U.S. ENVIRONMENTAL PROTECTION AGENCY .^1«>'S.,

\?

ul

SUPERFUND PROPOSED PLAN

JJ Seifert Machine Shop Superfund Site Remedy for Contaminated Soils and Ground Water

Ruskin, Hillsborough County, Florida June 2013

Introduction The United States Environmental Protection Agency (EPA) invites comment on a proposed clean-up plan for the JJ Seifert Machine Shop Superfund* Site ("JJ Seifert Site" or "Site"). In particular this action addresses contaminated ground water plumes in the surficial aquifer and Upper Floridan aquifer, as well as soil contaminants on the JJ Seifert property. The Proposed Plan is a document used by EPA to facilitate public involvement in the remedy selection process at Superfund Sites. This Proposed Plan presents options evaluated by EPA for the Site and provides the rationale for EPA's preferred alternative. A Record of Decision (ROD) will be issued after the public comment period.

EPA, in consultation with the Florida Department of Environmental Protection (FDEP), will select a final remedy for the Site after reviewing and considering infonnation submitted during the public comment period. EPA in consultation with FDEP, may modify the Preferred Alternative, or select another alternative presented in the Proposed Plan based on new information or public comments. Therefore, the public is encouraged to review and comment on all the alternatives presented in the Proposed Plan. The final decision regarding the selected remedy will be documented in a ROD. EPA is issuing this Proposed Plan as part of its public participation responsibilities under Section 117(a) of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA or Superfund) and Section 300.430(f)(2) of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). This Proposed Plan summarizes information that can be found in greater detail in the remedial investigation (RI) and feasibility study (FS) reports and other relevant documents contained in the Administrative Record and Information Repositories cited below.

PUBLIC COMMENT PERIOD June 17, 2013 - July 17, 2013

U.S. EPA will accept written comments on the Proposed Plan during the public comment period.

PUBLIC MEETING As a part of the public involvement, and during this comment period, a public meeting will be held on July 11, 2013 at the following location:

G&A Stucco 4228 U.S Highway 41

Sun City, Florida, 33586 Hours: Starting at 7:00 p.m.

MORE INFORMATION The Administrative Record and Information Repositories for the JJ Seifert Site are located at:

Southshore Regional Library 15816 Beth Shields Way

Ruskin, Florida 33573-4903 (813)273-3652

Hours: Mon-Fri 8:00 a.m.-4:30 p.m. and

U.S. EPA - Region 4 Superfund Records Center

61 Forsyth St., SW Atlanta, GA 30303

800-435-9234, ext. 2-8463

* Terms first appearing in bold are defined in a glossary at the end of this fact sheet.

Site Background The JJ Seifert Site is located at 4212 Old US Highway 41 in Ruskin, Hillsborough County, Florida, in an area of mixed residential and commercial development. Figure 1 illustrates the general Site location. The property consists of one parcel covering an area of about 0.75 acre. The property is bordered by Vidor Avenue, a vacant commercial building (former Hofer Machine Shop) and residential properties to the north; by G&A Stucco and Wire Lathe Corporation to the South; by Old US Highway 41 and residential properties to the west; and Hwy 41 to the east.

Current structures on the JJ Seifert property include a metal building, the former machine shop building, and a vacant mobile home. Additionally, there are three known septic tanks and a raised drain field located near the northwestern comer of the building that is associated with two of the septic tanks.

Operational History Starting in the early 1960s, a machine shop building was constructed on the JJ Seifert Site, which was used to manufacture products such as electronic components, tools, dies, jigs and fixtures using precision machining methods for forming, shaping, cutting, drilling, honing, and lathing until early 2011.

According to former employees of JJ Seifert Machine Shop, chlorinated solvents were formerly stored and used on the property as follows:

1. Solvent storage and rinsing activities occurred near the southern end of the machine shop.

2. Drums of solvent were stored in four different areas including the dmm storage area (see Figure 1), next to the vapor degreaser, inside the metal building, and at the back of the machine shop building.

3. A Tetrachloroethene (PCE) vapor degreaser station was first located inside the southern portion of the machine shop building adjacent to the location of the former plating tanks (Vapor Degreaser Location 1 on Figure 1). At an unspecified time, the vapor degreaser was moved outside the machine shop building to a covered area (Vapor Degreaser Location 2 on Figure 1).

Investigative History Environmental investigation of the JJ Seifert Site began in February 2000, when an environmental assessment was conducted at the Site, prior to a potential real estate transaction. The results from the assessment, and

subsequent additional assessments, indicated relatively high concentrations of PCE, trichloroethene (TCE), vinyl chloride and other chlorinated volatile organic compound (VOC) degradation products in ground water wells on the facility property. PCE and TCE are considered probable human carcinogens, and vinyl chloride is a known human carcinogen.

Prompted by the results of the private environmental assessment, FDEP requested that the Hillsborough County Health Department begin sampling nearby private wells. Based on the results of the private well samples, granular activated carbon filters were installed by FDEP on five wells in use for drinking water supply that contained chlorinated VOC concentrations above federal Maximum Contaminant Levels (MCLs).

In July and August 2008, EPA conducted a Site Investigation, which confirmed the presence of contaminated ground water emanating from the JJ Seifert Site and the presence of soil contamination capable of leaching into ground water. The results from the 2008 Site Inspection (SI), and a 2009 ground water investigation led to the JJ Seifert Site being listed to the National Priorities List (NPL).

Beginning in January 2011, and extending through December, 2012, EPA contractors performed a RI to further delineate the extent of the contaminated ground water plume, as well as any possible lingering sources of soil contamination on the JJ Seifert property.

Soil Contamination Summary Based on the RI, soil contamination at the JJ Seifert Site is concentrated in two areas, the former drum storage area and near the former location of vapor degreaser #2. At the drum storage area, concentrations of PCE, cis-1,2-dichloroethene (DCE) and vinyl chloride were detected in samples collected beneath and adjacent to the concrete pad at concentrations above FDEP soil cleanup target levels (SCTLs) for leachability. Low concentrations of PCE and cis-1,2-DCE were also detected near the former location of vapor degreaser #2, but none exceeded either FDEP or EPA soil screening levels.

The metals, barium, chromium, and lead, were detected in soils directly adjacent to the southern end of the machine shop building at concentrations above applicable soil screening levels. All three metals were detected at concentrations above FDEP Residential SCTLs. Chromium was also detected at one location above FDEP Leachability SCTL.

Ground water Contamination Summary The primary ground water contaminants of concern (COCs) at the Site are chlorinated VOCs. Concentrations of PCE and its degradation products, TCE, 1,1-DCE, cis-1,2-DCE, and vinyl chloride, are present in ground water beneath and near the Site at concentrations above EPA MCLs and FDEP ground water cleanup target levels (GCTLs). Chlorinated VOCs are the constituents detected with the highest frequency at the Site and are generally the most widespread across the Site area. Other VOC constituents, including ethylbenzene, toluene, methyl tert-butyl ether (MTBE), 1,2-dichloropropane, bromodichloromethane, and chloroform, were detected at a limited number of locations at concentrations above FDEP GCTLs and^or EPA MCLs but are not believed to be related to contamination from the JJ Seifert Site.

The metals aluminum, iron, manganese, molybdenum, and vanadium were also detected in some monitoring well samples at concentrations above FDEP GCTLs. Based on the RI and previous analytical results, metals are not believed to be significant contaminants of concern in ground water at the Site.

Horizontal ground water flow and contaminant migration at the JJ Seifert Site tends toward the west and southwest, but ground water contamination has been identified east-southeast of the Site as well. A depiction of the estimated contaminated ground water plume is shown in Figure 2.

The highest concentrations of ground water contamination at the Site were generally found in the surficial sand portion, approximately 20 to 25 feet below ground surface (bgs), of the surficial aquifer. The highest concentrations of ground water contamination in the Upper Floridan aquifer are directly west of the Site, underlying the western portion of the JJ Seifert property and the residential neighborhood to the west. The Upper Floridan aquifer begins approximately 225 ft. bgs.

Remedial Activities History To date, all remedial activities have been investigatory in nature. The proposed action put forth in this document will be the first remedial action to be performed at the JJ Seifert Site.

Scope and Role of Action This proposed action for the JJ Seifert Site will be to address both the contaminated soil and ground water, and is intended to be the final clean up for the JJ Seifert Site. The soil clean up will address the potential risk for exposure to the contaminated soil and address the

remaining source material that could contribute to the underlying ground water contamination. The ground water remedy will address human exposure to contaminated ground water.

It is EPA's current judgment that the Preferred Alternative identified in this Proposed Plan, or one of the other active measures considered in the Proposed Plan, is necessary to protect public health or welfare or the environment from actual or threatened releases of hazardous substances into the environment

Summary of Site Risks Risk assessments were conducted to determine the current and future effects of contaminants on human health and the enviromnent. The area is zoned for mostly residential and light industrial use. Therefore, the risk assessment evaluated the Site for residentiaFindustrial use. For detailed information regarding risk see the following text box, What is Risk and How is it Calculated?

The Human Health Risk Assessment (HHRA) focused on health effects for adults and children, in residential and industrial settings, that could result from current and future direct contact with: (1) contaminated soil, (2) indoor air as a result of Vapor Intmsion (VI) pathways, and (3) contaminated ground water. No ecological risks were identified at the Site.

Human Health Risk Assessment

The HHRA evaluated potential exposi^e scenarios taking into account land use, exposure points, and types of receptors. Based on the data collected for this investigation, risks were calculated for industrial worker and trespasser exposure on the JJ Seifert property, and residential exposure in the surrounding neighborhood, primarily through exposure to ground water.

• The cancer risk associated with exposure to contaminated ground water exceeded the l.OE-04 cancer risk level, based on a residential exposure assumption. Specifically, exposure to the surficial aquifer indicated that the total cancer risk was l.lE-02, while the total cancer risk associated with exposure to the contaminated portions of the Upper Floridan aquifer was 2.0E-04. EPA's acceptable cancer risk range is l.OE-06 to l.OE-04.

• The non-cancer risks associated with direct exposure to ground water exceeded EPA's acceptable non-cancer target benchmarks. Specifically, the hazard index for the surficial aquifer was 395, and the hazard index for

WHAT IS RISK AND HOW IS IT CALCULATED

A Superfund human health risk assessment estimates the "baseline risk". This is an estimate of the likelihood of health problems occurring if no cleanup action were taken at the Site. To estimate the baseline risk at a Superfund Site, EPA undertakes a four-step process:

Step 1 Step 2 Step 3 Step 4

Analyze Contamination Estimate Exposure Assess Potential Health Dangers Characterize Site Risk

In Step 1, EPA looks at the concentrations of contaminants found at a Site as well as past scientific studies on the effects these contaminants have had on people (or animals, when human studies are unavailable). A comparison between Site-specific concentrations and health-based concentrations helps EPA to determine which contaminants are most likely to pose the greatest threat to human health.

In Step 2, EPA considers the different ways that people might be exposed to the contaminants identified in Step 1, the concentrations that people might be exposed to, and the potential frequency and duration of exposure. Using this information, EPA calculates a "reasonable maximum exposure" (RME) scenario, which portrays the highest level of human exposure that could reasonably be expected to occur.

In Step 3, EPA uses the information from Step 2 combined with information on the toxicity of each chemical to assess potential health risks. EPA considers two types of risk: cancer risk and non-cancer risk. The likelihood of any kind of cancer resulting from a Superfund Site is generally expressed as an upper bound probability; for example, a "1 in 10,000 chance." In other words, the exposed individual would have an excess cancer risk of 1 in 10,000 due to Site contaminants. This excess risk would be over and above the existing cancer risk for the individual. For non-cancer health effects, EPA calculates a "hazard index". The key concept here is that a "threshold level" (measured usually as a hazard index of less than 1) exists below which non-cancer health effects are not expected.

In Step 4, EPA determines whether Site risks are excessive for people at or near the Superfund Site. The results of the three previous steps are combined, evaluated, and summarized. EPA adds up the potential risks for each receptor.

exposure to the contaminated portions of the Upper Floridan aquifer was 19, assuming residential exposure. EPA's acceptable non-cancer benchmark is a hazard index of 1.

• Exposures to Site soils (chromium and lead) indicate a cancer risk that is greater than the EPA risk threshold for the hypothetical future residents. Specifically, the hypothetical future resident would have a total cancer risk from Site soils of 5.1E-04. It should be noted that chromium in soil was assumed to be entirely in the hexavalent state, which is very unhkely.

• Sampling of soil vapor on and near the Site indicates that organic vapor intrusion into onSite and nearby buildings is not occurring and therefore there is no risk associated with this pathway at the JJ Seifert Site.

• Worker and trespasser risks associated with exposures to Site soils were below the EPA cancer and non-cancer risk thresholds.

Ecological Risk Assessment No ecological risks were identified at the Site, based upon the observation that no substantial ecological habitats are present at the Site. As a result, the exposure pathway for ecological receptors is incomplete. If Site conditions change in the future so that Site-related contamination becomes accessible to ecological receptors, an assessment of ecological risk will be considered.

Remedial Action Objectives (RAOs) The RAOs provide overall goals to guide the selection and implementation of remedial alternatives. In general, the RAOs are to prevent current and future exposure to contaminated soil and ground water and to permanently reduce the toxicity, mobility, and volume of Site contaminants of concern (COCs). This action will be the final action for the Site.

Soil RAOs:

• Prevent human exposure to surface and subsurface soil with concentrations of COCs above levels that are protective of residential and industrial use.

• Prevent migration of COCs to ground water to levels that are protective of beneficial use (drinking water use).

Ground Water RAOs:

• Prevent human exposure (ingestion, direct contact, and inhalation) to COCs in ground

water to levels that are protective of residential and industrial use.

• Restore ground water to levels that allow beneficial use (drinking water standards).

It is EPA's current judgment that the Preferred Alternative identified in the Proposed Plan, or one of the other active measures considered in the Proposed Plan, is necessary to protect the public health, welfare, or the environment from actual or threatened releases of hazardous substances into the environment.

The primary applicable or relevant and appropriate requirements (ARARs) for the ground water at this Site are the federal and state drinking water standards determined for each COC. The more stringent of the two will be used as the basis for the ground water cleanup levels. For the soil, state SCTLs are applicable and the SCTLs derived for the leachability to ground water will be used as the basis for the soil clean-up levels.

Cleanup Levels Cleanup levels are concentrations of contaminants in environmental media that, when attained, are protective and achieve RAOs. Cleanup levels are established to protect human receptors from adverse health effects, protect the enviromnent from detrimental impacts, and comply with federal and state ARARs.

The following tables indicate the cleanup levels for soil and ground water, and highlight the concentration ranges found at the JJ Seifert Site, and the criteria for selecting the cleanup level. Cells shaded in gray indicate the basis for determining final cleanup levels.

Soil C 'on taminants of C o n c e r n CTeanup Levels |

Soil Contaminant of Concern

retrachloroethene

cis-1,2-Dichloroethene

Vinyl Chloride

Barium

Chromium

Lead

Contaminant Concentration Range (mg/kg)

0 - 0.36

0-0.63

0-0.008

0 - 450

0-290

0 -450

FDEP Residential Soil Cleanup Target Level (mg/I^)

8.8

33

0.2

120

210

400

FDEP [ndustrial Soil Cleanup Target Level (mg/kg)

18

180

0.8

L30,000

470

1,400

FDEP Leachability Soil Cleanup Target Level (mg/kg)

0.03

0.4

0.007

1,600

38

N/A

Soil Cleanup Level (mg/I^)

0.03

0.4

0.OO7

120

38

400

G r o u n d W a t e r C o n t a m i n a n t s of C'oncern C l e a n u p Levels

GW Contaminant of Concern

Tetrachloroethene

Trichloroethene

cis-1,2-Dichloroethene

1,1 -Dichloroethene

Vinyl Chloride

Contaminant Concentration Range (^g/L)

0 - 17,000

0 - 2,300

0 - 3,400

0-38

0-780

EPA Maximum Contaminant Level (Mg/L)

5

5

70

7

2

FDEP Groundwater Cleanup Target Level (^ig/L)

3

3

70

7

1

Ground Water Cleanup Level (Hg^)

3

3

70

7

1

Introduction to Alternatives For the purposes of screening remedial alternatives during the FS, contamination at the JJ Seifert Site was evaluated based upon the affected media. Soil contamination was evaluated along with the ground water alternative evaluations.

Remedial alternatives for soils were created by combining several different remedial components, such as excavation, soil capping, or targeted treatment of contamination within the soil. Based upon the reviewed components the most viable options were evaluated further. These alternatives are described below in the 'Soil Alternatives' portion ofthis document.

Similarly, remedial alternatives for ground water involved combining several different remedial components. These components included active treatment of the ground water plume, passive treatment of the ground water plume, i.e. monitored natural attenuation (MNA), supplying alternative drinking water, and treating affected residential wells. As with the soil alternatives, the most viable combination of remedial components were evaluated further, and are described below in the 'Ground water Alternatives' portion ofthis document.

Monitored Natural Attenuation MNA is a remedial alternative that utilizes natural physical, chemical, and biological processes (i.e. natural attenuation) to restore ground water to drinking water use.

At the JJ Seifert Site, there are several lines of evidence that MNA is occurring. Specifically, the presence of breakdown products of PCE indicates that PCE is naturally degrading in the environment. Additionally, geochemical properties within the aquifer are conducive to the natural attenuation of chlorinated solvents at the Site. Favorable geochemistry includes the presence of low dissolved oxygen, the presence of a carbon source, and low concentrations of competing electron acceptors. These factors indicate that natural attenuation can occur at the Site. Further information pertaining to MNA may be found in the FS.

Soil Alternatives Alternative S-1: No Action Estimated Capital Cost: SO Estimated Net Present Worth O&M Cost: $0 Estimated Net Present Worth Cost: $0 Time to Construct: Nothing to construct The Superfund program requires the consideration of a No Action alternative to serve as a baseline comparison. Under this alternative EPA would take no action at the

Site to remediate or prevent the exposure to ground water contamination.

Alternative S-2A: Excavation, Off-Site Disposal, and ICs Estimated Capital Cost: $301,000 Estimated Net Present Worth O&M Cost: $94,000 Estimated Net Present Worth Cost: $395,000 Time to Construct: 3 months This alternative is a combination of excavation and disposal for soil containing Site COCs at concentrations above both FDEP residential and/or leachability SCTLs to a maximum depth of the water table. The excavated soil would be transported off Site for disposal in an approved landfill. Institutional Controls (ICs) would be required to address soil contamination (if found to be present beneath the building). Approximately 489 cubic yards would be excavated, characterized, and disposed of in an appropriate Resource Conservation and Recovery Act (RCRA) permitted landfill.

Alternative S-2B: Excavation, Off-Site Disposal, and ICs Estimated Capital Cost: $287,000 Estimated Net Present Worth O&M Cost: $94,000 Estimated Net Present Worth Cost: $381,000 Time to Construct: 3 months This alternative is a combination of excavation and disposal for soils near the drum storage pad containing VOC concentrations above FDEP leachability SCTLS to a maximum depth of the water table. The excavated soil would be transported off Site for disposal in an approved landfill. Soils with metals above FDEP residential SCTLs along the southern machine shop perimeter would be addressed using ICs to prohibit future residential use of the property. Approximately 456 cubic yards would be excavated, characterized, and disposed of in an appropriate RCRA permitted landfill.

Alternative S-3: Excavation, Off-Site Disposal, Capping, and ICs Estimated Capital Cost: $297,000 Estimated Net Present Worth O&M Cost: $102,000 Estimated Net Present Worth Cost: $399,000 Time to Construct: 4 months This alternative would excavate and remove contaminated soils near the dmm storage pad containing VOCs above FDEP leachability SCTLs to a maximum depth of the water table. The excavated soil would be transported off Site for disposal in an approved landfill. Soils along the southern perimeter of the machine shop building containing metals above FDEP residential and leachability SCTLs would be capped with impervious pavement to prevent human exposure and leaching to ground water. ICs would be required for the capped

areas to maintain the cap and prevent any unauthorized use of the soil. Approximately 456 cubic yards would be excavated, characterized, and disposed of in an appropriate RCRA permitted landfill. The installation of the cap over the southern perimeter of the machine shop will be constructed as a RCRA hazardous waste landfill cover.

Ground water Alternatives Alternative GW-1: No Action with Continued Wellhead Treatment Estimated Capital Cost: $0 Estimated Net Present Worth O&M Cost: $0 Estimated Net Present Worth Cost: $0 Time to Construct: Nothing to construct The Superfund program requires the consideration of a No Action alternative to serve as a baseline comparison. Under this alternative EPA would take no action at the Site to remediate or prevent the exposure to ground water contamination.

Alternative GW-2: Wellhead Treatment, MNA, and ICs Estimated Capital Cost: $235,000 Estimated Net Present Worth O&M Cost: $2,726,000 Estimated Net Present Worth Cost: $2,961,000 Time to Construct: 2 months This alternative would provide for the installation and maintenance of granular activated carbon (GAC) filters for wellhead treatment on water supply wells within the area that exceed COC concentrations above Federal MCLs and/or FDEP GCTLs. MNA would be implemented in the surficial and Upper Floridan aquifers. ICs would be implemented to prevent installation of new water supply wells within the contaminated ground water plume area.

Alternative GW-3A: W ellhead Treatment, ISEB, MNA, and ICs Estimated Capital Cost: $1, 735,000 Estimated Net Present Worth O&M Cost: $2,181,000 Estimated Net Present Worth Cost: $3,916,000 Time to Construct: 6 months This alternative would include the installation and maintenance of GAC filters for wellhead treatment on water supply wells within the area that exceed COC concentrations above Federal MCLs and/or FDEP GCTLs. Ground water in the surficial aquifer would be treated using In-Situ Enhanced Bioremediation (ISEB) and MNA would be implemented for the Upper Floridan aquifer. ISEB is a remedial technology that provides a carbon source, necessary for the degradation of the chlorinated solvents in ground water. Essentially, ISEB consists of the use of emulsified oil, which is injected into the ground water, to enhance the natural

biodegradation of contaminants. The injection of the emulsified oil will be diluted prior to injection. ICs would also be implemented to regulate installation of new water supply wells within the ground water plume area.

Alternative GW-3B: Wellhead Treatment, ISEB, MNA, and ICs Estimated Capital Cost: $2,238,000 Estimated Net Present Worth O&M Cost: $2,181,000 Estimated Net Present Worth Cost: $4,419,000 Time to Construct: 8 months This alternative would provide for the installation and maintenance of GAC filters for wellhead treatment on water supply wells within the area that exceed COC concentrations above Federal MCLs and/or FDEP GCTLs. The areas of highest ground water COC concentrations in the surficial aquifer and the Upper Floridan aquifer would be treated with ISEB to reduce COCs to below cleanup levels. MNA would be implemented for untreated areas of the surficial aquifer and the Upper Floridan aquifer to monitor reduction of COC concentrations by natural processes. ICs would be implemented to regulate installation of new water supply wells within the plume area.

Alternative GW-4: Alternative Drinking Water supply, MNA, and ICs Estimated Capital Cost: $4,139,000 Estimated Net Present Worth O&M Cost: $1,964,000 Estimated Net Present Worth Cost: $6,103,000 Time to Construct: 12 months This alternative would extend the existing Hillsborough County public drinking system to residents in the vicinity of the Site. MNA would be implemented in the surficial and Upper Floridan aquifers. ICs would be implemented to prohibit use of ground water for drinking water supply.

Alternative GW-5: Alternative Drinking Water Supply, ISEB, MNA, and ICs Estimated Capital Cost: $5,5 77,000 Estimated Net Present Worth O&M Cost: $1,589,000 Estimated Net Present Worth Cost: $7,166,000 Time to Construct: 12 months This alternative would provide alternative drinking water supply to the vicinity of the Site by extension of the Hillsborough County public drinking water system. Ground water in the surficial aquifer would be treated using ISEB and MNA would be implemented for the Upper Floridan aquifer. ICs would be implemented to prohibit use of ground water for drinking water supply.

Nine Criteria for Alternative Evaluation When selecting a remedial alternative, EPA evaluates alternatives based upon nine criteria. The nine criteria fall into three groups: threshold criteria, primary balancing criteria, and modifying criteria.

EPA's recommended clean-up alternative is one that meets both of the threshold criteria, and has the best balance amongst the five balancing criteria. After seeking concurrence from the State of Florida and considering public comment, EPA will determine state and community acceptance and may modify the preferred alternative accordingly.

A brief evaluation using these criteria is provided below, and is further discussed in the FS. Definitions for each criterion are provided on the left.

Soil Alternatives Comparison Overall Protectiveness of Human Health and the Environment S-1 would not be protective while S-2A, S-2B, and S-3 would be protective. Each of these three soil alternatives would excavate and remove soils near the drum storage pad, but differ in how they address metal concentrations along the southern machine shop perimeter. Alternative S-2A would be the most protective because it would clean up soils to residential levels, while S-2B and S-3 would leave contaminated soils on Site.

Compliance with ARARs S-1 would not comply with the chemical-specific ARARs, and action-specific ARARs do not apply since no action will be taken. S-2A would comply with the chemical-, location-, and action-specific ARARs. S-2B and S-3 would comply with location- and action-specific ARARs, but would not comply with the chemical-specific ARARs.

Long-term Effectiveness and Permanence S-1 would not be effective in the long term and offers no permanent solution. S-2A, S-2B, and S-3 would offer different degrees of long-tenn effectiveness and permanence. S-2A would have the greatest long-term effectiveness and permanence, while S-3 would have greater long-term effectiveness and permanence, since contaminated soils would be capped.

Reduction of Toxicity, Mobility, or Volume of Contaminants through Treatment None of the soil alternatives would involve the use of treatment in addressing contaminated soils. However, Each would reduce toxicity, mobility, and volume of contaminants to varying degrees, with the exception of

S-1. S-2A would achieve the greatest reductions, followed by S-3, then S-2B, and lastly S-1.

Short-term Effectiveness S-1 would not have any short term effects while S2-A, S2-B, and S-3 would all be equally effective during the implementation of the alternative with respect to the community, workers, and/or the enviromnent.

Implementability S-1 would be the easiest to implement, as there is nothing to implement, while S-2A, S-2B, and S-3 would be equally implementable.

Cost The costs outlined in the following table reflect the initial capital required to fund construction activities for each given remedy. The 30-yr Net Present Worth (NPW) of Operation and Maintenance (O&M) activities represents the dollar amount that would need to be set aside at the present time to fund O&M activities for the next thirty years, growing at an annual interest rate of 7%. The 30-yr NPW of the alternative is the summation of both the capital costs of constmction as well as the 30-yr NPW for O&M activities.

Cost of Ground Water Remedial Alternatives Alternative

S-1 S-2A S-2B S-3

Capital (S) 0

301,000 287,000 297,000

30-yr NPW of O&M (S)

0 94,000 94,000 102,000

30-yr NPW of Alternative ($)

0 395,000 381,000 399,000

State/Support Agency Acceptance The FDEP supports the Preferred Alternative.

Community Acceptance Community acceptance of the preferred alternative will be evaluated after the public comment period and will be described in the ROD for the Site.

Ground water Alternatives Comparison Overall Protectiveness of Human Health and the Environment GW-1 would not be protective since there will be no actions to address the risk posed by contaminated ground water. GW-5, GW-4, GW-3B, GW-3 A, and GW-2 would be protective, as they all achieve cleanup levels that are protective. GW-5 would be the most protective since it provides a permanent alternate water supply, treats surflcial aquifer contamination and controls ground water use. GW-4 would be slightly less protective that GW-5 but would be more protective than GW-3B. GW-3B is less protective than GW-4 and GW-

5 since treatment systems are being placed on individual drinking water systems, which require long term maintenance and is less reliable in ensuring protectiveness, and is more protective than GW-3A and GW-2, since it will achieve clean-up levels quicker in the Upper Floridan aquifer.

Compliance with ARARs GW-1 would not comply with the chemical-specific ARARs and action-specific ARARs do not apply since no action would be taken. GW-2, GW-3A, GW-3B, GW-4, and GW-5 would all achieve action-, location-, and chemical-specific ARARs.

Long-term Effectiveness and Permanence GW-1 would be neither effective nor permanent, while GW-5, GW-3B. GW-3A, GW-4, and GW-2 would be effective and permanent, in order of descending long-term effectiveness and permanence. GW-5 would be the most effective and pennanent through providing alternative water supply, treating the surficial aquifer, and controlling ground water use. GW-3B would be less permanent than GW-5 and GW-4 since alternative drinking water supply is not provided, but more effective than GW-5, GW-3A, GW-4, and GW-2, since it treats both the surficial and Upper Floridan aquifers. GW-4 would be less effective and permanent than GW-3B and GW-3 A since no treatment of either of the aquifers will occur, but will be more permanent than GW-2 through providing permanent alternative drinking water supply. GW-2 would be least effective and permanent since no treatment of contamination would occur, and no permanent alternative drinking water would be provided.

CRITERIA FOR EVALUATING ALTERNATIVES

In selecting a preferred cleanup alternative, EPA

uses the following criteria to evaluate those screened in

the FS. All nine criteria are explained in more detail

here.

Threshold Criteria:

1. Overall Protection of Human Health and the

Environment - Eliminates, reduces, or controls

health and environmental threats through

institutional or engineering controls or

treatment.

2. Compliance with Applicable or Relevant and

Appropriate Requirements (ARARs) -

Compliance with Federal/State standards and

requirements that pertain to the Site or whether

a waiver is justified.

Primary Balancing Criteria:

3. Implementability - Technical feasibility and

administrative ease of conducting a remedy,

including factors such as availability of

services.

4. Short-Term Effectiveness - Length of time to

achieve protection and potential impact of

implementation.

5. Long-Term Effectiveness and Permanence -

Protection of people and environment after

cleanup is complete.

6. Reduce Toxicity, Mobility, or Volume by

Treatment - Evaluates the alternative's use of

treatment to reduce the harmful effects of

principal contaminants and their ability to move

in the environment.

7. Cost - Benefits weighed against cost.

Modifying Criteria:

8. State Acceptance - Consideration of state's

opinion of the preferred alternative(s).

9. Community Acceptance - Consideration of

public comments on the Proposed Plan.

Reduction of Toxicity, Mobility, or Volume of Contaminants through Treatment GW-1, GW-2, and GW-4 would not treat contaminants in ground water. GW-3B would treat the largest volume of contaminants by treating both the surficial and Upper Floridan aquifers, while GW-3A and GW-5 would only treat the surficial aquifer.

Short-term Effectiveness GW-1 would have no short-term effects, and would likely never reach protectiveness of human health and the environment. Similarly, GW-2 would have minimal short-term effects. GW-5 and GW-4 would both have the greatest amount of short-term effects due to the water line extension. GW-5, GW-3B, and GW-3A would each reduce the time to reach clean-up goals, with GW-3B reaching clean-up goals the quickest.

Implementability GW-1 would be the easiest to implement, as there is nothing to implement. GW-2, GW-3A, GW-3B, GW-4, and GW-5 would all be implementable, in order of descending ease of implementability. GW-5 would be the most difficult to implement due to the construction of a water line extension coupled with the use of ISEB. GW-4 would also involve the construction of a water line, but would not employ ISEB. GW-3B would not involve the construction of a water line, but would involve treating the Upper Floridan aquifer in addition to the shallow aquifer, which is what would occur with GW-3A. GW-2 would be the easiest to implement, as it would not involve the use of ISEB or the construction of a water line extension.

Cost The costs outlined in the following table reflect the initial capital required to fund construction activities for each given remedy. The 30-yr Net Present Worth (NPW) of Operation and Maintenance (0»&M) activities represents the dollar amount that would need to be set aside at the present time to fund O&M activities for the next thirty years, growing at an annual interest rate of 7%. The 30-yr NPW of the alternative is the summation of both the capital costs of construction as well as the 30-yr NPW for O&M activities.

Cost of Soil Remedial Alternatives Alternative

GW-1 GW-2 GW-3 A GW-3B GW-4 GW-5

Capital (S) 0

235,000 1,735,000 2,238,000 4,139,000 5,577,000

30-yrNPW ofO&M($)

0 2,726,000 2,181,000 2,181,000 1,964,000 1,589,000

30-yr NPW of Alternative ($)

0 2,961,000 3,916,000 4,419,000 6,103,000 7,166,000

State/Support Agency Acceptance The FDEP supports the Preferred Alternative of S-2B andGW-3B.

Community Acceptance Community acceptance of the preferred alternative will be evaluated after the public comment period and will be described in the ROD for the Site.

Institutional Controls ICs for the JJ Seifert Site are an essential component of the overall Site remedial strategy for the protection of human health and are necessary to prevent ground water usage within the contaminant plume until cleanup levels are met. Institutional controls include the use of restrictive covenants, zoning restrictions, and coordination with permitting authorities for well construction.

Principal Threat Waste The NCP establishes an expectation that EPA will use treatment to address the principal threats posed by a Site wherever practicable (NCP Section 300.430(a)(l)(iii)(A)). The "principal threat" concept is applied to characterization of "source materials" at a Superfund Site. A source material is material that includes or contains hazardous substances, pollutants or contaminants that act as a reservoir for migration of contamination to ground water, surface water or air, or acts as a source for direct exposure. Contaminated ground water generally is not considered to be a source material; however Non-Aqueous Phase Liquids (NAPLs) in ground water may be viewed as source material.

Principal threat wastes are those source materials considered to be highly toxic or highly mobile that generally cannot be reliably contained, or would present a significant risk to human health or the environment should exposure occur. The decision to treat these wastes is made on a Site-specific basis through a detailed analysis of the alternatives using the nine remedy selection criteria. This analysis provides a basis for making a statutory finding that the remedy employs treatment as a principal element.

Principal threat wastes have not been found on the JJ Seifert property. Contaminant levels found in ground water are not indicative of the presence of NAPL.

EPA'S Preferred Alternative EPA's preferred alternative consists of using alternative S-2A for the soils portion of the Site, and alternative GW-3B for the ground water portion of the Site.

10

Specifically, the Preferred Alternative will consist of the following elements:

Soil Alternative S-2A: • Excavation of all COCs above the water table • Off Site Disposal of excavated soils • Institutional Controls for contaminants below

the water table.

Ground water Alternative GW-3B: • Continued Wellhead Treatment • In-Situ Enhanced Bioremediation of Surficial

Aquifer • In-Situ Enhanced Bioremediation of Upper

Floridan Aquifer • Monitored Natural Attenuation

As highlighted throughout this Proposed Plan, the Preferred Alternative can change in response to public comment or new information. However, based on information currently available, the lead agency believes the Preferred Alternative meets the threshold criteria and provides the best balance of tradeoffs among the other alternatives with respect to the balancing and modifying criteria. EPA expects the Preferred Alternative to satisfy the following statutory requirements of CERCLA §121(b), namely to: 1) be protective of human health and the environment; 2) comply with ARARs (or justify a waiver); 3) be cost effective; 4) utilize permanent solutions and alternative treatment technologies or resource recovery technologies to the maximum extent practicable; and 5) satisfy the preference for treatment as a principal element (or justify not meeting the preference).

11

GLOSSARY

Administrative Record: Material documenting EPA's selection of clean-up remedies at Superfund Sites, usually placed in the information repository near the Site.

Applicable or Relevant and Appropriate Requirements (ARARs): Refers to Federal and State requirements a selected remedy must attain which vary from Site to Site.

Aquifer: An underground layer of water-bearing permeable rock or unconsolidated materials (gravel, sand, silt, or clay) from which ground water can be usefully extracted using a water well.

Below Ground Surface (bgs): Below ground surface, used to indicate depth below ground.

Comprehensive Environmental Response, Compensation and Liability Act (CERCLA): Also known as Superfund, is a federal law passed in 1980 and modified in 1986 by the Superfund Amendments and Reauthorization Act (SARA). The act created a trust fund, to investigate and clean up abandoned or uncontrolled hazardous waste Sites.

Chemical of Concern (COC): COCs are identified in the Feasibility Study and are the contaminants that are to be addressed for a given remedial action.

Daughter Products: A compound that results directly from the biodegradation of another. For example, cis-1,2-dichloroethene (cis-1,2-DCE) is a daughter product of trichloroethene (TCE).

Dichloroethene (DCE): A chlorinated hydrocarbon which is the second breakdown product of PCE.

Feasibility Study (FS): Study conducted after the Remedial Investigation to determine what alternatives or technologies could be applicable to the Site-specific COCs.

Ground Water (GW): Water located beneath the ground surface in soil pore spaces and in the fractures of lithologic formations.

Human Carcinogen: A human carcinogen is any substance, radionuclide, or radiant that is an agent directly involved in causing cancer in humans.

Hydraulic Containment: Containment of a certain volume of ground water in an aquifer using hydraulic means, such as extraction wells.

In Situ: In its original place; unmoved unexcavated; remaining at the Site or in the subsurface.

In-Situ Enhance Bioremediation (ISEB): A remediation technology that promotes naturally occurring degradation of contaminants, often used to treat chlorinated solvents. This technology works by enhancing environmental factors, which are promote natural degradation of contaminants.

Information Repository: A library or other location where documents and data related to a Superfund project is placed to allow public access to the material.

Institutional Controls (ICs): Restrictions that limit exposure to contaminated media. The restriction could be implemented as a "deed restriction" and is designed to prevent harm to workers or potential residential development.

Maximum Contaminant Level (MCL): The maximum permissible level of a contaminant in water delivered to any user of a public system. MCLs are enforceable standards.

Methyl tert-butyl ether (MTBE): An organic compound that is commonly used as a gasoline additive to raise the octane number

Monitored Natural Attenuation (MNA): This term refers to the reliance on natural attenuation processes to achieve Site-specific remediation objectives. The natural attenuation processes that are at work in a remediation approach include a variety of physical, chemical, or biological processes that, under favorable conditions, act without human intervention to reduce the mass, toxicity, mobility, volume, or concentration of contaminants in soil or ground water.

Monitoring: The periodic or continuous surveillance or testing to determine fhe level of pollutants in various environmental media.

Ground water Cleanup Target Level (GCTL): State of Florida's promulgated cleanup levels for a specific contaminant in ground water.

Hexavalent Chromium: Refers to chemical compounds that contain the element chromium in the +6 oxidation sate.

Monitoring WeU: A well drilled at or near a hazardous waste management facility or a Superfund Site to collect ground water samples for the purpose of physical, chemical, or biological analysis to determine the amounts, types, and distribution of contaminants in the ground water beneath the Site.

Human Health Risk Assessment (HHRA): A qualitative and quantitative evaluation performed to define the risk posed to human health by the presence or potential presence and use of specific pollutants.

National Contingency Plan (NCP): The NCP is the federal government's blueprint for responding to both oil spills and hazardous substance releases. The National Contingency Plan is the result of our country's efforts to develop a national response capability and promote overall coordination among the hierarchy of responders and contingency plans.

12

National Priorities List (NPL): The NPL is a list of national priorities among the known releases or threatened releases of hazardous substances, pollutants, or contaminants throughout the United States and its territories. The NPL is intended primarily to guide the EPA in determining which Sites warrant further investigation.

Non-Aqueous Phase Liquid (NAPL): Water-immiscible organic liquids with a density greater than that of water at ambient temperature and pressure.

Plume: A visible or measurable discharge of a contaminant from a given point of origin.

Preferred Alternative: The Preferred Alternative is the remedial alternative that has been selected, as the alternative that best meets the nine criteria for remedial alternative evaluations.

Soil Cleanup Target Level (SCTL): State of Florida's promulgated cleanup target levels for a specific contaminant in soils.

Substrate: 1) The base on which an organism lives. 2) A reactant in a microbial respiration reaction (electron donor).

Superfund: The common name used for the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA), as amended in 1986 and the EPA activities implementing the Act.

Volatilization: To make volatile; cause to pass off as vapor.

Tetrachloroethene (PCE): Also known as perchloroethene, is a chlorinated hydrocarbon, which is commonly used in dry cleaning operations and previously used as an industrial solvent.

Principal Threat Wastes: Source materials considered to be highly toxic or highly mobile that generally cannot be reliably contained or would present a significant risk to human health or the environment should exposure occur.

Proposed Plan: Superfund public participation fact sheet that summarizes the preferred clean-up strategy and the rationale for its selection. The Proposed Plan also provides a summary oftheRI/FS.

Trichloroethene (TCE): A chlorinated hydrocarbon commonly used as an industrial solvent. TCE is the first breakdown product of PCE.

Volatile Organic Compound (VOC): Any organic compound that participates in atmospheric photochemical reactions except those designated by EPA as having negligible photochemical reactivity.

Record of Decision (ROD): A public document describing which clean-up altemative(s) will be used at National Priorities List Sites. The ROD is based on information and technical analysis generated during the RI/FS and consideration of pubhc comments.

Reasonable Maximum Exposure (RME): A RME is an exposure scenario which portrays the highest level of human exposure that could reasonably be expected to occur.

Resource Conservation and Recovery Act (RCRA): Enacted in 1976, RCRA is the principal federal law in the United States governing the disposal of solid waste and hazardous waste

Remedial Action Objectives (RAOs): Specific goals for protecting human health and the environment.

Remedial Investigation (RI): An investigation conducted to fully assess the nature and extent of the release, or threat of release, of hazardous substances, pollutants, or contaminants. The Rl gathers the necessary data to support the corresponding FS.

Site Inspection (SI): The SI is a part of the Superfund process that occurs prior to a Site being listed to the NPL. It involves collecting data to demonstrate whether a Site poses a risk to human health and the environment.

13

Figure 1 JJ Seifert Site Location and Layout

14

Figure 2 Surficial Ground Water Plume for Total VOC

Legend

n

i • _ _ _; J J. Seifert Profielv

Sample Locations

I 1 1 1 1

0 too ajQ a x «B WJTS3 Floiiaa Staip PBn* mea Ft

J.S S t l t * r t y * c h l r * Shiip US B*ALD* FUJ00O41Q232 Ruriijri, HNcbMougt iCojnty

Florida

Fi'gurft5-2 Hor i zon t ^ Er fB i t o l Totd

Chlof<nBt»d VOCs> W uflf l . i n SuFficisI Aquifer

/ T V T \ IM.WALIXR

15

USE THIS SPACE TO WRITE YOUR COMMENTS

Your input on the Proposed Plan for the J J Seifert Machine Shop Superfund Site is important in helping EPA select a remedy for the Site. You may use the space below to write your comments, then fold and mail. A response to your comment will be included in the Responsiveness Summary.

16

J J Seifert Machine Shop Superfund Site

PUBLIC COMMENT SHEET

Name Address, City State _Zip_

Atlanta, GA 30303

James Hou, Remedial Project Manager U. S. EPA, Region 4 Superfiind Remedial Branch Superfund Division 61 Forsyth St., SW