^^'"_:% U.S. ENVIRONMENTAL PROTECTION AGENCY ISS i Superfund Explanation of Significant Differences %p«o^%/ Eoambia Wood Treating Company Superfund Site Pensaco/a, Escambia County,

Pensacola, Escambia Coimly, Florida Mardi 2012

to these components do not fiuidainenraily alter the This fact sheet is being issued to document overall cleanup approach. The objective of controlling technical changes made during the Superfund human exposure remains unclianged and has been cleanup at the Escambia Wood Treating achieved by the cleanup, Company Superfund Site in Pensacola Florida. EPA made these changes because the Tliis ESD is being issued as part of EPA's public conditions found during coastmction differed participation responsibilities under Section 13 7(c) of the from the conditions known when the Record of Comprehensive EnvinmmenE^il Response, Compensation Decision was signed. When a Remedial Action and Liability Act (CERCLA), as amended by the is adjusted. EPA documents the decision in an Superfund Amendments and Reauthorization Act ''Explanation of Significant Differ^nces". (SARA). 42 U.S.C. §§ 9601 el seq.. and Section 300,435(e)(2)(i) of the National Contingency Plan Introduction (NCP),40C,F,R.Part300.

The U.S. Environmental Protection Agency (EPA) is This FSD will become part of the Administrative Record conducting a remedial action for the soils portion of in accordance with 40 C.F.R, ij 300.825(a)(2) of the Operable Unit 1 (OUl) at the Escambia Wood Treating NCP. The Administrative Record contains documents CompaEiy (ETC) Superfund Site (Site) located in used as the ha.sis for the remedy selected for the Sile, Pensacola. Florida. The EPA issued a Record of including the ROD and Responsiveness Summary. The Decision (ROD) for this remedy ga February 2, 2006. Adminisirative Record documents are available for and began remtdiai constnjction in August 2007. The public review in the ETC Site information repository overall cleanup approach is to treat principal threat located at llie following locations: wastes tKrough soliditicaiion/siabili7.ution and lo permanenlly isolate conlaminalcd soil in an on-site AdmJDistr^iii^e Record and l&focitiatifin RepositorJ<^$ conlainmenl cell. As of July 2010. ihe consiruciion of for the ETC Superfiind Site the cell was complele. Ag of February 2012, the remaining ROD requirements are closeout items, such as West Florida Regional U.S. EPA - Reiiicin 4 dewatering the cell, institutional controls and deed LibrdTv Genealogy Branch Supedund Records restrictions. The EPA carried out ihis cleanup llwougli a 5740 N. Ninth Ave Center partuership wifli the Fiorida Department of Pensacola. Fl 32504 6!FoRtyihSUSW Ai3ania.GA 30303 Environmeiital Protection, which provided teclmical support and 10% of Remedial Action costs. Site History

This ExpJana!ion of Significant Differences (ESD) The Site is located al 3910 North Palafox. Street in the explains changes to Llie cleanup goals and to City of Pensacola, Florida. Operable Unit I refers lo construction details specified in tlie ROD, The changes contaminated soils and includes the fonner ETC facihty area, which covers 26 acres, plus about 69 acres of In October 1991, EPA began a removal action to address surrounding neighborhoods purchased by the EPA, immediate risks of exposure and to stabilize the Site. which increases the total area of OUl to approximately EPA excavated about 225,000 cubic yards of 100 acres. contaminated material and stored it under a 60-mil (1.5 millimeters [mm]), High Density Polyethylene (HDPE) The ETC facility manufactured pressure-treated wood liner treated to be resistant to ultraviolet light. The products, primarily utility poles and foundation pilings. former process area and a fomier wastewater From 1942 to approximately 1970, coal-tar was pond/landtlll were excavated to approximately 40 feet the primary wood preservative. Starting in 1963, deep. The removal action was completed in 1992. Pentachlorophenol (PCP) dissolved in No. 6 diesel fuel was also used at the facility and was the sole EPA proposed the Site for inclusion on the National preservative in use from 1970 until 1982 when the Priorities List (NPL) in August 1994 and the listing on facility closed. In 1991, ETC tded for bankruptcy and the NPL was finalized on December 16. 1994. Cleanup abandoned the Site. The company defaulted on its actions were divided into two Operable Units; OUl environmentalliabilities, and the case was referred to the addresses soil contamination and OU2 addresses Department of Justice (DoJ) lo pursue settlement with contaminated ground water. the owners. DoJ reached a final settlement with the owners in 2002. In 1997, an biterim ROD was issued, selecting permanent relocation of 358 households from the The primary wastes managed at the facility were process neighborhoods north of the facility (Rosewood Terrace, wastewater and contaminated runoff from the former Oak Park, and Escambia Arms) and the Goulding treatment area. From the mid-1940s tlirough the mid- (Hennan and Pearl Streets) neighborhoods south of the 1950s, wastewater was sent to an unlined pond located site. The relocation was carried out as part of the in the northeastern part of the Site. After the mid-1950s, National Relocation Pilot Project. The relocation this pond was used as a landfill and process wastewater occurred from November 1997 to August 2005. The and contaminated runoff were managed by two separate Clarinda Triangle neighborhood was added to the systems. hiterim Remedy in the 2006 Final OUl ROD. The relocation of the residents in the Clarinda Triangle area Previous EPA Actions occurred from December 2006 to 2009. In total, more than 400 households and about 500 people were Starting in 1982, EPA and Ihe State of Florida cited the relocated, and about 70 acres of land was acquired by the ETC facility for numerous violations, including Federal Government. uncontrolled ground water contamination and inadequate financial assurance under hazardous waste regulations. OUl Final Remedial Action In June 1990, EPA conducted a Facility Assessment at the ETC facility to verify the fmdings of an earlier tile The 2006 Final OUl ROD presented the final remedy review, to assess the release or the potential for release for the contaminated soils. The overall cleanup strategy of hazardous wastes or constituents from the facility, and for the OU-1 final remedy is to treat principal tlireat to assess if further action was needed. The assessment wastes tlirough solidificationy stabilization and to identified 32 permanently isolate soil contaminated above the selected Solid Waste Management Units (SWMUs) and cleanup levels in an on-site contaimnent system in order recommended the entire facility be treated as an Area of to protect both human and ecological receptors. The Concern (AOC). The site was uncontrolled, and there major components of the Remedy include: were immediate pathways of exposure to open waste pits, contaminated soil, and chemical drums. • E.xcavation of contaminated soil on- and off-site; In response to the bankruptcy of ETC and the • Contaimnent of the containinated soil in a lined cell abandonment of the facility in 1991, EPA Region 4 followed by installation of a multi-layer cap over the activated the EPA Environmental Response Team to contaimnent area compatible, to the extent possible, with the intended future commercial use of the perform a preliminary assessment of the Site. The property; investigation indicated that a removal action was needed. ' Solidification/stabilization of identified principal based on achieving a residual excess risk for threat waste to form a sub-cap beneath the multi-layer direct exposure of less than one in a million (IxlO"'') for cap; future cormnercial/industrial land use and protection of • Operation & maintenance of the cap and containment groundwater from leaching of contaminants above system; drinking water standards. The key contaminants of concern (COCs) for OUl are chemicals related lo wood • Long-term monitoring of the containment system; treating operations that were identified in both soil and • Institutional controls to restrict future use of the Site to ground water. For Dioxin and PAHs, COCs found in commercial uses compatible with the remedy; soil, but not in ground water, the 2006 ROD clean up • Five-year reviews of the remedy to ensure goals were based on the direct human exposure pathway. protectiveness is maintained; and For COCs found in groundwater, the 2006 ROD cleanup goals were based on a groundwater exposure pathway, • Residential relocation within and immediately adjacent to the Clarinda Triangle neighborhood. and were calculated using the Summers model (EPA, 1989). Remedy Implementation The cleanup goals in the 2006 ROD have two limitations Construction activities began at the ETC site on that became evident during the remedial construction; September 24, 2007. The construction consisted of cleanup goals were not developed for all potential excavating, stockpiling, and placing containinated soil pathways for all contaminants, and the Summers model and debris in a containment cell. The bottom of the resulted in cleanup goals that were overly conservative. containment cell was lined with a composite liner made Of the nine COCs in the 2006 ROD, two were based on of 60 mil HDPE and a geosynthetic clay liner. The the direct exposure pathway, and seven were based on sloped walls of the contaimnent cell were lined with a 60 the groundwater exposure pathway, as shown in Table I. mil HDPE liner. The top of the containment cell was This ESD establishes cleanup goals for all COCs based lined with a composite liner to exclude water from on both the direct exposure and leaching-based entering the cell. A drainage system was installed above groundwater protection pathways. This ESD also the containment cell. During excavation and replaces the Summers model derived cleanup goals with construction, EPA conducted air monitoring, dust updated site-specific cleanup goals for groundwater control, and sile restoration to minimize the impacts of protection. the construction on the coinmunity. As seen in Table I, Dioxin and Polyaromatic Basis for ESD Hydrocarbon (PAH) cleanup goals in the 2006 ROD were based only on direct exposure. The 2006 ROD Tills ESD is being issued to change two parts of the anticipated that those COCs were limited to surface 2006 Final OUl ROD, and maintains the protectiveness contamination. As construction and confirmation of the remedy. This ESD adds and updates the cleanup sampling proceeded, Dioxin and PAHs were found in goals to reflect the appropriate level of protectiveness for subsurface soils which would remain buried due to the potential exposure pathways at the site. The new institutional controls placed on the property. EPA and cleanup goals are protective of human health and the FDEP agreed that a leachabilily-based cleanup goal was environment and achieve the objectives of the ROD. appropriate for subsurface Dioxin and PAH Also, this ESD changes certain construction contamination. requirements in the ROD that were over-specific, and were found to be impractical once the construction was The 2006 ROD established only leaching-based cleanup underway. goals for , Acenaphthene, Fluorene, Phenanthrene, 2-Methylnaphthalene, Carbazole, and Original Cleanup Goals from 2006 ROD Pentachlorophenol. Once construction and confiniiation sampling began, these COCs were found at the surface The cleanup goals in the 2006 Final OUl ROD were often enough that EPA determined a direct exposure derived from the human health risk assessment, and cleanup goal was needed. EPA and FDEP agreed to use applicable State regulations. The cleanup goals were the FDEP commercial/industrial soil cleanup target levels (SCTLs) for direct exposure as the cleanup goals Once Ihe limitations in applying the Summers Model for these seven compounds were identified, EPA and FDEP conducted a site- specific leaching study lo evaluate the leaching behavior Daring the review of the cleanup goals, the EPA noted of the COCs at the site. The Icacliing study followed that the 2006 ROD leacliing-based cleanup goals were FDEP's "Guidance for Detemnning Leachability by far more conservative than the established leaching- Analysis of SPI.P Resulls" which is consistent with F.PA based cleanup target levels used by the State i)f Florida guidance for conducting leachability studies. The study (SCTLs). Tliis is because the 2006 ROD used the confirmed that the Summers model does not accurately Summers model to derive the cleanup goals. Tlie predict the leaching of COCs from actual site soil and Summers model is a mathematical estimate of how that the Summers model derived cleanup goals were COCs would leach out of contaminated soil and into more conservative than necessary to achieve the groundwater. While the Summers Model is appropriate remedial action objectives established in the ROD. to use as a screening model, soil cleanup goals derived After evaluation of the data and discussion with FDEP, from the model tend to be higldy conservative. The HPA and FDEP agreed that the FDEP's leaching-based conservative nature of the Summers Model stems from SCTLs would be appropriate cleanup goals for the several of the simplifying assumptions made within the leaching-based groundwater protection exposure model, (e.g. an infinite source of chemical, no pathway. fractionation between pathways^ no biological or chemical degradation, and no adsorption to soil), and the one-dimensional solute fate and transport simulation employed.

Table 1. 2006 ROD Soil Cleanup Goals for ETC OU-1

LeacIting'Based Groundwater Direct Exposure Pathway E.xp0sure Pathway Contaminant of Concern 2006 ROD Cleanup Goal 2006 ROD rieaimp Goal (Summers Model) (jig/kg) Ben2o(a)pyrene EQ (cPAHs) 400 None Dioxin TEQ (2,3.7.8-TCDD) 0 1)30 None Naphthalene None 419 Acenaphthene None 1,954 Fluorene None 1,525 PhenanUirene None 3,829 2-Metl'iylnaphthalene None 2.394 Carbazole None 6.5 Pentachlorophenol None 5.1 Revised Cleanup Coals The EPA and FDEP modified the excavation plan so That Thjs ESD replaces the cleanup goals in the 2006 ROD the direct exposure cleanup goals were used in the with the cleanup goals in Table 2. Tiiese cleanup goals former neighborhoods, since there is no site-related more accurately refiect Ihe potential routes of exposure groundwater contamination in the former al ihe site, achieve the remedial action objectives neigliboriioods. For the top six feet of soils at the fonner established in the ROD. and provide for a cleanup that is facility, the more conservative of the direct exposure or protective oi human liealih and ihe environment under the leaching-based cleanup goals were used. For former the plaimed future use of the sile. Under Ihe National facility soils deeper than sLx feet, only the leaching- Contingency Plan, EPA's goal is to r«iuce the excess based cleanup goals were used. This is compatible with cancer risk to the range IxlO"^ (one in ten thou.sand) lo t3ie institutiona3 controls al the site, which will restrict IxlO'*^ (one in one million) for the expected future land digging deeper than six feet to protect the contaimnent use al ihe Sile. The new cleanup goals for OUl are cell. based on a future commercial/industrial land use for the ETC Site and on achieving a residual excess cancer risk Cleanup goaSs were applied to different areas on the site of less than 1x30"^ (one in one million) with a hazard based on the e\lent of coniamination in the area. Table 3 quotient less than 1. The AJAAR-based direct exposure presents the application of the cleanup goals in different cleanup goal for dioxin TEQ (2,3,7,8 TCDD) is parts of the sile. unchanged from the 2006 ROD and is based on Florida Statute Section 376.30701 requiring cleanups to attain an incremental lifetime cancer risk of < I X 10"^ (less than one in one million) and a hazard index of <1 (less than one) fornon-carcinogens.

Table 2. Revised Soil Cleanup Goals for ETC OU-l

teaching-Based Groundwater Exposure Direct Exposure Pathway Pathway

Revised Cleanup Go»] (^^kg) Revised Cleanup Goal (^g/kg) Source (FAC 62-777 Table II) Source ffA C 62-777 Table If) Contaminant of Concern Direct Exposure Commerciaiy Industrie Leachability Based on Groundwater SCTL Criteria SCTL B6rLZo(a)pyre[ie EQ (cPAUs) 700 8,000 Dioxin TEQ (2,3,7,S-TCDD) 0.030 3,000 Naphthalene 300.000 1,200 Acenaphthene 20.000.000 2.100 Fluorene 33.000.000 160.000 Phenantlirene 36.000,000 250,000 2*McLhylnaphthalene 2,100,000 8,500 Carbazole 240.000 200 Pentachlorophenol 28.000 30 Table 3. Application of Cleanup Goals Scope and Role of Action

The purpose of this ESD is to document the decision to Portion of Site Cleanup Goals Applied modify the soil cleanup goals and to modify construction requiremenls in the 2006 ROD. The original remedy, as Fonner neighborhoods - written in the 2006 ROD^ did not derive cleanup goals Direct exposure cleanup Surface soil for direct exposure and protection of groundwater for all goals only. coniamination only COCs, and was overly specific in certain design The more conservative of the requirements. Former Facility ~ direct exposure or leaching- Surface soils (0-6 feet) based cleanup goals. Applicable or Relevant and Appropriate Fomier Facihty ~ Requirements (ARARs) Leacliing-bascd cleanup Subsurface soils (deeper goals only. This ESD does not change the AJIAR analysis presented than 6 feet) in the 2006 ROD, which provides a detailed discussion of potential ARARs for a wide range of activities at the Site. Cleanup or remedial actions must comply with Revised Construction Specincatit>ns applicable or relevant and appropriate requirements (ARARs) under hedcral environmental laws, and State This ESD also documents changes in certain environmental or facility siting laws. Identification of construction requirements in the ROD that were over- ARARs must be done on a Site-specific basis. Although specific, and were found to be impractical once the on-Sitc portions of cleanup activities at CERCLA Sites construction was undeAvay. arc exempt from permitting requiremenls, they must meet the substantive requirements of the ARAJRs. The 2006 ROD specified 'The principal tlireat wastes will be mixed with cement to form a sub-cap three- to four-feet in thickness above the compacted soil to at or Impact of Modifications near to existing grade." The thicknes.s of the The implementation of the modified soil cleanup goals soUdified/stabilized sub-cap was based on the estimated resulted in some cost savings, while still providing the volume of principal threat waste and the anticipated area same degree of protection for human exposure and of the contaimnent cell. Once construction began, two groundwater. Figure I shows the excavation grids factors affected the thickness of the sub-cap; the where the leacliing based cleanup goal for Dioxin was dimensions of the cell changed, and less principal threat applied. The implementation of the reduced subcap waste was found. The layout of the cell increa.-icd to thickness prevented the unneeded stabilization/ about IS acres from about 15 acres because the volume solidification of tens of thousands of cubic yards of soil of the containment cell increased from 399,010 cubic to meet the ROD specification while providing yards to 557,000 cubic yards. Further, less principal significant cost savings and meeting the long-term threat waste wag encountered during the excavaiinns performance and reuse objectives established in the than estimated. The cast half of the sub-cap thickness ROD. was reduced after this became apparent. The sub-cap ihickiiess was reduced to two feet, but the compressive strength was increased, allowing the eastern sub-cap to maintain the equivalent shear resistance as the rest of the cap. To assure the strengtli of Ihc entire sub-cap, (he final lift of material contained a cement content of eight percent across the entire sub-cap. ligure 1. Grid Layout Showiiiy Grids witliSubsuriace Dioxiu above Surface SCTLS

OVERALL GRID LAYOUT FOR AREAS SOUTH OF FXC04

SUPFRRJNO Slip I nn pPSiMHmr »ciCH Wl ntp>M«9 rr ova*. *c TtM s FMJVOI ST- ORHP #07-1620.000 CUENT: CHC. INC. DATt: JA'/Oe Statutory Determination The changes to the ROD documented in this ESD are protective of human health and the environment, comply with Federal and State requirements that are applicable or relevant and appropriate to this remedial action, are cost effective, and use permanent solutions to the maximum extent practicable for this Site.

Who Can You Call For Answers? If you have a question about activities on the Site, please call Erik Spalvins, the EPA rernedial project manager. He can be reached at (800) 435-9234 or via email at [email protected].

Authorizing Signature

1 have determined that the remedy for the Site, as modified by this ESD, is protective of human health and the environment, and will remain so provided that the actions presented in this report are implemented as described above.

This ESD documents the significant changes related to the remedy at the Site. U.S. EPA selected these changes after consultation with the FDEP.

U.S. Environmental Protection Agency

lor Superfund Division

Date: