survey, Water Quality
Assurance Revolving Fund Program West Van Buren Project Area
Weston, 1992b, Draft Technical Memorandum for a Soil Gas Investigation in the Hilton
Avenue Vicinity, West Van Buren Project Area
Weston, 1993a, Draft Technical Memorandum: Preliminary Site Investigation, MCMM
Weston, 1993b, Split Soil Sampling Maryatt Industries, 720 W. Buchanan St. Phoenix
WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-16

8/10/2012

 Weston, 1993c, Technical Memorandum for Aquifer Test at RID Well No. 84, West Van
Buren Project Area
Weston, 1994, Draft Report, December 1993 Groundwater Sampling, West Van Buren
Project Area, (Task Assignment RW-WVB-4)
Weston, 1997a, Technical Memorandum for Aquifer Test at the North Sentinel Well,
West Van Buren Project Area
Weston, 1997b, 15th Avenue Aquifer Test Report
Weston, 1999, RID 104 Aquifer Test Analysis Report
Weston, 2000, Central Phoenix Groundwater Model, prepared for ADEQ
Weston, 2001, Central Phoenix Plume Model, Phase III: Groundwater Flow Model,
Final, 1996 – 1998 Validation Simulations
Woodward-Clyde Consultants, 1994, Jet A Fuel UST Site Characterization Report,
Phoenix Area Office - Operations and Maintenance Complex, Phoenix, Arizona

WVBA WQARF Registry Site
Remedial Investigation Report

Page 7-17

8/10/2012

 TABLES