Final Report of the Potential Fate and Transport of Benzene, 1,4-Dioxane, Lead and Arsenic at the Ringwood Mines Superfund Site Relative to the Wanaque Reservoir ~~~1'i1<9 I ·" North Jersey District Water Supply Commission Ringwood Mines Superfund Site Ringwood, New Jersey May 2017 *473337* 473337 TABLE OF CONTENTS List of Tables 2 Acronyms 2 Executive Summary 2 Introduction 6 Site Description 7 Geology 7 Hydrogeology 8 Peters Mine Pit Area (PMP) 9 Cannon Mine Pit Area (CMP) 10 O'Connor Disposal Area (OCDA) 11 1,4-Dioxane 11 Properties 11 Treatment 12 l,4-Dioxane Concentrations and Distribution 12 Benzene, Arsenic and Lead 17 Benzene Concentrations and Distribution 17 Arsenic and Lead 17 Remedial Plan for Operable Unit Two 17 Faulting and Seismic Activity Considerations 19 Risk Analysis 20 Summary of Results, Conclusions and Recommendations 20 Summary of Results 20 Conclusions 22 Recommendations 24 References 26 List of Figures: • Figure 1 - Ringwood Mines, New Jersey Peters Mine and O'Connor Disposal Area l,4-Dioxane Groundwater • Highest Historical Concentrations Figure 2 - Ringwood Mines, New Jersey Cannon Mine Area l,4-Dioxane Groundwater Historical Concentrations • Figure 3 - Peters Mine Pit Area Section A-A' l,4-Dioxane Concentrations 08/2015 Highest • Figure 4 - Ringwood Mines, New Jersey Peters Mine and O'Connor Disposal Area l,4-Dioxane Surface Water Highest Historical Concentrations • Figure 5 - Ringwood Mines, New Jersey Cannon Mine Area l,4-Dioxane Surface Water Highest Historical Concentrations • Figure 6 - Faults and Recent Seismic Activity in Wanaque Reservoir Area • Figure 7 - Proposed Monitor Well Locations • Figure 8 - AIl1,4-Dioxane Sampling Locations • Figure 9 - Shooting Range Site with Ford Site in View • Figure 10 - Shooting Range Site Appendix A - Technical Fact Sheet -l,4-Dioxane, United States Environmental Protection Agency List of Tables Preliminary Recommendations for Alternative Treatment Technologies 5, 25 Summary of Recommendations 6, 26 Summary of Regulations for l,4-Dioxane 13, 22 Summary of Water Quality Data 13, 20 Risk Analysis for Groundwater Contaminants Reaching Finished Water. 20 Summary of Conclusions 23 Acronyms CMP - Cannon Mine Pit OCDA- O'Connor Disposal Area EPA - United States Environmental Protection Agency OU - Operable Unit PMP - Peters Mine Pit ft bgs - feet below ground surface PRP- Potentially Responsible Party FS- feasibility study RI - remedial investigation J - estimated value ROD- Record of Decision LBG- Leggette, Brashears & Graham ug/L - micrograms per liter MCL - Maximum Contaminant Level VOC - volatile organic compounds msl- mean sea level WTP - Water Treatment Plant ND - nondetect NJDEP New Jersey Department of Environmental Protection 2 Executive Summary Background/History. The Ringwood Mines Superfund Site (hereinafter Ringwood, County of Passaic, State of New Jersey (hereinafter Environmental Protection "Site") in the Borough of the "Borough") is a United States Agency (EPA) Superfund Site due to historical dumping of wastes on the property and the resulting soil, surface water and groundwater contamination. The source of the waste is attributed to both the Ford Motor Company and the Borough dating to the 60s and 70s. Ford dumped paint sludge, high temperature salt bath sludge and standard refuse directly on the ground and in the mines. Municipal waste, including cars, was also dumped at the property by the Borough. In 1988 EPA found Ford Motor Company to be "a potentially responsible party at the Site under Section 107{a) of CERCLA42 U.S.c. 9607{a)". The Borough has a cost sharing agreement with Ford to pay for part of the cleanup. The Wanaque Reservoir, a 29-billion gallon water supply for millions of New Jersey residents and businesses, and the associated water treatment plant (WTP) owned and operated by North Jersey District Water Supply Commission (hereinafter the "Commission"), are downgradient of the contamination. Present Conditions at the Site. EPA's investigative reports, through February 2017, described three areas of concern at the Ringwood Mines Superfund Site: Peters Mine Pit (PMP) Area, Cannon Mine Pit (CMP) Area, and O'Connor Disposal Area (OCDA). The land area and soil in these areas are defined by EPA as Operable Unit 2 (OU2). water contaminants Soil contaminants include lead, arsenic and chromium. The primary which exceed groundwater The observed concentrations (Ilg/L)), local groundwater of l,4-dioxane (0.156-152 ug/L) water quality standards are benzene and l,4-dioxane. include: the PMP air shaft {146 micrograms and surface water (0.125-2.32 ug/L). per liter The groundwater detection of 152 ug/L was observed in Monitoring Well RW-3DD and is discussed in the Ringwood Mines/Landfill Mine Water, and Surface Water Sampling - 2016 Superfund Site Annual Groundwater, Report (Cornerstone Environmental, 2016d). Cornerstone Environmental concluded that while no specific reason was found to invalidate the reported value of 152 ug/L, the collective data suggest that this value is not representative concentration (Cornerstone Environmental, detected in groundwater 2016d). The next highest l,4-dioxane was 86.6 Ilg/L in February 2017 from Monitoring Well RW-llD (Cornerstone Environmental, 2017). The highest concentration of benzene (344 ug/L) was observed in a monitoring well just downgradient of Peters Pond. Benzene in groundwater was detected at the PMP Area in the air shaft, overburden monitoring wells, and shallow bedrock wells nearest the PMP. EPA has a health screening guideline of 0.35 ug/L for l,4-dioxane. The New Jersey Department of Environmental Protection (NJDEP) has interim Ground Water Quality Standards of 0.4 ug/L for l,4-dioxane for benzene. Lead and arsenic have also been detected in groundwater and 1 ug/L samples from these areas at levels exceeding the NJDEP Ground Water Quality Standards. The highest reported groundwater concentrations of lead (980 ug/L) and arsenic (26.6 ug/L) were detected in the Peters Mine air shaft and southeast of the PMP Area, respectively. EPA has proposed capping PMP and CMP and has proposed two soil clean-up options for OCDA: soil excavation and a cap. The Borough is reviewing whether to build a recycling center on top of the cap in OCDA. EPA has not yet proposed a solution for the groundwater contamination in any of the areas of concern. Groundwater in the area is defined as Operable Unit 3 (OU3). 2 Jacobs' Scope of Services. As part of the General Engineering Services work for the Commission, Jacobs reviewed data from a variety of sources through February 2017, including the EPA's investigation report, and summarized the nature and extent hydrogeological conditions in the aquifer. the contamination of ground and surface water contamination and the The primary objective of the work was to assess the risk of to affect the Commission's finished water quality. To that end, Jacobs assessed the likelihood of benzene, arsenic, lead and lA-dioxane reaching the Commission's Wanaque Reservoir intake as well as the ability of the current treatment scheme to remove those contaminants. The risk assessment utilized EPA's risk approach of assessing both the likelihood and the impact of event. Scores were allocated to both the likelihood and the impact of each contaminant affecting the finished water, and a risk score was determined. Conclusions Groundwater/Surface Water Monitoring at the Ringwood Mines Superfund Site. Additional groundwater, surface water and reservoir sampling is needed. While groundwater well distributed monitoring wells are across the Site for characterizing groundwater quality, additional monitoring wells are needed to address data gaps and provide a more complete understanding of potential source areas, contaminant distributions, and zones of discharge to local streams and surface water bodies. Similarly, additional monitoring surface water of these discharge areas would discharge areas and additional information provide verification on the magnitude of concentrations of these along stream paths. In addition, since both major surface water pathways to the reservoir from the mine areas converge prior to discharging, monitoring at the confluence of Ringwood Creek and the reservoir would identify mass loading to the reservoir by stream pathways. Benzene, Arsenic and Lead. There is a low probability of benzene at non-compliance levels (above 1 Ilg/L) reaching the finished water. The levels at the Ringwood Mines Superfund Site and the hydrogeological conditions along with benzene's volatility and the planned addition of powdered activated carbon feed to the WTP indicate that it will likely be removed in treatment to regulatory levels. While the impact of benzene exceeding standards would be significant, the overall risk of benzene impacting water treatment operations has been designated as low since the likelihood of noncompliance is very low. Arsenic is naturally occurring and prevalent within the bedrock formations and mine tailings at the Site and poses low risk of reaching the finished water. Arsenic can be oxidized with the addition of chlorine or potassium permanganate and removed from source water in conventional treatment. Adjustment of pH may be needed for arsenic removal. There is a low-moderate risk of lead reaching the finished water. Lead in source water can be removed through chemical precipitation, ion exchange or adsorption. l,4-Dioxane. lA-dioxane Based on preliminary analysis of current conditions at the Site, there is a low probability of threatening the Wanaque Reservoir intake or resulting in non-compliance with the Maximum Contaminant Level (MCL) of 0.35 Ilg/L in the finished water. However, since the existing plant cannot remove lA-dioxane, if the contaminant reaches the intake it will impact the finished water quality. Hence, the likelihood of non-compliance is higher than benzene. The impact of exceeding the regulatory standard is significant. The overall risk is designated as low-moderate. 3 There is a low risk of seismic activity affecting contaminant transport. Seismic Activity. Recommendations Short-Term Remedial Action. l,4-dioxane, Given the severity of the impact to the water supply if the contaminants, in particular reach the intake, Jacobs recommends that an active treatment for groundwater remediation dioxane concentrations approach be implemented particularly in the Peters Mine air shaft where some of the highest 1,4- have been detected. plume is one possible active treatment A pump and treat approach to contain the contaminant approach. This could include a well pump and treatment (e.g., advanced oxidation using hydrogen peroxide with ultraviolet light (UV) or ozone). The active treatment approach should ensure that contaminants do not migrate downgradient and impact the water supply. System redundancy and proper controls would be needed to prevent any untreated groundwater from being discharged to surface water. Both a remedial investigation (RI) addendum report and feasibility study (FS)for OU3 are expected to be completed in the summer of 2017 and will serve as the basis for the selection of a remedy for Site wide groundwater. groundwater, Typically, FS reports evaluate a variety such as active or passive treatment, ongoing monitoring. of options monitored to address natural attenuation contaminants in or no action with The Commission should review the recommended option once EPA completes its work and solicits public comments on the plan. Modeling. Models of the reservoir and local and/or regional groundwater determine the levels of l,4-dioxane are recommended to better and lead on Site which may threaten the water supply. The modeling would use information from the enhanced monitoring program described below. Challenges in developing a representative groundwater flow and transport model include the fractured nature of the bedrock beneath the Site, and the fact that contaminants are known to migrate through these zones. In these cases, simplifying assumptions may be required to address flow and transport in the fractured zone, with the model primarily simulating behavior in the saturated overburden, and discharge to local streams and other surface water bodies (ponds and the reservoir). A surface water model may be useful to evaluate the degree of mixing and any channelization through the Wanaque Reservoir and the effects of these factors on potential influent concentrations at the intake. Long-Term Monitoring. The currently monitored groundwater and surface water locations should continue to be monitored. Some of the sources of known groundwater contamination recommends the addition of groundwater monitoring have not been identified. wells and surface water Jacobs sample locations, upgradient of the reservoir. This would help better define groundwater flow directions and magnitudes, and provide a better understanding of contaminant distributions to help identify likely active sources. It would also allow better characterization of any changes in the source(s) at the Site, serve as an "early warning" of likely downgradient contaminant transport, and, along with data from more downgradient locations, provide perspective on any reductions in contaminant dilution, volatilization levels along the streams due to or other transport processes. 4 New wells placed upgradient and at vertically separated intervals along the flowpaths associated with historic l,4-dioxane detections can be used to better characterize the extent of contamination the likelihood of l,4-dioxane discharge to the reservoir. and thus, Applicable locations include: 1) downgradient of suspected Peters Mine and Cannon Mine source areas; 2) near the intersection of Cannon Mine Road and Peters Mine Road; and 3) near the intersection of Peters Mine Road and Margaret King Avenue. Additional surface water monitoring locations should be identified along local streams such as Park Brook, Peters Mine Brook (also named the Ringwood Creek Tributary), and Ringwood Creek. Based on the conceptual model of groundwater flow and discharge at the Site, these streams serve as some of the primary potential contaminant migration pathways to the reservoir. Park Brook is an indirect tributary to Ringwood Creek, initially discharging to Sally's Pond. Additional monitoring locations along it, and the upper reaches of Peters Mine Brook, could help identify initial groundwater locations. To help characterize potential contaminant contaminant discharge discharge to the reservoir, additional surface water monitoring is also recommended for the confluence of Ringwood Creek and the reservoir. As a precaution, monitoring implemented. of the water intake at the Wanaque Reservoir for l,4-dioxane should be In addition, a review of l,4-dioxane results from any public water sources in the vicinity of Ringwood Mines is recommended, along with a determination of the need for additional sampling at these locations. Treatment at the Wanaque WTP. If, at any point during the span of the remediation, monitoring results show evidence of increased levels of contamination in surface water or groundwater that would threaten the reservoir water quality, EPA would also be tasked with adding upgrades at the Wanaque WTP. In anticipation technologies to recommendations of that possibility, the Commission may wish to assess alternative address these contaminants at the plant as detailed Contaminant l,4-Dioxane Treatment Technology Preliminary Recommendation Assessment of advanced oxidation process systems Assessment of activated carbon and/or packed tower aerator systems Evaluation of removal options including chemical precipitation, ion exchange, adsorption and a coagulation-flocculation-solids separation process Assessment of oxidation via addition of chlorine or potassium permanganate and the need for pH adjustment Benzene lead Arsenic This evaluation would provide a preliminary plan in the event contaminant include implementation. treatment preliminary below: Preliminary Recommendations for Alternative plan would in the treatment options, a recommended The Commission could begin implementation treatment, levels continue to rise. The cost, and a timeframe for if and when levels rise in the flowpaths. 5 Summary of Recommendations Recommendation Active remediation of groundwater to control the source particularly at Peters Mine Shaft Modeling of groundwater contamination Additional surface and groundwater monitoring Additional monitoring at Wanaque Reservoir and Intake Treatment evaluation at Wanaque WTP Short/Long Term Short Responsibility EPA Short Long EPA EPA Long Commission Long term levels rise - if EPA Introduction The Ringwood Mines Superfund Site in Ringwood, New Jersey is an EPA Superfund Site due to historical dumping on the property and the resulting soil, surface water and groundwater contamination. The source ofthe waste is attributed to both the Ford Motor Company and the Borough. Ford dumped paint sludge, high temperature salt bath sludge and standard refuse directly on the ground and in the mines. Municipal waste was also dumped at the property by the Borough. Company to be 9607(a)./I In 1988 EPA found Ford Motor "a potentially responsible party at the Site under Section 107(a) of CERCLA42 U.S.c. The Borough has a cost sharing agreement with Ford to pay for part of the cleanup. The Wanaque Reservoir, a 29 billon gallon water supply for millions of New Jersey residents and businesses, and the associated WTP owned and operated by the Commission, are downgradient of the contamination. Following recent detections of lA-dioxane on the Superfund Site, Jacobs has been requested by the Commission to assess the effectiveness of the proposed remedial plan (capping) and the risk of the contaminants, particularly lA-dioxane, impacting the Wanaque Reservoir and finished water quality. The water intake for the Commission is located near Raymond Dam at the southern extent of the Wanaque Reservoir, approximately 7.5 miles south-southwest ofthe Ringwood Mines Superfund Site. Jacobs met with Joseph Gowers, EPA; Kenneth Petrone, NJDEP;and a representative from Ford on June 16, 2016, to tour the Site and better understand the remediation plan. A subsequent meeting with NJDEP, EPA and the Commission was held on April 12, 2017. A conference call with the Borough's consultant, Excel Environmental documentation Resources, was held on April 24, 2017. available through Cornerstone Environmental, the EPA website, Relevant and historical including the remediation plan prepared by dated March 25, 2016, sampling data results through February 2017, and several investigative reports by Arcadis, have been reviewed by Jacobs. Several environmental studies and sampling events have been conducted at the Site, and many of the more recent reports are available from the EPA website for review. This report summarizes much of the Site and contaminant analysis described in some of the more recent reports by Cornerstone Environmental and Arcadis, which were hired by Ford to conduct site investigations. Groundwater Remedial Investigation In particular, the Ringwood Mines Site-Related Report (Arcadis 2015a) is frequently referenced. Jacobs has not 6 conducted any testing or participated in the preparation Ringwood Mines Superfund Site or the remediation available documents plan. of any of the reports provided for the This report is limited to a review of the on the EPA website, which are referenced herein and listed in the References Section. This report has several objectives: • Provide a brief description of the Site and an overview of known lA-dioxane, benzene, arsenic and lead contaminant distributions onsite • Provide a qualitative evaluation of the monitoring well and surface water monitoring network onsite • Assess the remedial plan in the context of groundwater and surface water contamination • Identify locations for additional monitoring to address possible data gaps • Describe the status of the regulatory process for the operable units onsite • Assess the short-term and long-term risks of the contaminants reaching the Wanaque Reservoir intake • Conduct a qualitative evaluation of the risk of contamination in the Wanaque Reservoir and at the water intake based on recent and historical benzene, lead, arsenic and lA-dioxane Site in groundwater detections at the and surface water samples It is noted that the report is not intended to be a comprehensive summary of all of the studies that have been conducted at the Site, or to provide an independent assessment of any reports, studies or their results/conclusions. Site Description There is an extensive record of data collection characterizing the Site geologic, hydrogeologic, and other site features related to the previous mining and waste disposal activities. Historical data on lA-dioxane at the Site is more limited with the record of sampling dating from August 2015 to February 2017. There are three Areas of Concern: the PMP Area, the CMP Area, and the OCDA. EPA has defined these land areas as Operable Unit 2 (OU2). In addition, there is Site-Related Groundwater, defined as Operable Unit 3 (OU3). Benzene and lA-dioxane concentrations concentration are two of the primary contaminants, for which the groundwater exceed NJDEP Ground Water Quality Standards. The highest reported of lA-dioxane the flooded Peters Mine air shaft; the highest groundwater found in RW-6, a monitoring arsenic and chromium. groundwater (152 ug/L) was from monitoring well RW-3DD, located near the PMP and well just downgradient concentration of benzene (344 Ilg/L) was of Peters Pond. Soil contaminants Lead and arsenic have also been detected in groundwater NJDEP Ground Water Quality Standards. include lead, samples from these areas at levels exceeding the The highest reported groundwater concentrations of lead (980 Ilg/L) and arsenic (26.6 Ilg/L) were detected in the Peters Mine air shaft and southeast of the PMP Area, respectively. GeQIQ~ The Site is located in the southeastern extension of the New England Highlands Physiographic Province, which is characterized by a series of north-northeast/south-southwest trending valleys interrupted by 7 east-west trending valleys associated with past glacial ice erosion and deposition which occurred in the region about 12,000 years ago (Leggette, Brashears & Graham, Incorporated encountered at approximately primarily underlain by Precambrian-age gneiss, a foliated There are occurrences 2016 (LBG)). Bedrock is 25 to 50 feet below ground surface (ft bgs). of pegmatite, magnetite iron ore (Arcadis 2015a). rock formed pyroxene-amphibolites, In general, the Site is by regional metamorphism. biotite-quartz feldspar gneiss, and Granite gneiss and pegmatite form sharp ridges separated by narrow troughs underlain by less resistant gneiss (Arcadis 2015a). The gneisses are moderately to well foliated, have mineral lineation, and display evidence of three distinct folding events. Geologic structural features of the New Jersey Highlands, which are regionally related either spatially or tectonically, include folds, faults, lineation trends, and jointing (Arcadis 2015a). Major cross faults are visible as trench-like features that interrupt strike approximately minor drainage lines, and offset small valleys and ridges. These faults generally east-west across the predominant northeast strike of the major ridges and valleys (Hotz 1953). Joints are prevalent in the bedrock and are moderately to steeply dipping with spacing from one foot to several tens of feet (Volkert 2008). Several sets of vertical or steeply dipping joints occur in the Precambrian rocks. One set is parallel to the regional structure. A second set is transverse to it, and a third set is oblique to the regional structure. The transverse joints are the most abundant and the most prominent set (Carswell and Rooney 1976). Unconsolidated soil and sediment deposits are primarily confined to the stream valleys and corridors. Based on the findings of a RI conducted by Arcadis, the unconsolidated deposits range from approximately 25 to 50 feet thick and are thickest in the eastern and southern parts of the Site (Arcadis 2015a). The overburden consists of the Rahway Till dating from the Pleistocene age and is reddish- brown, light reddish-brown, reddish-yellow Silty sand to sandy silt containing some to many sub-round and sub-angular pebbles and few sub-rounded Activity Considerations' Site and groundwater boulders (Arcadis 2015a). The 'Faulting and Seismic section below contains additional information on the geologic setting for the occurrence as it relates to faulting and seismic activity. HydrQ&:eQIQ~ The geological characteristics of the area not only significantly affect the expression of surficial features in the area, but the characteristics of groundwater flow beneath the Site. In unconsolidated and in friable consolidated openings. Groundwater rocks, groundwater is stored in and moves through deposits the intergranular in the consolidated rocks occurs in and moves through cleavage planes, joints, fractures, and faults. These openings become fewer and tighter with increasing depth below the land surface but tend to be distributed in an orderly geometric attitude within rock units of homogeneous composition. The openings are better developed and enlarged in some rocks than others; however, the openings form a comparatively small volume in comparison to the volume of the rock as a whole (Carswell and Rooney 1976). The movement metamorphic of groundwater in the Precambrian igneous and rocks is probably largely in a direction transverse to the regional structure of the beds (southeasterly and not directly toward Wanaque Reservoir). Openings along the joint set transverse to the regional structure have probably been selectively enlarged by weathering more than those openings along joints parallel and oblique to the regional structure. The greater weathering of transverse joints is indicated by their greater abundance and prominence and by the dominant east-west alignment 8 (parallel to the direction of dominant jointing) of streams cutting the Precambrian rocks (Carswell and Rooney 1976). In Passaic County the groundwater reservoir is a few hundred feet thick and can be visualized as a number of small basins separated by divides, which at land surface coincide with surface water drainage divides. In the subsurface these groundwater divides do not necessarily descend vertically through the zone of fresh water circulation but may in places become essentially horizontal where they form divides between shallow local flow systems and deeper and larger flow systems. Groundwater flow systems in the county are generally small; the largest underlie probably only a few square miles. No regional groundwater flow system underlies the entire area (Carswell and Rooney 1976). On hilltops or divides a comparatively small volume of water enters and moves through the secondary openings, limiting the amount of weathering. Water-bearing fractures at different surface contain water under different depths below land hydraulic heads. On stream drainage divides, hydraulic heads decrease with increasing depth, and in major valleys they increase with increasing depth below land surface (Carswell and Rooney 1976). This is an important factor to note with respect to contaminant migration, as it results in upward gradients in valley areas, which tend to drive water (contaminated and uncontaminated) from fractured bedrock zones to local surface water features. Peters Mine Pit Area (PMP) The PMP Area is located near the northern portion of the Site (Figure 1). The Peters Mine was one of the most productive magnetite iron ore mines on the Site and was in operation from the mid-1700s until the 1930s. Ownership of the PMP Area is currently divided between the Borough of Ringwood and the NJDEP,which owns Ringwood State Park (Arcadis 2015a). A flooded air shaft is located adjacent to the pit. The volume of water in the Peters Mine air shaft is approximately 213 million gallons when flooded (Arcadis 2015a). Wanaque Reservoir is approximately By comparison, 29.63 billion gallons (approximately the capacity of 140 times the volume of the Peters Mine air shaft). The ground surface opening to the air shaft is approximately 15 feet by 15 feet. Based on downhole logging, the shaft extends approximately 232 ft bgs. Within the air shaft, there is a thermal and geochemical stratification of the water at approximately 170-180 ft bgs that limits the physical mixing of water at the deeper zones, where there are elevated concentrations of benzene and l,4-dioxane, and the more shallow zones (Arcadis 2015a). Historical dewatering rates for the mine shaft were very low, which suggests the hydraulic conductivity of the surrounding bedrock is limited (Arcadis 2015b). Groundwater in the unconsolidated overburden fill and sediments in the PMP Area occurs under unconfined conditions at depths of approximately 15 ft bgs. Data generated during the RI indicates that the pond water surface within the former PMP is a surface expression of the unconfined overburden water table. Based on topography and measurements from groundwater monitoring wells within the PMP Area, the unconfined overburden groundwater flows in a southeasterly direction across the PMP Area (Arcadis 2015a). 9 In the PMP Area, groundwater indicates possible hydraulic groundwater in bedrock has an upward vertical potentiometric communication in the overlying between overburden. shallow The overburden gradient, which and deep bedrock groundwater and also with mixed with the bedrock groundwater is discharging to Park Brook and through seeps in the vicinity of State Road 3. Excesswater from storms that enters the PMP over land also discharges through overburden Surface water within Park Brook ultimately to surface water. discharges into Sally's Pond (also known as Furnace Dam Pond or Ringwood Mill Pond), which ultimately discharges to Ringwood Creek approximately upstream of its confluence with Wanaque Reservoir. The reservoir is located approximately 1 mile 1.5 miles downstream of the PMP Area (Arcadis 2015a). A more complete description of the PMP Area, including known history of mining and waste disposal activities, is available in the Site-Related Groundwater Remedial Investigation Report (Arcadis 2015a). Cannon Mine Pit Area (CMP) The CMP Area is located in the southwestern-most portion of the Site near the cul-de-sac at the end of Van Dunk Lane on a bedrock ridge that slopes steeply to the west and gently to the south and east (Figure 2). Because this area of concern is located on a bedrock ridge, the overburden is thin to non- existent and, where present, is draped over shallow bedrock encountered at depths of less than 10 ft bgs. The pit at Cannon Mine is approximately 150 feet wide by 300 feet long and between 140 and 180 feet deep. The pit was not filled to ground surface after it was closed, and was subsequently used as a landfill where industrial and municipal-type vertical mine shaft, located approximately wastes were deposited above the blast rock. There is a 500 feet east of the pit at the intersection of Van Dunk Lane and Milligan Lane. The vertical shaft is approximately 500 feet deep and currently sealed with railroad ties and a 6-inch-thick concrete slab, which is located at approximately 3 ft bgs. A review of historical records by Arcadis indicated that the pit at Cannon Mine was backfilled to grade with a combination of rock blasted from the sides of the pit wall, municipal-type and industrial solid waste, and imported fill soil (Arcadis 2015a). Groundwater occurs in the shallow and deeper bedrock and within the mine pit, but the overburden, where it occurs, is too thin to sustain a water-bearing zone and is unsaturated. Because the overburden in the CMP Area is thin to non-existent, heavy precipitation tends to run off as storm water to surface water rather than infiltrate into bedrock, although recharge directly into the pit will occur. Groundwater flow may be variable near the bedrock ridge, as there is a groundwater flow divide present, and is also somewhat complicated by the hydraulic influence of the mine pit. Groundwater flows radially away from the crown of the bedrock ridge (higher elevations to lower elevations) toward Mine Brook in a manner similar to storm water runoff (Arcadis 2015a). A sinkhole was discovered and reported near Van Dunk Lane on November 23,2016. Since Jacobs' scope involves groundwater transport, this development was determined to be irrelevant to the analysis. A more complete description ofthe CMP Area, including the known history of mining and waste disposal activities, is available in the Site-Related Groundwater Remedial Investigation Report (Arcadis 2015a). 10 O'Connor Disposal Area (OCDA) The OCDA is located south of the PMP Area, just west of Park Brook, a small stream that flows southeast from the PMP Area to Sally's Pond (Figure 1). The OCDA was used during active mine operations as a "slime pond" for the settlement of waste mine tailings from the wet ore processing operations. "Slime" is a mining industry term that refers to silt size and finer mine tailings. Based on visual inspection of the OCDA, the slime pond berm is still present along the eastern perimeter of the OCDA adjacent to Park Brook (Arcadis 2015a). As detailed in the Remedial Investigation Report for OCDA (Arcadis 2013), test trenching and test pitting events conducted as part of the RI within the OCDA showed that, at many locations within OCDA, fill material contained a varied abundance of debris (including refuse and rubbish) that was intermixed with mine tailings and reworked soil (Arcadis 2015a). Shallow groundwater flows through the native overburden soil upgradient of the OCDA and then through OCDA fill materials and mine process waste prior to discharging to Park Brook and wetlands on the eastern, downgradient OCDA boundary. Groundwater elevations confirm groundwater into Park Brook (Arcadis 2015a). As expected, the depth to groundwater discharge fluctuates seasonally and is typically deeper during drier summer months, with some wells being dry, or nearly dry, during drought conditions. As a result, groundwater detections of lA-dioxane discharge volumes to Park Brook vary seasonally. Low-level have been observed in overburden monitoring well OB-14B, screened from 25-35 ft bgs. Higher concentrations have been reported in downgradient Monitoring Well OB-17. No bedrock monitoring wells are present in or downgradient of the OCDA. A more complete description of the OCDA, including known history of mining and waste disposal activities, is available in the Site-Related Groundwater Remedial Investigation Report (Arcadis, 2015a). This report primarily focuses on contamination detection and the concentration associated with the PMP Area, as the number of values at the PMP Area are significantly greater than observed at the CMP or OCD Areas. l,4-Dioxane Properties lA-dioxane is a clear liquid used as a solvent in the manufacture of chemicals. It has also been used as a stabilizer in chlorinated solvents. It can be found in paint, adhesives, pesticides and some consumer products such as household cleaners, detergents, shampoos, deodorants industrial use is in degreasing solvents where it is present in combination and cosmetics. Its main with other chemicals (EPA 2006). lA-dioxane is among the most mobile organic contaminants in the saturated zone. As a result, it may be found far in advance of any solvents with which it might have entered the subsurface originally (EPA CluIn Technical Overview, 2017). lA-dioxane is hydrophilic, is only minimally retarded in groundwater, and is not prone to sorption to soil. These properties generally make it a good candidate for pump-and-treat remediation (EPA 2006), although other technologies may be equally effective depending on site conditions. 11 Treatment A Remedial Investigation Addendum Report and a Candidate Technologies Memorandum (CTM) should be provided to the EPA in May 2017. Both of the reports will be developed for Ford by Cornerstone Environmental. The CTM will include an evaluation of potential treatment onsite groundwater contaminants, including l,4-dioxane. technologies for addressing Those technologies will be screened, usually based on the effectiveness of the technology to meet site objectives, and those passing will be further evaluated and described in an FSdue to EPAin June 2017. Some treatment technologies that may be considered in the development of the CTM and/or FSwould include in situ biological treatment, treatment (pump and treat), in situ chemical oxidation treatment, and subsurface injection technologies. groundwater extraction In situ biological treatment technologies include: • Bioremediation - enhances introduced or existing microbes which are capable of degrading a contaminant • Bioaugmentation contaminant • Monitored introduces specifically adapted for degradation of a natural attenuation - relies on the attenuation of a contaminant by natural processes including biodegradation, Infrastructure, • microorganisms (AMEC Environment & Infrastructure, Inc. 2015) abiotic degradation, adsorption, and dilution (AMEC Environment & Inc. 2015) Phytoremediation - uses plants to destroy or remove a contaminant In situ chemical oxidation introduces an oxidant such as persulfate to degrade/destroy such as l,4-dioxane. injection treatment a contaminant Pump and treat involves ex situ treatment of water prior to discharge. Subsurface technologies may include push probe injection, recirculation wells, and hydraulic fracturing, all designed to improve the effectiveness of any agent injected into the subsurface (AMEC Environment & Infrastructure, As a hydrophilic Inc. 2015). contaminant, l,4-dioxane is not amenable to the conventional technologies typically used for chlorinated account its challenging chemical and physical properties. coagulation, sedimentation, biofiltration and filtration), Conventional water treatment practices (e.g., aeration, GAC adsorption, ozone, ultraviolet light (UV), and have proven to be ineffective Foundation, 2014). ex situ treatment solvents. Successful remedial technologies must take into at removing l,4-dioxane from water (Water Research However, advanced oxidation techniques involving hydrogen peroxide and UV or ozone have been applied successfully to destroy it (EPA 2006). Other processes shown to be effective for removing l,4-dioxane include photocatalysis using titanium dioxide, sonication with or without irradiation, zero-valent iron, distillation, UV and electrolysis. However, these techniques have very limited drinking water application and/or can be prohibitively expensive. le4-Dioxane Concentrations and Distribution EPA has not established a Federal drinking water standard or MCL for l,4-dioxane. lowered its Interim Ground Water Quality Standard for l,4-dioxane NJDEP recently to 0.4 ug/L There is no current NJDEPsurface water standard or drinking water limit for the contaminant. A Technical Fact Sheet issued 12 by the EPA outlines the environmental characterization methods, and health related risks of lA-dioxane, and treatment Federal and State guidelines for lA-dioxane guidelines, detection and methods (Appendix A). The following table summarizes from the fact sheet. Summary of Regulations for 1,4-Dioxane Organization/Authority Type of Guideline EPA Guideline Value Drinking water concentration representing a 1 x 10'6 cancer risk level * Federal MCL 0.35Ilg/L 1-day health advisory in drinking water for a 10-kg child 4.0 mg/L EPA 10-day health advisory in drinking water for a 10-kg child 0.4 mg/L California Department of Public Health Notification level for drinking water 11lg/L New Hampshire Department of Environmental Services Massachusetts Department of Environmental Protection NJDEP Reporting limit for all public water supplies 0.25Ilg/L Drinking water guideline level 0.3Ilg/L Interim specific ground water quality criterion OAllg/L EPA EPA *Risk level assumes an exposure through water consumption None of 2L/day by a 70 kg human at 035 I1g/L of 1,4-dioxane years. The cancer risk level means there is a risk of one additional exposure assumptions, Based on the sample results available in reports on the EPAwebsite, sampling for lA-dioxane began in August 2015. The highest concentrations in groundwater within or downgradient (ND) to 152 Ilg/L. over 70 occurrence of cancer, in one million people, at the given at the Site have generally been in wells located of the PMP Area (Figure 1). Concentrations in these wells range from nondetect A snapshot of lA-dioxane levels from the August 2015 sampling event is shown in Figure 3. The cross-section suggests that lA-dioxane fractured bedrock and overburden. is migrating from the PMP Area through saturated, The vertical distribution reflective of the depth of occurrence of the contributory of this compound varies and is most likely discontinuities (e.g., fractures, and faults) (LBG). It is uncertain whether concentrations have reached a steady-state condition or will decrease or increase significantly in the future. A longer record of monitoring at the Site will be required to more definitively determine contaminant trends. Summary of Water Quality Data Well PMP Air PMP Air PMP Air PMP Air PMP Air PMP Air PMP Air Shaft Shaft Shaft Shaft Shaft Shaft Shaft Sample Source (230) (230) (230) (230) (230) (180) (180) Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Distance to Reservoir 2 Yz miles 2 Yz miles 2 Yz miles 2 Yz miles 2 Yz miles 2 Yz miles 2 Yz miles Date August 2015 December 2015 June 2016 August 2016 February 2017 August 2015 December 2015 Concentration of l,4-Dioxane 1401lg/L 31.1Ilg/L 1441lg/L 1461lg/L 1291lg/L 121lg/L 5.76J ug/L 13 Well Sample Source PMP Air Shaft (180) Distance to Concentration Date Reservoir Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater 2 X miles 2 X miles 2 X miles 21/3 miles 21/3 miles 21/3 miles Groundwater August 2015 August 2016 February 2017 August 2015 August 2016 RW-2 (441-472) RW-3DD (175-180) Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater 21/3 miles 2/3 miles 2/3 miles 2/3 miles 2/3 miles 2/3 miles 2/3 miles 21/3 miles February 2017 August 2015 RW-3DD (175-180) RW-3DD (175-180) Groundwater Groundwater 21/3 miles 21/3 miles December 2015 May 2016 RW-3DD (175-180) Groundwater 21/3 miles August 2016 152/29.2J/20.9* Ilg/L RW-3DD (175-180) RGMW1 RGMW1 SW-PAB-04 SW-PAB-04 SW-PAB-04 SW-PAB-04 SW-PAB-04 SW-PAB-03 SW-PAB-03 SW-PAB-03 SW-PAB-03 SW-PAB-03 SW-PMB-02 SW-PMB-02 Groundwater Groundwater Groundwater Surface Water Surface Water Surface Water Surface Water Surface Water Surface Water Surface Water Surface Water Surface Water Surface Water 21/3 miles February 2017 September 2016 27.7/23Ilg/L O.lllg/L ND O.27U Ilg/L 21/3 miles 21/3 miles 21/3 miles 2 X miles 2 X miles 2 X miles 2 X miles Surface Water Surface Water SW-PMB-02 Surface Water PMP Air Shaft (180) PMP Air Shaft (180) OB-17 OB-17 OB-17 OB-17 RW-2 (279-289) RW-2 (279-289) RW-2 (279-289) RW-2 (441-472) RW-2 (441-472) U - Indicates that the analyte / compound J - Indicates an estimated June 2016 August 2016 February 2017 August 2015 May 2016 August 2016 February 2017 1 X miles 1 X miles 21/3 miles 21/3 miles 21/3 miles of l,4-Dioxane September 2016 August 2015 March 2016 May 2016 18.21lg/L 20.31lg/L 15.21lg/L 171lg/L 2.9Ilg/L 17.5 ug/L 161lg/L lOllg/L 11.9 Ilg/L 10.61lg/L 4.7J ug/L 0.901 Ilg/L 1.181lg/L 2Ollg/L 8.951lg/L 4.9/28.1Ilg/L 0.157Ilg/L 0.8Ilg/L 0.341lg/L 2 X miles 2 X miles August 2016 February 2017 August 2015 March 2016 May 2016 August 2016 February 2017 August 2015 May 2016 0.766Ilg/L 2.3J ug/L <0.0735 Ilg/L 2 X miles August 2016 <0.0735 Ilg/L 0.678Ilg/L 0.29J Ilg/L 0.125 Ilg/L 0.902Ilg/L 0.442Ilg/L was analyzed for, but not detected. value. This flag is used either when estimating or when the data indicates the presence of an analyte / compound greater than zero. The flag is also used in data validation a concentration for a tentatively identified but the result is less than the sample Quantitation to indicate a reported value should be considered compound limit, but estimated due to associated quality assurance deficiencies. Note - numbers in parentheses following Well/Location IDs represent ft bgs, either of the sample elevation for mine shaft samples, or the screened interval of wells. *- First two results via 8270 SIM-ID, second result outside of hold time, third result is via Method part of isotope study (Cornerstone Environmental 522 from Pace Analytical as 2017). 14 The maximum lA-dioxane at approximately detection in the Peters Mine air shaft was 146 Ilg/L in August 2016, observed 230 ft bgs. The maximum concentration in a shallower zone (180 ft bgs) of the air shaft, also observed in August 2016, was 20.3 Ilg/L. However, as noted previously, deeper water in the Peters Mine air shaft has been found to have very limited or no hydraulic connectivity with overburden and bedrock, resulting in negligible mixing of mine pool water and downgradient groundwater. Outlying detections have been observed in Monitoring Well OB-17, located just east ofthe OCDA (Figure 1), with concentrations ranging from 2.9 to 17.5 ug/t. Groundwater flow directions in this area are eastward toward Park Brook, suggesting a local source in or near the OCDA. More recent sample results from the OB-17 in February 2017 show concentrations of 16 and 13 Ilg/L. The isolated nature of the detections suggests that this is likely indicative of a relatively small zone of contamination, some discharge of lA-dioxane and although to Park Brook from this area is likely already occurring, widespread zone that would result in elevated concentrations unlikely. This is supported by the non-detections of lA-dioxane a more across a larger area downgradient is in monitoring wells located near OB-17, such as OB-16, OB-18, and OB-28. Another outlier in the data given the values of nearby monitoring wells is well RW-2, which is located approximately 800 feet east ofthe CMP area, and within 75 feet ofthe Cannon Mine air shaft. RW-2 has been sampled three times for lA-dioxane, highest groundwater concentration with results ranging from 10 to 11.9 Ilg/L. It represents the of lA-dioxane in the southern portions of the monitoring area. The straight-line distance from RW-2 to the uppermost extent of the Wanaque Reservoir is approximately 2/3 of a mile. The screened interval in which the detection occurred was from 279 to 289 ft bgs. At a deeper interval (452 to 462 ft bgs), the reported high concentration OB-4 was ND for lA-dioxane was 4.7J ug/L Overburden well during sampling for the contaminant at the well in August 2015, and in August 2016 the reported concentration was 0.079J ug/L The most recent publicly available monitoring data for the Site is from sampling events conducted in February 2017. concentrations In general, of volatile sample organic analyses of compounds mine water and groundwater (VOCs) were at levels consistent indicate with that historical concentrations. Six relatively recent lA-dioxane samples were collected at monitoring wells at the Shooting Range (Figure 2), the intake at Raymond Dam and the headwater of Ringwood Creek on 09/21/2016 (see additional Figures 8-10). All of these were ND, with the exception of a value of 0.1 Ilg/L in Monitoring Well RGMW1, located at the Shooting Range. The method detection limit for the laboratory analysis was reported as 0.07 ug/L. A re-sampling of the well was ND for lA-dioxane. No information on the depth, screen interval or water level(s) in Monitoring Well RGMWl was available at the time of this report. With regards to surface water in the PMP Area, lA-dioxane concentrations appear to be discharging in low levels to Park Brook and Peters Mine Brook, which flows from the OCDA to a tributary of Ringwood Creek (Figures 1 and 4). The most downgradient surface water detection of lA-dioxane along the Park Brook stream path is at SW-PAB-04, located at Sally's Pond, near the Park Brook discharge point into the 15 pond. Observed detections range from 0.157 to 0.8 Ilg/L. Detections at surface water sample location SW-PAB-03, located farther upstream, range from 0.125 to 0.902 Ilg/L. Along Peters Mine Brook, the southernmost detection of l,4-dioxane was in August 2015 at SW-PMB-02 (2.3J Ilg/L) (Figure 5). This was an estimated value, and more recent sample results at the same location in March, May/June, and August 2016 were ND for l,4-dioxane Regarding the collection samples with independently Cornerstone (Cornerstone Environmental 2016b and 2016c). analysis of the l,4-dioxane Excel, an independent analyze groundwater submitted their environmental samples, it is noted that Cornerstone consulting firm retained shared by the Borough to data collected by Ford's remediation agent, Arcadis, and the EPA. samples to Test America Laboratories submitted their samples to Alpha Analytical. Environmental 2016b), the l,4-dioxane and SGS Accutest, and Excel As noted in the May/June 2016 report (Cornerstone results reported by Alpha Analytical were consistently higher (by a factor of 3.9 on average) than those reported by Test America and SGSAccutest, which is another lab used by Cornerstone. While the labs used the same method for analyzing l,4-dioxane, the difference in results may be attributable to a variation in the analysis protocol for l,4-dioxane May/June 2016 report by Cornerstone. The variation allows for the concentration calculated as a percentage of the surrogate recoveries of l,4-dioxane. as described in the of l,4-dioxane to be Perhaps the most dramatic difference in the analytical results occurred in the split sample from the Peters Mine air shaft at the 230 ft bgs interval, where the reported concentration from either Test America or SGSAccutest (the testing lab was not readily identifiable from the report) was 15 ug/L and the result from Alpha Analytical was 144 ug/L Figures in this report showing historical high concentrations of l,4-dioxane America/SGS Accutest reported values. It is noted that concentrations are based on Test of other VOCs tested by the various labs from split samples were generally consistent, suggesting no large discrepancy for those VOCs based on individual lab methods or protocols. As a result of the discrepancy in the l,4-dioxane results, Ford will direct laboratories analyzing future samples of l,4-dioxane to use the Alpha Analytical method for analysis (Cornerstone Environmental 2016c). The recent l,4-dioxane samples collected at monitoring wells, the intake at Raymond Dam and the headwater of Ringwood Creek were analyzed by ALS Environmental located in Middletown, similar to EPA Method 8270. PA. The method of analysis was EPA Method 522, which is It is unknown if ALS used surrogate recoveries in determining the concentrations of l,4-dioxane. The majority of the mass of l,4-dioxane Mine air shaft and is somewhat appears to be located approximately isolated hydrologically due to the relatively limited capacity of the surrounding bedrock to transmit groundwater. locations of the underground hydraulic communication 230 ft bgs in the Peters Studies indicate that the bedrock groundwater mine workings has an upward vertical gradient, between the deeper bedrock groundwater in the resulting in possible and the groundwater in the overburden and shallow bedrock (Arcadis 2016a). Therefore, it is likely that the bulk of any contaminant contribution to the Wanaque Reservoir from the PMP Area will occur through shallow groundwater and surface water flowpaths. through In the PMP Area, the primary groundwater shallow bedrock and overburden flowpath to the reservoir is to the southeast, with much of it discharging to Park Brook. Surface water then flows to Sally's Pond, which flows into Ringwood Creek, which discharges to the reservoir. Another flowpath from the PMP Area is south along Peters Mine Brook. 16 Benzene, Arsenic and Lead Benzene Concentrations Benzene in groundwater and Distribution at the PMP Area has been detected in the air shaft, overburden wells, and shallow bedrock wells nearest the PMP. It has been detected predominantly monitoring downgradient of the PMP with higher, but still slight, concentrations reported either in wells immediately downgradient of the PMP or at the base of the Peters Mine air shaft (Arcadis 2015a). The maximum historical benzene concentration was 344 IJ,g/L in Monitoring Well RW-6 in March 2015. RW-6 is screened at approximately 110 ft bgs and is located downgradient of Peters Pond (Figure 1). This concentration is significantly higher than any previously reported in any PMP Area bedrock or overburden monitoring well. The detection concentrations appears to have been related to a "hot spot" of contamination, as benzene observed in the well in the five sampling events conducted subsequent to the March 2015 detection have all been equal to or less than 2.2 IJ,g/L. There have been sporadic low-level detections of benzene in the CMP Area, one of which was attributed to sample equipment cross-contamination (Arcadis 2015b). With respect to surface water, although trace concentrations of benzene have been reported in one of the two groundwater seeps in the vicinity of the SR-3 Area located downgradient has never been detected in groundwater of the PMP, benzene in the OCDA located immediately downgradient of this seep or in the adjacent Park Brook surface water or sediment. Arsenic and Lead Total arsenic and total lead were detected in groundwater and mine water samples from all three target areas. The highest reported groundwater concentration of arsenic (26.6 IJ,g/L)was detected southeast of the PMP Area at OB-11R in September 2014. High levels of arsenic were also detected at OB-27, OB-25 and RW-3DD. Arsenic is naturally occurring and prevalent within the bedrock formations and mine tailings at the Site. Arsenic can be removed from source water via oxidation in the reservoir if enough dissolved oxygen is present in the water. The highest reported groundwater concentration of lead (980 IJ,g/L)was detected at the Peters Mine air shaft in August 2015. High concentrations of lead were also detected in the Cannon Mine air shaft and directly outside the Cannon Mine Pit Area at RW-2 and RW-5. In samples for which total concentrations exceeded water quality standards, dissolved lead concentrations lead were not above standards. This indicates that the lead detections reported were primarily associated with particulates in the groundwater samples. Dissolved lead can be removed via chemical precipitation, ion exchange or adsorption. Remedial Plan for Operable Unit Two The Preliminary Remedial Design Report (Cornerstone Environmental 2016a) describes requirements of the Record of Decision (ROD) and preliminary remedial options for OU2. The ROD was issued by the EPA in June 2014 and is intended to address waste contained in the three disposal areas comprising OU2, 17 which are the PMP Area, the OCDA, and the CMP Area (Cornerstone Environmental 2016a). The response action described in the ROD represents the second of three planned remedial phases, or operable units, for the Site. The third phase (OU3) addresses the groundwater across the Site. The RI Addendum and FSfor OU3 is ongoing and will serve as the basis for the selection of a remedy for Sitewide groundwater. A remedy for OU1, presumed to encompass the entire Site, was originally intended to comprehensively address contamination at the Site. However, subsequent to the completion of the OUl remedy and deletion of the Site from the National Priorities List, additional contamination found at the Site that resulted in the need for further implementation evaluation of conditions was at the Site and of OU2 and OU3 (EPA 2014). EPA has been designated as the lead agency for cleanup of the Site, with NJDEP functioning in a support role. Investigations and cleanup actions conducted at the Site have been primarily funded by Ford, which has been identified as a Potentially Responsible Party (PRP)(EPA 2014). There is a cost sharing agreement in place between Ford and the Borough. The current remedial plan for OU2 was designed by Cornerstone Environmental and includes capping the contaminated zones within the three areas with clean, permeable soil. The cap is designed to prevent physical contact with the soil. EPA estimated 70,000 tons of material in the Peters Mine Pit area, more than 100,000 tons in OCDA and 40,000 tons in the Cannon Mine Pit area. These weights include contaminated and uncontaminated material. In addition to capping contaminated zones, areas of contaminated soil will be excavated and the soil removed, along with drums and paint waste. It is unknown if the removal of these soil and waste areas and the associated capping will address any continuing or potential sources of contamination, or result in a decline in groundwater concentrations of benzene or l,4-dioxane. monitoring Determination wells is often complicated of specific source areas for groundwater samples collected in by several factors, including a lack of detailed history of the location, quantity, characteristics and timing of the placement of waste. Waste disposal activities at the Site have been extensive, and although generally not detailed variability in the direction of groundwater making determination Three-dimensional many are fairly well documented, the historical record is enough to identify individual sources or source areas. flow and groundwater In addition, natural level magnitudes may be significant, of specific sources difficult. groundwater flow models may be used with reverse particle tracking to help identify these locations, but these are often steady-state models that do not reflect the natural variability of rainfall and hydraulic gradient direction and magnitude that may affect the ultimate location of contaminants. downgradient In addition, well-calibrated groundwater models require Significant time and effort to develop. As part of the ROD for OU2, groundwater monitoring at the Site will continue until a groundwater remedy is selected, which mayor may not involve a pump and treat option. The cap is estimated to be built by 2018 and, if selected as a remedy, any groundwater treatment may be installed by 2019. 18 Faulting and Seismic Activity Considerations The bedrock units underlying the Site are reportedly penetrated by naturally occurring brittle structural features, such as fractures movement groundwater and faults (large scale fractures which are the result of breakage and of the comprising rock mass) (LBG). These brittle features in bedrock can influence movement and storage, as well as contaminants that may occur in the groundwater The available information indicates that a major fault (oriented northeast-southwest shorter northwest-southeast (LBG). and connected to oriented faults) exists in the study area (although removed from source areas), paralleling the main stem of Ringwood Creek and through the Wanaque Reservoir (Figure 6). This fault and the shorter connected faults are "active" faults and are classified as "normal" faults (with a relative steep angle or dip) (LBG). They are sometimes identifiable by way oftopographic and bedrock exposure features. Besides these surficially recognizable faults, faults have also been documented occurring within the PMP and CMP. In the PMP, a few small faults along which there has been very slight displacement have been observed (Hotz 1953). It is unlikely these extend significant distances from the mine. A larger fault is present in the Cannon Mine, identifiable across four levels ofthe mine with a northeast strike. Based on the reported orientation depth. of this fault, it is conceivable that it may intercept the Wanaque Reservoir at While the extent of this fault is unknown, the nature of contaminants in the CMP and Cannon Mine air shaft, and the fact that the fault has not been shown to be a conduit of significant groundwater flow, currently make it of lower concern. Based on investigations completed by others, the bedrock units underlying the PMP and CMP are of very low groundwater for contaminated groundwater in these units to potentially bearing potential. As such, the ability impact local surface water bodies is reportedly minimal (LBG). In the event of significant future seismic activity associated with known and unknown faults, additional future contributions breakage and fracturing may occur, which may change the potential for to local surface-water bodies. The possibility of impact would rely in part on the concentration of the contaminant, and the volume of water in the receiving surface water body (LBG). Besides identifying the location, type, and extent of faults, information regarding their local seismic activity is also of importance when trying to assess potential for related future changes in groundwater conditions (and possible contaminant impacts) (LBG). To this end, information available from the New Jersey Geological Survey and the United States Geologic Survey was used to identify the locations of past seismic activity (e.g., earthquake) in the study area. Based on this information, a minor intensity earthquake occurred along the fault underlying the Wanaque Reservoir as recently as January 2016 (Figure 6) (LBG). Historically, numerous minor earthquakes along this and nearby structurally related faults have occurred going back at least to 1978, and possibly as far back as the 1800s and earlier (LBG). This indicates the faults in the study area are active, and will most likely experience future seismic activity (LBG). The intraplate setting of the area, which limits potential seismic stresses, combined with the relatively numerous faults in the region which serve to alleviate the stresses that do occur, renders the chances of a very strong earthquake in the region low. In addition, the long history of seismic activity in the region and the fact that the bedrock units underlying the PMP and CMP have not been extensively fractured by this activity suggest that the chances of new faults/fractures large enough to serve as conduits to the reservoir are minor. 19 Risk Analysis The EPA's risk analysis approach was utilized to assessthe risks of benzene and l,4-dioxane reaching the Commission's finished water. This approach involves assigning ratings for both the likelihood and the severity of each scenario. The bases for ratings in each of these categories are defined below: Likelihood Rating 1- Scenario has little to no chance of occurrence 2 - Scenario has a 25% chance of occurrence 3 - Scenario has a 50% chance of occurrence 4 - Scenario has a 75% chance of occurrence 5 - Scenario is assumed to occur Severity Rating 1- Scenario will likely not have any health impacts 2 - Scenario will impact fewer than 10% of customers and/or have minimal health impacts 3 - Scenario will impact 10%-25% of customers and/or have moderate impacts to health 4 - Scenario will impact 25%-50% of customers and/or have long term impacts to health 5 - Scenario will have a widespread impact (>50% of customers) and/or cause danger to life and health Risk Score. MUltiplying the likelihood and severity ratings results in a final risk score for each scenario. The risk scores are categorized below: 11:4-Low 15:9 - Low-Moderate 110:16 - Moderate-High 117:25 - High Risk Analysis for Groundwater Contaminants Reaching Finished Water Scenario (Contaminant) Likelihood Rating Severity Rating 1 1 2 2 4 4 4 4 Benzene Arsenic Lead l,4-dioxane Risk Score (Likelihood x Severity) 4-Low 4-Low 8 - Low-Moderate 8 - Low-Moderate Summary of Results, Conclusions and Recommendations Summary of Results Summary of Water Quality Data Well Peters Peters Peters Peters Peters Mine Mine Mine Mine Mine Air Air Air Air Air Sample Source Shaft Shaft Shaft Shaft Shaft 230 230 230 230 230 Groundwater Groundwater Groundwater Groundwater Groundwater Distance to Reservoir 2 Y, 2 Y, 2 Y, 2 Y, miles miles miles miles 2 Y, miles Date Concentration of l,4-Dioxane August 2015 December 2015 June 2016 August 2016 14Ollg/L 31.1Ilg/L February 2017 1291lg/L 1441lg/L 1461lg/L 20 Well Peters Peters Peters Peters Peters OB-17 Mine Mine Mine Mine Mine Air Air Air Air Air Sample Source Shaft Shaft Shaft Shaft Shaft 180 180 180 180 180 OB-17 OB-17 OB-17 RW-2 (279-289) RW-2 (279-289) RW-2 (279-289) RW-2 (441-472) RW-2 (441-472) RW-2 (441-472) RW-3DD (175-180) RW-3DD (175-180) RW-3DO (175-180) RW-3DO (175-180) RW-3DO (175-180) RGMWl RGMWl SW-PAB-04 SW-PAB-04 SW-PAB-04 SW-PAB-04 SW-PAB-04 SW-PAB-03 SW-PAB-03 SW-PAB-03 SW-PAB-03 SW-PAB-03 SW-PMB-02 SW-PMB-02 SW-PMB-02 Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater Groundwater U - Indicates that the analyte / compound Water Water Water Water Water Water Water Water Water Concentration of l,4-Dioxane Date 2]1, miles 2]1, miles 2]1, miles 2]1, miles August 2015 December 2015 June 2016 August 2016 February 2017 12 Ilg/L 5.76J Ilg/L 18.2 ug/L 21/3 miles August 2015 21/3 miles 21/3 miles 21/3 miles 2/3 miles May 2016 August 2016 February 2017 August 2015 August 2016 February 2017 August 2015 August 2016 February 2017 August 2015 December 2015 May 2016 August 2016 17 Ilg/L 2.9 ug/L 17.5llg/L 2/3 miles 2/3 miles 2/3 miles 2/3 miles 2/3 miles 21/3 miles 21/3 miles 21/3 miles 21/3 miles Groundwater Groundwater Groundwater Surface Water Surface Water Surface Water Surface Water Surface Surface Surface Surface Surface Surface Surface Surface Surface Distance to Reservoir 2]1, miles 21/3 miles 1]1, miles 1]1, miles February 2017 September 2016 September 2016 August 2015 March 2016 May 2016 21/3 miles 21/3 miles 21/3 miles 21/3 miles 21/3 miles 21/3 miles 2]1, miles 2]1, miles 2]1, miles 2]1, miles 2]1, miles 2]1, miles 2]1, miles August 2016 February 2017 August 2015 March 2016 May 2016 August 2016 February 2017 August 2015 May 2016 August 2016 20.3 ug/L 15.2 Ilg/L 16 Ilg/L 10 Ilg/L 11.9 Ilg/L 10.6 ug/L 4.7J 0.901 1.18 20 8.95 4.9/28.1 152/29.2J/20.9* 27.7/23 O.lllg/L NO O.27U Ilg/L 0.157 ug/L 0.8 Ilg/L 0.34 ug/L 0.678 Ilg/L 0.29J Ilg/L 0.125 ug/L 0.902Ilg/L 0.442 ug/L 0.766 Ilg/L 2.3J Ilg/L <0.0735 Ilg/L <0.0735 Ilg/L was analyzed for, but not detected. J - Indicates an estimated value. This flag is used either when estimating a concentration or when the data indicates the presence of an analyte / compound greater than zero. The flag is also used in data validation for a tentatively identified but the result is less than the sample Quantitation to indicate a reported value should be considered compound limit, but estimated due to associated quality assurance deficiencies. Note - numbers in parentheses following Well/Location IDs represent ft bgs, either of the sample elevation for mine shaft samples, or the screened interval of wells. * - First two results via 8270 SIM-ID, second result outside of hold time, third result is via Method part of isotope study (Cornerstone Environmental 522 from Pace Analytical as 2017). 21 l,4-Dioxane in the Shooting Range. The most recent sample results from monitoring Shooting Range included a low-level detection of l,4-dioxane wells near the (0.1 ug/L), A resampling of the well resulted in a ND value. It has also been detected in relatively high concentrations (10 Ilg/L in Monitoring Well RW-2) in groundwater approximately 2/3 of a mile from those areas. Summary of Regulations for 1,4-Dioxane Organization/Authority Type of Guideline Guideline Value Drinking water concentration representing a 1 x 10-6 cancer risk level * Federal MCL 0.35 Ilg/L EPA 1-day health advisory in drinking water for a 10-kg child 4.0 mg/L EPA 10-day health advisory in drinking water for a 10-kg child 0.4 mg/L California Department of Public Health Notification level for drinking water 11lg/L New Hampshire Department of Environmental Services Reporting limit for all public water supplies 0.25 Ilg/L Massachusetts Department of Environmental Protection NJDEP Drinking water guideline level 0.3 Ilg/L Interim specific ground water quality criterion 0.4Ilg/L EPA EPA None "Risk level assumes an exposure through water consumption of 2L/day by a 70 kg human at 0.35 j.lg/L of 1,4-dioxane over 70 years. The cancer risk level means there is a risk of one additional occurrence of cancer, in one million people, at the given exposure assumptions. Conclusions Groundwater/Surface monitoring Water Monitoring wells are well distributed at the Ringwood Mines Superfund Site. While groundwater at the Site for characterizing groundwater quality, additional monitoring wells would address data gaps and provide a more complete understanding source areas, contaminant bodies. Similarly, verification distributions, additional and zones of discharge to local streams and surface water surface water monitoring of these discharge areas would of these discharge areas and additional information along stream paths. of potential provide on the magnitude of concentrations In addition, since both major surface water pathways to the reservoir from the mine areas converge prior to discharging, monitoring at the confluence of Ringwood Creek and the reservoir would identify mass loading to the reservoir by stream pathways. Benzene, Arsenic and Lead. The higher benzene concentrations are generally restricted to the groundwater and surface water areas near the PMP. These relatively low levels suggest that there is not a high-mass source of benzene that could generate concentrations far enough downgradient to be a threat to the headwaters of the Wanaque Reservoir, and certainly not as far as the water intake, which is located approximately than l,4-dioxane, degradation. 7.75 miles from the PMP Area. Benzene is less persistent in the environment being more susceptible to natural attenuation Previous studies also indicate that degradation including volatilization processes such as volatilization and of benzene is occurring at the Site, of benzene that does enter Park Brook (Arcadis 2015b). Arsenic is naturally 22 occurring and prevalent within the bedrock formations and mine tailings at the Site, and poses low risk of reaching the finished water. Arsenic can be oxidized with the addition of chlorine or potassium permanganate and removed from source water in conventional treatment. needed to remove arsenic. There is a low-moderate Adjustment of pH may be risk of lead reaching the finished water. Lead in source water can be removed through chemical precipitation, ion exchange or adsorption. It is possible for some removal of lead to be accomplished with coagulation as floc has some precipitative properties; however, this would need to be verified at bench scale. l,4-Dioxane. Primary flowpaths from the PMP Area to the reservoir appear to be through shallow bedrock and overburden groundwater, mostly discharging to local surface water ponds and streams, which then discharge to the reservoir. Direct groundwater transport of l,4-dioxane from bedrock fractures to the reservoir in large volumes appears unlikely. Seismic activity of a magnitude that could change this is also unlikely. Based on the observed concentrations of l,4-dioxane shaft (146 ug/L], local groundwater inferred that (0.156-152 Ilg/L) in the Peters Mine air and surface water (0.125-2.32 ug/L], it was levels at the intake are unlikely to exceed the EPA action level (0.35 ug/L), consequence of elevated l,4-dioxane cannot treat for l,4-dioxane. at the intake is significant. The current water treatment The plant A capital-intensive upgrade of the plant involving an advanced oxidation process would likely be required .. Risk of Seismic Activity Affecting Contamination Transport. Based on the known seismic history of the area, the limited potential for large-magnitude seismic events, and the observed nature of bedrock underlying the PMP and CMP Areas, it is unlikely that future seismic activity will significantly alter contaminant flowpaths or change the conceptual model of flow and transport at the Site. Variability in lab Results for l,4-Dioxane. (Cornerstone Environmental l,4-dioxane It is noted that the most recent quarterly monitoring report 2016c) from May/June 2016 describes variability in analytical results for in samples collected by Cornerstone and split with Excel Environmental. results are consistently higher. This may result in higher acknowledged concentrations across the Site and increase the concern that l,4-dioxane Alpha Analytical of l,4-dioxane may leave the Site in concentrations greater than the NJDEPinterim Ground Water Quality Standard of 0.4 Ilg/L. Summary of Conclusions The following table summarizes the conclusions of this report and the basis upon which they were made. Conclusion 1. Additional groundwater, surface water and reservoir sampling is needed 2. Low risk of benzene and arsenic threatening the finished water 3. Low-moderate risk of l,4-dioxane and lead threatening the finished water 4. Low risk of seismic activity affecting contamination transport 5. Variability in l,4-dioxane results Basis for Conclusion Data analysis Water quality analysis, groundwater and surface water transport analysis Water quality analysis, groundwater and surface water transport analysis Seismic hydrogeological analysis Data analysis 23 Recommendations Short-Term Remedial Action. Given the severity of the impact to the water supply if the contaminants, in particular l,4-dioxane, reach the intake, Jacobs recommends that an active treatment for groundwater concentrations remediation particularly in the Peters Mine air shaft where the highest l,4-dioxane have been detected. one possible active treatment A pump and treat approach to contain the contaminant approach. This could include a well pump and treatment oxidation using hydrogen peroxide and UV or ozone). The active treatment contaminants approach be implemented do not migrate downgradient plume is (e.g., advanced method should ensure that and impact the water supply. System redundancy and proper controls would be needed to prevent any untreated groundwater from being discharged to surface water. An RI addendum report and FSfor OU3 is expected to be provided to EPA in May 2017 and will serve as the basis for the selection of a remedy for Site-wide groundwater. evaluate a variety of options to address contaminants treatment, monitored natural attenuation Typically, feasibility in groundwater, studies will such as active or passive or no action with ongoing monitoring. The Commission should review the recommended option once EPA completes its work and solicits public comments on the plan. Modeling. Models of the reservoir and local and/or regional groundwater determine the levels of l,4-dioxane modeling would utilize information are recommended to better and lead onsite which may threaten from the enhanced monitoring the water supply. This program described below. The fractured nature of the bedrock beneath the Site, and the fact that contaminants are known to migrate through these zones, pose a challenge in the development of a representative groundwater flow and transport model. In these cases, simplifying assumptions may be required to address flow and transport in the fractured zone, with the model primarily simulating behavior in the saturated overburden and discharge to local streams and other surface water bodies (ponds and the reservoir). A surface water model may be useful to evaluate the degree of mixing and any channelization through the Wanaque Reservoir and the effects of these factors on potential influent concentrations at the intake. Long-Term Monitoring. The currently monitored groundwater and surface water locations should continue to be monitored. Some of the sources of known groundwater contamination recommend wells and surface water the addition of groundwater monitoring have not been identified. We sample locations, upgradient of the reservoir. This would help better define groundwater flow directions and magnitudes, and provide a better understanding of contaminant distributions to help identify likely active sources. It would allow better characterization warning" of likely downgradient locations, provide perspective dilution, volatilization of any changes in the source(s) at the Site, serve as an "early contaminant transport, and along with data from more downgradient on any reductions in contaminant levels along the streams due to or other transport processes. 24 New wells placed upgradient and at vertically separated intervals along the flowpaths associated with historic l,4-dioxane detections can be used to better characterize the extent of contamination thus, the likelihood of l,4-dioxane discharge to the reservoir. Applicable locations and, include: 1) downgradient of suspected Peters Mine and Cannon Mine source areas; 2) proximal to the intersection of Cannon Mine Road and Peters Mine Road; and 3) near the intersection of Peters Mine Road and Margaret King Avenue. Additional surface water monitoring locations should be identified along local streams such as Park Brook, Peters Mine Brook (also named the Ringwood Creek Tributary), and Ringwood Creek. Based on the conceptual model of groundwater flow and discharge at the Site, these streams serve as some of the primary potential contaminant migration pathways to the reservoir. Park Brook is an indirect tributary to Ringwood Creek, initially discharging to Sally's Pond. Additional monitoring locations along it, and the upper reaches of Peters Mine Brook, could help identify initial groundwater locations. To help characterize potential contaminant contaminant discharge discharge to the reservoir, additional surface water monitoring is also recommended for the confluence of Ringwood Creek and the reservoir. As a precaution, monitoring implemented. of the water intake at the Wanaque Reservoir for l,4-dioxane In addition, a review of l,4-dioxane should be results from any public water sources in the vicinity of Ringwood Mines is recommended, along with a determination of the need for additional sampling at these locations. Treatment at the Wanaque WTP. If at any point during the span of the remediation, show evidence of increased levels of contamination monitoring results in surface water or groundwater that would threaten the reservoir water quality, EPA would also be tasked with adding upgrades at the Wanaque WTP. In anticipation of that possibility, the Commission may wish to assess alternative technologies to address these contaminants at the plant. Preliminary recommendations treatment to address each contaminant are listed in the table below: Preliminary Recommendations Contaminant l,4-Dioxane Benzene Lead Arsenic for Alternative Treatment Technologies Preliminary Recommendation Assessment of advanced oxidation process systems Assessment of activated carbon and/or packed tower aerator systems Evaluation of removal options including chemical precipitation, ion exchange, adsorption and a coagulation-flocculation-solids separation process Assessment of oxidation via addition of chlorine or potassium permanganate and the need for pH adjustment This evaluation would provide a preliminary plan in the event levels continue to rise. The plan would include treatment options, a recommended treatment, Commission could begin implementation cost, and timeframe for implementation. The if and when contaminant levels rise in the flowpaths. 25 Summary of Recommendations Recommendation Short/Long Term Responsible Active remediation of groundwater to control the source, particularly at Peters Mine air shaft Short EPA Modeling of groundwater contamination Additional surface and groundwater monitoring Short Long EPA EPA Additional monitoring and Intake Long Commission at Wanaque Reservoir Treatment evaluation at Wanaque WTP Long rise if levels Party EPA References Adamson, David T., R. Hunter Anderson, Shaily Mahendra, and Charles J. Newell. 2015. Evidence of 1,4Dioxane Attenuation at Groundwater Sites Contaminated with Chlorinated Solvents and l,4-Dioxane. Environ. Sci. Technol., 2015, 49 (11), pp 6510-6518. AMEC Environment & Infrastructure, Inc. 2015. l,4-Dioxane Remediation Approach Focused Feasibility Study. January 2015. ARCADIS. 2013. Remedial Investigation Report for O'Connor Disposal Area. Ringwood Mines/Landfill Site, Ringwood, New Jersey. June 2013. ARCADIS. 2015a. Site-Related Groundwater Remedial Investigation Report. Ringwood Mines/Landfill Site, Ringwood, New Jersey. January 2015. ARCADIS. 2015b. Draft Baseline Human Health Risk Assessment for Site-Related Groundwater, Ringwood, New Jersey. May 2015. Carswell, L.D. and J.G. Rooney. 1976. Summary of geology and ground-water resources of Passaic County, New Jersey, 1976. United States Geological Survey Water-Resources Investigations Report 7675. Cornerstone Environmental Incorporated. 2015. Ringwood Mines/Landfill Superfund Site Annual Groundwater and Surface Water Sampling. November 2015. Cornerstone Mines/Landfill Environmental Incorporated. 2016a. Preliminary Remedial Design Report, Ringwood Superfund Site, Operable Unit Two, Ringwood, New Jersey, EPA ID# NJD980529739. March 2016. Cornerstone Environmental Incorporated. 2016b. Ringwood Mines/Landfill Surface Water Sampling l,4-dioxane Superfund Site March 2016 Results (Letter Report). April 2016. 26 Cornerstone Environmental Incorporated. 2016c. Ringwood Mines/Landfill Superfund Site May/June 2016 Groundwater, Mine Water, and Surface Water Sampling. August 2016. Cornerstone Environmental Incorporated. 2016d. Ringwood Mines/Landfill Superfund Site Annual Groundwater, Mine Water, and Surface Water Sampling - 2016. October 2016. Cornerstone Environmental Incorporated. 2017. Ringwood Mines/Landfill Superfund Site February 2017 Groundwater, Mine Water, and Surface Water Sampling. March 2017. EPA Clu-In lA-Dioxane Technical Overview. 2017. Retrieved from https://clu- in.org/contaminantfocus/default.focus/sec/1A-Dioxane/cat/Overview/ Hotz, P.E. 1953. Magnetite Economic Geology, 1952. Deposits of the Sterling Lake, N.Y. - Ringwood, N.J. Area. Contributions Geological Survey Bulletin 982-F. U.S. Government Printing to Office, Washington. 1953. Leggette, Brashears & Graham, Incorporated. 2016. Potential for Faulting and Seismic Activity to Affect Contaminant Transport in Groundwater [Memorandum]. from the Ringwood Mines Complex - Ringwood, New Jersey October 2016. Mohr, Thomas K. G., Julie A. Stickney, and William H. DiGuiseppi. 2010. Environmental Investigation and Remediation lA-Dioxane and other Solvent Stabilizers. CRCPress. 2010. United States Environmental Protection Agency (EPA) 2006. Treatment Technologies for lA-Dioxane: Fundamentals and Field Applications. EPA-542-R-06-009. December 2006. EPA2014. Record of Decision Ringwood Mines/Landfill Superfund Site Operable Unit Two. June 2014. Volkert, R. 2008. Bedrock Geologic Map of the Greenwood Lake Quadrangle, Passaic and Sussex Counties, New Jersey. New Jersey Geological Survey Open-File Map (unpublished). Water Research Foundation 2014. lA-Dioxane White Paper (White Paper). Water Research Foundation, Denver, CO. Zimmer, David M. Ringwood residents urge EPA to scrap Superfund cap. NorthJersey.com, December 2016 27 FIGURES 1,4-Dioxane Groundwater Concentrations • •• 0 0.00 - 0.40 0.41 - 2.50 2.51 -15.00 15.10 - 40.00 (llg/L) N ! Ringwood Mines, New Jersey Peters Mine and O'Connor Disposal Area 1,4-Dioxane Groundwater Highest Historical Concentrations 1,4-DioxaneGroundwater Concentrations ("gILl • o Mines, New Jersey 0.41 -2.50 • 2.51 - 15.00 o • 15.10 - 40.00 ~~~~~iiiiiiiiiiiiiiiiiiiiil Feet .c Source: GIS data provided by New Jersey Geographic Information Network 8! N 0.00-0.40 Data Projection: NAD_1983_SP_New_JerseyJIPS_2900Jeet 1:7,000 375 750 1 Cannon Mine Area 1,4-Dioxane Groundwater Highest Historical Concentrations .. B' .. ~ .~ B' ~ ~...s ~ A ~~ .~~ ~ <..i .ClJ IQ:550 ~ ~~ ~V) ~~ ,-Q -s 9.~'$'~~ #~ .. "" ~ (d:.~Q= (\~ ~ ~ . ClJ ~ r;v ~ ~ ~"y -E Vl 450 o Q:- -~--I : r--i------+-i I :I r--! ::::.. -14.3J t6C 'ND 2J I I 11.5J 16.8 400 I 138J 120 0 ro > OJ UJ --------- i 22 2.7J . c :;:; _ I " I .j..J ~ , I I ~NDI I AI ~ ~"" , 500 B' ~8 <..i Q:-6> Q:- .. B' ",ClJ •. c-B' • ClJ n. 350 ~12 i 300 J-f-140 ~1.lJ 126J 250 -100 ~oo -Y°o 9'00 0'00 ~V 6'00 0'00 Distance (ft) ~OBS· • A "14~ ~egelJ9 Monitoring Well Screened Interval with 1,4-Dioxane Concentration (lJg/L) is , 6.8 - •. Projected: wells are not directly on the A-A' section and their location is projected to that line. Topography Bedrock Surface o 120 --.~--~-----.~--~~-------.---~-- Peters Mine Pit Area Section A-A' 1,4-Dioxane Concentrations 08/2015 Ringwood Mines, Ringwood, New Jersey "r Scale in Feet 05/09/17 JD 1_4_Dioxane Section.dwg ! Figure 3 Legend 1,4-DioxaneSurface Water Concentrations (llg/L) ~ • 0.06-0.40 o 0.40 - 2.50 • 2.51 -15.00 • 15.01 - 40.00 Source: GIS data provided by New Jersey Geographic Information Network Data Projection: NAD_1983_SP_New_Jersey_FIPS_2900_Feet N JACOBS~ Ringwood Mines, New Jersey o 375 750 ~~~~§iiiiiiiiiiiiiiiiiiiiiiil Feet 1:7,000 Peters Mine and O'Connor Disposal Area 1,4-Dioxane Surface Water Highest Historical Concentrations ~ Ringwood, NJ Wanaque Reservoir 1,4-Dioxane Surface Water Concentrations (llg/L) • o N 0.00 -DAD OA1 Ringwood Mines, New Jersey - 2.50 • 2.51 - 15.00 o • 15.10-40.00 ~~~~§iiiiiiiiiiiiiiiii. Feet Source: GIS data provided by New Jersey Geographic Information Network ~L:D:at~a~p~ro~~~ct~ro~n~:N~~~D~_~1:98;3~_:SP~_~N~e~W~_J~e;fS;e~y_~F~/P~S~_~2;9:00~_~F:ee~t 1_:7_,OOO 375 750 1 ~ Cannon Mine Area 1,4-Dioxane Surface Water Highest Historical Concentrations ~ ~~~ __ ~~_' N I ".<"~:I> 'Ij+'~. I..~ ~;J * RINGWOOD MINES PASSAIC COUNTY RINGWOOD, NEW JERSEY Legend • Earthquake Sample Epicenter Location / Fault/Linear /' Fracture Trace/Lineaments Associated with Folds / Bedrock o Feature Geology Contact Sand and Gravel Deposit 8 .N~Jl!m!)' Quadrangle Locatio" FAULTS AND RECENT SEISMIC ACTIVITY IN WANAQUE RESERVOIR AREA Diotlt. .! 11' J~ Quartz.oligocl.le Gneiss Polililic Feldlpar Gneiss - 1,000 500 0 Legend * Proposed • Sample ,.... Fault/Linear /" Fracture Trace/Lineaments Associated wilh Folds ,.... Bedrock .• o Monitor Well Earthquake Epicenter Location . Feature Geology Contact Sand and Gravel Deposit ~ . INI!WJl!ru), Ulladrangie Locatio" All 1,4 Dioxane Sampling Locations Legend •. e Figure 8 Other Sample Locations 1,4 Dioxane positive test o Boa ,600 3,200 4,800 -- --- 6,400 Feet Shooting Range Site With Ford Site in View Legend .•. e Other Sample Locations 1,4 Dioxane positive test Figure 9 -- - --- Shooting Range Site Legend .•• e Other Sample Locations 80 1,4 Dioxane positive test Figure 10 120 160 I --iFee~ APPENDIX A Technical Fact Sheet 1,4-Dioxane United States Environmental Protection Agency (EPA) ~EPA United States Environmental Protection Agency Technical Fact Sheet1,4·Dioxane January 2014 TECHNICAL FACT SHEET - 1,4-DIOXANE At a Glance .:. .•.· .:. .•.· .:. .:. .:. .:. .•.· Flammable liquid and a fire hazard Potentially explosive if exposed to light or air. Found at many federal facilities because of its widespread use as a stabilizer In certain chlorinated solvents. paint strippers. greases and waxes Short-lived in the atmosphere may leach readily from soil to groundwater migrates rapidly in groundwater and is relatively resistant to biodegradation in the subsurface Classified by the EPA as . likely .. to be carcinogenic to humans by all routes of exposure Short-term exposure may cause eye nose and throat irritation long-term exposure may cause kidney and liver damage No federal maximum contaminant level (MCL) has been established for 14-dloxane in drinking water Federal screening levels state health-based drinking water quidance values and federal occupational exposure limits have been established Modifications to existing sample preparation procedures may be required to achieve the Increased sensitivity needed for detection of 14-dioxane Common treatment technologies include advanced oxidation processes and biorernedratron United States Environmental Protection Agency Introduction This fact sheet, developed by the U.S. Environmental Protection Agency (EPA) Federal Facilities Restoration and Reuse Office (FFRRO), provides a summary of the contaminant 1,4-dioxane, including physical and chemical properties; environmental and health impacts; existing federal and state guidelines; detection and treatment methods; and additional sources of information. This fact sheet is intended for use by site managers who may address 1,4-dioxane at cleanup sites or in drinking water supplies and for those in a position to consider whether 1,4-dioxane should be added to the analytical suite for site investigations. 1,4-Dioxane is a likely human carcinogen and has been found in groundwater at sites throughout the United States. The physical and chemical properties and behavior of 1,4-dioxane create challenges for its characterization and treatment. It is highly mobile and has not been shown to readily biodegrade in the environment. What is 1,4-dioxane? .:. 1,4-Dioxane is a synthetic industrial chemical that is completely miscible in water (EPA 2006) . •:. Synonyms include dioxane, dioxan, p-dioxane, diethylene dioxide, diethylene oxide, diethylene ether and glycol ethylene ether (EPA 2006; Mohr 2001) . •:. 1,4-Dioxane is unstable at elevated temperatures and pressures and may form explosive mixtures with prolonged exposure to light or air (DHHS 2011; HSDB 2011) . •:. 1,4-Dioxane is a likely contaminant at many sites contaminated with certain chlorinated solvents (particularly 1,1, 1-trichloroethane [TCA]) because of its widespread use as a stabilizer for chlorinated solvents (EPA 2013a; Mohr 2001) .:. It is used as: a stabilizer for chlorinated solvents such as TCA; a solvent for impregnating cellulose acetate membrane filters; a wetting and dispersing agent in textile processes; and a laboratory cryoscopic solvent for molecular mass determinations (ATSDR 2012; DHHS 2011; EPA 2006) . •:. It is used in many products, including paint strippers, dyes, greases, varnishes and waxes. 1,4-Dioxane is also found as an impurity in antifreeze and aircraft deicing fluids and in some consumer products (deodorants, shampoos and cosmetics) (ATSDR 2012; EPA 2006; Mohr 2001). Disclaimer: Tlile U.S. EPA prepared this fact sheet from publically-available sources; addifional information can be obtained from the source docurments. This fact sheet is not intended to be used as a primary source of information and is not intended, nor can it be relied upon, to create any rights enforceable by any party in litigation with the United States. Mention of trade names or commercial products does not constitute endorsement or r.ecommendation for use. Office of Solid Waste and Emergency Response (5106P) 1 EPA 505-F-14-011 January 2014 Technical Fact Sheet - 1,4-Dioxane What is 1,4-dioxane? .:. (continued) 1A-Dioxane is used as a purifying agent in the manufacture of pharmaceuticals and is a byproduct in the manufacture of polyethylene terephthalate (PET) plastic (Mohr 2001). .:. Traces of 1A-dioxane may be present in some food supplements, food containing residues from packaging adhesives or on food crops treated with pesticides that contain 1A-dioxane as a solvent or inert ingredient (ATSDR 2012; DHHS 2011). Exhibit 1: Physical and Chemical Properties of 1,4-Dioxane (ATSDR 2012; Howard 1990; HSDB 2011) Property Chemical Abstracts Service (CAS) Number Value 123-91-1 Clear, flammable liquid with a faint, pleasant odor 88.11 Physical Description (physical state at room temperature) Molecular weight (g/mol) Water solubility Miscible Melting point (DC) 11.8 101.1DC Boiling point (DC) at 760 mm Hg Vapor pressure at 25DC (mm Hg) 38.1 Specific gravity 1.033 Octanol-water partition coefficient (log Kow) -0.27 Organic carbon partition coefficient (log KDe) 1.23 4.80 X 10-6 Henry's law constant at 25 DC(atm-rnvrnol) .. • 0 Abbreviations. g/mol- grams per mole, C - degrees Celsius; mm Hg - millimeters of mercury; atm-mvmol - atmosphere-cubic meters per mole. What are the environmental .:. .:. .:. impacts of 1,4-dioxane? from surface water bodies (DHHS 2011; EPA 2006). 1A-Dioxane is released into the environment during its production, the processing of other chemicals, its use and its generation as an impurity during the manufacture of some consumer products. It is typically found at some solvent release sites and PET manufacturing facilities (ATSDR 2012; Mohr 2001). It is short-lived in the atmosphere, with an estimated 1- to 3-day half-life as a result of its reaction with photochemically produced hydroxyl radicals (ATSDR 2012; DHHS 2011). Breakdown products include aldehydes and ketones (Graedel 1986). .:. Migration to groundwater is weakly retarded by sorption of 1A-dioxane to soil particles; it is expected to move rapidly from soil to groundwater (EPA 2006; ATSDR 2012). .:. It is relatively resistant to biodegradation in water and soil and does not bioconcentrate in the food chain (ATSDR 2012; Mohr 2001). .:. As of 2007, 1A-dioxane had been identified at more than 31 sites on the EPA National Priorities List (NPL); it may be present (but samples were not analyzed for it) at many other sites (HazDat 2007). It may migrate rapidly in groundwater, ahead of other contaminants and does not volatilize rapidly What are the routes of exposure and the health effects of 1,4-dioxane? .:. Potential exposure could occur during production and use of 1A-dioxane as a stabilizer or solvent (DHHS 2011). •:. Exposure may occur through inhalation of vapors, ingestion of contaminated food and water or dermal contact (ATSDR 2012; DHHS 2011). .:. 2 Inhalation is the most common route of human exposure, and workers at industrial sites are at greatest risk of repeated inhalation exposure (ATSDR 2012; DHHS 2011) . Technical Fact Sheet - 1,4·Dioxane What are the routes of exposure and the health effects of 1,4-dioxane? (continued) .:. 1A-Dioxane is readily adsorbed through the lungs and gastrointestinal tract. Some 1A-dioxane may also pass through the skin, but studies indicate that much of it will evaporate before it is absorbed. Distribution is rapid and uniform in the lung, liver, kidney, spleen, colon and skeletal muscle tissue (ATSDR 2012). .:. Animal studies showed increased incidences of nasal cavity, liver and gall bladder tumors after exposure to 1A-dioxane (DHHS 2011; EPA IRIS 2013). .:. EPA has classified 1A-dioxane as "likely to be carcinogenic to humans" by all routes of exposure (EPA IRIS 2013) . .:. The U.S. Department of Health and Human Services states that 1A-dioxane is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals (DHHS 2011). .:. The American Conference of Governmental Industrial Hygienists (ACGIH) has classified 1A-dioxane as a Group A3 carcinogen confirmed animal carcinogen with unknown relevance to humans (ACGIH 2011). .:. The National Institute for Occupational Safety and Health (NIOSH) considers 1A-dioxane a potential occupational carcinogen (NIOSH 2010). Short-term exposure to high levels of 104dioxane may result in nausea, drowsiness, headache, and irritation of the eyes, nose and throat (ATSDR 2012; EPA 2013b; NIOSH 2010). .:. Chronic exposure may result in dermatitis, eczema, drying and cracking of skin and liver and kidney damage (ATSDR 2012; HSDB 2011). .:. 1A-Dioxane is weakly genotoxic and reproductive effects in humans are unknown; however, a developmental study on rats indicated that 1A-dioxane may be slightly toxic to the developing fetus (ATSDR 2012; Giavini and others 1985). •:. Are there any federal and state guidelines and health standards for 1,4-dioxane? .:. Federal and State Standards and Guidelines: • • • EPA's Integrated Risk Information System (IRIS) database includes a chronic oral reference dose (RfD) of 0.03 milligrams per kilogram per day (mg/kg/day) based on liver and kidney toxicity in animals and a chronic inhalation reference dose (RfC) of 0.03 milligrams per cubic meter (mg/m3) based on atrophy and respiratory metaplasia inside the nasal cavity of animals (EPA IRIS 2013). The Agency for Toxic Substances and Disease Registry (ATSDR) has established minimal risk levels (MRLs) for inhalation exposure to 1A-dioxane: 2 parts per million (ppm) for acute-duration (14 days or less) inhalation exposure; 0.2 ppm for intermediate-duration (15 to 364 days) inhalation exposure; and 0.03 ppm for chronic-duration (365 days or more) inhalation exposure (ATSDR 2012). Oral exposure MRLs have been identified as 5 mg/kg/day for acute-duration oral exposure; 0.5 mg/kg/day for intermediateduration oral exposure; and 0.1 mg/kg/day for chronic-duration oral exposure (ATSDR 2012). 3 • The cancer risk assessment for 1A-dioxane is based on an oral slope factor of 0.1 mg/kg/day and the drinking water unit risk is 6 2.9 x 10- micrograms per liter (I-Ig/L) (EPA IRIS 2013). • EPA risk assessments indicate that the drinkin~ water c~ncentration repr~sentin~ a 1 x 10- cancer risk level for 1A-dioxane IS 0.35 fl,g/L (EPA IRIS 2013). • 1A-Dioxane may be regulated as hazardous waste when waste is generated through use as a solvent stabilizer (EPA 1996b). • No federal maximum contaminant level (MCL) for drinking water has been established; however, an MCL is not necessary to determine a cleanup level (EPA 2012). • 1A-Dioxane was included on the third drinking water contaminant candidate list, which is a list of unregulated contaminants that are known to, or anticipated to, occur in public water systems and may require regulation under the Safe Drinking Water Act (EPA 2009). Technical Fact Sheet-1,4-Dioxane Are there any federal and state guidelines and health standards for 1,4-dioxane? (continued) .:. Federal and State Standards and Guidelines .:. Workplace Exposure Limits: (continued): • The EPA has established drinking water health advisories for 1A-dioxane, which are drinking water-specific risk level concentrations for cancer (10-4 cancer risk) and concentrations of drinking water contaminants at which noncancer adverse health effects are not anticipated to occur over specific exposure durations. The EPA established a 1-day health advisory of 4.0 milligrams per liter (mg/L) and a 10-day health advisory of 0.4 mg/L for 1A-dioxane in drinking water for a 10-kilogram child. EPA also established a lifetime health advisory of 0.2 mg/L for 1A-dioxane in drinking water (EPA 2012). • The EPA's drinking water equivalent level for 1A-dioxane is 1 mg/L (EPA 2012). • EPA has calculated a screening level of 0.67 IJg/L for 1A-dioxane in tap water, based on a 1 in 10-6 lifetime excess cancer risk (EPA 2013c). 1.2 • • .:. • The Occupational Safety and Health Administration set a general industry permissible exposure limit of 360 mg/m3 or 100 ppm based on a time-weighted average (TWA) over an 8-hour workday for airborne exposure to 1A-dioxane (OSHA 2013). • The ACGIH set a threshold limit value of 72 mg/m3 or 20 ppm based on a TWA over an 8hour workday for airborne exposure to 104dioxane (ACGIH 2011). • The NIOSH has set a ceiling recommended exposure limit of 3.6 mg/m3 or 1 ppm based on a 30-minute airborne exposure to 1A-dioxane (NIOSH 2010). • NIOSH also has established an immediately dangerous to life or health concentration of 500 ppm for 1A-dioxane (NIOSH 2010). Other State and Federal Standards and Guidelines: • EPA has calculated a residential soil screening level (SSL) of 4.9 milligrams per kilogram (mg/kg) and an industrial SSL of 17 mg/kg. The soil-to-groundwater risk-based SSL is 1.4 x10-4 mg/kg (EPA 2013c). Various states have established drinking water and groundwater guidelines, including the following: Colorado has established an interim groundwater quality cleanup standard of 0.35 1J9/L(CDPHE 2012); California has established a notification level of 1 1J9/Lfor drinking water (CDPH 2011); EPA has also calculated a residential air screening level of 0.49 micrograms per cubic 3 meter (lJg/m ) and an industrial air screening level of 2.5 IJg/m3 (EPA 2013c). New Hampshire has established a reporting limit of 0.25 IJg/L for all public water supplies (NH DES 2011); and Massachusetts has established a drinking water guideline level of 0.3 IJg/L (Mass DEP 2012). 1 Screening Levels are developed using risk assessment guidance from the EPA Superfund program. These risk-based concentrations are derived from standardized equations combining exposure information assumptions with EPA toxicity data. These calculated screening levels are generic and not enforceable cleanup standards but provide a useful gauge of relative toxicity. Tap water screening levels differ from the IRIS drinking water concentrations because the tap water screening levels account for dermal, inhalation and ingestion exposure routes; age-adjust the intake rates for children and adults based on body weight; and timeadjust for exposure duration or days per year. The IRIS drinking water concentrations consider only the ingestion route, account only for adult-intake rates and do not time-adjust for exposure duration or days per year. 2 4 • The Food and Drug Administration set 10 mg/kg as the limit for 1-4-dioxane in glycerides and polyglycerides for use in products such as dietary supplements. FDA also surveys raw material and products contaminated with 1A-dioxane (FDA 2006). • 1A-Dioxane is listed as a hazardous air pollutant under the Clean Air Act (CM) (CM 1990). • A reportable quantity of 100 pounds has been established under the Comprehensive Environmental Response, Compensation, and Liability Act (EPA 2011). Technical Fact Sheet - 1,4·Dioxane What detection and site characterization 1,4-dioxane? .:. As a result of the limitations in the analytical methods to detect 1A-dioxane, it has been difficult to identify its occurrence in the environment. The miscibility of 1A-dioxane in water causes poor purging efficiency and results in high detection limits (ATSDR 2012; EPA 2006). .:. Conventional analytical methods can detect 1A-dioxane only at concentrations 100 times greater than the concentrations of volatile organic compounds (EPA 2006; Mohr 2001). .:. Modifications of existing analytical methods and their sample preparation procedures may be needed to achieve lower detection limits for 1A-dioxane (EPA 2006; Mohr 2001). .:. High-temperature sample preparation techniques improve the recovery of 1A-dioxane. These techniques include purging at elevated temperature (EPA SW-846 Method 5030); equilibrium headspace analysis (EPA SW-846 Method 5021); vacuum distillation (EPA SW-846 Method 8261); and azeotrophic distillation (EPA SW-846 Method 5031) (EPA 2006). matrices by azeotropic microdistillation are 12 IJg/L (reagent water), 15 IJg/L (groundwater) and 16 1J9/L(leachate) (EPA 2003). .:. NIOSH Method 1602 uses gas chromatographyflame ionization detection (GC-FID) to determine the concentration of 1A-dioxane in air. The detection limit is 0.01 milligram per sample (ATSDR 2012; NIOSH 2010). .:. EPA SW-846 Method 8015D uses gas chromatography (GC) to determine the concentration of 1A-dioxane in environmental samples. Samples may be introduced into the GC column by a variety of techniques including the injection of the concentrate from azeotropic distillation (EPA SW-846 Method 5031). The detection limits for 1A-dioxane in aqueous What technologies .:. .:. EPA SW-846 Method 82608 detects 1A-dioxane in a variety of solid waste matrices using GC and mass spectrometry (MS). The detection limit depends on the instrument and choice of sample preparation method (ATSDR 2012; EPA 1996a). .:. A laboratory study is underway to develop a passive flux meter (PFM) approach to enhance the capture of 1A-dioxane in the PFM sorbent to improve accuracy. The selected PFM approach will be field tested at 1A-dioxane contaminated sites. The anticipated projection completion date is 2014 (DoD SERDP 2013b). .:. The presence of 1A-dioxane may be expected at sites with extensive TCA contamination; therefore, some experts recommend that groundwater samples be analyzed for 1A-dioxane where TCA is a known contaminant (Mohr 2001). .:. methods are available for .:. EPA Method 1624 uses isotopic dilution gas chromatography - mass spectrometry (GC-MS) to detect 1A-dioxane in water, soil and municipal sludges. The detection limit for this method is 10 1J9/L(ATSDR 2012; EPA 2001 b). .:. EPA SW-846 Method 8270 uses liquid-liquid extraction and isotope dilution by capillary column GC-MS. This method is often modified for the detection of low levels of 1A-dioxane in water (EPA 2007, 2013a) .:. GC-MS detection methods using solid phase extraction followed by desorption with an organic solvent have been developed to remove 1A-dioxane from the aqueous phase. Detection limits as low as 0.024 1J9/Lhave been achieved by passing the aqueous sample through an activated carbon column, following by elution with acetonedichlormethane (ATSDR 2012; Kadokami and others 1990). .:. EPA Method 522 uses solid phase extraction and GC/MS with selected ion monitoring for the detection of 1A-dioxane in drinking water with detection limits ranging from 0.02 to 0.026 1J9/L (EPA 2008). are being used to treat 1,4-dioxane? Pump-and-treat remediation can treat dissolved 1A-dioxane in groundwater and control groundwater plume migration, but requires ex situ treatment tailored for the unique properties of 1A-dioxane (such as, a low octanol-water partition coefficient that makes 1A-dioxane hydrophilic) (EPA 2006; Kiker and others 2010). light or ozone is used to treat 1A-dioxane in wastewater (Asano and others 2012; EPA 2006). .:. A study is under way to investigate facilitatedtransport enabled in situ chemical oxidation to treat 1A-dioxane-contamined source zones and groundwater plumes effectively. The technical approach consists of the co-injection of strong oxidants (such as ozone) with chemical agents that facilitate the transport of the oxidant (DoD SERDP 2013d). Commercially available advanced oxidation processes using hydrogen peroxide with ultraviolet 5 Technical Fact Sheet - 1,4·Dioxane What technologies are being used to treat 1,4-dioxane? (continued) .:. Ex situ bioremediation using a fixed-film, movingbed biological treatment system is also used to treat 1,4-dioxane in groundwater (EPA 2006). .:. Phytoremediation is being explored as a means to remove the compound from shallow groundwater. Pilot-scale studies have demonstrated the ability of hybrid poplars to take up and effectively degrade or deactivate 1,4-dioxane (EPA 2001a, 2013a; Ferro and others 2013). .:. Microbial degradation in engineered bioreactors has been documented under enhanced conditions or where selected strains of bacteria capable of degrading 1,4-dioxane are cultured, but the impact of the presence of chlorinated solvent cocontaminants on biodegradation of 1,4-dioxane needs to be further investigated (EPA 2006, 2013a; Mahendra and others 2013). .:. .:. generate desirable enzymatic activity for 1,4-dioxane biodegradation; (2) assess biodegradation by methane oxidizing bacteria in coupled anaerobic-aerobic zones; (3) and evaluate branched hydrocarbons as stimulants for the in situ cometabolic biodegradation of 1,4-dioxane and its associated co-contaminants (DoD SERDP 2013c, e and f). Results from a 2012 laboratory study found 1,4-dioxane-transforming activity to be relatively common among monooxygenase-expressing bacteria; however, both TCA and 1,1-dichloroethene inhibited 1,4-dioxane degradation by bacterial isolates (DoD SERDP 2012). .:. Photocatalysis has been shown to remove 1,4-dioxane in aqueous solutions. Laboratory studies documented that the surface plasmon resonance of gold nanoparticles on titanium dioxide (Au - Ti02) promotes the photocatalytic degradation of 1,4-dioxane (Min and others 2009; Vescovi and others 2010). .:. Other in-well combined treatment technologies being assessed include air sparging; soil vapor extraction (SVE); and dynamic subsurface groundwater circulation (Odah and others 2005). .:. SVE is known to remove some 1,4-dioxane, but substantial residual contamination is usually left behind because of 1,4-dioxane's high solubility, which leads to preferential partitioning into pore water rather than vapor. The DoD SERDP is conducting a project to evaluate and demonstrate the efficacy of enhanced or extreme SVE, which uses a combination of increased air flow, sweeping with drier air, increased temperature, decreased infiltration and more focused vapor extraction to enhance 1,4-dioxane remediation in soils (DoD SERDP 2013a). Several Department of Defense Strategic Environmental Research and Development Program (DoD SERDP) projects are under way to investigate 1,4-dioxane biodegradation in the presence of chlorinated solvents or metals. Laboratory studies will (1) identify microbial cultures as well as biogeochemistry, which Where can I find more information about 1,4-dioxane? .:. Asano, M" Kishimoto, N., Shimada, H., and Y. Ono. 2012. "Degradation of 1,4-Dioxane Using Ozone Oxidation with UV Irradiation (Ozone/UV) Treatment." Journal of Environmental Science and Engineering. Volume A (1). Pages 371 to 279. .:. Agency for Toxic Substances and Disease Registry (ATSDR). 2012. "Toxicological Profile for 1,4-Dioxane." www.atsdr.cdc.gov/toxprofiles/tp187.pdf .:. American Conference of Governmental Industrial Hygienists (ACGIH). 2011. "2011 Threshold Limit Values (TLVs) for Chemical Substances and Physical Agents Biological Exposure Indices." Cincinnati, Ohio. •:. California Department of Public Health (CDPH). 2011. "1 ,4-Dioxane." Drinking Water Systems. www.cdph.ca.gov/certlic/drinkingwater/Pages/1 ,4dioxane.aspx .:. Clean Air Act Amendments of 1990 (CM). 1990. "Hazardous Air Pollutants". 42 USC § 7412. .:. Colorado Department of Public Health and the Environment (CDPHE). 2012. "Notice of Public Rulemaking Hearing before the Colorado Water Quality Control Commission." Regulation No. 31 and No. 41. www.sos.state.co.us/CCRlUpload/NoticeOfRulem aking/ProposedRuleAtlach2012-00387. PDF .:. Ferro, A.M., Kennedy, J., and J.e. LaRue. 2013. "Phytoremediation of 1,4-Dioxane-Containing Recovered Groundwater." International Journal of Phytoremediation. Volume 15. Pages 911 to 923. .:. Giavini, E., Vismara, C., and M.L Broccia. 1985 . "Teratogenesis Study of Dioxane in Rats." Toxicology Letters. Volume 26 (1). Pages. 85 to 88. 6 Technical Fact Sheet - 1,4·Dioxane Where can I find more information about 1,4-dioxane? (continued) .:. .:. .:. .:. .:. .:. .:. .:. .:. .:. .:. .:. Graedel, T.E. 1986. Atmospheric Chemical Compounds. New York, NY: Academic Press. Hazardous Substances Data Bank (HSDB). 2011 . "1A-Dioxane." htt(;rlltoxnet. nlm. nih.gov/cgi-bin/ sis/htmlgen?HSDB HazDat. 2007. "1 A-Dioxane." HazDat Database: ATSDR's Hazardous Substance Release and Health Effects Database. Atlanta, GA: Agency for Toxic Substances and Disease Registry. Howard, P.H. 1990. Handbook of Environmental Fate and Exposure Data for Organic Chemicals. Lewis Publishers, Inc., Chelsea, MI. Pages 216 to 221. Kadokami, K, Koga, M. and A. Otsuki. 1990. "Gas Chromatography/Mass Spectrometric Determination of Traces of Hydrophilic and Volatile Organic Compounds in Water after Preconcentration with Activated Carbon." Analytical Sciences. Volume 6(6). Pages 843 to 849. .:. .:. .:. Kiker, J.H., Connolly, J.B., Murray, W.A., Pearson, S.C.; Reed, S.E., and R.J. Robert. 2010. "Ex-Situ Wellhead Treatment of 1A-Dioxane Using Fenton's Reagent." Proceedings of the Annual International Conference on Soils, Sediments, Water and Energy. Volume 15, Article 18. .:. Mahendra, S., Grostern, A. and L. Alvarez-Cohen . 2013. "The Impact of Chlorinated Solvent CoContaminants on the Biodegradation Kinetics of 1A-Dioxane." Chemosphere. Volume 91 (1). Pages 88 to 92. .:. Massachusetts Department of Environmental Protection (Mass DEP). 2012. "Standards and Guidelines for Contaminants in Massachusetts Drinking Waters." www.mass.gov/del2/water/dwstand·l2df .:. Min, B.K., Heo, J.E., Youn, N.K., Joo, O.S., Lee, H., Kim, J.H., and H.S. Kim. 2009. ''Tuning of the Photocatalytic 1A-Dioxane Degradation with Surface Plasmon Resonance of Gold Nanoparticles on Titania." Catalysis Communications. Volume 10 (5). Pages 712 to 715. .:. Mohr, T.K.G. 2001. "1 A-Dioxane and Other Solvent Stabilizers White Paper." Santa Clara Valley Water District of California. San Jose, California. .:. National Institute for Occupational Safety and Health (NIOSH). 2010. "Dioxane." NIOSH Pocket Guide to Chemical Hazards. www.cdc.gov/niosh/nl2g/nl2gd0237.html 7 New Hampshire Department of Environmental Services (NH DES). 2011 "Change in Reporting Limit for 1A-Dioxane." httl2:lIdes.nh.gov/organization/divisions/waste/hwr b/sss/hwrl2/documentslrel2ort-limits14dioxane·l2df Occupational Safety and Health Administration (OSHA). 2013. "Dioxane." Chemical Sampling Information. www.osha.gov/dts/chemicalsaml2ling/ data/CH 237200.html Odah, M.M., Powell, R., and D.J. Riddle. 2005. "ART In-Well Technology Proves Effective in Treating 1A-Dioxane Contamination." Remediation Journal. Volume 15 (3), Pages 51 to 64 . U.S. Department of Defense (DoD). Strategic Environmental Research and Development Program (SERDP). 2012. "Oxygenase-Catalyzed Biodegradation of Emerging Water Contaminants: 1A-Dioxane and N-Nitrosodimethylamine." ER1417. www.serdl2.org/Program-Areas/ Environmental-Restoration/ContaminatedGroundwater/Emerging-lssues/ER-1417/ER-1417 DoD SERDP. 2013a. "1 A-Dioxane Remediation by Extreme Soil Vapor Extraction (XSVE)." ER201326. www.serdl2.org/Program-Areas/ Environmental-Restoration/Contaminated-Ground water/Emerging-lssues/ER-201326/ER-201326 DoD SERDP. 2013b. "Development of a Passive Flux Meter Approach to Quantifying 1A-Dioxane Mass Flux." ER-2304. www.serdl2.org/ProgramAreas/Environmental-Restoration/ContaminatedGroundwater/Emerging-lssues/ER-2304/ER-2304/ DoD SERDP. 2013c. "Evaluation of Branched Hydrocarbons as Stimulants for In Situ Cometabolic Biodegradation of 1A-Dioxane and Its Associated Co-Contaminants." ER-2303. www.serdl2.org/Program-Areas/EnvironmentalRestoration/Contam inated-Grou ndwater/ Emerging-lssues/ER-2303/ER-2303 DoD SERDP. 2013d. "Facilitated Transport Enabled In Situ Chemical Oxidation of 1 ADioxane-Contaminated Groundwater." ER-2302. www.serdl2.org/Program-Areas/EnvironmentalRestoration/Contaminated-Groundwater/ Emerging-lssues/ER-2302/ER-2302/(language}/ eng-US DoD SERDP. 2013e. "In Situ Biodegradation of 1A-Dioxane: Effects of Metals and Chlorinated Solvent Co-Contaminants." ER-2300. www.serdl2.org/Program-Areas/EnvironmentalRestoration/Contaminated-Groundwater/ Emerging-lssues/ER-2300/ER-2300 Technical Fact Sheet - 1,4·Dioxane Where can I find more information about 1,4-dioxane? (continued) .:. DoD SERDP. 2013f. "In Situ Bioremediation of 1,4-Dioxane by Methane Oxidizing Bacteria in Coupled Anaerobic-Aerobic Zones." ER-2306. www.serdp.org/Program-Areas/EnvironmentalRestoration/Contaminated-Groundwater/ Emerging-lssues/ER-2306/ER-2306 .:. U.S. Department of Health and Human Services (DHHS). 2011. "Report on Carcinogens, Twelfth Edition." Public Health Service, National Toxicology Program. iz" Edition. http://ntp.niehs.nih.gov/ntp/roc/twelfth/roc12.pdf .:. U.S. Environmental Protection Agency (EPA). 1996a. "Method 8260B: Volatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS)." www.epa.gov/osw/ hazard/testmethods/sw846/pdfs/8260b. pdf .:. EPA. 1996b. "Solvents Study." EPA 530-R-96017. .:. EPA. 2001 a. "Brownfields Technology Primer: Selecting and Using Phytoremediation for Site Cleanup." EPA 542-R-01-006. www.brownfieldstsc.org/pdfs/phvtoremprimer.pdf •:. EPA. 2001b. "Method 1624." Code of Federal Regulations. Code of Federal Regulations. 40 CFR Part 136. Pages 274 to 287. •:. EPA. 2003. "Method 8015D: Nonhalogenated Organics Using GC/FID." SW-846. www.epa.gov/ osw/hazard/testmethods/pdfs/80 15d r4.pdf •:. EPA. 2006. "Treatment Technologies for 1,4-Dioxane: Fundamentals and Field Applications." EPA 542-R-06-009. www.epa.gov/tio/download/remed/542r06009.pdf •:. .:. EPA. 2007. "Method 8270D: Semivolatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS)." .:. EPA. 2009. "Drinking Water Contaminant Candidate List 3 - Final." Federal Register Notice. www.federalregister.gov/articles/2009/1 0/08/E924287/drinking-water-contaminant-candidate-list3-final .:. EPA. 2011. "Reportable Quantities of Hazardous Substances Designated Pursuant to Section 311 of the Clean Water Act. Code of Federal Regulations." 40 CFR 302.4. www.gpo.gov/fdsys/pkg/CFR-2011-title40voI28/pdf/CFR-2011-title40-voI28-sec302-4.pdf .:. EPA. 2012. "2012 Edition of Drinking Water Standards and Health Advisories." water.epa.gov/action/advisories/drinking/upload/d wstandards2012.pdf .:. EPA. 2013a. "1 ,4-Dioxane." www.ciu-in.org/conta minantfocus/default.focus/sec/1.4-Dioxane/ cat/Overview/ .:. EPA. 2013b. "1 ,4-Dioxane (1,4-Diethyleneoxide)." Technology Transfer Network Air Toxics Website. www.epa.gov/ttnatw01/hlthef/dioxane.html .:. EPA. 2013c. Regional Screening Level (RSL) Summary Table . www.epa.gov/reg3hwmd/risk/human/rbconcentration table/Generic Tables/index.htm .:. EPA. Integrated Risk Information System (IRIS) . 2013. "1,4-Dioxane (CASRN 123-91-1)." www.epa.gov/iris/subst/0326.htm .:. U.S. Food and Drug Administration (FDA). 2006 . "Food Additives Permitted for Direct Addition to Food for Human Consumption; Glycerides and Polyglycides." Code of Federal Regulations. 21 CFR 172.736 . .:. Vescovi, T., Coleman, H., and R. Amal. 2010. "The Effect of pH on UV-Based Advanced Oxidation Technologies - 1,4-Dioxane Degradation." Journal of Hazardous Materials. Volume 182. Pages 75 to 79. EPA. 2008. "Method 522: Determination of 1,4-Dioxane in Drinking Water By Solid Phase Extraction (SPE) and Gas Chromatography/Mass Spectrometry (GC/MS) with Selected Ion Monitoring (SIM)." EPAl600/R-08/101. Additional information on 1,4-dioxane can be found at www.cluin.org/contaminantfocus/default.focus/sec/1 .4-Dioxane/cat/Overview Contact Information If you have any questions or comments on this fact sheet, please contact: Mary Cooke, FFRRO, by phone at (703) 603-8712 or by email at cooke.marvt@epa.gov. 8