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EPA Region I Proposed Superfund Program . „ Plan & Q f . D_, f Superfund Records Center Salem Acres sn E: Salem, Massachusetts BRFAK.: H .1

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June 1992

EPA Proposes Cleanup Plan for the Salem Acres Site

The U.S. Environmental Protection Agency (EPA) is proposing a cleanup plan, referred to as a preferred alternative, to address contamination at the Salem Acres Superfund' site in Salem, Massachusetts. This Proposed Plan presents a preferred cleanup option recommended from among those that were evaluated during the Remedial Investigation (RI) and Feasibility Study (FS) performed for the site. In accordance with Section 117(a) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), EPA is publishing this Proposed Plan to provide opportunity for public review and comment on the cleanup alternatives, known as remedial alternatives, under consideration for the site. EPA will consider public comments as part of the final decision-making process for selecting the cleanup remedy for the site.

The preferred alternative includes 1) treatment of lagoon sludge with a fly ash fixation process to render the waste nonhazardous and 2) disposal of the treated waste at an off-site solid waste landfill. In the event that the sludge fixation process does not render the waste nonhazardous or if a landfill is not available locally then an on-site impermeable cap would be employed as a contingency. The preferred alternative is described in greater detail on pages 10 and 11 of this document.

This Proposed Plan: 1. explains the opportunities for the public to comment on the remedial alternatives; 2. includes a brief history of the site and the principal findings of site investigations: 3. provides a brief description of the preferred alternative and other alternatives

evaluated in the FS; 4. outlines the criteria used by EPA to propose an alternative for use at the site, and

briefly analyzes whether the alternatives meet each criterion; and 5. presents EPA's rationale for its preliminary selection of the preferred alternative.

To help the public participate in reviewing the cleanup options for the site, this document also includes information about where interested citizens can find more detailed descriptions of the remedy process and the alternatives under consideration for the Salem Acres site.

'Note: Words that appear in bold italic print in this document are defined in the glossary on pages 19 through 22.

The Public's Role in Evaluating Remedial Alternatives

Public Informational Meeting EPA will hold a public informational meeting on June 24, 1992 at 7:30 p.m. at the Old

Town Hall, 32 Derby Square, in Salem, Massachusetts to describe the preferred alternative and other alternatives evaluated in the Feasibility Study. The public is encouraged to attend the meeting to hear the presentations and to ask questions.

Public Comment Period EPA is conducting a 30-day public comment period from June 25, 1992 to July 25,

1992, to provide an opportunity for public involvement in the final cleanup decision. During the comment period, the public is invited to review this Proposed Plan and the RI and FS reports and to offer comments to EPA.

Informal Public Hearing EPA also will hold an informal public hearing on July 15, 1992 at 7:30 p.m. at the Old

Town Hall. 32 Derby Square, in Salem, Massachusetts, to accept oral comments on the cleanup alternatives under consideration for the site. This hearing will provide the opportunity for people to comment on the cleanup plan after they have heard the presentations made at the public informational meeting and reviewed this Proposed Plan. Comments made at the hearing will be transcribed, and a copy of the transcript will be added to the site Administrative Record available at the EPA Records Center at 90 Canal Street in Boston, Massachusetts, and at the Salem Public Library. The hours of operation of these information repositories are listed on page 3.

Written Comments If, after reviewing the information on the site, you would like to comment in writing on

EPA's preferred alternative, any of the other cleanup alternatives under consideration, or other issues relevant to the site cleanup, please deliver your comments to EPA at the Public Hearing or mail your written comments (postmarked no later than July 25. 1992) to:

Joseph DeCola, Remedial Project Manager U.S. Environmental Protection Agency Waste Management Division (HRM-CAN3) JFK Federal Building Boston, MA 02203-2211 (617) 573-5733

EPA's Review of Public Comments EPA will review comments received from the public as part of the process of reaching a

final decision on the most appropriate remedial alternative, or combinations of alternatives, for cleanup of the Salem Acres site. EPA's final choice of a remedy will be issued in a Record of Decision (ROD) for the site. The ROD should be completed by September 1992. A document called a Responsiveness Summary, that summarizes EPA's responses to comments received during the public comment period will be issued with the ROD. Once the ROD is signed by the EPA Regional Administrator, it will become part of the Administrative Record, which contains documents used by EPA to choose a remedy for the site.

2 EPA Superfund Program: Proposed Plan

Additional Public Information Because this Proposed Plan provides only a summary description of the investigation of

the Salem Acres site and the cleanup alternatives considered, the public is encouraged to consult the Administrative Record, which contains the Remedial Investigation and Feasibility Study reports and other site documents, for a more detailed explanation of the site and all of the remedial alternatives under consideration.

The Administrative Record is available for review at the following locations:

EPA Records Center Salem Public Library 90 Canal Street, 1st Floor Essex Street Boston, MA 02114 Salem, MA 01970 (617) 573-5729 (508) 744-0860

Hours: Hours:

Mon.-Fri.: 10:00 a.m. to 1:00 p.m. Mon.-Thurs.: 9:00 a.m. to 9:00 p.m. and 2:00 p.m. to 5:00 p.m. Fri.-Sat.: 9:00 a.m. to 5:00 p.m.

Sun.: 1:00 p.m. to 5:00 p.m. (closed Sundays Memorial Day through Labor Day)

Site History

The Salem Acres site is located in Salem and Peabody, Massachusetts. The Peabody city line forms the northern and western site boundaries (see Figure 1). The land is wooded to the north and west, while residential properties border the site to the south and east The total site area is approximately 235 acres, but hazardous waste disposal only occurred in an area covering approximately 13 acres at the southern end of the site. Contaminated soil and/or sludge are confined to several subareas located within this section of the site. Wetlands border the disposal area to the east and west (see Figure 2).

Beginning in 1947, the South Essex Sewerage District (SESD) began disposing of sewage material on the site under an agreement with the property owner. The sewage material, which included grease, a semi-solid sludge, and tannery waste was generated at the SESD Grease and Grit Chambers in Salem and Peabody. The sludge was dumped into eight open unlined lagoons within subareas DA-1 (Disposal Area #1) and DA-2 (Disposal Area #2), treated with lime, and periodically covered with gravel (see Figure 2). The land was sold to Salem Acres, Inc. in December 1969. Soon after, the Salem Acres, Inc. notified SESD that they could no longer use the site for dumping sewerage sludge. However, nonauthorized dumping of sludge and tannery wastes is alleged to have occurred on the site after 1969 and as late as 1980.

There is an abandoned landfill on site that occupies about one-half acre and is located approximately 100 feet north of the gate on Barcelona Avenue. The site also contains a one-half acre fly ash pile which was brought to the site during the 1940s and 1950s. The fly ash originated from the former Lynn Gas and Electric Company in Lynn, Massachusetts. In addition, there are several debris piles scattered over the northern portion of the site.

Salem Acres Site 3

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Salem Acres Site 5

Following citizen complaints of continued dumping, the Massachusetts Department of Environmental Quality Engineering (MA DEQE, currently known as the Department of Environmental Protection [DEP]) inspected the site in September 1980 and reported signs of recent excavations and grading by heavy equipment, oily and chemical residues on some of the lagoons, scattered leather scraps, and odors. In 1983, the U.S. EPA initiated preliminary investigations into the nature and extent of hazardous waste contamination at the site. Sampling of the sludge lagoons in 1983 and 1985 revealed a wide range of contaminants including metals, volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs). In 1986, due to the documented presence of contamination on the property, EPA added the site to the Superfund National Priorities List (NPL), a list of the nation's most contaminated hazardous waste sites. Placement on the NPL prioritizes a site for federal action under EPA's Superfund program.

Cleanup Activities to Date

In 1984, the South Essex Sewerage District (SESD) under the direction of DEP constructed a fence around the lagoons in DA-1 and DA-2 to prevent exposure of the public to sludges. In April 1987, following a period of heavy rain that resulted in the discharge of hazardous material from the sludge lagoons to a nearby brook and wetlands, the EPA began an emergency Removal Action to prevent any further release of contaminants from the lagoons. As part of this response, EPA removed liquids from the lagoons; placed synthetic caps over the lagoons; constructed slurry walls between the lagoons and wetlands (a slurry wall is a trench, filled with highly impermeable materials such as clay, which inhibits the flow of ground water past the wall); installed gas vents; and replaced the fence around subareas DA-1 and DA-2.

The Removal Action, completed in December 1987, was a temporary measure to reduce discharge from the lagoons and to prevent access to the disposal areas. In order to define the nature and extent of contamination and find a long-term remedy for site contamination, the EPA entered into an Administrative Order by Consent with the SESD in June 1987. Under this order, SESD agreed to conduct and pay for a Remedial Investigation, Public Health Risk Assessment, and Feasibility Study of Cleanup Alternatives for the Salem Acres site.

Results of the Remedial Investigation

The Remedial Investigation was conducted to define the nature and extent of contamination at the Salem Acres site. The investigation included sampling and analysis of the following'to media:

soil and sludge from the lagoons; soil from areas adjacent to the lagoons; soil from the fly ash and landfill disposal areas; soil from debris piles; surface water and sediment from nearby wetland areas; fish and turtle tissue from wetland areas; ground water from monitoring wells and residential wells; and air.


Seventy-four contaminants were detected in one or more of the environmental media (lagoon sludge, soil, surface water, sediment, and ground water) at the site. The highest levels of contamination were generally found in subareas DA-1 and DA-2 (sludge lagoon areas), SL-4 (the ash pile), and SL-5 (the old landfill). Results from these investigations are summarized below.

1. Sludge Lagoons (Areas DA-1 and DA-2): Sludge and soil samples were collected from subareas DA-1 and DA-2 during the RI. Organic contaminants detected in the sludge include volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs), including polynuclear aromatic hydrocarbons (PAHs). Elevated concentrations of a number of the metals were also detected, including arsenic, beryllium, chromium, and lead. In addition, low levels of dioxins, polychlorinated biphenyls (PCBs), and pesticides were detected in some samples.

2. Soils (Areas SL-1 to SL-5): Soil samples were collected from five separate areas adjacent to or nearby the sludge disposal areas. These areas are designated as SL-1 through SL-5, including the ash pile (SL-4) and old landfill (SL-5). One sample was also collected from each of the smaller disposal areas in the northern portion of the site, which contained construction and household debris, and discarded appliances.

Soil samples from areas adjacent to the lagoons were obtained from excavated pits and borings made during monitoring well installation. Contaminants detected in these soil samples were similar in type to those detected in the lagoons. The primary organic compounds in Area SL-1 were PAHs detected in the surficial soils. PAHs were the only organic compounds detected in Area SL-2, though at concentrations lower than those in SL-1. Elevated levels of beryllium and lead were detected in SL-1 and SL-2.

The contaminants of concern detected in Area SL-3 included SVOCs, PAHs, PCBs, and chromium. The material sampled in this area is believed to be sludge similar to that in the adjacent lagoons in DA-2. However, the concentrations detected in SL-3 were generally lower than those detected in the lagoon sludges in DA-2.

Contaminants detected in the ash pile (SL-4) and old landfill (SL-5) varied somewhat from those detected in and around the lagoons. Samples from the ash pile contained arsenic, chromium, and PAHs. Samples from the old landfill contained high levels of PAHs.

Only three of the debris piles (SL-6, SL-12. and SL-13) contained elevated levels of contaminants including low levels of PCBs and PAHs. VOCs were not detected in any samples from the debris piles.

3. Wetlands Analysis: Surface water and sediments were sampled in wetland areas. Surface water samples revealed slightly elevated contamination in wetlands at two locations near the disposal areas near DA-1 and DA-2. Contaminants found were similar to those detected in the lagoons, though at much lower concentrations. The most recent analyses of sediments did not show the presence of PCBs and contained only trace levels of SVOCs. Some additional testing in wetlands will be done during the remedial design phase in order to confirm the levels of contaminants found.

An investigation of the wetland areas at the Salem Acres site revealed a variety of healthy wildlife and wetland vegetation.

Salem Acres Site 7

4. Ground Water: Twelve monitoring wells were installed at the Salem Acres site during the RI. Analyses of samples collected from these wells indicate that the ground water next to DA-1 and DA-2 contains low concentrations of VOCs, SVOCs, and some metals. Ground water from the site is below the Maximum Contaminant Levels (MCLs), which ar the standards established for maintaining safe drinking water quality. ^_

With the exception of a trace concentration of chloroform in one drinking water well (not attributable to site contamination), water from the three residential wells sampled during the RI did not contain any elevated levels of organic or metal contamination.

In addition to the ground water sampling described above, the RI included characterization of local geology (including soil and bedrock types and the extent and orientation of fractures in the bedrock) and local hydrogeology to define the direction of ground water flow and potential for movement of contaminants from the site.

5. Air: Air sampling was conducted at both on- and off-site locations to determine if wind-borne contaminants pose a health risk to the public. Sampling occurred twice, during the spring and late summer of 1989, in order to assess contamination at times when dust is least and most likely to be generated. The filters in the air collection devices were analyzed for PCBs and metals. PCBs were not detected during either sampling event. Most samples did not contain detectable levels of metals.

6. Fish and Turtle Tissue: Fish and turtle were collected from the on-site wetlands. Analyses of tissue revealed the presence of low levels of several metals, PCBs, and two pesticides. No physical disorders (e.g., tumors or lesions) were observed in the fish and turtle collected from Salem Acres surface waters. Fish are known to accumulate concentrations of PCBs in their tissue at concentrations up to 30,000 times greater than that found in the surrounding water. Therefore, even when PCB concentrations in surface water and sedimer are below detectable levels, PCBs may be found in fish tissue.

Summary of Site Risks

A baseline risk assessment was prepared for the Salem Acres site. The baseline risk assessment evaluates the present and future potential risks to public health and the environment associated with exposure to contaminants at the site, assuming no remedial action is taken. Both carcinogenic (cancer-producing) and noncarcinogenic effects associated with exposure to the 74 contaminants detected in sludge, soils, surface water, sediment, ground water, air, and/or fish tissue at the Salem Acres site were evaluated. Exposures to soil and sludge contaminants were shown to pose the greatest potential for adverse health effects at the site. A summary of site-related risks and the contaminants contributing most to these risks is presented below.

Lagoon Sludge: If an individual were to come in contact with and ingest lagoon sludge, adverse health effects would likely result. Dioxins, chromium, arsenic, beryllium, PCBs, and PAHs (DA-2 only) would contribute most to these effects.

Soils: Exposure to contaminated site soils could also present significant risk of adverse health effects if no action were taken at the site. The risk assessment considered potential exposures to recreational users of the site under present site conditions. The risk assessment also assumed future exposures resulting from possible residential development of the site. Exposures considered include skin contact with, or incidental ingestion of soils, or inhalation of contaminated dust. SL-5 (Ash Landfill) soils were associated with the greatest risk of

"—^


adverse effects primarily due to exposures to PAHs. as well as to chromium, arsenic, and beryllium. The other subareas (SL-1 through SL-4) also showed risks associated with exposures to these same contaminants but to lesser extents.

Surface Water and Sediment: It was determined that low levels of health risks exist if an individual were exposed to site sediments and surface waters during swimming or wading.

Ground Water: No current or potential future risk is associated with ingestion of ground water. The contaminant concentrations are below maximum contaminant levels (MCLs) for drinking water, which are the maximum permissible levels of contaminants in water that is consumed as a drinking water supply. Future ground water monitoring will be conducted on site to assure compliance with drinking water MCLs.

Air: Under normal conditions, there is no risk associated with air at the site. There is a potential risk associated with airborne particulates if dust is generated.

Fish: Slightly increased cancer risks, due to the presence of PCBs detected in fish tissue, would be expected if fish from site surface waters were ingested.

Actual or threatened releases of hazardous substances from this site, if not addressed by the preferred alternative or one of the other active measures considered, may present a current or potential threat to public health, welfare, or the environment. For a complete explanation of risks posed by contamination at the Salem Acres site, please refer to the Baseline Risk Assessment report that is available at the information repositories at the Salem Public Library and EPA Records Center.

Proposed Cleanup Objectives and Levels

Using the information gathered during the RI. FS, and risk assessment, EPA has identified the remedial action objectives for cleanup of the Salem Acres site. The focus of the remedial action will be to address the soil/sludge contamination in DA-1, DA-2 and SL-1 through SL-6, SL-12, and SL-13. The cleanup objectives are to reduce the combined risk associated with all soil exposure pathways (ingestion, skin contact, and inhalation) to levels that are protective of human health and the environment, and to prevent the further migration of hazardous substances at the site to ground water and surface water.

To meet these objectives, EPA has established site-specific target cleanup levels that will be protective of human health and the environment. The remedial alternative selected for the site must achieve EPA's cleanup levels for reducing contamination at the site. During the RI, 68 of the 74 organic compounds or metals detected on site were detected in on-site soils. Cleanup goals for site soils have been established for three groups of organic compounds (carcinogenic PAHs, dioxins, and PCBs) and four metals (arsenic, beryllium, chromium, and lead). These seven groups of compounds comprise the majority of the risk associated with soil contamination at the Salem Acres site. The cleanup goals are listed in the following table.

Salem Acres Site 9

Contaminants of Concern Cleanup Goal

PAHs (carcinogenic) 1.2 ppm

Dioxins 1.0 ppb

PCBs 1.0 ppm

Arsenic 40.0 ppm

Beryllium 0.35 ppm

Total Chromium 900.0 ppm

Lead 500.0 ppm

ppm = parts per million ppb = parts per billion

EPA's Preferred Alternative

EPA's selection of the preferred cleanup alternative for the Salem Acres site, as described in this Proposed Plan, is the result of a comprehensive evaluation and screening process. The FS for the site was conducted to identify and analyze the alternatives considered for addressing contamination at the site. The FS report for the Salem Acres site describes the alternatives considered, as well as the process and criteria EPA used to narrow the list to nine potential remedial alternatives to address soil/sludge contamination. (For details on EPA's screening methodology, see Sections 3 and 4 of the FS report.) The following sections describe the preferred alternative and the other alternatives EPA retained for detailed analysis.

Preferred Alternative

Alternative 7B: Sludge Fixation/Off-site Disposal

The preferred alternative would include the in-situ (in place) treatment of lagoon sludges with fly ash and soil, followed by the excavation of the treated sludge and other soils for disposal in an off-site landfill. In order for these materials to be disposed off-site, they would have to be shown to be non-hazardous under the Resource Conservation and Recovery Act (RCRA) (including the RCRA tests for toxicity and flammability). Testing of the treated sludge would be performed in order to determine if off-site disposal is possible. Off-site disposal would also be dependent upon the availability of a local landfill.

If off-site disposal is not feasible, a cap would be placed over the source areas as is described in Alternative 2 in the following section. In addition to the cap, a concrete barrier wall would be constructed between area DA-1 and the adjacent wetlands, and concrete retaining walls would be constructed around the west side of areas SL-4 and SL-5. The walls would provide sideslope stability in addition to preventing the migration of contaminants to the wetlands. In addition, future development would be limited through deed restrictions and


new fencing would be installed around the entire capped area. If future ground water monitoring should indicate the cap were not effective, additional treatment would be applied (e.g., immobilization as described under Alternative 7 in the following section).

The following is a detailed discussion of each component of the preferred alternative (Alternative 7B), assuming that off-site disposal will be possible.

1. Fly ash and soils would be mixed in the lagoons with the lagoon sludge at DA-1 and DA-2. Approximately 26,000 tons of material would be required to immobilize the contaminants in the sludge. Approximately 7,000 tons of fly ash would be excavated and used from area SL-4; the remaining amount would be purchased and transported to the site.

2. Following treatment, approximately 40,000 cubic yards of immobilized sludge would be excavated from the lagoons. Approximately 17,000 cubic yards of untreated soils from other disposal areas at the site would also be excavated.

3. The treated sludge and untreated soils would be transported to a locally available off-site landfill with the capacity and willingness to accept the waste.

4. Excavated areas would be backfilled, covered with clean topsoil, graded, and seeded.

5. Ground water monitoring would be required to confirm the effectiveness of the removal.

Estimated Time for Remediation: 22 months Estimated Time of Operation (includes monitoring): 5 years Estimated Capital Cost: $9,032,000 Estimated Operation and Maintenance Cost (net present worth): $91,000 Estimated Total Cost (net present worth): $9,123,000

Other Alternatives Evaluated in the Feasibility Study

The public is invited to comment not only on the preferred cleanup alternative, but also on the other eight alternatives that EPA evaluated in detail.

Alternative Number Name Total Cost

No Action $ 330,000 Capping $ 4,410,000

3 Incineration/Stabilization $ 30,825,000 4 Thermal Desorption/Dechlorination/Stabilization $ 26,765,000 5 Solvent Extraction/Stabilization $ 19,237,000 6 In-Situ Vitrification $ 44,923,000 7 Immobilization $ 15,442,000

Immobilization/Off-Site Disposal $ 18,026,000 Sludge Fixation/Off-Site Disposal $ 9,123,000

Salem Acres Site 11

Each of these alternatives is described briefly below. A more detailed description of each alternative can be found in the Feasibility Study (FS) report.

Alternative 1: No Action: This alternative was evaluated in detail in the FS to serve as a baseline for comparison with the other remedial alternatives under consideration. Under this alternative, no treatment or containment of disposal areas would occur and no effort would be made to restrict potential exposure to site contaminants. However, a ground water monitoring program would be instituted.

Estimated Time for Remediation: Not Applicable Estimated Time of Operation (includes monitoring): 30 years Estimated Capital Cost: $0 Estimated Operation and Maintenance Cost (net present worth): $330,000 Estimated Total Cost (net present worth): $330,000

Alternative 2: Capping: In the event that the preferred alternative (7B) is not feasible, this alternative would be employed. Alternative 2 would involve the placement of a RCRA-grade impermeable cap over the contaminated areas (DA-1, DA-2, SL-1. Sl-2. SL-3, SL-4. SL-5). RCRA requires the placement of a composite cap, consisting of a compacted clay layer covered with a synthetic membrane liner. This double layer (clay and the liner) would provide an additional level of protection against both infiltration of contaminants to ground water and direct human contact with underlying waste materials. The composite cap would be covered with a layer of soil to maintain the cap's integrity and to allow for vegetative growth. After capping, existing site fencing would be replaced with new fencing around the entire capped area. Future development in the southern portion of the property would be limited through deed restrictions. Finally, a ground water monitoring program would be developed to allow periodic evaluation of the cap's effectiveness in preventing the migration of soil contaminants to ground water. Concrete retaining walls would be used to protect wetlands and to provide for cap stability. In addition, a gas venting system would have to be installed.

Estimated Time for Design and Construction: one year Estimated Time of Operation (includes monitoring): 30 years Estimated Capital Cost: $3,841,000 Estimated Operation and Maintenance Cost (net present worth): $569,000 Estimated Total Cost (net present worth): $4,410,000

Alternative 3: Incineration/Stabilization: This alternative would involve excavation and pretreatment of contaminated soil, on-site incineration of soil contaminated by organic compounds, stabilization/solidification of soil contaminated by metals, and on-site burial of processed soil. Pretreatment would include the removal and decontamination of oversized debris (to be re-buried onsite or disposed off-site in a sanitary landfill) and the screening, shredding, and mixing of remaining soils and wastes. This process would create a more uniform-sized soil/waste mixture which could be more efficiently incinerated or stabilized. If this alternative were chosen, the method of incineration would be selected from the following


options: rotary kiln, infrared, or fluidized bed incineration. The stabilization/solidification process would involve the addition of cement to the contaminated soil and incinerator ash. In addition, deed restrictions and a ground water monitoring program would be employed.


Alternative 4: Thermal Desorption/Dechlorination/Stabilization: This alternative would remove organic contaminants from the soil through the processes of thermal desorption and dechlorination. Thermal desorption involves the heating of contaminants without the release of toxics to the air. Dechlorination, accomplished simultaneously with desorption, removes PCB and dioxin/furan contaminants through reactions between the soil and chemical additives. The contaminants removed from the soil would be condensed into a liquid which would be treated in an on-site wastewater treatment facility. Sludge generated by the treatment system would be shipped off site for disposal. Following treatment for organic contamination, soil would be stabilized/solidified and buried on site. Deed restrictions and ground water monitoring would be included in this alternative.

Estimated Time for Remediation: 18 months Estimated Time of Operation (includes monitoring): 30 years Estimated Capital Cost: $26,442,000 Estimated Operation and Maintenance Cost (net present worth): $323.000 Estimated Total Cost (net present worth): $26,765,000

Alternative 5: Solvent Extraction/Stabilization: This alternative would involve the excavation and treatment of contaminated soils followed by on-site burial of the treated soil. A solvent extraction process would be used to remove organic contamination from the soil. In this process, contaminants in the soil become dissolved in a chemical solvent that has been added to the soil. The solvent can then be removed from the soil through a process such as distillation. After this initial treatment, the organic contaminant-free soil would undergo a stabilization/solidification process similar to that described in Alternative 3. This alternative would also include deed restrictions to prevent future development of the site, and ground water monitoring.


Alternative 6: In-Situ Vitrification: This is the only alternative that would include treatment of organic and metal contamination without any excavation. Using conductive materials placed on the ground surface and electrodes placed in the ground, the contaminated

Salem Acres Site 13

soil would be electrically melted, forming a glass-like material once cooled. Alternative 6 has been eliminated from consideration because of the danger of fire resultant from the high temperatures used in this process.

Estimated Time for Remediation: 22 months Estimated Time of Operation (includes monitoring): 30 years Estimated Capital Cost: $44,600,000 Estimated Operation and Maintenance Cost (net present worth): $323,000 Estimated Total Cost (net present worth): $44.923,000

Alternative 7: Immobilization: This alternative would involve the excavation and pretreatment of contaminated soil followed by immobilization and re-burial of the treated soil in the original excavations. Organics would be immobilized through the addition of materials such as organophillic clay prior to the addition of a cement-based mixture. Alternative 7 would use only immobilization/solidification to treat soils unlike Alternatives 3, 4, and 5 which would use other processes to destroy or remove organic contaminants prior to stabilization. This alternative would include deed restrictions and ground water monitoring.


Alterative 7A: Immobilization/Off-site Disposal: This alternative varies from Alternative 7 in that a chemical stabilizer rather than organophillic clay would be used to immobilize organic contaminants in the soil. The treated soil would be disposed at an off-site landfill.


Alternative 7B: Sludge Fixation/Off-site Disposal: See pages 10 and 11 for a description of Alternative 7B, the preferred alternative.

Summary of the Comparative Analysis of Alternatives

EPA uses nine criteria to evaluate each remedial alternative retained for detailed analysis in the FS. The nine criteria are used to select a remedy that meets the national Superfund program goals of protecting human health and the environment, maintaining protection over time, and minimizing untreated waste. Definitions of the nine criteria and a summary of EPA's evaluation of the alternatives using the nine criteria are provided below:

14 EPA Superfund Program; Proposed Plan

1. Overall Protection of Human Health and the Environment addresses how an alternative as a whole will protect human health and the environment. This includes an assessment of how public health and environmental risks are properly eliminated, reduced, or controlled through treatment, engineering controls, or institutional controls, such as deed restrictions.

The preferred alternative (Alternative 7B) would provide a high degree of overall protection because contaminated soils and sludges would be removed from the site. Alternative 2 (capping) would protect human health and the environment over the short-term by preventing exposures. The effectiveness of capping may not be as permanent as 7B. Ground water monitoring would be employed to evaluate the long-term effectiveness of the cap.

In the event that the cap were shown to be ineffective, additional treatment would have to be employed. Alternative 3 (incineration/stabilization), Alternative 4 (desorption/dechlorination/stabilization), Alternative 5 (solvent extraction/stabilization). Alternative 7 (immobilization), and Alternative 7A (immobilization/off-site disposal of organics) would all offer a high degree of overall protection by either destroying or removing organic contamination and by containing metal contamination. The No Action alternative would not protect human health and the environment over the long term because the existing synthetic cap over the lagoons was only planned for use as an interim solution and would be expected to eventually fail.

2. Compliance with Applicable or Relevant and Appropriate Requirements (ARARS) addresses whether or not a remedy complies with all state and federal environmental and public health laws and requirements that apply or are relevant and appropriate to the conditions and cleanup options at a specific site. If an ARAR cannot be met, the analysis of the alternative must provide the grounds for invoking a statutory waiver.

Alternative 2 (capping) would comply with EPA capping requirements and Superfund protectiveness requirements over the short-term. Long-term effectiveness would have to be determined by monitoring of ground water. Alternatives 3, 4, 5, 7, 7A, and 7B would achieve compliance with Superfund protectiveness requirements and all state and federal action- and location-specific ARARS (including state landfill regulations, air quality regulations, hazardous waste storage and transportation regulations, process discharge water regulations, wetlands regulations, and health and safety regulations). The No Action alternative would not meet state or federal ARARs.

3. Long-Term Effectiveness and Permanence refers to the ability of an alternative to maintain reliable protection of human health and the environment over time once the cleanup goals have been met.

The preferred alternative (sludge fixation/off-site disposal) would achieve longterm effectiveness by removing all organic and metal contamination from the site. Alternatives 3, 4, 5, 7, and 7A would all achieve long-term effectiveness by destroying or removing organic contamination and by stabilizing metal contamination. Deed restrictions would provide adequate controls against future exposures to stabilized soils buried on site. Alternative 2 would provide short-term effectiveness in preventing exposures, and would require deed restrictions, and fencing. Long-term effectiveness

Salem Acres Site 15

would have to be assured through a program of ground water monitoring. The No Action alternative would not provide long-term protection of human health and the environment; risks associated with human exposures to contaminated soil and sludge would remain high.

4. Reduction of Toxicity, Mobility, or Volume through Treatment are three principal measures of the overall performance of an alternative. The 1986 amendments to the Superfund statute emphasize that, whenever possible, EPA should select a remedy that uses a treatment process to permanently reduce the level of toxicity of contaminants at the site, the spread of contaminants away from the source of contamination, and the volume or amount of contamination at the site.

The preferred alternative (Alternative 7B) would reduce the toxicity and mobility of contaminants through treatment and/or off-site disposal. Alternative 4 (desorption/dechlorination/ stabilization) and Alternative 5 (solvent extraction/stabilization) would reduce toxicity and mobility of contaminants by permanently removing or destroying organic contaminants at an estimated 98 percent efficiency and would immobilize all metals through the stabilization process.

Alternatives 4 and 5 would require the off-site treatment and disposal of an estimated 9500 gallons of concentrated organics. Alternative 3 (incineration/ stabilization) would result in virtually complete destruction of organic contaminants while immobilizing metals through stabilization. Alternatives 3, 4. 5, 7 (immobilization), 7A (immobilization/off-site disposal of organics), and 7B would result in an approximately 20 to 40 percent increase in soil volume caused by the stabilization process and the addition of clean fill. Incineration of lagoon sludge (Alternative 3) would produce a significant volume reduction. The No Action alternative and Alternative 2 (capping) would not provide any destruction or treatment of hazardous materials, nor would they provide a reduction in toxicity or volume. However, the mobility of contaminants would be reduced under Alternative 2 by eliminating infiltration.

5. Short-Term Effectiveness refers to the likelihood of adverse impacts on human health or the environment that may be posed during the construction and implementation of an alternative until cleanup goals are achieved.

Although air monitoring would be implemented on site to prevent unacceptable exposures, the potential exists for exposure of workers and adjacent residents to fugitive dusts generated during construction and excavation activities associated with Alternatives 2, 3, 4, 5, 7, 7A, and 7B. Workers would also be potentially exposed to soil contaminants during excavation and handling operations, but stringent worker health and safety requirements would be imposed (such as air monitoring and the use of protective clothing).

The potential for short-term impact to adjacent wetlands exists under Alternatives 3. 4. 5, 7. 7A and 7B if significant amounts of contaminated sediment runoff from disturbed areas or process wastewater were to reach the wetlands. Measures to control sediment runoff and wastewater discharge during construction and waste treatment would need to be imposed.


6. Implementability refers to the technical and administrative feasibility of an alternative, including the availability of materials and services needed to implement the alternative.

The preferred alternative (sludge fixation/off-site disposal) as well as Alternatives 4, 5, 7, and 7A would involve the use of commonly available construction methods, equipment, and materials. The preferred alternative would be easily implemented since treatment would occur without excavation of lagoon sludges. Solvent extraction (Alternative 5) has been proven on soils containing similar contaminants (PCBs, PAHs). Some operational difficulties may be encountered implementing Alternative 3 (incineration/stabilization) and Alternative 4 (desorption/ dechlorination/ stabilization) due to the non-uniform, high-BTU content of soils and sludges. Similar difficulties may be encountered implementing Alternative 5 (solvent extraction/stabilization), Alternative 7 (immobilization), and Alternative 7A (immobilization/off-site disposal of organics) due to the non-uniform, oily consistency of the wastes. Each of these alternatives (3, 4, 5, 7, and 7A) could require extensive pretreatment. Alternative 2 (capping) is easily implemented and would rely on commonly available construction materials, methods, and equipment.

The overall effectiveness of each alternative, with the exception of the No Action alternative, would be evaluated through ground water monitoring and confirmatory soil sampling. None of the alternatives would impede future remediation activities, should they be necessary.

7. Cost includes the capital (up-front) cost of implementing an alternative as well as the cost of operating and maintaining the alternative over the long term, and net present worth of both capital and operation and maintenance costs.

The capital, operation and maintenance, and total cost for each alternative is provided as part of the site description in the preceding sections on "EPA's Preferred Alternative" and "Other Alternatives Evaluated in the FS."

8. State Acceptance addresses whether, based on its review of the RI, FS and Proposed Plan, the state concurs with, opposes, or has no comment on the alternative EPA is proposing as the remedy for the site.

To date, the MA DEP has not provided EPA with a formal opinion on the preferred alternative.

9. Community Acceptance addresses whether the public concurs with EPA's Proposed Plan. Community acceptance of this Proposed Plan will be evaluated based on comments received at the upcoming public meetings and during the public comment period.

Of the nine criteria, overall protection of public health and the environment and compliance with applicable and relevant and appropriate requirements are considered threshold requirements that must be met by all remedies. EPA balances its consideration of alternatives with respect to long-term effectiveness and permanence; reductions of toxicity. mobility, or volume through treatment; short-term effectiveness; implementability; and cost. State and community concerns are considered as modifying

Salem Acres Site 17

criteria factored into a final balancing of all criteria to select a remedy. Consideration of state and community comments may prompt EPA to modify aspects of the preferred alternative or decide that another alternative considered provides a more appropriate balance.

EPA's Rationale for Proposing the Preferred Alternative

Based on current information and analysis of the RI and FS reports, EPA believes that the preferred alternative for the Salem Acres site (sludge fixation/off-site disposal) is consistent with the requirements of the Superfund law and its amendments, specifically Section 121 of CERCLA, and to the extent practicable, the National Contingency Plan.

All of the alternatives presented in this Proposed Plan would provide overall protection of human health and the environment with the exception of the No Action Alternative and Alternative 6 which is considered not applicable because of the associated fire hazard. In EPA's estimation, however, the preferred alternative would achieve the best balance among the criteria used by EPA to evaluate the alternatives. The preferred alternative would provide short- and long-term protection of human health and the environment, would attain federal and state applicable or relevant and appropriate public health and environmental requirements (ARARs), would reduce the mobility and toxicity of contaminated soils and sludges, and would utilize permanent solutions to the maximum extent practicable. The movement of the treated waste to a landfill would provide a permanent solution to the site by eliminating contamination and related risk and preclude the necessity for a long-term operation, maintenance and monitoring plan on site. In the event that the sludge fixation method fails to pass RCRA tests or if a local landfill is not available to accept the treated waste, a RCRA impermeable cap would be placed over the lagoons and soil areas on site. The contingency plan for capping would be equally protective as long as a ground water monitoring program is implemented. In the event that monitoring were to determine that ground water contaminants are above the MCLs for drinking water, the cap would be temporarily removed and treatment would be implemented.

For More Information

If you have any questions about the site or would like more information, you may call or write to:

Joseph DeCola, Remedial Project Manager Diane Ready U.S. Environmental Protection Agency Community Relations Coordinator Waste Management Division (HRM-CAN3) U.S. Environmental Protection Agency JFK Federal Building OR Office of External Programs (REA) Boston, MA 02203-2211 JFK Federal Building (617)573-5733 Boston. MA 02203-2211

(617) 565-3425

18 EPA Superfund Program. Proposed Plan

Glossary

Administrative Order on Consent (AOC): A legal agreement entered into by EPA and one or more Potentially Responsible Parties (PRPs) that sets forth the studies and cleanup actions to be carried out by the PRPs under the supervision of EPA.

Applicable or Relevant and Appropriate Requirements (ARARs): ARARs include any state or federal statute or regulation that pertains to protection of public health and the environment in addressing certain site conditions or using a particular cleanup technology at a Superfund site. A state law to preserve wetland areas is an example of an ARAR. EPA must consider whether a remedial alternative meets ARARs as part of the process for selecting a cleanup alternative for a Superfund site.

Baseline: With respect to the alternatives evaluated, a statement of existing conditions and their relative consequences should no further action be taken.

Bedrock: The layer of rock located below the glacially deposited soil and rock under the ground's surface. Bedrock can be either solid or fractured (cracked); fractured bedrock can support aquifers.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA): A federal law passed in 1980 and modified in 1986 by the Superfund Amendments and Reauthorization Act (SARA). The act created a special tax that goes into a Trust Fund, commonly known as Superfund, to investigate and clean up abandoned or uncontrolled hazardous waste sites. Under the program, EPA can either: 1) pay for site cleanup when parties responsible for the contamination cannot be located or are unwilling or unable to perform the work or 2) take legal action to force parties responsible for site contamination to clean up the site or pay back the federal government for the cost of the cleanup.

Dioxin: A man-made organic compound, used primarily as a pesticide, which has been banned for use by the Food and Drug Administration. Dioxins are considered probable human carcinogens.

Feasibility Study (FS) Report: Report that summarizes the development and analysis of remedial alternatives that EPA considers for the cleanup of Superfund sites.

Fluidized Bed Incineration: In this technology, contaminated materials are fed into a chamber and contaminants are destroyed as air is forced upward to suspend the materials. Exhaust gases are passed into a secondary chamber to complete destruction of the contaminants. Exhaust gases are treated prior to release into the atmosphere.

Ground Water: Water found beneath the earth's surface that fills pores between materials such as sand, soil, gravel, and cracks in bedrock and often serves as a principal source of drinking water.

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Infrared Incineration: In this technology, contaminated materials are fed on a conveyor belt system where the materials pass beneath a series of infrared heating elements to destroy the contaminants. Exhaust gases are passed into a secondary chamber to complete destruction of the contaminants and given final treatment prior to release into the atmosphere.

Leachate: A liquid that is formed when rain or surface water filters through a landfill or dump and comes into contact with the waste material. If leachate is not controlled, it eventually mixes with and contaminates ground water and possibly surface water.

Maximum Contaminant Levels (MCLs): The maximum permissible level of a contaminant in water that is consumed as drinking water. These levels are determined by EPA and are applicable to all public water supplies.

Monitoring Well: A well drilled to "monitor" ground water quality and movement. A well of this type does not supply water for drinking or industrial use. A sample from a monitoring well is analyzed to determine whether contaminants are present. Comparing water levels in monitoring wells shows the direction of ground water flow.

National Priorities List (NPL): EPA's list of the most serious uncontrolled or abandoned hazardous waste sites identified for possible long-term remedial action under Superfund.

Net Present Worth: The amount of money necessary to secure the promise of future payment, or series of payments, at an assumed interest rate.

Organophillic Clay: A clay material with a chemical affinity for organic materials.

Parts per Billion (ppb): A unit of measurement used to describe levels of contamination. For example, one gallon of solvent in one billion gallons of water is equal to one part per billion.

Parts per Million (ppm): A unit of measurement used to describe levels of contamination. For example, one gallon of solvent in one million gallons of water is equal is to one part per million.

Polychlorinated Biphenyls (PCBs): PCBs are a family of organic compounds used in electrical transformers, lubricants, and adhesives. PCBs are extremely persistent in the environment and do not break down into less harmful substances. EPA banned the use of PCBs in 1979. EPA has classified PCBs as probable human carcinogens based on evidence in animals and humans showing a link between PCBs and increased cancer risks.

Polynuclear Aromatic Hydrocarbons (PAHs): A class of chemicals that are used industrially in the production of automobile tires, rubber stoppers, and glass. PAHs are also often found as byproducts of the refining and combustion processes of petroleum and coal and are found


in cigarette smoke. Some PAHs have been classified by EPA as probable human carcinogens based on evidence from laboratory animals and, in some cases, human studies showing a link between PAHs and increased cancer rates.

Record of Decision (ROD): A public document that explains the cleanup alternative to be used at a National Priorities List (NPL) site. The ROD is based on information and technical analyses generated during the RI/FS and on consideration of public comments and community concerns.

Remedial Alternative: Option evaluated by EPA to address the source and/or migration of contaminants at a Superfund site to meet health based cleanup goals.

Remedial Investigation (RI): The Remedial Investigation determines the nature and extent and composition of contamination at a hazardous waste site, and directs the types of cleanup options that are developed in the FS.

Removal Action: An immediate action taken over the short-term to address a release or threatened release of hazardous substance at a hazardous waste site.

Rotary Kiln Incineration: In this technology, contaminated materials are fed into a kiln (rotating chamber) where they are mixed with air and subjected to very high temperatures to destroy contaminants. Exhaust gases from the kiln are passed into a secondary chamber to complete destruction of the contaminants. Exhaust gases are treated prior to release into the atmosphere.

Sediments: The sand or mud found at the bottom and sides of bodies of water, such as creeks, rivers, streams, lakes, swamps, and ponds. Sediments typically consist of soil, silt, clay, plant matter, and sometimes gravel.

Semi'Volatile Organic Compounds (SVOC): A type of volatile organic compound that is heavier and has a higher vapor pressure such that it does not volatilize (or evaporate) as readily as other VOCs.

Superfund: The common name given to the Comprehensive Environmental Response, Compensation, and Liability Act (1980) as amended by the Superfund Amendments and Reauthorization Act (1986).

Treatability Study: A series of small-scale experiments with various technologies used to determine the most effective process for accomplishing the cleanup of contamination at a specific hazardous waste site.

Volatile Organic Compound (VOC): A group of chemical compounds composed primarily of carbon and hydrogen that are characterized by their tendency to evaporate (or volatilize) into the air from water or soil. VOCs include substances that are contained in common solvents and cleaning fluids. Some VOCs are known to cause cancer.

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Wetlands: Areas such as marshes, bogs, and swamps that are saturated with water long enough each year to affect the type of soil and vegetation found in the area. Wetlands are federally protected because they purify water, prevent floods, feed and shelter fish and wildlife, and offer recreational opportunities.


Mailing List Additions If you or someone you know would like to be placed on the Salem Acres Superfund Site mailing list, please fill out and mail this form to:

Diane Ready Community Relations Coordinator U.S. Environmental Protection Agency Office of External Programs (RE A) JFK Federal Building Boston, Massachusetts 02203-2211 (617) 565-3425

Name:

Address:

Affiliation: Phone:

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Region I

REGION I Office of External Programs JOHN F. KENNEDY FEDERAL BUILDING John F. Kennedy Federal Building

BOSTON, MASSACHUSETTS 02203 Boston, MA 02203 ForuMding tnd AdOraas Carnation Ftsquaetod

Official Business First Class Mail Penalty for Private Use

$300 Postage and Fees Paid EPA Permit No. G-35

Inside: Salem Acres Superfund Site Proposed Plan

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