Environmental Protection
Agency Region 6 Announces
Proposed Plan
San Jacinto River Waste Pits Site
Harris County, Texas
September 2016
The Purpose of this Proposed Plan is to:

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Identify the United States Environmental Protection Agency’s preferred remedial alternative to
address risks associated with contaminants in fish, impounded paper mill waste, sediment, and
soil at the San Jacinto River Waste Pits Site;
Provide the Environmental Protection Agency’s analysis of the results of the Remedial
Investigation and Risk Assessments;
Describe the remedial alternatives evaluated in the Feasibility Study Report;
Solicit public review and comment on the remedial alternatives and information contained in the
Administrative Record file; and
Provide information on how the public can be involved in the remedy selection process.

The Preferred Remedy for cleaning up the Site is Alternative 6N (Removal of Materials Exceeding Cleanup
Levels, Monitored Natural Recovery, and Institutional Controls) for the northern impoundments and aquatic
area, and Alternative 4S (Removal and Offsite Disposal with Institutional Controls) for the southern
impoundment. The institutional controls will be developed, implemented, and maintained in accordance
with the Environmental Protection Agency’s Institutional Controls guidance (OSWER Directive 9355.0-89).
The Site, located in Harris County, Texas (Figure 1), consists of a set of impoundments built in the mid1960s for the disposal of solid and liquid pulp and paper mill wastes, and the surrounding areas containing
sediments and soils impacted by waste materials disposed in the impoundments. The northern set of
impoundments, approximately 14 acres in size, are located on the western bank of the San Jacinto River,
north of the Interstate-10 (I-10) Bridge over the San Jacinto River (Figure 2). These northern
impoundments are partially submerged in the river. The southern impoundment, less than 20 acres in size,
is located on a small peninsula that extends south of I-10. The wastes that were deposited in the
impoundments are contaminated with polychlorinated dibenzo-p-dioxins (dioxins) and polychlorinated
dibenzofurans (furans). Dioxins persist in the environment for a long time because their structure is
resistant to chemical or biological degradation.
The Environmental Protection Agency is issuing this Proposed Plan to solicit public comment on the remedial
alternatives. This Proposed Plan is being issued in accordance with and as part of its public participation

*100001061*
076814

100001061

 responsibilities under the Comprehensive
Environmental Response, Compensation, and
Liability Act (CERCLA or Superfund) §117(a), 42
U.S.C. § 9617(a) and the Code of Federal
Regulations (CFR) § 40 Code of Federal
Regulations §300.430(f)(2).
The recommendations and alternatives set forth in
this Proposed Plan are based on information and
documents contained in the Administrative Record
file for the Site. The Environmental Protection
Agency will select a final remedy for the Site after
the public comment period has ended and the
comments have been reviewed and considered,
and the Environmental Protection Agency has
responded to the comments received. The
Environmental Protection Agency may select a
different alternative or a modified version of the
Preferred Remedy based on new information or
public comments.
The Environmental Protection Agency Region 6
office is the lead agency for this Site. The Texas
Commission on Environmental Quality is the
support agency. As the support agency, the State
reviews and comments on the remedial
investigation and feasibility study, the proposed
plan, the Record of Decision, and the remedial
design. As part of the Public Comment Period, the
state’s position and key concerns related to the
preferred alternative and other alternatives will be
assessed prior to the Environmental Protection
Agency making a final remedy selection.

How to Submit Public Comment
EPA will accept comments on the Proposed Plan during the
public comment period. Initially, the EPA planned a 30-day
public comment period, however, in response to requests
from the community, an additional 30-day comment period
was added resulting in 60-days for the comment period. The
60-day public comment period on this Proposed Plan and
the information contained in the Administrative Record file
begins on September 29, 2016, and closes on November
28, 2016. Comments may be submitted in one of four ways.
Written comments postmarked no later than November 28,
2016, should be sent to:
EPA Remedial Project Manager
EPA Region 6 (6SF-RA)
1445 Ross Avenue, Suite 1200
Dallas, Texas 75202
Comments also may be submitted no later than November
28, 2016 either by e-mail:
R6_San_Jacinto_Waste_Pits_Comments@epa.gov
or Online:
www.epa.gov/tx/forms/sjrwp-comments
In addition, oral comments may be made on the record at
the public meeting on October 20, 2016
EPA will include responses to all comments that are
received during the official public comment period in a
responsiveness summary that will accompany the final
cleanup plan (also called the Record of Decision).

Scope and Role of Response Action
The purpose of this response action is to implement a site wide strategy that addresses the contaminated
material at the Site with the primary objectives of preventing human and ecological exposure to
contaminants, and preventing further migration of contaminants. This response action will:

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Prevent releases of dioxins from the former waste impoundments;
Reduce human exposure to dioxins from consumption of fish;
Reduce human exposure to dioxins from contact with contaminated materials; and
Reduce exposures of benthic macroinvertebrates (clams, crabs, etc.) to dioxin.

The Preferred Alternative, 6N and 4S, consisting of removal of waste materials that exceed the Preliminary
Remediation Goals, Monitored Natural Recovery, and Institutional Controls, is intended to address the
threats to human health and environment. The Preferred Alternative is the only one that will reliably result in
no catastrophic future release of waste material upon completion of construction. The San Jacinto River
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076815

 has been subject to severe flooding in the past and future flooding may even be more severe. The river has
also experienced significant changes over the last 50 to 60 years as a result of subsidence and flooding
cutting new channels. This is expected to continue in the future.
Dioxin in the environment is very persistent, and is expected to remain toxic for hundreds of years. Therefore,
any cleanup approach involving containment would have to reliably achieve containment for hundreds of
years. The methods that can be used to predict the long-term performance of the river and the stability of a
containment remedy have a high degree of uncertainty, as well as not being able to predict future changes in
the river channels and riverbanks. The containment alternatives, while costing less, cannot be shown to
reliably contain the waste material long-term. The benefit of removal of the dioxin waste material is that it will
eliminate the possibility of a catastrophic release that could result in a much more severe impact to the
environment.

Community Participation
This Proposed Plan highlights information contained in the Administrative Record for the Site. The Administrative
Record includes the Remedial Investigation Report, risk assessment reports, the Evaluation of the San Jacinto
Waste Pits Feasibility Study Remediation Alternatives report prepared by the U.S. Army Corps of Engineers, the
Feasibility Study Report, and other documents and reports used in the preparation of this Proposed Plan.
The Environmental Protection Agency encourages the public to review these documents to obtain more
information about the Superfund activities that have been conducted. The Environmental Protection Agency also
encourages the public to participate in the decision-making process for the Site. The Administrative Record file is
available on the internet at the following website:
https://www.epa.gov/tx/sjrwp

The Administrative Record file is also available at the following information repository locations:
Highlands Public Library
Stratford Branch Library
509 Stratford Street
Highlands, Texas 77562
281-426-3521

U.S. Environmental Protection
Agency, Region 6
1445 Ross Avenue, Suite 700
Dallas, Texas 75202
800-533-3508

Texas Commission on
Environmental Quality
Central File Room
12100 Park 35 Circle, Building E
Austin, Texas 78753
512-239-2900

The Environmental Protection Agency will hold a public meeting to inform residents of the proposed remedy
and obtain comments on the Proposed Plan. The public meeting is being held in a fully accessible facility.
Should you have questions about this facility’s compliance with the Americans with Disabilities Act, please
contact the Environmental Protection Agency Community Involvement Coordinator (contact information
provided below). For specific information about the Texas Commission on Environmental Quality’s
participation in the Superfund process, please contact the Texas Commission on Environmental Quality
Project Manager (contact information provided below).
EPA Community Involvement Coordinator
Donn Walters
EPA Region 6 (6SF)
1445 Ross Avenue, Suite 1200
Dallas, Texas 75202
214-665-6483; walters.donn@epa.gov

TCEQ Project Manager
Satya Dwivedula
MC-136
Texas Commission on Environmental Quality
PO Box 13087
Austin, Texas 78711-3087
512-239-3548; satya.dwivedula@tceq.texas.gov
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076816

 Site History
In the 1960s, McGinnes Industrial
Management Corporation
transported liquid and solid pulp
and paper mill wastes by barge
from the Champion Papers, Inc.
paper mill in Pasadena, Texas to
impoundments located north of I10, adjacent to the San Jacinto
River, where the waste was
stabilized and disposed.
Champion Papers, Inc. business
records indicate the paper mill
produced pulp and paper using
chlorine as a bleaching agent.
The pulp bleaching process
forms dioxins and furans as byproducts.
The northern impoundments
were used for waste disposal
from September 1965 to May
1966. Details regarding the
southern impoundment are less
well known; however, the
southern impoundment was
used by Ole Peterson
Construction Company prior to
construction of the northern
impoundments for disposal of
the same type wastes generated
by Champion Papers, Inc.
Sand mining also occurred in
the vicinity of the Site; sand
mining operations contributed to
the release of waste from the
pits, specifically by the creation
of an area of elevated dioxin
contamination in the sand
separation area. In August
2016, the EPA notified
MegaSand Enterprises, Inc., of
its potential liability as a result
of its sand mining operations.

Temporary Armored Cap
Since its completion in July 2011, the armored cap has generally isolated
the waste, but has required many repairs and extensive maintenance. The
following instances of erosion or missing armor stone have occurred since
the time of armored cap installation:


July 2012: Approximately 200 square feet (ft2) of stone eroded and
geotextile exposed (armor materials had moved down slope). Following
EPA approval of the repair plan, additional stone was added to achieve
the required cap thickness. Repairs were completed August 3, 2012.



January 2013: Five areas missing part or all of armor stone with
exposed geotextile in some areas of the Eastern Cell. Following EPA
approval of a repair plan, additional stone was added to achieve the
required cap thickness. Repairs were completed January 30, 2013.



January 2014: The U.S. Army Corps of Engineers evaluated the
design & construction of the cap and found that improvements were
needed, including flatter slopes and larger rock in some areas.
Following EPA approval of a repair plan, additional rock was added with
construction completed on January 13, 2014.



December 2015: Following an inspection by the EPA Dive Team,
approximately 500 ft2 of cap was missing or deficient in cover (no
geotextile, paper mill waste exposed to the river, sediment
concentration measured at 43,700 ng/kg dioxin exposed to river). The
EPA ordered repair of this area, and following EPA approval of a repair
plan, geotextile & new rock was added to repair the area with
construction completed on January 4, 2016.



February 2016: Missing rock in portions of eastern cell (five areas up
to 6 ft2 each with some exposed geotextile). The EPA ordered repair of
this area, and after EPA approval of the repair plan, new rock was
added to repair the area with construction completed on March 15,
2016.



March 2016: Approximately 500 locations in the Eastern Cell were
probed to check for cap thickness and eight additional areas of missing
rock were found. During repairs, additional areas of missing rock and
exposed geotextile were found. Following EPA approval of the repair
plan, new rock was added over a total area of 170 ft2 with construction
completed on March 31, 2016.



June 2016: Following an inspection by the EPA Dive Team, ten areas
of missing rock were found in the Western Cell up to 300 ft2. Following
EPA approval of the repair plan, new rock was added to repair the
areas with construction completed on June 17, 2016.

The cap was designed to withstand a hundred year storm, yet the above
cases of eroded or missing armor stone all occurred with flooding less than
less that the design 100-year storm.
4

076817

 Early Investigations

Contamination

Between 1993 and 1995, the City of Houston conducted a
toxicity study of the Houston Ship Channel that included the
San Jacinto River. Sediment, fish, and crab samples collected
near the Site indicated elevated dioxin and furan levels.

Improper disposal of paper mill
wastes has resulted in contaminated
sediment, soil, and fish. The paper
mill waste is considered Principal
Threat Waste.

Between 2002 and 2004, the Texas Commission on
National Priorities Listing
Environmental Quality conducted a study of total maximum
daily loads (TMDL) for dioxins and furans in the Houston Ship
The site was proposed for listing on
Channel. Sediment, fish, and crab samples indicated the
the National Priorities List on
presence of dioxin and furan contamination in the San Jacinto
19 September 2007, and was placed
River surrounding the Site. In April 2005, the Texas Parks and
on the list effective 19 March 2008
(73 FR 14723).
Wildlife Department sent a letter notifying the Texas
Commission on Environmental Quality of the existence of
former waste pits in a sandbar in the San Jacinto River north of I-10. The letter included: 1) discussion of
anecdotal evidence, that indicated the pits were likely used from the mid-1960’s to mid-1970’s for disposal
of paper mill waste; 2) data collected during the Houston Ship Channel Toxicity Study and TMDL study,
discussed in the paragraph above; 3) documentation of U.S. Army Corps of Engineers dredge and fill
permits in the area; and 4) requested that the Texas Commission on Environmental Quality further
investigate the Site.
A preliminary assessment and screening site inspection was completed in 2006 to determine if the Site was
eligible for proposal to the National Priorities List. Sediment sample results indicated elevated concentrations
of dioxin congeners. The former surface impoundments were identified as the source of hazardous
substances at the Site. Following this assessment and inspection, the site was proposed for listing on the
National Priorities List on September 19, 2007, and was placed on the list effective March 19, 2008.
Unilateral Administrative Order for Remedial Investigation/Feasibility Study
In July 2009, the Environmental Protection Agency provided International Paper Company and McGinnes
Industrial Maintenance Corporation an opportunity to negotiate an agreement to perform the Remedial
Investigation and Feasibility Study for the San Jacinto River Waste Pits Site. They failed to submit a good
faith offer to negotiate an Administrative Order on Consent for the Remedial Investigation and Feasibility
Study, and, because of the ongoing release of hazardous substances at the Site, the Environmental
Protection Agency concluded that work at the Site could no longer be delayed. Therefore, on November 20,
2009, the Environmental Protection Agency issued a Unilateral Administrative Order to International Paper
Company and McGinnes Industrial Management Corporation. International Paper Company is the
successor to Champion Papers, Inc. Champion Papers, Inc. had arranged for the disposal of the paper mill
waste materials containing dioxin that were disposed of at the Site.
The paper mill waste contains Comprehensive Environmental Response, Compensation, and Liability Act
hazardous substances. McGinnes Industrial Maintenance Corporation operated the waste disposal facility
at the time of disposal of the waste. The Unilateral Administrative Order directed International Paper
Company and McGinnes Industrial Management Corporation to conduct a Remedial Investigation and
Feasibility Study in accordance with provisions of the order; the Comprehensive Environmental Response,
Compensation, and Liability Act; the National Oil and Hazardous Substances Pollution Contingency Plan;
and Environmental Protection Agency guidance.

5
076818

 Between 2010 and 2013, site-specific data were collected for the remedial investigation. The remedial
investigation included the collection of paper mill waste, sediment, tissue (i.e., hardhead catfish, Gulf
killifish, rangia clam, and blue crabs), soil, and groundwater samples for analyses including dioxins and
furans, polychlorinated biphenyls (PCBs) as
Aroclors, metals, semivolatile organic compounds,
Public Participation Activities
volatile organic compounds, and pesticides. Physical
data collected during the remedial investigation
EPA in coordination with State, County and local
included: a bathymetric survey, current velocity,
agencies has provided public information and outreach
material, geotechnical, riverbed properties, sediment
for the site area since 2011 by:
loading, erosion rates of cohesive sediment, and net
 Hosting 10 community meetings or Open Houses that
sedimentation rates.
provided updates to community members on the
status of remedial investigations, upcoming actions,
The Potentially Responsible Parties prepared a draft
and cap repair updates.
Feasibility Study report under Environmental
 Coordinating 15 Community Awareness Committee
Protection Agency oversight. Following review and
Meetings or Teleconferences that provided a forum for
comment by the Environmental Protection Agency
members to express concerns on issues and to
and other Site stakeholders on the draft, a revised
ensure that EPA provided answers in a timely manner.
draft Feasibility Study was submitted to the
Environmental Protection Agency. Following review
 Three Harris County Elected Officials briefings were
of the Potentially Responsible Parties’ second draft,
held to provide updates to the officials.
the Environmental Protection Agency decided to
 A Technical Assistance Grant was awarded to the
revise and complete the Feasibility Study report. The
Galveston Bay Foundation in May 2011 to provide
Environmental Protection Agency entered into an
members an ongoing explanation of technical issues.
agreement with the U.S. Army Corps of Engineers to
The Grant funding has now expired.
review the Feasibility Study and to provide additional
information and modelling analysis.
 The site was included as a pilot under the Community
Administrative Settlement Agreement and Order
on Consent for Removal Action
In 2010, the Environmental Protection Agency
decided that it was necessary to stabilize the site,
temporarily abating the release of dioxins until the
Site was fully characterized and a remedy could be
implemented. On May 11, 2010, the Environmental
Protection Agency filed the Administrative
Settlement Agreement and Order on Consent for
Removal Action, which was entered into voluntarily
by the Environmental Protection Agency,
International Paper Company, and McGinnes
Industrial Management Corporation. The
Administrative Settlement Agreement and Order on
Consent for Removal Action provided for the
performance of a Time Critical Removal Action.
The Environmental Protection Agency Administrative
Order required the Potentially Responsible Parties to
construct the temporary armored cap to stabilize the
northern impoundments to withstand forces
sustained by the river, including a cover design that

Engagement Initiative. Region 6 provided a World
Café format at a nearby community in 2010 to kick-off
the site work. Residents and media participated to
learn more about the Project.

 EPA worked with the Texas Department of State
Health Services who has provided 3 different
neighborhood health door to door surveys to identify
concerns and provide health related information.
 EPA worked with the State to provide extensive River
use Warnings, and posting Fish Advisory Signage
throughout the area. Health agencies working with the
Potentially Responsible Parties provided the signs.
EPA continues to plan and coordinate community meetings,
open houses, elected officials briefings, media interviews,
public notices, and fact sheets to inform the public and keep
residents updated on all site developments that affect
cleanup actions. Site fact sheets are available on the Site
profile webpage identified on page 2.

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 considered storm events with a return period of 100 years, and prevent direct human and benthic organism
contact with waste materials. Elements of the selected temporary armored cap construction included a
perimeter fence on the uplands to prevent unauthorized access; placement of warning signs around the
perimeter of the northern impoundments and on the perimeter fence; design and implementation of an
operations, monitoring, and maintenance plan; and installation of an armored temporary cap with the
following items:


A stabilizing geotextile underlayment over the northern impoundment eastern cell



Treatment through solidification of a portion (6,000 cubic yards in the upper 3 feet over 1.2 acres)
of the western cell for construction equipment access



An impervious geomembrane underlayment in the northern impoundment western cell



A cover consisting of small rock grains over the northwestern area of the northern impoundment
western cell

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A cover consisting of small rock grains above the geotextile and geomembrane in the northern
impoundment western cell

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A cover consisting of small rock grains above the geotextile in the northern impoundment eastern cell.

From December 2010 through July 2011, the Potentially Responsible Parties constructed a temporary
armored cap under Environmental Protection Agency oversight. After the repairs in 2012, the Corps of
Engineers reviewed the design of the damaged area and made recommendations that included flattening
the impoundment slopes and adding bigger size rock. Even after these changes and repairs, the
impoundment continued to experience numerous damages and deficiencies from floods that were less than
a 20-year flood, even though the northern impoundment was designed for a 100-year flood.
The Potentially Responsible Parties have continuing obligations with respect to the temporary cap,
including cap inspections, surface and bathymetric surveys, sign and fencing inspections, and
maintenance. The Operation, Monitoring, and Maintenance Plan has been modified because the original
program of regular inspections failed to identify
deficiencies in the cap discovered in December
2015 by the Environmental Protection Agency’s
Dive Team. The temporary armored cap
inspection events now include: 1) visual
inspection of the security fence, signage and the
armored cap, 2) collection of topographic survey
data for the portions of the armored cap that are
located above the water surface, 3) collection of
bathymetric survey data for the portions of the
armored cap that are below the water surface,
and 4) manual probing of armored cap thickness
at areas identified by the topographic or
bathymetry surveys as more than 6 inches lower
N
in elevation than during the prior survey.
General Area of the Time Critical Removal Action
Inspection and repair reports, as needed, are
Modified from: Integral Consulting Inc. and Anchor QEA, LLC. 2013. Remedial
submitted to the Environmental Protection
Investigation Report, San Jacinto River Waste Pits Superfund Site. Prepared for:
Agency.
McGinnes Industrial Maintenance Corporation, International Paper Company, and
U.S. Environmental Protection Agency, Region 6. May.

7
076820

 Site Characteristics
United States Army Corps of Engineers Evaluation
The United States Army Corps of Engineers 2016 report was prepared for EPA in order to evaluate and
supplement Feasibility Study work performed by the Potentially Responsible Parties. Alternative 6N* from
the Corps report is the same as EPA’s 6N used in this Proposed Plan. An EPA analysis of the United
States Army Corps of Engineers 2016 report can be found in the Feasibility Study. The United States
Army Corps of Engineers report’s evaluation of containment is contingent on the continued integrity of the
armored cap and is limited by uncertainties in modeling. For example, the report provided the following
information that is relevant to consideration of the temporary armored cap and long-term permanence.
According to the report, the most severe event simulated was the hypothetical synoptic occurrence of
Hurricane Ike and the October 1994 flood, with a peak discharge of approximately 115,000 cubic feet per
second occurring at the time of the peak storm surge height at the Site. The results during the peak of the
storm surge showed that the sections using Armor A (3-inches diameter) were completely eroded, while
the sections using Armor D (10-inches diameter) were eroded more than 12 inches in about 33 percent of
those sections. The sections using Armor B and C (6-inches diameter) incurred a net erosion of more than
9 inches in about 75 percent of those areas. Overall about 80% of the cap experienced significant erosion
with scour reaching approximately 2.4-feet through the cap and into the waste material. The scenario
defined above may cause significant erosion of the paper mill waste. The releases from catastrophic
events can potentially be addressed by additional cap improvements, including upgrading the blended
filter in the Northwestern Area to control sediment migration into the cap, upgrading the armor stone size
to a diameter of 15 inches and adding 2 feet of additional armor stone over the existing cap across the
waste pits to minimize the potential for disturbance during very severe hydrologic and hydrodynamic
events. However, the uncertainty inherent in any quantitative analysis technique used to estimate the longterm (500 years or more) reliability of the cap is very high.
The Corps report did not consider changing river conditions. New channels eroding during flooding as well
as changes in channel cross section due to bank erosion, shoreline breaches, etc. during a high flow event
caused by a major flood or hurricane is beyond the ability of existing sediment transport models to
simulate. In addition, the report’s evaluation of excavation and removal often focuses on risks which will be
reduced and/or eliminated through use of best management practices.
There appears to be no documented cases of any armored cap or armored confined disposal facility
breaches. However, there have been many occurrences of breaches and slope failures of armored dikes,
jetties, and breakwaters, with some of those structures confining dredged material.

The Site is located in the estuarine portion of the lower San Jacinto River where the river begins to
transition from a river system to a delta. River conditions have significantly changed with respect to the
location of the waste impoundments. See Figures 3 through 6. These photos clearly show that the river
channel has changed due to weather events and sand mining operations. These river changes will continue
and could cause a catastrophic release of the highly toxic waste materials from the impoundments, if they
remain in place.
Extreme weather events also could result in severe flooding and the possibility of damage to the cap and a
release of contaminants from the Site.
8
076821

 Tropical weather systems in the region can have tremendous impacts on regional precipitation and
hydrology along the Gulf Coast. Heavy precipitation events produce wide variations in the volume of
discharge into and out of the San Jacinto River and may significantly affect variations in flow velocities,
sediment transport, suspended sediment loads, and water levels. Floods in the river occur primarily during
tropical storms, hurricanes, or intense thunder storms. Extreme flood events have flow rates of 200,000
cubic feet per second or greater. Floods can cause water surface elevations to increase by 10 to 20 feet or
more (relative to average flow conditions) and force the river out of its main channel.
Between 1851 and 2004, 25 hurricanes have made landfall along the north Texas Gulf Coast, seven of which
were major (Category 3 to 5) storms. Tropical Storm Allison, which hit the Texas Gulf Coast in June 2001,
resulted in 5-day and 24-hour rainfall totals of 20 and 13 inches, respectively, in the Houston area, resulting in
significant flooding. More recently, Hurricane Rita made landfall in September 2005 as a Category 3 storm
with winds at 115 miles per hour. The storm surge caused extensive damage along the Louisiana and
extreme southeastern Texas coasts. In September 2008, the eye of Hurricane Ike made landfall at the east
end of Galveston Island. Ike made its landfall as a strong Category 2 hurricane, with Category 5 equivalent
storm surge, and hurricane-force winds that extended 120 miles from the storm’s center.
In October 1994, heavy rainfall occurred in southeast Texas resulting in the San Jacinto River Basin
receiving 15 to 20 inches of rain during a week-long period. One of the largest measurements of stream
flow ever obtained in Texas, 356,000 cubic feet per second (cfs), was made on the San Jacinto River near
Sheldon on 19 October 1994 at a stage of 27 feet. During the measurement, velocities of water that
exceeded 15 feet per second (about 10 miles per hour) were observed. Another storm occurring in 1940
had a river stage height of 31.5 feet at the same Sheldon location. The 100-year flood, which is defined as
the peak stream flow having a one percent chance of being equaled or exceeded in any given year, was
exceeded at 18 of 43 stations monitoring the area. For those stations where the 100-year-flood was
exceeded, the flood was from 1.1 to 2.9 times the 100 year-flood.
The 1994 flooding caused major soil erosion and created water channels outside of the San Jacinto River
bed. This flooding caused eight pipelines to rupture and 29 others were undermined at river crossings and
in new channels created in the flood plain outside of the San Jacinto River boundaries. The largest new
channel was cut through the Banana Bend oxbow just west of the Rio Villa Park subdivision, about 2½
miles northwest of the Site. This new channel was approximately 510-feet wide and 15-feet deep. A second
major channel cut through Banana Bend just north of the channel through the oxbow. Both of these new
channels were cut through areas where sand mining had been done before, as is the case in the vicinity of
the Site. Sonar tests in a 130-foot section south of the I-10 Bridge located adjacent to the Site found about
10 to 12-feet of erosion from the bottom of the river bed.
The San Jacinto River is a very dynamic system, subject to changes in size and flow paths as experienced
during the 1994 storm. A series of aerial photographs illustrate this variability. An aerial photograph taken in
1956 (Figure 3), before the waste pits were established, shows I-10 crossing the river and extensive islands
and land to the north. The next photograph, from 1966 (Figure 4), shows the northern pits located just west
of the I-10 Bridge (the pits were built and in operation in the mid–1960s); significant changes to the north
can be seen compared to the 1956 photograph. Land erosion and subsidence is evident in the next
photograph from 1973 (Figure 5); there is a new passage to the west of the site since the 1966 photograph.
Photographs in the 1990’s and later (Figure 6) show continued loss of land.

9
076822

 The Corps of Engineers performed an evaluation of the San
Jacinto River and the armor cap using hydrodynamic and
sediment transport models. These models have to predict the
river conditions for a very long time because dioxin is
extremely persistent in the environment and will remain toxic
for a very long time. The uncertainty inherent in any
quantitative analysis technique used to estimate the long-term
performance of the river and cap is very high. Further,
changes in the river channel due to bank erosion, shoreline
breaches, etc. during a high flow event caused by a major
flood or hurricane is beyond the ability of any existing
sediment transport model to simulate. The changes that the
river has experienced over the last 50 years as described
above will likely continue in the future; and these changes are
specifically what the current models cannot simulate.
Therefore, the model predictions should be considered as
having a very limited long term reliability.
Future flooding may be even more intense. According to the
U.S. National Climate Assessment, flooding along rivers and
other areas following heavy downpours and prolonged rains is
exceeding the limits of flood protection infrastructure designed
for historical conditions. Sea level rise, storm surge, and
heavy downpours in combination with the pattern of continued
development in coastal areas are increasing damage to U.S.
infrastructure and are also increasing risks to ports and other
installations. Because the intensity of future storms and
flooding may increase, estimates regarding the ability of a cap
(even a cap with increased armoring) to contain the dioxin
waste material is highly uncertain.
The waste material is highly toxic and may be highly mobile in
a severe storm and therefore is considered a Principal Threat
Waste. The Environmental Protection Agency considers
material at the Site with more than 300 ng/kg dioxin to be
Principal Threat Waste. This concentration was calculated by
multiplying the sediment Preliminary Remediation Goal of 30
ng/kg by a factor of 10.
Nature and Extent of Contamination – Waste Pits North of I-10

Principal Threat Wastes
The National Contingency Plan establishes
an expectation that EPA will use treatment to
address the principal threats posed by a site
wherever practicable (National Contingency
Plan § 300.430(a)(1)(iii)(A)). In general,
principal threat wastes are those source
materials considered to be highly toxic or
highly mobile and which generally cannot be
contained in a reliable manner or would
present a significant risk to human health or
the environment should exposure occur. The
“principal threat” concept is applied to the
characterization of “source materials” at a
Superfund site.
Elevated concentrations of dioxin have
been detected at the Site:
 Waste material in the waste pits (more
than 43,000 ng/kg)
 Soil in the Southern Impoundment
(more than 50,000 ng/kg).
Dioxin is highly toxic and persistent in nature
(will not breakdown for hundreds of years).
With the regular occurrence of severe storms
and flooding in the area, there is uncertainty
that the waste material can be reliably
contained over the long term and therefore
should be considered potentially highly mobile
due to its location in a dynamic river
environment.
Because the dioxin waste in the northern
impoundments and southern
impoundment at the site is both highly
toxic and potentially highly mobile (due to
river flooding), it is considered a principal
threat waste. The Environmental Protection
Agency considers material at the Site with
more than 300 ng/kg of dioxin to be Principal
Threat Waste.

The waste material in the Site pits contains tetra-chlorinated
dioxin, which is one of the most toxic kinds of dioxin. Surface
water samples prior to construction of the cap show that there
were dioxin releases to the river (samples collected from 2002
to 2009); and the University of Houston indicated that high
levels of dioxin were present in the river surrounding the Site and within a mile downstream of the Site.
Dioxins biodegrade very slowly. The Environmental Protection Agency estimates that, for dioxins that are
not exposed to sunlight, the dioxin half-life is in a range from 25 to 100 years. The tetra-dioxin found at the
Site has much more bio-concentration potential in organisms as opposed to the more highly chlorinated
10
076823

 dioxin congeners, including the octa-chlorinated dioxin, which is generally found in higher concentrations
throughout the River. The tetra-dioxin also is more resistant to biotransformation in the environment than
the octa-dioxin.
The EPA classifies dioxin as a probable human carcinogen. Dioxin increases the risk for several individual
cancers, including soft-tissue malignant tumor (sarcoma), lung cancer, cancer of the lymphatic tissue (nonHodgkin’s lymphoma), and malignant enlargement of the lymph nodes, spleen, and liver (Hodgkin’s
disease). Dioxins have also been linked to many non-cancer effects, including birth defects, reproductive
abnormalities, developmental effects, immune dysfunction, liver damage (hepatotoxicity), peripheral nerve
damage (neuropathy), hormone disruption, and dermatological disorders (chloracne).
The waste material in the pits north of I-10 contain elevated concentrations of dioxins and polychlorinated
bi-phenyls. The highest average concentrations of dioxin in surface and subsurface material north of I-10
occur in the northern impoundments (Figure 7). The maximum dioxin concentration in surface material
(43,000 ng/kg) occurs in the northwest portion of the western cell of the impoundments. A water sample
collected from within the waste pits contained 3,770 pg/L dioxin
The sample with the highest dioxin-like polychlorinated bi-phenyl concentration of 2.83 ng/kg was collected
from within the northern impoundments. Concentrations of polychlorinated bi-phenyls in sediments were
either significantly correlated with concentrations of dioxins or were non-detect.
Ground water sampling was conducted at three locations within the perimeter of the northern waste pits
from each of two ground water bearing units below the waste pits. These ground water units contained
brackish to saline ground water. Samples from five of the six wells did not detect any dioxins. The sixth well
screened in the uppermost ground water bearing unit below the waste pits did detect dioxin/furan at a
concentration (2.64 pg/L) that is much lower than the maximum contaminant level of 30 pg/L for a drinking
water zone. Harris County also sampled a total of 101 private water wells near the Site located to the east
of the San Jacinto River. The analysis results did not find any exceedances of dioxin drinking water
standards.
Surface soil samples were collected from areas adjacent to the waste pits on both the east and west banks
of the San Jacinto River. These samples, collected within the 100-year flood plain, contained a maximum
dioxin level of 12 ng/kg, which is within the background dioxin range for soils (0.4 to 23 ng/kg).
Nature and Extent of Contamination – Surface Water and Sediment
Sediment is the material deposited at the bottom of the San Jacinto River outside of the waste pits. Dioxin
results in this sediment are typically three to four orders of magnitude lower than the waste within the pits.
The attached map shows that there are elevated levels of dioxins associated with Site wastes in sediments
outside of the waste pits (Figure 7). The maximum background sediment dioxin level is less than 7.2 ng/kg.
The highest dioxin levels outside of the waste pits are in the sand separation area, which is located in the
San Jacinto River approximately 1000 feet northwest from the waste pits. The sand separation area
(Figure 2) is where sand was separated from the rest of the dredged material during sand mining. To date,
two sample results over 300 ng/kg were found in the sand separation area, but based on other samples,
the EPA does not believe these two results are representative, and additional sediment sampling may be
conducted there.
Surface water samples collected between 2002 and 2009 by the Texas Commission on Environmental
Quality and the University of Houston showed elevated levels of dioxins in the San Jacinto River near and
downstream from the waste pits.
11
076824

 The average surface sediment dioxin concentration within the Preliminary Site Perimeter, including the
sand separation area, is 12.5 ng/kg outside of the temporary cap. About 190 acres (Figure 8) in this area
exceed the sediment background concentration. Even though the average sediment concentration is 12.5
ng/kg, there are about 43 acres (Figure 9) that exceed the sediment PRG of 30 ng/kg, discussed in the
“Remedial Action Objectives and Preliminary Remediation Levels” section below. The location of the
surface sediment background samples is shown in Figure 10.
The dioxin-like Polychlorinated Bi-Phenyl concentrations outside of the waste pits are below 1 ng/kg except
for one surface sample (6.85 ng/kg) and one subsurface sample (1.58 ng/kg) located along the northwest
portion of the peninsula south of I-10. The dioxin-like Polychlorinated Bi-Phenyl concentrations do not
significantly add to the total dioxin equivalent concentration.
Nature and Extent of Contamination – Tissue
Tissue samples were collected from three Site fish collection areas (Figure 11):


Downstream of I-10, referred to below as “downstream”



In the area surrounding the impoundments north of I-10 and the sand separation area, referred to
as “adjacent to the northern impoundments”



Immediately upstream of the northern impoundments and upland separation area, referred to as
“upstream.”

Data for blue crab, hardhead catfish, and Gulf killifish are summarized in the figures below. The maximum
detected values and highest mean values of dioxin and dioxin-like polychlorinated bi-phenyl generally were
collected from the fish collection area adjacent to the northern impoundments.

12
076825

 Summary of Average Tissue Results
0.739

Blue Crab
0.8
0.7
0.6
0.5

0.119

0.242

0.23

0.14

0.146

0.2

0.0907

0.3

0.157

0.4

0.1
0
BACKGROUND

FCA3

Dioxin (ng/kg)

FCA2

FCA1

Dioxin‐like Polychlorinated Bi‐Phenyl (ng/kg)

FCA 3: Immediately Upstream
FCA 2: Adjacent to the Northern Impoundments
FCA 1: Immediately Downstream

Hardhead Catfish
3.87

4.5

3.5

2.94

3.29

4

3

1

1.28

1.36
0.48

1.5

0.865

2

1.28

2.5

0.5
0
BACKGROUND
Dioxin (ng/kg)

FCA3

FCA2

FCA1

Dioxin‐like Polychlorinated Bi‐Phenyl  (ng/kg)

13
076826

 2.7

Gulf Killifish
3
2.5

0.102

0.51

0.404

0.5

0.13

1

0.295

1.5

0.525

1.26

2

0
BACKGROUND
Dioxin (ng/kg)

FCA3

FCA2

FCA1

Dioxin‐like Polychlorinated Bi‐Phenyl  (ng/kg)

Nature and Extent of Contamination – Impoundment South of I-10
The Southern Impoundment located south of I-10 at the San Jacinto River was constructed and used in the mid1960s for the disposal of paper mill waste containing dioxin. This impoundment contains the paper mill waste
and debris, which was covered with soil. The maximum surface soil dioxin concentration in the Southern
Impoundment is 36.9 ng/kg (Figure 12) which is below the level considered protective for nonrestrictive use.
In subsurface soils from 6 to 24 inches, dioxin results are 303 ng/kg, with an average of 16.5 ng/kg. Dioxin
results deeper than 2 feet have a maximum of 50,100 ng/kg and an average of 743 ng/kg.
Ground water sampling was conducted at two locations outside of the southern impoundment; one was
below the impoundment and the other was located downgradient to the west of the impoundment. The
water in this area is brackish. Neither of these samples detected any dioxin or furan. Water samples
collected from within the southern impoundment contained dioxin up to a maximum of 60.2 pg/L.
Summary of Nature and Extent of Contamination
There are high levels of dioxin/furans in the waste material in the northern impoundments and at the 6 -10
foot depth in the southern impoundment. Tetra-dioxin contamination associated with the Site is also present
in sediments surrounding the impoundments, although not at levels, when averaged, that are above the
sediment cleanup level. Tissue samples from blue crab, hardhead catfish, clams and Gulf killifish show
elevated levels of dioxins in the vicinity of the Site.
Resource Use
Current land use at the Site is primarily industrial and commercial use. Current land use surrounding the
Site includes mixed residential and industrial uses to the west, and undeveloped or residential areas to the
east and north. Immediately south of the Site is commercial/industrial land use. The future land use is not
anticipated to be different from the current land use.
The area south of the Site is dominated by activities associated with the Houston Ship Channel, specifically
industrial sites that are served by the barges and ocean-going vessels that use the Houston Ship Channel.
From the Site north to Lake Houston, there is less industrialization along the river.
14
076827

 Commercial and recreational fishing activity occurs throughout Galveston Bay. The San Jacinto River
along with nearby Upper Galveston Bay, Tabbs Bay, and the San Jacinto State Park have many points of
public access. Through Texas Department of State Health Services (TDSHS) outreach activities, most of
the people interviewed along the San Jacinto River, Houston Ship Channel, and Upper Galveston Bay have
told TDSHS that they are fishing and/or crabbing for recreational purposes. However, some people do
admit to consuming fish and/or crabs from these areas despite the fact that consumption of mollusks and
shellfish (clams, mussels, and oysters) taken from public fresh waters is prohibited by TDSHS. Within
public salt waters, these shellfish may be taken only from waters approved by TDSHS. TDSHS shellfish
harvest maps designate approved or conditionally approved harvest areas. Waters near the Site are not
included on these maps.
Although the Site is private land, nearby access points along the San Jacinto River allow for a variety of
recreational activities including picnicking, swimming, nature walks, bird watching, wading, fishing, boating,
water sports, and other shoreline uses. In the area to the south of the I-10 Bridge on the west side of the
river, children and adults have been reported to play along the shoreline, wade in the water, and fish.

Scope and Role of Response Action
The purpose of this response action is to implement a site-wide strategy that addresses the contaminated
material at the Site with the primary objectives of preventing human and ecological exposure to
contaminants, and preventing further migration of contaminants. The Preferred Alternative, 6N and 4S,
consisting of removal of waste materials that exceed the Preliminary Remediation Goals, Monitored Natural
Recovery, and Institutional Controls, is intended to address the threats to human health and environment.
This response action will prevent future releases of dioxins from the former waste impoundments, reduce
human exposure to dioxins from consumption of fish, reduce human exposure to dioxins from contact with
contaminated materials; and reduce exposures of benthic macroinvertebrates (clams, crabs, etc.) to dioxin.
The Preferred Alternative is the only one that will reliably result in no future catastrophic release. The San
Jacinto River has been subject to severe flooding in the past and future flooding may even be more severe.
The river has also experienced significant changes over the last 50 to 60 years as a result of subsidence
and flooding cutting new channels. This is expected to continue in the future. Dioxin in the environment is
very persistent, and is expected to remain toxic for hundreds of years. Therefore, any cleanup approach
involving containment would have to reliably achieve containment for a very long time. The methods that
can be used to predict the long-term performance of the river and the stability of a containment remedy
have a high degree of uncertainty, as well as not being able to predict future changes in the river channels
and riverbanks. The containment alternatives, while costing less, cannot be shown to reliably contain the
waste material long-term due to the location of the waste pits in the San Jacinto River, which is prone to
severe storms and flooding, and the uncertainty of available methods to assess the long-term capability of
the containment systems. The benefit of removal of the dioxin waste material is that it will eliminate the
possibility of a catastrophic release that could result in a much more severe impact to the environment.

Summary of Site Risks
A Baseline Human Health Risk Assessment (human health risk assessment) and Baseline Ecological Risk
Assessments (ecological risk assessments) were conducted to estimate the potential for current/future risk
from exposure to contaminants from the Site. The human health risk assessment and ecological risk
assessments were conducted to determine potential pathways by which people (human receptors) or animals
(ecological receptors) could be exposed to upland or aquatic contamination in waste material, sediment, soil,
water, or biota; the amount of contamination receptors of concern may be exposed to; and the toxicity of
those contaminants if no action were taken to address contamination at the Site. Some of the human health
15
076828

 risk determinations subsequently were modified by the Environmental Protection Agency based on further risk
analysis as documented in memoranda included as part of the Site administrative record.
The risk assessments were conducted on the baseline conditions that existed before the installation of the
temporary armored cap over the northern waste pits that was completed as part of a removal action. This
temporary cap was built to stabilize the northern waste pits and prevent direct human exposures until a
permanent remedy could be selected for the Site. These assessments provide the basis for taking action
and identify the contaminants and exposure pathways that need to be addressed by the remedial action.
What is Risk and How is it Calculated?
A Superfund human health risk assessment estimates the “baseline risk.” This is an estimate of the
likelihood of health problems occurring if no cleanup action was taken at a site. To estimate the baseline
risk at a site, a four-step process is used:
Step 1:
Step 2:
Step 3:
Step 4:

Analyze Contamination
Estimate Exposure
Assess Potential Health Dangers
Characterize Site Risk

In Step 1, the concentrations of contaminants found at a site are examined as well as past scientific studies
that demonstrate the effects these contaminants may have on people (or animals, when human studies are
unavailable). Comparisons between site-specific concentrations and concentrations reported in past studies
help determine which contaminants are most likely to pose the greatest threat to human health.
In Step 2, the different ways that people might be exposed to the contaminants identified in Step 1, the
concentrations that people might be exposed to, and the potential frequency and duration of exposure are
considered. Using this information, a "reasonable maximum exposure" scenario is calculated, which
portrays the highest level of human exposure that could reasonably be expected to occur.
In Step 3, the information from Step 2 is combined with information on the toxicity of each chemical to
assess potential health risks. Two types of risk, cancer risk and non-cancer risk, are considered. The
likelihood of any kind of cancer resulting from a site is generally expressed as an upper-bound probability;
for example, a "1 in 10,000 chance." In other words, for every 10,000 people that could be exposed, one
extra cancer may occur as a result of exposure to site contaminants. An extra cancer case means that one
more person could get cancer than would normally be expected to from all other causes. For non-cancer
risks, a hazard index (HI) is calculated. The key concept here is that a "threshold level" exists below which
non-cancer health effects are no longer predicted.
In Step 4, it is determined if site risks are great enough to cause health problems for people at or near the site.
The results of the three previous steps are combined, evaluated, and summarized. The potential risks from the
individual chemicals are added up. If cancer or non-cancer risks are found to be unacceptable, the contributing
chemicals are then identified as contaminants of concern. For cumulative cancer risks, the EPA has determined
increased cancer risk in excess of 10-4 (1 in 10,000) is unacceptable. The risk range of 10-6 to 10-4 may be
evaluated to determine whether risk is acceptable for future site conditions (such as land use and potential
users). For cumulative non-cancer risks, the EPA has established an HI of less than 1.0 as acceptable.
It is the Environmental Protection Agency’s current judgment that the Preferred Remedy identified in this
Proposed Plan is necessary to protect public health or welfare or the environment from actual or threatened
releases of hazardous substances into the environment.
16
076829

 Human Health Risk
The human health risk assessment identified non-cancer hazards greater than one for some recreational
fisher exposure scenarios (direct exposure to surface areas identified and the ingestion of catfish, clam, or
crab from fishing areas identified), for some recreational visitor exposure scenarios (direct exposure to the
surface area identified), and for some future construction worker exposure scenarios. The tables below
provide a summary of Site related non-cancer hazard quotients above one. Hazard quotients greater than one
indicate the potential of contaminants of concern (e.g. dioxin) may cause adverse health effects to those that
are exposed in the manner specified in the tables. There were no cancer risks above the upper limit of the
Environmental Protection Agency’s target cancer risk range (1x10-4) for all surface areas identified in the
human health risk assessment except for Beach Area E, which had an excess cancer risk of 6.6 x 10-4 for a
recreational fisher exposed through ingestion and dermal contact with surface waste material and sediment.
The basis for action at the Site are the unacceptable hazards to the recreational fisher (Hazard Index 65), to
the recreational visitor (Hazard Index 66), and to the construction worker (Hazard Index 46). The three tables
below provide more information on these hazards. For the recreational fisher (Figures 13 and 14) and the
recreational visitor (Figure 14), risk assessments were done for areas both north and south of I-10. For the
construction worker, the risk assessment applies to the area south of I-10 (Figure 15).
Non-Cancer Hazards for a Recreational Fisher
Non-Cancer Hazard Quotient
Incidental
Dermal
Consumption of
Ingestion of
Contact with
Fish or
Chemical
Primary Target Organ
Sediment
Sediment
Shellfish
Scenario 1A: Direct Exposure Beach Area A; Ingestion of Catfish from Fish Collection Area 2/3
Dioxins and dioxin-like
Reproductive/Developmental
0.0006
0.0016
1.8
Polychlorinated Bi-Phenyls
Scenario 2A: Direct Exposure Beach Area B/C; Ingestion of Catfish from Fish Collection Area 2/3
Dioxins and dioxin-like
Reproductive/Developmental
0.0081
0.0229
1.8
Polychlorinated Bi-Phenyls
Scenario 3A: Direct Exposure Beach Area E; Ingestion of Catfish from Fish Collection Area 2/3
Dioxins and dioxin-like
Reproductive/Developmental
16
47
1.8
Polychlorinated Bi-Phenyls
Scenario 3B: Direct Exposure Beach Area E; Ingestion of Clam from Fish Collection Area 2
Dioxins and dioxin-like
Reproductive/Developmental
16
47
0.27
Polychlorinated Bi-Phenyls
Scenario 3C: Direct Exposure Beach Area E; Ingestion of Crab from Fish Collection Area 2/3
Dioxins and dioxin-like
Reproductive/Developmental
16
47
0.008
Polychlorinated Bi-Phenyls
Scenario 4A: Direct Exposure Beach Area D; Ingestion of Catfish from Fish Collection Area 1
Dioxins and dioxin-like
Reproductive/Developmental
0.0027
0.0076
1.8
Polychlorinated Bi-Phenyls
Note:
Polychlorinated Biphenyls - PCBs
Dioxins – see Glossary

Exposure
Route Total
1.8
1.8
65
64
63
1.8

Non-Cancer Hazards for a Recreational Visitor
Incidental
Ingestion of
Sediment

Primary
Chemical
Target Organ
Scenario 3: Direct Exposure Beach Area E
Reproductive/
Dioxin
17
Developmental
Note:
Dioxin – 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalent quotient

Non-Cancer Hazard Quotient
Incidental
Dermal
Ingestion of
Contact with
Soil
Sediment
0.03

49

Dermal
Contact with
Soil

Total

0.0021

66

17
076830

 Non-Cancer Hazards for a Future Construction Worker

Chemical
Primary Target Organ
Scenario DS-1: Direct Exposure to Surface and Subsurface Soils
Dioxin
Reproductive/Developmental
Scenario DS-2: Direct Exposure to Surface and Subsurface Soils
Dioxin
Reproductive/Developmental
Scenario DS-4: Direct Exposure to Surface and Subsurface Soils
Dioxin
Reproductive/Developmental
Scenario DS-5: Direct Exposure to Surface and Subsurface Soils
Dioxin
Reproductive/Developmental
Note:
Dioxin – 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalent quotient

Non-Cancer Hazard Quotient
Dermal Contact
Incidental
Ingestion of Soil
with Soil

Total

9.6

0.49

10

44

2.2

46

32

1.6

34

2.2

0.11

2.3

Ecological Risk
Baseline risks to ecological receptors associated with the wastes in the impoundments north of I-10 are the
result of exposures to dioxins localized to the immediate vicinity of the impoundments. Baseline ecological
risks include reproductive risks to mollusks from dioxin, but primarily in the area that surrounds the former
waste impoundments north of I-10, and low risks of reproductive effects in individual mollusks in sediments
adjacent to the sand separation area, but not to populations of mollusks. Baseline risks include moderate
risks to individual birds like the killdeer or spotted sandpiper whose foraging area could regularly include
the shoreline adjacent to the impoundments north of I-10, but low risk to populations because of the low to
moderate probability that individual exposures reach effects levels. Baseline risks include risks to individual
small mammals with home ranges that include areas adjacent to the impoundments such as the marsh rice
rat, but low to negligible risks to small mammal populations because of the moderate probability that
exposures will reach levels associated with reproductive effects in individuals, and because small mammals
reproduce rapidly. Baseline risks to benthic macroinvertebrate communities and populations of fish, birds,
mammals, and reptiles resulting from the presence of metals, bis(2-ethylhexyl) phthalate, Polychlorinated
Bi-Phenyls, carbazole, and phenol on the Site are negligible. Risks to fish populations from all chemicals of
potential concern are negligible.
There are negligible risks to populations of wading birds represented by the great blue heron, and to
populations of diving birds like the neotropic cormorant. There are negligible risks to populations of
terrestrial mammals such as the raccoon. There are low to negligible risks to individual terrestrial
insectivorous birds like the killdeer from exposure to zinc, and negligible risks to populations of such birds.
Although the upper bound of estimated daily intakes of zinc by individual killdeer is about equal to
conservative effects thresholds, the exposure estimate is influenced by the use of generic models to
estimate zinc concentrations in the foods of the killdeer, and this model likely overestimates ingested tissue
concentrations, resulting in overestimates of exposure and risk. The highest exposures of killdeer to zinc
occur outside of the northern impoundment perimeter, and background exposures less than 30 percent
were lower than on the Site. In addition, the low probability of individual exposures exceeding effects levels
indicates low risk to populations. There are also low to negligible risks to individual terrestrial insect eating
birds from exposure to dioxins. The ecological risk assessments identified risk to ecological receptors as
summarized in the tables below.

18
076831

 Ecological Risks
Receptor of Concern
Benthic Macroinvertebrates

Feeding Guild

Contaminant
of Concern

Mollusks

Filter feeders

2,3,7,8-TCDD

Individual mollusks

Filter feeders

2,3,7,8-TCDD

Baseline Risk Identified
Reproductive risks to mollusks (primarily in the area
which surrounds the waste impoundments)
Low risks of reproductive effects (sediments adjacent to
the sand separation area)

Birds
Spotted sandpiper
Invertivore (probing)
Dioxin
Low risk to populations
Killdeer
Invertivore (terrestrial)
Dioxin
Low risk to populations
Mammals
Marsh rice rat
Omnivore
Dioxin
Low to negligible risk to populations
Note:
2,3,7,8-TCDD – 2,3,7,8-tetrachlorodibenzo-p-dioxin
Dioxin – toxicity equivalent quotient for 2,3,7,8-tetrachlorodibenzo-p-dioxin calculated using toxicity equivalent factors for mammals

Remedial Action Objectives and Preliminary Remediation Levels
Remedial Action Objectives describe what the proposed site cleanup is expected to accomplish. According to
the National Contingency Plan, 40 Code of Federal Regulations §300.430(a)(1)(i), the “national goal of the
remedy selection process is to select remedies that are protective of human health and the environment, that
maintain protection over time, and that minimize untreated waste.” Based on information relating to types of
contaminants, environmental media of concern, and potential exposure pathways, site specific remedial action
objectives were developed. The remedial action objectives developed consider the current and reasonably
anticipated future land use including the use for industrial applications and by recreational fishers.
Concentrations of polychlorinated bi-phenyls in waste materials and sediments were either significantly
correlated with concentrations of dioxins or were generally below detection limits. Therefore, no remedial action
objective was developed for polychlorinated bi-phenyls because remediation of material contaminated with
dioxins will also remediate the co-located polychlorinated bi-phenyls. While the human health risk assessment
considered subsistence fisher populations, the Texas Department of State and Health Services (DSHS) could
not identify subsistence fishers in the area of the Site. Therefore this receptor is not considered to be consistent
with the current or future land use. The Environmental Protection Agency used the next most conservative value
of a child recreational fisher for its risk calculations.
The following Preliminary Remediation Goals provide numerical criteria that will be used to measure the
progress in meeting the Remedial Action Objectives. The preliminary remediation goals are acceptable
exposure levels (i.e., contaminant concentration levels) that are protective of human health and the
environment, and are developed considering applicable, relevant, and appropriate requirements, as specified
in the National Contingency Plan. Site risk-based preliminary remediation goals are presented below:





Dioxin in sediment – 30 ng/kg (recreational fisher). This level is also protective for ecological risk.



Texas Surface Water Quality Standard for Dioxins/Furans – 7.97 x 10-8 µg/L (as TCDD
equivalents). [30 Texas Administrative Code §307.6(d)(a)(A) and (B) and §307.10]. This standard
was updated by the Texas Commission on Environmental Quality in 2014 and approved by the
Environmental Protection Agency to base the dioxin standard on water column criteria. The
standard was calculated based on an oral cancer slope factor of 156,000 found in in the
Environmental Protection Agency 2002 National Recommended Water Quality Criteria Matrix.
19

076832

Dioxin in paper mill waste material in the waste pits – 200 ng/kg (recreational visitor).
Dioxin in paper mill waste material and soil in the Southern Impoundment – 240 ng/kg (Southern
Impoundment construction worker).

 The sediment Preliminary Remediation Goal of 30 ng/kg was developed for the Site based on protecting
human health of the most vulnerable potentially exposed group or individual of the community. In this case
a recreational child fisher was assumed to get exposed to contaminated sediment through incidental
ingestion, dermal contact, and from the ingestion of fish/shellfish. The 30 ng/kg is associated with a noncancer Hazard Index of one with the understanding that by protecting at a Hazard Index of one will also be
protecting for cancer effects near the middle (2.1 x 10-5) of the Environmental Protection Agency’s generally
acceptable cancer risk range.
For the river areas outside of the armor cap, the surface area–weighted average dioxin concentration in
sediment located just south of the waste pits (Figure 11) is 16.1 ng/kg, and the surface area–weighted
average dioxin concentration in sediment in areas located adjacent to and upstream of the waste pits is
11.2 ng/kg. Because the average dioxin concentrations in sediment both upstream and downstream of the
waste pits are less than the 30 ng/kg Preliminary Remediation Goal for sediment, remediation of the
sediment is not required.
The 200 ng/kg Preliminary Remediation Goal for the waste material areas is associated with a non-cancer
Hazard Index of one. In this case a recreational visitor was assumed to get exposed to contaminated waste
material and sediment. The waste material areas include the northern waste pits (Figure 2).
The 240 ng/kg Preliminary Remediation Goal applies to waste material and soil for the Southern
Impoundment (Figure 15) and is associated with a non-cancer Hazard Index of one. In this case a
construction worker was assumed to get exposed to contaminated soils in the area during construction
activities. The surface soil in this area is less than the protective level of 51 ng/kg for unlimited use and
unrestrictive access.
The background sediment upstream from the Site has a dioxin concentration of 7.2 ng/kg, which is well
below the sediment Preliminary Remediation Goal of 30 ng/kg. Therefore re-contamination of the Site by
new sediment being carried downstream is not likely.
There are no preliminary remediation goals for fish tissue because the required sediment cleanup
measures at the Site will reduce contaminant concentrations in tissue, but these concentrations will
continue to be affected by factors outside the scope of the Comprehensive Environmental Response,
Compensation, and Liability Act Site cleanup, including upstream and downstream dioxin inputs from other
sources. Measuring trends against target tissue concentrations is useful for assessing risk reduction and for
risk communication, but tissue preliminary remediation goals are not required to evaluate these trends.
It is anticipated that the 200 ng/kg dioxin Preliminary Remediation Goal for the waste material areas, as
well as the 30 ng/kg dioxin Preliminary Remediation Goal in sediment, will be achieved relatively soon after
construction of the Preferred Alternative (Alternative 6N) is completed, or approximately 2 years after
construction begins. The 240 ng/kg dioxin Preliminary Remediation Goal for the Southern Impoundment will
be achieved when construction of the Preferred Alternative there (Alternative 4S) is completed, or
approximately 7 months after construction begins.

20
076833

 Summary of Remedial Alternatives
The feasibility study identified and screened possible response actions and remedial technologies
applicable to the Site. Following the screening process, remedial alternatives were developed to address
the area north of I-10 and the area south of I-10. Alternatives that address the area north of I-10 and
aquatic environment include the letter “N” in the title (e.g., 1N, 2N), and alternatives that address the area
south of I-10 include the letter “S” in the title (e.g., 1S, 2S). During the Feasibility Study, cost estimates are
developed for each remedial action alternative for comparison purposes. The expected accuracy of
Feasibility Study cost estimates ranges from –30 percent to +50 percent. The total present worth costs for
this and all other alternatives are calculated using a 30 year timeframe and a 7% discount rate.

Alternatives for the San Jacinto River and Area North of I-10:
Alternative 1N – Temporary Armored Cap and Ongoing Operations, Inspection, and Maintenance
(No Further Action)
Estimated Maintenance Cost (e.g., inspection, maintenance): $0.4 million
Estimated Total Present Worth Cost: $0.4 million
Estimated Construction Time: Construction complete
Under this alternative, No Further Action would be conducted for the temporary armored cap constructed
under the Time Critical Removal Action and no additional remedial action would be implemented.
Treatment through solidification of a portion (6,000 cubic yards) of the paper mill waste material was
completed to aid construction of the cap. However, this alternative has no further provision for treatment or
removal of the Principal Threat Waste. This alternative includes ongoing operations, inspection, and
maintenance of the armored cap, which includes inspection and periodic maintenance. This alternative has
no provision for the sand separation area.
Alternative 2N – Armored Cap, Institutional Controls, Ground Water Monitoring, and Monitored
Natural Recovery
Estimated Maintenance Cost: $2.0 million
Estimated Total Present Worth Cost: $2.0 million
Estimated Construction Time: Construction complete
This alternative includes all of the elements discussed under Alternative 1N, plus institutional and
engineering controls, ground water monitoring, and Monitored Natural Recovery. Monitored Natural
Recovery would be used to achieve the Preliminary Remediation Goal for sediment in the sand separation
area and the Texas Surface Water Quality Standard in the San Jacinto River. Hydrodynamic and sediment
transport modeling of the San Jacinto River in the vicinity of the Site determined that there is a net
deposition of sediment that will support Monitored Natural Recovery. Further, approximately two feet of
sediment deposition found over the toe of the cap in the northwest area during an Environmental Protection
Agency Dive Team inspection of the cap also supports the depositional nature of the area. Because future
sedimentation is uncertain, monitoring will be conducted to access natural recovery.
This Alternative 2N this would not result in treatment of the Principal Threat Waste other than the
solidification for the original construction of the cap.

21
076834

 Ground water monitoring would be implemented to ensure that there are no long-term unacceptable
impacts to ground water resulting from the waste left in place. Under this remedial alternative, the following
institutional and engineering controls would be implemented:


Restrictions on dredging and anchoring would be established to protect the integrity of the armored
cap and to limit potential disturbance and resuspension of buried sediment under the residuals
cover layers.



Alert property owners of the presence of subsurface materials exceeding Remediation Levels.



Public notices and signage around the perimeter of the temporary armored cap site would be
maintained or provided, as appropriate.



As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.

This alternative includes ongoing operations, inspection, and maintenance of the armored cap, which
includes inspection and periodic maintenance, and the Environmental Protection Agency 5-year reviews as
required under the National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2). A
periodic sampling and analytical program would also be implemented to monitor the progress of natural
recovery. The current temporary cap has had no impact on
Institutional Controls
navigation, and this alternative is not expected to be different.
Institutional controls are non-engineered
Alternative 3N – Upgraded Cap, Institutional Controls,
instruments such as administrative and
Ground Water Monitoring, and Monitored Natural Recovery
legal controls that help minimize the
potential for human exposure to
Estimated Capital Cost: $1.77 million
contamination and protect the integrity of a
Estimated In-Direct and Operation & Maintenance Cost: $2.38
remedy by limiting land or resource use.
million
Engineering Controls
Estimated Total Present Worth Cost: $4.1 million
Estimated Construction Time: 2 months
Engineering controls are physical
measures such as fencing or signage that
This alternative includes the actions described under Alternative
are used to limit access to contaminated
2N plus additional improvements to the temporary armored cap
areas or areas that may pose a physical
to create an upgraded cap. The improvements use a higher
hazard.
factor of safety of 1.5 for sizing the armor stone, and include
Monitored Natural Recovery
flattening submerged slopes from 2 horizontal to 1 vertical
(2H:1V) to 3H:1V and flattening the slopes in the surf zone from
Monitored Natural Recovery is a
3H:1V to 5 horizontal to 1 vertical (5H:1V). In addition, the
technology in which contaminant
Upgraded Cap uses larger rock sized for the “No Displacement”
concentrations are monitored with no other
design scenario, which is more conservative than the “Minor
remedial actions taken to address
Displacement” scenario used in the Armored Cap’s design. This
contamination. Monitored Natural
alternative will increase the long-term stability of the armored cap
Recovery assesses the natural attenuation
compared to Alternatives 1N and 2N. However, the upgraded
of contaminants by physical, chemical, and
cap under Alternative 3N is expected to experience 80% erosion
biological processes.
of the cap during a severe storm as determined by the Corps of
Engineers’ report (Appendix A of the Feasibility Study). Cost
estimates for this alternative also include additional measures to protect the upgraded cap from potential
vessel traffic in the form of a protective perimeter barrier and could include construction of a 5-foot high
submerged rock berm outside the perimeter of the upgraded cap, in areas where vessels could potentially
impact the cap. Monitored Natural Recovery would be used to achieve the Preliminary Remediation Goal for
sediment in the sand separation area and the Texas Surface Water Quality Standard in the San Jacinto River.
22
076835

 This Alternative 3N would not result in treatment other than the solidification for construction of a portion of
the Principal Threat Waste, which is defined as material containing dioxin greater than 300 ng/kg.
Upon completion, the Upgraded Cap would be constructed to a standard that exceeds Environmental
Protection Agency and United States Army Corps of Engineers design guidance, and meets or exceeds the
recommended enhancements suggested by the United States Army Corps of Engineers in their 2013
evaluation. Ground water monitoring would be implemented to ensure that there are no long-term
unacceptable impacts to ground water resulting from the waste left in place. Institutional controls would be
implemented to place restrictions on dredging and anchoring to protect the integrity of the armored cap and
to limit potential disturbance and resuspension of buried sediment near the sand separation area. Under
this remedial alternative, the following institutional and engineering controls would be implemented:


Restrictions on dredging and anchoring would be established to protect the integrity of the armored
cap and to limit potential disturbance and resuspension of buried sediment under the residuals
cover layers.



Alert property owners of the presence of subsurface materials exceeding Remediation Levels.



Public notices and signage around the perimeter of the temporary armored cap site would be
maintained or provided, as appropriate.



As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.

This alternative includes ongoing operations, inspection, and maintenance of the armored cap, which
includes inspection and periodic maintenance, and the Environmental Protection Agency 5-year reviews as
required under the National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2). A
periodic sampling and analytical program would also be implemented to monitor the progress of natural
recovery. The current temporary cap has had no impact on navigation, and this alternative is not expected
to be different.
Alternative 3aN – Enhanced Cap, Protective Pilings, Institutional Controls, Ground Water
Monitoring, and Monitored Natural Recovery
Estimated Capital Cost: $19.7 million
Estimated In-Direct and Operation & Maintenance Cost: $5.1 million
Estimated Total Present Worth Cost: $24.8 million
Estimated Construction Time: 15 months
The Corps of Engineers determined that the cap considered for Alternative 3N may experience 80%
erosion of the armor cap (Appendix A of the Feasibility Study), and substantial erosion of the underlying
paper mill waste material in a future severe storm. This alternative, 3aN, includes the actions described
under Alternative 3N plus additional enhancements to the armored cap recommended by the Corps of
Engineers to create an enhanced cap with increased long-term stability.
The additional cap enhancements added for this alternative include pre-stressed concrete or concrete filled steel
pipe pilings placed 30 feet apart around the perimeter of the cap to protect from barge strikes. The spacing is
designed to catch a typical barge, which is 35 feet wide. An additional armor stone cap with a thickness of at
least 24 inches would be placed over the armor cap for Alternative 3N. The armor stone would have a median
diameter of 15 inches. This additional armor stone would cover 13.4 acres of the 17.1 acre armored cap. Also, a
23
076836

 course gravel filter layer would be placed on 1.5 acres of the Northwest Area where there is currently no
geotextile under the armor cap. The actual scope and design of the cap enhancements, and additional area
needed to construct the required slopes, would be determined in the Remedial Design. This additional weight of
rock on top of the waste pits may cause cap settling and/or pushing the waste material out the sides of the cap;
the Remedial Design will consider the significance of and design issues related to this. Monitored Natural
Recovery would be used to achieve the Preliminary Remediation Goal for sediment in the sand separation area
and the Texas Surface Water Quality Standard in the San Jacinto River.
This Alternative 3aN this would not result in treatment of the Principal Threat Waste, which is defined as
Site material containing dioxin greater than 300 ng/kg, with the exception of the solidification for
construction of the western cell of the original cap. Alternative 3aN also would require ongoing
maintenance to ensure cap integrity over the hundreds of years the Site waste will remain toxic.
Ground water monitoring would be implemented to ensure that there are no long-term unacceptable
impacts to ground water resulting from the waste left in place. Institutional controls would be implemented
to place restrictions on dredging and anchoring to protect the integrity of the armored cap and to limit
potential disturbance and resuspension of buried sediment near the sand separation area. Under this
remedial alternative, the following institutional and engineering controls would be implemented:


Restrictions on dredging and anchoring would be established to protect the integrity of the armored
cap and to limit potential disturbance and resuspension of buried sediment under the residuals
cover layers



Alert property owners of the presence of subsurface materials exceeding Remediation Levels



Public notices and signage around the perimeter of the temporary armored cap site would be
maintained or provided, as appropriate
As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.



This alternative includes ongoing operations, inspection, and maintenance of the armored cap, which
includes inspection and periodic maintenance, and the Environmental Protection Agency 5-year reviews as
required under the National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2). A
periodic sampling and analytical program would also be implemented to monitor the progress of natural
recovery. The current temporary cap has had no impact on navigation, and this alternative is not expected
to be different
Alternative 4N – Partial Solidification/Stabilization, Upgraded Cap, Institutional Controls, Ground
Water Monitoring, and Monitored Natural Recovery
Estimated Capital Cost: $11.1 million
Estimated In-Direct and Operation & Maintenance Cost: $3.7 million
Estimated Total Present Worth Cost: $14.8 million
Estimated Construction Time: 17 months
This remedial alternative provides for solidification and stabilization of the most highly contaminated material.
The purpose of solidification/stabilization at the Site is to reduce the mobility of the waste material thereby
reducing the potential for a dioxin release into the San Jacinto River. A dioxin and furan value that exceeds
13,000 ng/kg dioxin was used to define the most highly contaminated material. This alternative would result in
treatment of a portion of the Principal Threat Waste. Under this alternative, 3.6 acres of the armor cap would
be removed and about 52,000 cubic yards of materials beneath the cap exceeding 13,000 ng/kg dioxin,
24
076837

 regardless of waste material depth, would undergo solidification and stabilization. The type of amendments
would be determined during the Remedial Design. The extent of the area for partial solidification and
stabilization is the western cell and a portion of the eastern cell that is currently covered by the armored cap.
The maximum depth of solidification and stabilization in the western cell would be to approximately 10-feet
below the current base of the armored cap and on average approximately 5-feet below the current base of the
armored cap in the eastern cell and northwestern area.
For solidification/stabilization, amendments, such as Portland cement or other materials, would be mixed
with the waste material. Mixing of amendments and the waste material could be accomplished using largediameter augers or conventional excavators. Before mixing, portions of the armored cap armor rock where
mixing will occur would need to be removed and stockpiled for reuse, if possible, or washed to remove
adhering sediment and disposed in an appropriate facility. The geotextile and geomembrane in those areas
would also need to be removed and disposed of as contaminated debris. Submerged areas to be stabilized
would need to be isolated from the surface water with sheet piling and mostly dewatered prior to mixing
with treatment reagents using conventional or long reach excavators.
Finally, an upgraded cap would be constructed as described in 3N, including replacement of the armor rock
layer geomembrane and geotextile over the solidification and stabilization footprint; and the measures
described under Alternative 3N to protect the upgraded cap from vessel traffic would be implemented.
Monitored Natural Recovery would be used to achieve the sediment Preliminary Remediation Goal in the
sand separation area and the Texas Surface Water Quality Standard in the San Jacinto River. Institutional
controls would be implemented to place restrictions on dredging and anchoring to protect the integrity of the
armored cap and to limit potential disturbance and resuspension of buried sediment near the sand
separation area. Under this remedial alternative, the following institutional and engineering controls would
be implemented:


Restrictions on dredging and anchoring would be established to protect the integrity of the armored
cap and to limit potential disturbance and resuspension of buried sediment under the residuals
cover layers.



Alert property owners of the presence of subsurface materials exceeding Remediation Levels.



Public notices and signage around the perimeter of the temporary armored cap site would be
maintained or provided, as appropriate.



As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.

Ground water monitoring would be implemented to ensure that there are no long-term unacceptable
impacts to ground water resulting from the waste left in place.
The estimated footprint of this alternative is approximately 2.6 acres in the western cell and 1.0 acre of
submerged waste material spanning the eastern cell and the northwestern area. Based on the horizontal and
vertical limits identified for this alternative, a total of approximately 52,000 cubic yards of soil and waste
material would be treated.
This alternative includes ongoing operations, inspection, and maintenance of the armored cap, which includes
inspection and periodic maintenance, and the Environmental Protection Agency 5-year reviews as required
under the National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2). A periodic sampling
and analytical program would also be implemented to monitor the progress of natural recovery. The current
temporary cap has had no impact on navigation, and this alternative is not expected to be different.
25
076838

 Alternative 5N – Partial Removal, Upgraded Cap, Institutional Controls, Ground Water Monitoring,
and Monitored Natural Recovery
Estimated Capital Cost: $24.86 million
Estimated In-Direct and Operation & Maintenance Cost: $4.94 million
Estimated Total Present Worth Cost: $29.8 million
Estimated Construction Time: 13 months
This remedial alternative provides for removal and offsite disposal of the most highly contaminated
material. A dioxin and furan value that exceeds 13,000 ng/kg dioxin was used to define the most highly
contaminated material; however, this would not result in removal or treatment of all of the Principal Threat
Waste, which is defined as Site material containing dioxin greater than 300 ng/kg. Under this alternative,
3.6 acres of the armor cap would be removed and about 52,000 cubic yards of materials beneath the cap
exceeding 13,000 ng/kg dioxin, regardless of waste material depth, would be removed. The lateral and
vertical extent and volume of waste material removed under this alternative is the same as the waste
material to be treated as described in the previous section for alternative 4N. Construction of an upgraded
cap, institutional controls, and Monitored Natural Recovery for the sand separation area, as described in
Alternative 3N, are also included in this remedial alternative.
To mitigate potential water quality issues, submerged areas would need to be isolated using berms, sheet
piles, and/or turbidity barrier/silt curtains prior to excavating waste material. Upland areas would not need to
be isolated with sheet piling, but the excavation would require continuous dewatering and may need to be
timed to try to avoid high water and times of year when storms are most likely.
Excavated waste material would be dewatered or solidified for disposal at an off-site approved permitted facility.
Effluent from excavated waste material dewatering would need to be handled appropriately, potentially including
treatment prior to disposal. Following completion of the excavation, the work area would be backfilled to replace
the excavated waste material and then the upgraded cap would be constructed, including replacing the armor
rock layer above the excavation footprint and the geomembrane and geotextile layers. Institutional controls
would be implemented to place restrictions on dredging and anchoring to protect the integrity of the armored cap
and to limit potential disturbance and resuspension of buried sediment near the sand separation area. Under this
remedial alternative, the following institutional and engineering controls would be implemented:


Restrictions on dredging and anchoring would be established to protect the integrity of the armored cap
and to limit potential disturbance and resuspension of buried sediment under the residuals cover layers.



Alert property owners of the presence of subsurface materials exceeding Remediation Levels.



Public notices and signage around the perimeter of the temporary armored cap site would be
maintained or provided, as appropriate.



As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will be
essentially permanent measures.

Ground water monitoring would be implemented to ensure that there are no long-term unacceptable
impacts to ground water resulting from the waste left in place.
This alternative includes ongoing operations, inspection, and maintenance of the armored cap, which includes
inspection and periodic maintenance, and the Environmental Protection Agency 5-year reviews as required
under the National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2). A periodic sampling
and analytical program would also be implemented to monitor the progress of natural recovery. The current
temporary cap has had no impact on navigation, and this alternative is not expected to be different.
26
076839

 Alternative 5aN - Partial Removal, Upgraded Cap, Institutional Controls, Ground Water Monitoring,
and Monitored Natural Recovery
Estimated Capital Cost: $60.38 million
Estimated In-Direct and Operation & Maintenance Cost: $9.21 million
Estimated Total Present Worth Cost: $69.6 million
Estimated Construction Time: 19 months
For this alternative, the Preliminary Remediation Goal for a recreational visitor (200 ng/kg dioxin) was
considered for the areas within the armored cap, which are either above the water or where the water depth
is 10 feet or less. As an additional criterion, locations exceeding 13,000 ng/kg dioxin are also removed
regardless of water depth; however, all samples exceeding 13,000 ng/kg dioxin are located in areas where
the water depth is 10 feet or less. This alternative entails removal of approximately 137,600 cubic yards of
waste material from the waste pits.
As with Alternatives 4N and 5N, the existing armored cap (consisting of cap rock, geomembrane, and
geotextile) would need to be removed prior to beginning excavation work.
This alternative also includes an engineered barrier to manage water quality during construction. In shallow
water areas (water depths up to approximately 3 feet), this barrier would be constructed as an earthen
berm, extending to an elevation at least 2 feet above the high water elevation in consideration of windgenerated waves and vessel wakes.
Submerged areas would need to be isolated using berms, sheet piles, and/or turbidity barrier/silt curtains
prior to excavating waste material. Excavated waste material would be offloaded, dewatered, and stabilized
at a dedicated offloading location, as necessary, to eliminate free liquids for transportation and disposal.
Following removal of impacted waste material, the area from which waste materials are removed would be
covered with a residuals management layer of clean cover material.
In the deeper water areas of the waste pits where removal is not conducted, the existing armored cap
would be maintained. Monitored Natural Recovery would be used to achieve the Preliminary Remediation
Goal for sediment in the sand separation area. Institutional controls would be implemented to place
restrictions on dredging and anchoring to protect the integrity of the armored cap and to limit potential
disturbance and resuspension of buried waste material near the sand separation area. Under this remedial
alternative, the following institutional and engineering controls would be implemented:


Restrictions on dredging and anchoring would be established to protect the integrity of the armored
cap and to limit potential disturbance and resuspension of buried sediment under the residuals
cover layers.



Alert property owners of the presence of subsurface materials exceeding Remediation Levels.



Public notices and signage around the perimeter of the temporary armored cap site would be
maintained or provided, as appropriate.



As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.

Ground water monitoring would be implemented to ensure that there are no long-term unacceptable
impacts to ground water resulting from the waste left in place.
27
076840

 This alternative includes ongoing operations, inspection, and maintenance of the armored cap, which includes
inspection and periodic maintenance, and the Environmental Protection Agency 5-year reviews as required
under the National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2). A periodic
sampling and analytical program would also be implemented to monitor the progress of natural recovery. The
current temporary cap has had no impact on navigation, and this alternative is not expected to be different.
Alternative 6N - Removal of Waste Materials Exceeding Cleanup Levels, MNR, and Institutional Controls
Estimated Capital Cost: $ 77 million
Estimated In-Direct and Operation & Maintenance Cost: $10 million
Estimated Total Present Worth Cost: $ 87 million
Estimated Construction Time: 19 months
This alternative involves the removal of all waste material that exceeds the Preliminary Remediation Goal
of 200 ng/kg regardless of depth in the northern waste pits. Sheet piles will be used around all areas to be
removed to reduce resuspension of the waste material. Monitored Natural Recovery (MNR) will be used for
the sediment in the sand separation area. This would involve removal of the majority of the existing
armored cap and the removal of 152,000 cubic yards of material. Alternative 6N includes Best Management
Practices recommended by the Corps of Engineers.
This removal alternative will utilize Best Management Practices to reduce and control the re-suspension of
waste material and sediment. While the Best Management Practices identified below were recommended
by the Corps of Engineers and were used for costing purposes, the final use and design of Best
Management Practices will be determined during the Remedial Design. The Best Management Practices
may include, but are not limited to, the following:


The removal will be completed in stages or sections as appropriate to limit the exposure of the
uncovered sections of the waste pits to potential storms.



Raised berms and sheet piles in addition to dewatering and removal in the dry where feasible will
be used to reduce the re-suspension and spreading of the removed material.



The berms would be armored on both sides with armor material removed from the areas that have
geotextile present.



Approximately three-fourths of the waste material will be excavated in the dry behind sheet pile
walls. An excavation dewatering and water treatment system will operate on any day of
excavation.



Residual concentrations of contaminants following excavation and removal will be covered by at
least two layers of clean fill to limit intermixing of residual material with the clean fill.



Removal of submerged waste materials in the Northwest area will include isolation of the work
area with berms/sheet piles if practicable.

Excavated waste material would be dewatered (decanted) and stabilized by addition of Portland cement or
other additive at the offloading location, as necessary, to eliminate free liquids for transportation and disposal.
Some operations, such as water treatment, may be barge mounted. In the Northwest area only, the residual
concentrations of contaminants following excavation and removal will be covered by at least two layers of
clean fill to limit intermixing of residual material with the clean fill, and armored. The protective berms will be
28
076841

 left in place after construction to provide a barrier, limiting barge and boat traffic over the site. Institutional
controls will be used to prevent disturbance of the sediment residuals below the residual cover layers.
This alternative entails removal of approximately 152,000 cubic yards of waste material from the waste pits
footprint, which would require a relatively large offloading and waste material processing facility to efficiently
accomplish the work. Additional activities would include management and disposal of dewatering effluent,
including treatment if necessary. Material that is removed would be transported in compliance with applicable
requirements and permanently managed in an approved permitted facility cleared by the Environmental
Protection Agency’s regional offsite rule contact. Approximately 13,300 truck trips may be required to
transport the waste material to the off-site approved permitted facility; however, capacity of roads to handle
the loads will impact the truck size that can be used. The method of transportation and number of trips will be
determined during the Remedial Design, as well as other transportation alternatives, including rail transport.
The material will require dewatering by removal and/or treatment so that there are no free liquids.
Under this remedial alternative, the following institutional and engineering controls would be implemented:





Restrictions on dredging and anchoring would be established to protect the integrity of the armored cap
and to limit potential disturbance and resuspension of buried sediment under the residuals cover layers
Alert property owners of the presence of subsurface materials exceeding Remediation Levels.
Public notices and signage around the perimeter of the temporary armored cap site would be
maintained or provided, as appropriate.
As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.

This alternative includes the Environmental Protection Agency 5-year reviews as required under the
National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2). The current temporary cap
has had no impact on navigation, and this alternative is not expected to be different.

Alternatives for the Former Southern Impoundment:
Alternative 1S – No Action
Estimated Capital Cost: $0
Estimated In-Direct and Operation & Maintenance Cost: $0
Estimated Total Present Worth Cost: $0
Estimated Construction Time: None
Under this remedial alternative for the area of investigation south of I-10, impacted soil would remain in
place and no steps would be taken to alert future landowners or construction workers of the presence, at
depth, of dioxin concentrations exceeding cleanup goals.
Alternative 2S – Institutional Controls and Ground Water Monitoring
Estimated Capital Cost: $65,000
Estimated In-Direct and Operation & Maintenance Cost: $959,000
Estimated Total Present Worth Cost: $1.02 million
Estimated Construction Time: None
This alternative would apply to locations in the area south of I-10 where the dioxin concentration in certain
levels within the upper 10 feet of soil exceed the cleanup goal for the future construction worker (240 ng/kg
TEQDF,M). The upper 10 feet depth is based on the depth for the exposure scenario, i.e., construction
29
076842

 worker. Dioxin concentrations in the upper 10 feet of soil exceed the Preliminary Remediation Goal. Ground
water monitoring would be implemented to ensure that there are no long-term unacceptable impacts to
ground water resulting from the waste left in place. Under this remedial alternative, the following
institutional controls would be implemented:


Deed restrictions would be applied to parcels in which the depth-weighted average dioxin
concentrations in the upper 10 feet of subsurface soil exceed the soil cleanup goal for the future
construction worker.



Notices would be attached to deeds of affected properties to alert potential future purchasers of the
presence of waste and soil with dioxin concentrations exceeding the soil cleanup goal.



As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.

This alternative includes ongoing ground water monitoring, and the Environmental Protection Agency 5-year
reviews as required under the National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2).
Alternative 3S – Enhanced Institutional Controls and Ground Water Monitoring
Estimated Capital Cost: $367,000
Estimated In-Direct and Operation & Maintenance Cost: $1.04 million
Estimated Total Present Worth Cost: $1.4 million
Estimated Construction Time: 1 month
This remedial alternative would incorporate the Institutional controls identified in Alternative 2S and add
physical features to enhance the effectiveness of the institutional controls. The physical features would
include bollards to define the areal extent of the remedial action areas at the surface and a marker layer
that would alert workers digging in the area that deeper soil may be impacted.
Implementation of this remedial alternative may include the following steps:






Removing up to 2 feet of surface soil.
Temporarily stockpiling the soil onsite.
Placing the marker layer (such as a geogrid or similar durable and readily visible material) at the
bottom of the excavation.
Returning the soil to the excavation and re-establishing vegetative cover.
Placing bollards at the corners of the remedial action areas.

Under this remedial alternative, the following institutional controls would be implemented:


Deed restrictions would be applied to parcels in which the depth-weighted average dioxin
concentrations in the upper 10 feet of subsurface soil exceed the soil cleanup goal for the future
construction worker.



Notices would be attached to deeds of affected properties to alert potential future purchasers of the
presence of waste and soil with dioxin concentrations exceeding the soil cleanup goal.



As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.

This alternative includes ongoing ground water monitoring, and the Environmental Protection Agency 5-year
reviews as required under the National Contingency Plan in 40 Code of Federal Regulations 300.430 (f)(iv)(2).

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 Alternative 4S – Removal and Offsite Disposal, Institutional Controls
Estimated Capital Cost: $9.07 million
Estimated In-Direct and Operation & Maintenance Cost: $0.85 million
Estimated Total Present Worth Cost: $9.9 million
Estimated Construction Time: 7 months
This remedial alternative involves excavation and replacement of soil in the areas exceeding the
preliminary remediation goal. Implementation of this remedial alternative would require dewatering to lower
the water table to allow excavation of impacted soil in relatively dry conditions, and may need to be timed to
try to avoid high water and periods when storms are most likely. Excavated soil would be further dewatered
or solidified, as necessary, prior to transporting it for disposal. Effluent from excavation and subsequent
dewatering would need to be handled appropriately, potentially including treatment prior to disposal.
Excavated soil would be disposed of at an approved permitted landfill, the excavation would be backfilled
with imported soil, and vegetation would be re-established. An existing building (an elevated frame
structure) and a concrete slab would need to be demolished and removed prior to excavating the
underlying soil. These features would be replaced, if necessary. Ground water monitoring is not a part of
this Alternative 4S because material containing dioxin above the Preliminary Remediation Goal will be
removed and disposed of off-site.
The removal volume (50,000 cubic yards) was calculated assuming a conservative excavation side slope of 2
horizontal to 1 vertical. Transportation and disposal costs were estimated assuming that all of the excavated
material would be transported to a licensed landfill for disposal. Institutional controls will applied to insure the
continued industrial use of the area.
Under this remedial alternative, the following institutional controls would be implemented:


Deed restrictions would be applied to parcels where dioxin concentrations do not allow for
unrestricted use and unlimited access.



Notices would be attached to deeds of affected properties to alert potential future purchasers of the
presence of waste and soil with dioxin concentrations exceeding protective level of 51 ng/kg for
unlimited use and unrestrictive access.



As a result of the long term persistence of dioxin, it is anticipated that the institutional controls will
be essentially permanent measures.

Evaluation of Alternatives
The National Contingency Plan requires the use of nine criteria to evaluate the difference of remediation
alternatives individually and in comparison to each other. These criteria include threshold criteria, which requires
that each alternative must meet in order to be eligible for selection. Primary balancing criteria are used to weigh
major trade-offs among alternatives, and modifying criteria involve state and community acceptance.
The two threshold criteria are: 1) overall protection of human health and the environment, and 2)
compliance with applicable, relevant, and appropriate requirements. The five primary balancing criteria are:
3) long-term effectiveness and permanence; 4) reduction of toxicity, mobility, or volume through treatment;
5) short-term effectiveness; 6) implement-ability; and 7) cost. The two modifying criteria are: 8) state
acceptance, and 9) community acceptance. Environmental Protection Agency assesses public comment on
the Proposed Plan to gauge community acceptance.
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 This section of the Proposed Plan discusses the relative performance of each alternative against the nine
criteria and the rationale for selecting the Preferred Alternatives.
Several treatment technologies, including thermal (in-pile thermal desorption) and chemical (solvated
electron technology and base catalyzed decomposition) processes, were also considered for use at the
Site but were not included in a remedial alternative, as discussed further in the Feasibility Study. The
feasibility study contains a detailed analysis of each alternative against the criteria and a comparative
analysis of how the alternatives compare to each other. A summary is provided below.
Threshold Criteria
The two threshold criteria are overall protection of human health and the environment, and compliance with
applicable, relevant, and appropriate requirements. The containment alternatives (2N through 5aN) will only
remain protective if they are properly maintained for the length of time (hundreds of years) that the impounded
waste retains its toxicity, and their integrity is not compromised by extreme weather events, barge strikes and/or
changes in the river channel which could result in a future release. Alternative 6N best realizes the Threshold
Criteria because the waste material would be removed and therefore not subject to a potential future release.
One of the applicable requirements is the Clean Water Act §404(b)(1), which addressed discharges of
dredge and fill material into waters of the United States. The San Jacinto River is a water of the United
States. Dredge and fill permits are applicable to dredging, in‐water disposal, capping, construction of
berms or levees, stream channelization, excavation and/or dewatering. Permits are not required, however,
for on-site CERCLA actions. Under the 404(b)(1) guidelines, efforts should be made to avoid, minimize,
and mitigate adverse effects on the waters of the U.S. and, where possible, select a practicable
(engineering feasible) alternative with the least adverse effects. The substantive requirements of Section
404 were considered in the selection of the preferred remedial action. The preferred remedial action is
designed to minimize adverse impacts to waters of the United States through the use of best management
practices to minimize releases to the San Jacinto River. Additional evaluations will be conducted during the
Remedial Design to determine the potential habitat impacts related to impacts of dredging and placement
of the clean residual layer management materials to document compliance with CWA Section 404(b)(1).
Several facilities have been identified for the excavation alternatives that could potentially receive the waste
material, however, the actual disposal location would be determined during the Remedial Design. Any potential
releases during excavation will be reduced through implementation of best management practices.
There are significant differences between the northern area alternatives regarding the amount of potential dioxin
impacts to the San Jacinto River, and when those impacts may occur. For example, Alternatives 3N would not
result in any significant short term dioxin impact during construction because the existing cap is not removed.
However, based on the Corps of Engineers review (Appendix A of the Feasibility Study), a severe future storm
could result in significant erosion of 80% of the armor cap and up to 2.4 feet of scour into the waste pits.
Removal alternatives will result in some releases of waste materials during implementation, estimated by the
Corps of Engineers to be between 0.2% and 0.34%.
For the area south of I-10, other than Alternative 1S, the remedial alternatives considered in the Feasibility
Study Report meet both of the threshold criteria: protectiveness and compliance with applicable, relevant,
and appropriate requirements. However, the removal alternative (4S) is more protective in the long-term
and permanent because the waste material could not be potentially compromised by future extreme
weather events. The potentially affected receptor (future construction worker) would be protected from
exposure to soil with elevated dioxin concentrations by warnings and restrictions (Alternatives 2S and 3S)
or removal of impacted soil (Alternative 4S).
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 Primary Balancing Criteria – Long-Term Effectiveness and Permanence
All alternatives that leave waste material in place (Alternatives1N through 5aN) are less permanent than the
removal alternative (6N).
Alternatives 1N, 2N, and 3N are containment alternatives with some long-term protectiveness. However,
the area is prone to tropical storms and hurricanes which could damage a cap. In addition, future flooding
may be even more intense than experienced in the past, which would increase the uncertainty of the longterm effectiveness of all of the containment alternatives.
Alternative 3aN is an enhanced capping alternative with armor cap improvements (larger 15” armor stone, 24” of
additional cap thickness on top of the Alternative 3N cap) recommended by the Corps of Engineers to address
the deficiencies of Alternative 3N. Alternative 3aN would be better able to withstand a future severe storm,
although the Corps of Engineers did not model this. However, there still remains the uncertainties related to
changes in channel planform morphology that may occur due to bank erosion, shoreline breaches, etc. during a
high flow event caused by a major flood or hurricane, which is beyond the ability of existing sediment transport
models to simulate, as well as the uncertainty of making predictions that would have to remain relevant for
hundreds of years into the future. To add to these uncertainties, future flooding may be even more intense.
According to the U.S. National Climate Assessment, flooding along rivers and other areas following heavy
downpours and prolonged rains is exceeding the limits of flood protection infrastructure designed for historical
conditions. Sea level rise, storm surge, and heavy downpours in combination with the pattern of continued
development in coastal areas are increasing damage to U.S. infrastructure and are also increasing risks to ports
and other installations. Aerial photographs document that the Site, even over just the last 60 years, is in a
dynamic river environment that raises concerns about the permanence of any manmade structure.
Alternatives 4N, 5N, and 5aN all provide increased long term effectiveness compared to Alternatives 1N, 2N,
and 3N because the most highly contaminated waste would either be stabilized or removed. However,
uncertainties still remain regarding long-term effectiveness of the cap and the potential impact of severe future
storms and hurricanes. Alternative 6N provides the greatest long-term protectiveness and effectiveness
because the waste material would be permanently removed from the San Jacinto River and there would be no
potential for a future release above the risk based level from the Site. Also, with Alternative 6N, there would be
no concerns regarding the long-term viability and effectiveness of a maintenance program that would have to
endure for an extremely long time (more than 500 years). Alternative 6N is also the only alternative that provides
for complete removal of the Principal Threat Waste from the northern impoundments.
Ground water monitoring would be included in Alternatives 2N through 5aN, where waste above the preliminary
remediation goals is left in place, to confirm that there would be no long-term future unacceptable impacts to
ground water.
For the area south of I-10, soil with dioxin concentrations exceeding the cleanup goal is isolated from the surface
by relatively clean overburden. The only route of potential exposure is through excavation into the impacted
depth interval. The physical markers (Alternative 3S) would draw attention to the institutional controls and
enhance their effectiveness. Alternative 4S would achieve long-term effectiveness by permanently removing the
impacted soil from the 0- to 10-foot depth interval from the Site and securely disposing of the soil in an approved
permitted landfill. While the institutional controls, particularly with the addition of physical markers (Alternative
3S), would provide reliable long-term protection, they rely on the integrity of future construction workers to
comply with the restrictions. Therefore, complete removal of the impacted soil in the depth interval of potential
excavation (Alternative 4S) will provide the highest level of long-term effectiveness because it is not subject to
inappropriate future use of the area or any erosion/scour of the waste material that may result from a future
extreme storm. Alternative 4S is also the only alternative that provides for complete removal of the Principal
Threat Waste from the southern impoundment. Ground water monitoring would be included in Alternatives 2S
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 and 3S, where waste above the preliminary remediation goals is left in place, to confirm that there would be no
long-term future unacceptable impacts to ground water.
Primary Balancing Criteria – Reduction of Toxicity, Mobility, or Volume through Treatment
Alternatives 1N, 2N, 3N, or 3aN do not include additional measures to reduce the toxicity, mobility, or volume
of material. However, a portion of the soils in the western cell were previously solidified during the temporary
armored cap construction. Thus, these alternatives are comparable in reduction of toxicity, mobility, or
volume of material. Alternative 3N further reduces potential mobility, and to a further extent 3aN, within the
temporary armored cap site by increasing the protection of the armored slopes, and both rank more favorably
than Alternatives 1N and 2N. Alternatives 4N and 5N take additional measures through solidification and
stabilization (Alternative 4N) or removal (Alternative 5N) of approximately 52,000 cubic yards of waste
materials, and are comparatively better than Alternative 3N and 3aN for reduction of toxicity, mobility, or
volume of material. Alternative 5aN removes approximately 137,600 cubic yards of waste material, and thus
compares more favorably for reduction of toxicity, mobility, or volume of material than Alternatives 4N and 5N.
Alternative 6N has the greatest volume of removal – 200,100 cubic yards. This alternative is the most
effective in reducing the toxicity, mobility, and volume of waste compared to all of the other alternatives.
Alternatives 1S, 2S and 3S do not include any reduction in the toxicity, mobility, or volume of impacted soil.
Alternative 4S is the only alternative that reduces the volume by complete removal of soils above the Preliminary
Remediation Goal. The excavated soil will likely require dewatering either by physical removal and/or treatment
with Portland cement or a similar material to eliminate free liquids for transportation and disposal.
Primary Balancing Criteria – Short-Term Effectiveness
Alternatives 1N and 2N do not entail any construction, and thus have no short-term impacts. Alternative 3N
has the shortest construction duration (two months) of the remaining alternatives. Alternatives 3aN, 4N, 5N,
5aN, and 6N have estimated construction durations ranging from 13 to 19 months. Alternative 3N does not
result in water column, sediment, or tissue impacts (except for minor turbidity during armor rock placement),
and has the lowest risk to worker safety, the lowest greenhouse gas and particulate matter emissions, and the
least traffic and ozone (smog) impact. Further, Alternative 3N does not disturb the armored cap or require
handling of waste materials. Compared to Alternatives 4N, 5N, 5aN, and 6N, which all include at least some
cap removal, Alternatives 3N and 3aN rank more favorably for short-term effectiveness because there is no
cap removal and little potential for short-term dioxin releases to the San Jacinto River.
All of the alternatives involving either partial or full removal of the waste materials, including Alternatives 5N,
5aN, and 6N, would have re-suspension of sediment. Alternative 5N uses silt curtains to control the resuspension of sediment. Silt curtains are the least effective controls. Alternative 5aN uses more effective resuspension controls including sheet piles and earthen berms. Alternative 6N adds removal in the dry in addition
to sheet piles and earthen berms and results in the most effective control of re-suspension. The actual design
and application of Best Management Practices for construction will be determined during the Remedial Design.
Alternatives 4N, 5N, 5aN, and 6N each have short-term impacts associated with sediment residuals and resuspension as well as a high-water event during construction. However, the actual impacts would be
reduced to the maximum extent practicable by the use of Best Management Practices during construction,
especially in Alternative 6N with the most extensive application of Best Management Practices.
Alternative 5aN and 6N has a longer construction duration than the other alternatives. Compared to the
other alternatives, there is higher potential worker safety issues and higher environmental impacts due
emissions of ozone precursors, particulate matter (smog-forming), and greenhouse gases.
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 Best Management Practices can successfully mitigate and control re-suspension of sediment. Alternative 6N,
the preferred alternative, will include design and construction methodologies to mitigate and reduce the impact of
storms during construction. These methodologies may include armor cap removal in sections, raised berms,
operational controls, etc. Substantial containment structures are needed to isolate the removal operations,
residuals and exposed sediment. To control the sediment re-suspension during construction, the containment
structures would consist of berms and sheet pile walls or caissons to an elevation of about +10 NAVD88
(protection from 25-year or 50-year flood stage). If performing excavation of the waste materials in the dry, the
top of the berms would preferably be no lower than +5 NAVD88 (protection from 5-year or 10-year flood stage).
For the Southern Impoundment, Alternative 2S for the southern area does not entail any construction, and
thus has no short-term impacts. Excavations (Alternatives 3S and 4S) would require Best Management
Practices to control dust and storm water. Short-term impacts associated with Alternative 3S would be
minimal given the shallow depth of excavation, limited volume of material that would be moved, and absence
of significant concentrations of contaminants of concern in the shallow soil. Alternative 4S would require
exposing soil with dioxin concentrations exceeding the Preliminary Remediation Levels, which introduces the
potential for exposure to contaminants of concern through direct contact with the soil, inhalation or ingestion of
impacted dust, and contact with impacted soil suspended in runoff. The volume of soil and the duration of the
project would also be greater than for Alternative 3S; and Alternative 4S would require offsite transportation of
the soil to a disposal facility, increasing the potential for exposure to contaminants of concern, emissions of
greenhouse gasses, nitrogen oxides, and particulate matter, and potential tracking of contaminants of concern
offsite. However, measures developed in the Remedial Design would be implemented to reduce the amount
of any materials lost during transportation. During the Remedial Design, a plan will be prepared for notification
of downstream stakeholders regarding Site activities and any unexpected conditions at the Site.
Primary Balancing Criteria – Implementability
Alternatives 1N and 2N do not have any implementability issues because they do not entail construction.
Both are more favorable from an implementability standpoint compared to Alternatives 3N, 4N, 5N, 5aN,
and 6N. Alternative 3N is a short-duration project that entails proven technology (i.e., the same activities
were demonstrated during construction of the temporary armored cap) that can be deployed with readilyavailable materials and local, experienced contractors.
Implementability issues, such as the temporary armored cap site access, limited staging areas, restrictions on
equipment size, and availability of offsite staging area properties are greater for Alternatives 4N, 5N, 5aN, and
6N compared to Alternative 3N and 3aN because of the much larger scope and scale of these alternatives.
Identifying and securing an offsite staging area is considered an even greater challenge for Alternatives 5N,
5aN, and 6N compared to Alternative 4N because removed waste material and sediment may need to be
managed at the offsite staging area, which requires a larger footprint, and given the nature of the dredged
material, might make finding a willing landowner difficult. Proper management of cap material and excavated
wastes, and onsite processing and management for removed sediments for offsite transportation to
neighboring roadways, will be critical for effective implementation of Alternatives 5N, 5aN, and 6N.
For the southern area, there are no significant implementability concerns associated with Alternatives 2S and
3S. None of the alternatives requires specialized equipment, techniques, or personnel. Coordination with
property owners would be required to establish institutional controls and for access to the project work site.
Alternative 4S would involve more physical activity for implementation, including offsite transportation of
impacted soil, but the operations are routine for remedial actions. The additional implementability concerns are
the increased truck traffic on Market Street and the potential for flooding while impacted soil is exposed during
implementation of Alternative 4S. Provisions may need to be made to handle the additional volume of traffic. The
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 duration of the excavation should not exceed 7 months, and implementation could be timed for periods when
high water is least likely.
Primary Balancing Criteria – Cost
The estimated present worth costs for alternatives range from $0.4 million for Alternative 1N to $87 million
for Alternative 6N, and from $0 for Alternative 1S to $9.9 million for Alternative 4S. Costs for each
alternative are presented with the descriptions of each alternative.
Modifying Criteria
The Texas Commission on Environmental Quality, the support agency, has been informed about the Preferred
Remedy for the Site. Community acceptance will be determined through the Public Comment process based on
letters and emails received during the public comment period and the questions received at the public meeting.
Prior to the public comment period, the Environmental Protection Agency has received about 4,000 letters and
emails supporting either the full removal alternative or the capping alternative.

Preferred Remedy
The Preferred Remedy for cleaning up the Site is Alternative 6N (Removal of Waste Materials Exceeding
Cleanup Levels, Monitored Natural Recovery, and Institutional Controls) and Alternative 4S (Removal and
Offsite Disposal with Institutional Controls). These alternatives will achieve protectiveness by removal of dioxin
waste materials that are considered Principal Threat Waste and removal dioxin contaminated materials at
concentrations greater than the Preliminary Remediation Goals, resulting in a permanent solution to address the
highly toxic dioxin waste materials from the Northern and Southern impoundments. The removed material will be
transported to and disposed of at an approved permitted disposal facility.
Based on the information available at this time, the Environmental Protection Agency believes that the Preferred
Remedy is protective of human health and the environment, complies with applicable, relevant, and appropriate
requirements, and provides the best balance of tradeoffs among the balancing criteria. It reduces risks within a
reasonable time frame, provides for long-term reliability of the remedy, and minimizes reliance on institutional
controls. It will achieve substantial risk reduction by removing the contaminated materials and manages the
remaining risks to human health through institutional controls. The Environmental Protection Agency considered
several options for contaminated materials. The Environmental Protection Agency’s preferred remedy includes
full removal of contaminated waste materials above cleanup levels for the following reasons:
 The material is highly toxic and may be highly mobile in a severe storm and therefore is considered a
Principal Threat Waste. The Environmental Protection Agency considers material at the Site with more
than 300 ng/kg dioxin to be Principal Threat Waste. This concentration was calculated by multiplying
the sediment Preliminary Remediation Goal of 30 ng/kg by a factor of 10.
 The location of materials, either partially submerged within the San Jacinto River (northern
impoundments) or on a small peninsula on the San Jacinto River (southern impoundment), is in a
river environment that is subject to dramatic change, creating concerns about the permanence of an
armored cap.
 The area has a high threat of repeated storm surges and flooding from hurricanes and tropical storms,
which, if the material was left in place, could result in a release of hazardous substances.
 The history of repeated armor cap maintenance as a result of floods that are much less severe than
the design 100-year flood.

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 For all of these factors, the Preferred Remedy provides greater permanence in comparison to other
alternatives. Less costly alternatives rely on remedies that have a higher chance of failure by leaving
Principal Threat Waste materials in the river, resulting in greater uncertainty as to their long-term
effectiveness. The Preferred Remedy can change in response to comment received during the public
comment period or new information presented to the Environmental Protection Agency.
EPA Enforcement Process
Following the public comment period and consideration of the comments received, the Environmental Protection
Agency, in consultation with the Texas Commission on Environmental Quality, will issue a Record of Decision to
select a remedial action for the Site. The Record of Decision will also include a Responsiveness Summary where the
Environmental Protection Agency will respond to the comments received during the comment period.
Once the Environmental Protection Agency signs the Record of Decision, it will use the special negotiation
procedures found in Section 122(e) of the Comprehensive Environmental Response, Compensation and Liability Act
to facilitate a settlement between the Potentially Responsible Parties and the Environmental Protection Agency for
implementation of the selected response action. Pursuant to Section 122(e), the Environmental Protection Agency
will send special notice letters to the Potentially Responsible Parties, which will trigger a sixty (60)-day moratorium on
certain Environmental Protection Agency response activities at the Site while negotiations commence. During this 60day moratorium, the Environmental Protection Agency will not begin response action at the Site, although the
Environmental Protection Agency reserves the right to take action at the Site at any time should a significant threat to
the human health or the environment arise.
If, after 60 days, the parties provide the Environmental Protection Agency with a good faith offer to conduct or finance
the response action and reimburse the Environmental Protection Agency for its costs incurred to date, the
Environmental Protection Agency will extend the negotiation period for an additional 60 days. If settlement is reached
between the Environmental Protection Agency and the Potentially Responsible Parties, the settlement will be
embodied in a Consent Decree for Remedial Design/Remedial Action. Because a Remedial Design/Remedial Action
Consent Decree is a highly complex agreement, the period for negotiation after receipt of a good faith offer often
extends longer than the additional 60 days. Once approved by the Environmental Protection Agency and the U.S.
Department of Justice, the Consent Decree will then be lodged in federal court for judicial approval.
If a timely settlement cannot be reached, the Environmental Protection Agency may take appropriate action at the
Site, which may include either of the following options: (1) the Environmental Protection Agency may issue a
Unilateral Administrative Order to the potentially responsible parties under Section 106(a) of the Comprehensive
Environmental Response, Compensation and Liability Act, requiring the parties to perform the remedy described in
the Record of Decision; or (2) the Environmental Protection Agency may fund the remedial action and pursue a cost
recovery claim under 107 of the Comprehensive Environmental Response, Compensation and Liability Act against
the Potentially Responsible Parties. If the recipients of a Unilateral Administrative Order refuse to comply with the
Order, the Environmental Protection Agency may pursue civil litigation against the recipients to require compliance.
Once either a Consent Decree or a Unilateral Administrative Order is in place, the Potentially Responsible
Parties must develop work plans for construction of the remedy and for protection of the public during
construction. Next, a contractor must be selected subject to review by the Environmental Protection Agency
prior to mobilizing for construction. As a result, there will likely be a period of approximately two years or more
following the signing of the Record of Decision before physical construction of the remedy begins at the Site.

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 Glossary
Administrative Record – All documents which the Environmental Protection Agency considered or relied upon in
selecting the response action at a Superfund site, culminating in the Record of Decision for a Remedial Action.
Applicable, Relevant, and Appropriate Requirements (ARARs) – Generally, any Federal, State, or local
requirements or regulations that would apply to a remedial action if it were not being conducted under the
Comprehensive Environmental Response, Compensation, and Liability Act, or that while not strictly applicable,
are relevant in the sense that they regulate similar situations or actions and are appropriate to be followed in
implementing a particular remedial action.
Contaminants of Concern - Those chemicals that are identified as a potential threat to human health or the
environment, are evaluated further in the baseline risk assessment, and are identified in the remedial
investigation/feasibility study as needing to be addressed by the response action proposed in the Record of Decision.
Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) – Also known as
Superfund. The Comprehensive Environmental Response, Compensation, and Liability Act is a Federal law
passed in 1980 and modified in 1986 by the Superfund Amendments and Reauthorization Act. Under the
Comprehensive Environmental Response, Compensation, and Liability Act, the Environmental Protection Agency
can either pay for the site cleanup or take legal action to force parties responsible for site contamination to clean
up the Site or pay back the Federal government for the cost of the cleanup.
Baseline Ecological Risk Assessment– A study that determines and evaluates risks that site contamination
poses to ecological receptors.
Code of Federal Regulations (CFR) - Codification of the general and permanent rules published in the Federal
Register by the departments and agencies of the Federal Government.
Dioxins - A mixture of up to 7 dioxin and 10 furan chemical compounds combined using the toxicity equivalence
approach. Toxicity Equivalents, or TEQs, are used to report the toxicity-weighted mass of mixtures of dioxins and
furans. Within the TEQ method, each dioxin or furan compound is assigned a Toxicity Equivalence Factor (TEF). This
factor denotes a given dioxin, or furan compound's toxicity relative to 2,3,7,8-tetra chlorodibenzo-p-dioxin (2,3,7,8TCDD, or TCDD), which is assigned the maximum toxicity designation of one. Other dioxin or furan compounds are
given equal or lower numbers, with each number roughly proportional to its toxicity relative to that of 2,3,7,8-TCDD.
Toxicity equivalence is the product of the concentration of an individual dioxin like compound in an environmental
mixture and its corresponding toxicity equivalence factor for that compound. Dioxin TEQs can also be combined with
dioxin-like Polychlorinated Bi-Phenyl TEQs (see Dioxin-like Polychlorinated Bi-Phenyls below) when appropriate.
Dioxin-Like Polychlorinated Bi-Phenyls - A mixture of up to 12 Polychlorinated biphenyl (PCB) chemical
compounds that have a mechanism of toxicity very similar to 2,3,7,8-tetra chlorodibenzo-p-dioxin (2,3,7,8-TCDD, or
TCDD). Dioxin-like Polychlorinated Bi-Phenyls can also be combined using the toxicity equivalence approach. Toxicity
Equivalents, or TEQs, are used to report the toxicity-weighted mass of mixtures of dioxin-like Polychlorinated BiPhenyls. Within the TEQ method, each dioxin-like Polychlorinated Bi-Phenyl compound is assigned a Toxicity
Equivalence Factor (TEF). This factor denotes a given compound's toxicity relative to 2,3,7,8-TCDD, which is assigned
the maximum toxicity designation of one. Other dioxin and dioxin-like Polychlorinated Bi-Phenyl compounds are given
equal or lower numbers, with each number roughly proportional to its toxicity relative to that of 2,3,7,8-TCDD. Toxicity
equivalence is the product of the concentration of an individual dioxin-like Polychlorinated Bi-Phenyl compound in an
environmental mixture and its corresponding toxicity equivalence factor for that compound. Dioxin-like Polychlorinated
Bi-Phenyl TEQs can also be combined with dioxin TEQs (see Dioxins above) when appropriate.

076851

 Engineering Controls – Instruments such as fencing or signage that are used to limit access to contaminated
areas or areas that may pose a physical hazard.
Feasibility Study– A detailed evaluation of alternatives for cleaning up a site.
Five-Year Reviews – A review generally required by statute or program policy when hazardous substances
remain at a site above levels which permit unrestricted use and unlimited exposure. Five-year reviews provide an
opportunity to evaluate the implementation and performance of a remedy to determine whether it remains
protective of human health and the environment. Reviews are performed five years after completion of the
remedy construction at Superfund-financed sites, and are repeated every succeeding five years so long as future
uses at a site remain restricted.
Hazard Index (HI) – In the baseline risk assessment, ration of the dose calculated for a receptor divided by the
toxicity value. When the HI exceeds 1.0, a health risk or ecological risk is assumed to exist.
Human Health Risk Assessment – Estimates the current and possible future risk if no action were taken to
clean up a site. The Environmental Protection Agency’s Superfund risk assessors determine how threatening a
hazardous waste site is to human health and the environment. They seek to determine a safe level for each
potentially dangerous contaminant present (e.g., a level at which ill health effects are unlikely and the probability
of cancer is very small). Living near a Superfund site doesn’t automatically place a person at risk; that depends
on the chemicals present and how a person is exposed to the chemical.
Implementability – One of the Environmental Protection Agency’s primary balancing criteria addresses the
technical and administrative feasibility of a remedy from design through construction and operation. Factors such
as availability of services and materials, administrative feasibility, and coordination with other governmental
entities are also considered.
Institutional Controls – Non-engineered instruments, such as administrative and/or legal controls, that help to
minimize the potential for human exposure to contamination and/or protect the integrity of the remedy.
Institutional controls work by limiting land or ground water use and/or providing information that helps modify or
guide a person’s action at a site. Some common examples include restrictive covenants, deed notices, or local
ordinances.
Long-term Effectiveness and Permanence – One of the Environmental Protection Agency’s primary balancing
criteria that refers to the expected residual risk and the ability of a remedy to maintain reliable protection of human
health and the environment over time, once cleanup levels have been met. This criterion includes the consideration
of residual risk that will remain onsite following remediation and the adequacy and reliability of controls.
Monitored Natural Recovery - A technology in which contaminant concentrations are monitored with no other
remedial actions taken to address contamination. Monitored Natural Recovery assesses the natural attenuation
of contaminants by physical, chemical, and biological processes.
Operable Unit - An operable unit is a discrete action that comprises an incremental step toward comprehensively
addressing site contamination.
Nanograms per Kilogram (ng/kg) - Is a measurement of concentration used to measure how many nanograms
of a contaminant are present in one kilogram of solid material (e.g., soil, sediment, tissue). One ng/kg is equal to
0.000001 milligrams per kilogram (mg/kg).
National Priorities List (NPL) – The Environmental Protection Agency’s list of the most serious uncontrolled or
abandoned hazardous waste sites identified for possible long-term remedial response.
076852

 Preliminary Remediation Goal - Upper concentration limits for specific chemicals in specific environmental
media that are anticipated to protect human health or the environment.
Principal Threat Wastes - Those materials considered to be highly toxic or highly mobile that generally cannot
be reliably contained, or would present a significant risk to human health or the environment should exposure
occur. The Environmental Protection Agency expects to use treatment when practical to address the principal
threats posed by a site. The "principal threat" concept is applied to the characterization of "source materials" at a
Superfund site. A source material is material that includes or contains hazardous substances, pollutants, or
contaminants that act as a reservoir for migration of contamination to ground water, surface water, or air, or acts
as a source for direct exposure.
Reasonable Maximum Exposure– The maximum exposure reasonably expected to occur in a population.
Reduction of Toxicity, Mobility, or Volume Through Treatment – One of the Environmental Protection
Agency’s primary balancing criteria that refers to the anticipated performance of the treatment technologies that
may be included as part of the remedy.
Remedial Investigation– The collection and assessment of data to determine the nature and extent of
contamination at a site.
Sediment - material that sinks to the bottom of the river.
Surface Area - Weighted Average Concentration – Average concentration for an area calculated by applying a
surface area weighting factor to each concentration value.
Short-term Effectiveness – One of the Environmental Protection Agency’s primary balancing criteria that
addresses the period of time needed to implement the remedy and any adverse impacts that may be posed to
workers, the community, and the environment during construction and operation of the remedy until cleanup
levels are achieved.
TEQDF,M – 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalent quotient calculated using toxicity equivalent
factors for mammals
TEQP,M – Dioxin-like Polychlorinated Bi-Phenyl congener toxicity equivalent quotient calculated using toxicity
equivalency factors for mammals.
Waste Material – the waste that was transported and disposed of at the Site.

076853

  

 

076854

 

 

 

 

076855

SITE FIGURES

 

 

Highlands

I-10

TCRA Site
Monmouth Exit, I-10

Channelview

Lynchburg
Exit, I-10

Bu
ffa
lo

Ba
yo
u

330

5000

0
Scale in Feet

TEXAS
Project Site
Houston

225
Not to Scale

145
Modified from: Anchor QEA, LLC. 2014. Draft Final Interim Feasibility Study Report,
San Jacinto Waste Pits Superfund Site. Prepared for: McGinnes Industrial
Maintenance Corporation, International Paper Company, and U.S. Environmental
Protection Agency, Region 6. March.
076856

Figure 1
Site Location
San Jacinto River Waste Pits Site

 J A C I N T O

RI V
E R

S A N

Upland Sand
Separation Areaa

§
¦
¥
10

Area Shown

USEPA’s Preliminary Site Perimeter

Original 1966 Perimeter of the
Impoundments North of I-10
Approximate TCRA Footprint
Soil Investigation Area 4

0
FEATURE SOURCES:
Aerial Imagery: 0.5-meter. Photo Date: 01/14/2009
Texas Strategic Mapping Program (StratMap), TNRIS

[

800

Figure 2
Site Overview
San Jacinto River Waste Pits Site

Scale in Feet

a

Designation of the sand separation area is intended to be a general reference to areas in which such activities
are believed to have taken place based on visual observations of aerial photography from 1998 through 2002.

Modified from: Integral Consulting Inc. and Anchor QEA, LLC. 2013. Remedial Investigation Report, San Jacinto River Waste Pits Superfund Site.
Prepared
for: McGinnes Industrial Maintenance Corporation, International Paper Company, and U.S. Environmental Protection Agency, Region 6. May.
076857

  

 

1966

076859

 

3a  Iacinto Riverf@ I- 195 

1973 ,w 

 

 

82111
a;
199

Figure 6

9111 
it??

i

1 River 

 

 

 

SA

N
JA

CI

NT

SJNE033
17.8 J

O

3.43 J

RI

VE

40.6 J
47.5 J
42.2 J

R

44.9 J
59 J
96.9 J
8.62 J
1.99 J

SJNE032
198 J

59.8 J
34.5 J
349 J
79.5 J
339 J

SJNE050
24.3 J

12.2 J
17.4 J
3.89 J
19.3 J
2.84 J
0.212 J

SJNE041
6.66 J

7.81 J
4.06 J
3.89 J
2.71 J

5.77 J
0.673 J
0.228 J

0.598 J
0.379 J

1.09 J

0.157 J

0.149 J

1.07 J

0.0848 J

0.185 J

0.252 J

0.106 J

0.176 J

0.358 J

0.16 J

0.188 J

0.438 J

0.49 J

0.661 J

0.33 J
0.677 J

31600 J

0.249 J
SJNE028
0.367 J

SJGB013

48.5 J
34.8 J

SJNE035
3.38 J

0.426 J

SJGB014

0.989 J

SJNE026
71.1 J

12.9 J
7.6 J
9.36 J
0.453 J

SJNE029
0.503 J

SJNE043
0.895 J

5100 J
1740 J

SJSH035
10.9 J SJSH033
8.94 J
2.07 J

SJNE030
0.683 J

531 J

0.144 J

SJSH044
0.129 J

SJSH040
SJSH029
0.398 J
0.386 J
SJSH042
0.869 J
SJSH036
0.178 J
0.495 J
SJSH031
0.316
SJSH027
0.536 J
0.442 J
0.747

1.22 J

0.43 J
0.26 J

SJSH038
0.351 J

SJGB015

210 J

0.162 J

338 J

213 J

0.369 J

0.449 J
0.16 J

104 J

0.64 J

0.243 J
1.48 J

0.427 J
0.0593 J

18.6 J

0.365 J

1.29 J

25.2 J

1.51 J
0.85 J

1.32 J

SJSH025
SJSH019
SJSD001
3.69 J
5.6 J
19.2 J
SJSH023
6.56 J
1.35
J
SJSH017
SJSH021
2.61 J
6.74 J
9.44 J

10

SJNE023
0.787 J
0.434 J
0.246 J

SJGB016
SJSH008
8.5 J
SJSH009
SJGB011
9.98 J
SJSH010
14.3 J
12700 J

SJSD002
4.47 J
8.41 J
8.86 J
SJSD003
12.1 J
11.6 J
6.67 J

SJGB012

SJGB010

4050 J

4720 J

SJSD004
8.19 J
21 J
15.8 J

25100 J

26900 J

24400 J

6350 J
194 J

SAMPLE03

9430 J
14800 J

1.46 J
0.909 J
0.853 J

SJSH005
1.04 J

0.559 J

3520 J

1.54 J
0.392 J

75.3 J

0.989 J
1.94 J

0.464 J
2.33 J
6.15 J

0.177 J

8710 J
3.37 J

SJSH004
1.18 J
SJSH003
2.5 J

16.5 J

29.7 J

1.95 J

SJSH014
0.333 J
1.13 J
SJSH012
2.9 J

SAMPLE01

SAMPLE02

74.6 J

17700 J

22200 J

SJGB017

SJNE008
1.11 J

SJNE012
6.08 J

0.79 J

7.41 J
1.31 J

1.09 J
0.341 J

SJSH002
1.36 J

SJSH001
0.644 J

SJNE007
2.92 J

2.4 J

9.94 J
6.86 J
51.1 J
39.1 J
3.53 J
16.2 J
3.54 J
1.32 J

133 J

69.6 J

USEPA’s Preliminary Site Perimeter

Core Location

TEQDF,M (ng/kg dw)

Original 1966 Perimeter of the
Impoundments North of I-10

Surface Sediment
Sample Location

Cores

Notes:
TEQDF,M = Toxicity equivalent for 2,3,7,8-TCDD calculated for dioxins and furans
using mammalian TEFs from van den Berg et al. (2006) (nondetect = 1/2
detection limit)
J = Estimated. One or more congeners used to calculate the TEQDF,M was not
detected.
Concentrations in bold indicate values above reference envelope value (REV);
REV= 7.2 ng/kg dw

Centimeter
0
30.48

Feet
0
1

60.96

2

91.44

3

121.92

4

182.88

6

Figure 7
TEQDF Concentrations in
Waste Material & Sediment Cores

=10000
1000 - 10000
100 - 1000
10 - 100
1 - 10

0

800

San Jacinto River Waste Pits Site

Scale in Feet

<1
No analysis

076862
Modified
from: Integral Consulting Inc. and Anchor QEA, LLC. 2013. Remedial Investigation Report, San Jacinto River Waste Pits Superfund Site.
Prepared for: McGinnes Industrial Maintenance Corporation, International Paper Company, and U.S. Environmental Protection Agency, Region 6. May.

 Surface Sediment Areas Above
Background Level of 7ng/kg
San Jacinto River Waste Pits

Cap Boundary

South Impoundment

Sand Separation Area

*Surface Sediment > Background of 7ng/kg
Preliminary Site Perimeter

*189.6 Acres in the Area above Background

Sand
Separation
Area
Cap
Site
South
Impoundment

n
Sa
EPA Region 6
Superfund
GIS Support
076863
8/29/2016

o
int
c
Ja

er
v
i
R

Sources: Esri World Imagery; Surface Sediment Area by
EPA R6 SF based on Anchor QEAIntegral "TEQDF,M
Concentrations in Surface Sediment, Remedial Investigation
Report, 4/2013". Other boundaries by EPA R6 SF GIS.

10
§
¦
¨

Figure 8
Surface Sediment
Greater Than Background
of 7 ng/kg

µ

0

500

1,000

Feet
20160829ML02

1,500

 Surface Sediment Areas with
PRG Greater than 30ng/kg
San Jacinto River Waste Pits
Cap Boundary

South Impoundment

Sand Separation Area

Surface Sediment with PRG > 30ng/kg
Preliminary Site Perimeter

*42.6 Acres in the Area above 30ng/kg

Sand
Separation
Area
Cap
Site
South
Impoundment

n
Sa
EPA Region 6
Superfund
GIS Support
076864
8/29/2016

o
int
c
Ja

er
v
i
R

Sources: Esri World Imagery; Surface Sediment Area by
EPA R6 SF based on Anchor QEAIntegral "TEQDF,M
Concentrations in Surface Sediment, Remedial Investigation
Report, 4/2013". Other boundaries by EPA R6 SF GIS.

10
§
¦
¨

Figure 9
Surface Sediment
Greater Than Preliminary
Remediation Goal of 30 ng/kg

µ

0

500

1,000

Feet
20160829ML01

1,500

 SJUP009
SJSH051
SJNE069

( SJUP008
!
(
!

(
!

(
!
SJNE070 !
(

SJSH055

(
!

(
!

SJSH053

( SJSH049
!
( SJSH047
!
( SJUP007
!
( SJUP002
!
SJNE066 !
(

(
!

SJUP006

(
SJNE067 !
SJNE068 !
(

( SJUP010
!

( SJUP018
!
( SJUP016
!
(
SJNE062 !

P:\Projects\C643_SJWaste_IPC\Production_MXDs\RI_Report\Figure_2-3_Upstream_Sed_Samples.mxd 12/3/2012 11:12:35 AM

SJNE065 !
(

SJNE064 !
(

(
SJSH064 !
SJSH063 !
(

(
SJNE063 !

SJNE061 !
(

(
SJSH062 !

! SJUP015
(

S A N
R
SJNE060

IV

E

R

(
!

( SJUP014
!

TO
I N
C
A
J

§
¦
¥
10

LAKE SANDY

USEPA's Preliminary Site Perimeter
1-Meter 1995 Bathymetric Contour

0

[

Actual Sample Location

(
!

Surface Sediment
a
for BHHRA (Primary COPCs)

!
(
(
!
(
!

Surface Sediment (Dioxins and Furans only)

Sampling Transect
BERA = Baseline Ecological Risk Assessment
BHHRA = Baseline Human Health Risk Assessment
COPC = Chemical of Potential Concern

800

Scale in Feet
076865

FEATURE SOURCES:
Aerial Imagery: 0.5-meter 2008/2009 DOQQs
- Texas Strategic Mapping Program (StratMap), TNRIS;
Contours: NOS Survey H10619 (1995)

Figure 10
Upstream Background Sediment Sampling Locations
Remedial Investigation Report

a

Surface Sediment COPCs)

San Jacinto River Waste Pits Superfund Site

Surface Sediment for BERA (Primary COPCs)

Subsurface samples were collected at SJSH047 and SJSH055
but were determined to be unnecessary (Integral 2011a), and were disposed.

 J A C I N T O

RI V
E R

S A N

SJFCA3

Upland Sand
Separation Areaa
SJTTR6

SJFCA2

SJTTR4

SJTTR5

§
¦
¥

P:\Projects\C643_SJWaste_IPC\Production_MXDs\RI_Report\Figure_2-6_fish_collection_tissue_sampling.mxd 5/10/2013 4:21:17 PM

10

SJTTR3

SJTTR2

SJTTR1

SJFCA1

0

[
Scale in Feet
076866

USEPA's Preliminary Site Perimeter

Clams and Small Fish

Original 1966 Perimeter of the
Impoundments North of I-10

Small Fish

Approximate TCRA Footprint

Figure 11
Fish Collection Areas (FCA) and Tissue Sampling Transects

Clams
Large Fish and Blue Crab Fish Collection Areas

within USEPA's Preliminary Site Perimeter
Remedial Investigation Report
San Jacinto River Waste Pits Superfund Site

800

a

Designation of the sand separation area is intended to be a general reference to areas in which such activities
are believed to have taken place based on visual observations of aerial photography from 1998 through 2002.
FEATURE SOURCES:
Aerial Imagery: 0.5-meter January 2009 DOQQs - Texas Strategic Mapping Program (StratMap), TNIS

 SA

N
JA

CIN

TO
RI

SJSB001
31.1 J
1.59 J
4.43 J
1.16 J

SJSB008

SJSB006
23.7 J
38.8 J
15 J
59.3 J

SJSB004
3.25 J
3.21 J
6.4 J

1.41 J
SJSB015
15.6 J
4.64 J
2.91 J

196 J
489 J

8.8 J

262 J

78.4 J

11.9 J

27 J

44.6 J

0.229 J

20.2 J

54.1 J

3.07 J

SJSB017
14.2 J
19.3 J
15.7 J

R

SJSB002
SJSB007
7.29 J
6.59 J
3.4 J
2.16 J
2.74 J
2.86 J
2.81 J
38.5 J

5.15 J

49.5 J

35.8 J

11.5 J

16.7 J

13.3 J

164 J

0.819 J

3.92 J

261 J

0.288 J

0.163 J

127 J

7.74 J

0.269 J

SJSB010

97 J

1.26 J

160 J

0.468 J

0.7 J

28.2 J
239 J

3.26 J
SJSB013
6.94 J
4.23 J
10.3 J

VE

21.5 J

41.9 J

513 J

97 J

7.06 J
SJSB012
14 J
12.6 J
0.134 J

0.752 J

5.15 J

8.31 J

22.9 J

70.5 J
1880 J

5.77 J

SJTS033
22.7 J
8.42 J
SJTS032
1.97 J
13.9 J
121 J

99.8 J
84.9 J
67.7 J
3.12 J

6530 J
4990 J
447 J

1160 J

14.2 J

8.84 J

14.9 J

4.35 J
6.84 J

9.99 J

249 J
2950 J
2.42 J

SJSB003
16.6 J
8.55 J
7.58 J

1290 J

1.06 J
2.51 J
SJSB014
31.7 J
25.2 J
6.99 J

SJSB019
SJSB016
9.95 J
6.22 J
12.8 J
8.77 J
12.6 J SJSB020
0.675 J
13.4 J
3.22 J
13 J
SJSB009
24.9 J SJSB022
11.6 J
SJTS034
7.26 J
13.4 J
11.1 J
4.58 J
0.958 J
1.35 J
6.64 J
1.11 J
26.7 J
SJSB023
8.29 J
26.8 J
11.6 J
50.2 J
36.9 J
36.8 J
SJSB018
26.2
J
210 J
50100 J
303 J SJSB026
8.58 J
18.4 J
SJSB021
11.2 J
6.79 J
29.6
J
2380 J
SJSB024
11.3 J
21.1 J
378 J
SJSB025
515 J
18.3 J
43.1 J
2.08 J
9.28 J
23.5 J SJSB027
4.59 J
32.8 J
7.64 J
3.17 J
14.1
J
22.2 J
20.8 J
35500 J
6.74
J
22 J
3J
115 J
14.9 J
419 J
2.44 J
1.12 J
2.1 J
1.14 J
3.76 J
9.05 J
79.4 J
195 J
331 J
640 J
98.8 J
13.9 J
169 J
4.43 J
1570 J
3.45 J
2.86 J
272 J
31.2 J
453 J
0.525 J
2050 J
325 J
8.99 J
0.838 J
1.04 J
64.4 J
733 J
65.4 J
23.5 J
26.7 J
4.16 J
4.37 J
1.96 J
1.7 J
443 J
0.552 J
2.75 J
0.2 J
3270 J
3.07 J
0.794 J
0.684 J
511 J
0.0917 J
6.18 J
2.47 J
26.6 J
0.685 J
0.543 J
3.02 J
2.11 J
0.192 J
61.2 J
0.142
12.9 J
0.111 J

SJSB005
3.91 J
9.38 J
3.59 J

0.244 J

29.3 J

4.13 J

9.08 J

9.4 J

72.9 J

15.2 J

6.14 J

22.2 J

4.54 J

81 J

33.7 J
45.4 J

56.4 J

2250 J

217 J

4.64 J

284 J

40.8 J

1.74 J

5.78 J

Centimeter
0

USEPA’s Preliminary Site Perimeter

Feet
0

30.48

1

60.96

2

91.44

3

121.92

4

182.88

6

Soil Boring Location TEQDF,M (ng/kg dw)

Original 1966 Perimeter of the
Impoundments North of I-10

Cores
=10000

Notes:
TEQDF,M = toxicity equivalent for dioxins and furans using
mammalian TEFs from van den Berg et al. (2006) (nondetect =1/2 detection limit)

1000 - 10000

J = Estimated, One or more congeners used to calculate the TEQDF,M was not detected

10 - 100

Concentrations in bold indicate values above reference envelope value (REV);
REV= 24.3 ng/kg dw

1 - 10

100 - 1000

0

400
Feet

Figure 12
Distribution of TEQDF in Soil Investigation Area 4
and Adjacent Soils
San Jacinto River Waste Pits Site

FEATURE SOURCES:
Parcel Boundaries: Harris County Appraisal District
Hydrology: Harris County Flood Control District

<1
No analysis

Modified076867
from: Integral Consulting Inc. and Anchor QEA, LLC. 2013. Remedial Investigation Report, San Jacinto River Waste Pits Superfund Site.
Prepared for: McGinnes Industrial Maintenance Corporation, International Paper Company, and U.S. Environmental Protection Agency, Region 6. May.

 SA

N
JA

CI

NT

O
RI

VE

R

"

SJFCA3

"

Upland Sand
Separation Area

"
"

SJTTR6
SJTTR4
"

SJFCA2
SJTTR5

"

SJTTR3
"
"

"

11193 !
(

SJTTR1

"

SJFCA1

(
!

Large Fish Collection Location
(University of Houston and Parsons, 2009)

Original 1966 Perimeter of the
Impoundments North of I-10

Large Fish and Blue Crab
Fish Collection Area

USEPA’s Preliminary
Site Perimeter

Hardhead Catfish Fillet and
Blue Crab Exposure Unit: “FCA 1”
Hardhead Catfish Fillet and
Blue Crab Exposure Unit: “FCA 2/3”
"

"

Clam Exposure Unit: “FCA 1/3”

"

"

Clam Exposure Unit: “FCA 2”

0

[

Figure 13 
Exposure Units for Fish and Shellfish Tissue, Area
North of I-10 and Aquatic Environment
San Jacinto River Waste Pits Site
1,000

Feet

Modified076868
from: Integral Consulting Inc. and Anchor QEA, LLC. 2013. Baseline Human Health Risk Assessment, San Jacinto River Waste Pits Superfund Site.
Prepared for: McGinnes Industrial Maintenance Corporation, International Paper Company, and U.S. Environmental Protection Agency, Region 6. May.

 SA

N
JA

CI

NT

O
RI

V

ER

Beach Area A
SJSH042
(!
SJSH044 !
( !
(
SJSH036

!
( SJSH038
!
(

SJSH040
Beach Area B/C
!
( SJSH031
!
(SJSH029
!
( SJSH027
( SJSH035
(!
SJSH033 !

Beach Area E
( !
SJSH025 !
(
SJSH023
(
SJSH021 !
!
(
!
(
SJSH019
SJSH017

!
(

!
(

(
!!
(
!
( !
(
!
(
!
(
!
(
!
(

!
(

!
(
!
!
(
(

!
(
!
(
!
(

Beach Area D

!
( SJSH014
!
( SJSH012

!
( SJSH005
!
( SJSH004

!
( SJSH003

!
( SJSH002

!
( SJSH001

SJVS001

Point#1&2

!
(

!
(

SJGB012
(
SJGB006
( !
SJA2 !
!
(

!
(

!
(
! SJA1
(
!
(
SJGB001
SJGB011
!
(
SJGB010

(!
!!
(
(

Point#3
SJNE022-1
SJNE022-3
SJNE022-2

!
(

SJGB009

( SJSH008
SJSH009 !
(!
!
( SJSH010

Surface Sediment Sample Location

!
(

Exposure Unit Designation
USEPA’s Preliminary Site Perimeter
a

0 Contour (NAVD 88)

0

[

-2 (feet)b
-1 (feet)b

Feet

1,000

Figure 14
Exposure Units for Sediment, Area North of I-10 and
Aquatic Environment Baseline
San Jacinto River Waste Pits Site

a

Notes: Tidal conditions under which this contour
was measured are unknown.
b
Contours reflect pre-TCRA conditions.

Modified from: Integral Consulting Inc. and Anchor QEA, LLC. 2013. Baseline Human Health Risk Assessment, San Jacinto River Waste Pits Superfund Site.
076869
Prepared
for: McGinnes Industrial Maintenance Corporation, International Paper Company, and U.S. Environmental Protection Agency, Region 6. May.

 (
SJSB001 !
(SJSB002 !
SJTS032 !
(

SJSB007 !
(

SJSB004 !
(

SJTS033 !
(
(SJSB012
SJSB003 !
(
!

DS-1
SJSB005 !
(

SJSB014 !
(
SJSB006 !
(

SJSB013 !
(

SJSB015 !
(

SJSB016 !
(
SJTS034 !
(

SJSB017 !
(

SJSB018 !
(
SJSB019 !
(

DS-2
SJSB020 !
(

(
SJSB021 !

SJSB022 !
(

DS-3
SJSB023 !
(

DS-4

SJSB024 !
(

SJSB025 !
(
SJSB026 !
(

DS-5

SJSB027 !
(

[
0

(
!

Surface and Subsurface Soil Sample Location
Exposure Unit for Deep Soils, 0-10 feet

400

FEATURE SOURCES:
Aerial Imagery: 0.5-meter 2008/2009 DOQQs - Texas Strategic Mapping Program (StratMap), TNRIS

Figure 15
Exposure Unit for Soils, Area of Investigation
on the Peninsula South of I-10, 0-10 feet
San Jacinto River Waste Pits Site

Feet

Modified from: Integral Consulting Inc. and Anchor QEA, LLC. 2013. Baseline Human Health Risk Assessment, San Jacinto River Waste Pits Superfund Site.
Prepared for: McGinnes Industrial Maintenance Corporation, International Paper Company, and U.S. Environmental Protection Agency, Region 6. May.
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