PB96-963125
                                 EPA/ESD/R01-96/126
                                 March 1997
EPA   Superfund
       Explanation of Significant Difference
       for the Record of Decision:
       Pinette's Salvage Yard Superfund Site,
       Washburn, ME
       6/20/1996

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                DECLARATION FOR THE EXPLANATION OP
                      SIGNIFICANT DIFFERENCES
 SITE NAME AND LOfATTOM

 Pinette's Salvage Yard Superfund Site
 Washburn,  Maine

 STATEMENT OF PURPOSE

 This decision document sets  forth the basis for the determination
 to issue the attached Explanation of Significant Differences
 (ESD)  for the Pinette's Salvage Yard Superfund Site in Washburn,
 Maine.

 STATUTORY BASIS FOR ISSUANCE OF ESD

 Section 117(c)  of the Comprehensive Environmental Response,
 Compensation and Liability Act (CERCLA)  requires that, if any
 remedial or enforcement action is taken  under Section 106 of
 CERCLA after adoption of a final remedial action plan, and if
 such action differs in any significant respects from the final
 plan (i.e.,  scope,  performance or cost),  the United States
 Environmental Protection Agency (EPA)  shall publish an
 explanation of the significant differences and the reasons such
 changes were made.   Current  EPA guidance (OSWER Directive 9355.3-
 02)  further provides that issuance of an ESD is appropriate  where
 the Agency determines the need for changes to the ROD which  are
 significant but which do not fundamentally alter the overall
 remedy.   In the present case,  because the required adjustments to
 the ROD do not fundamentally alter the selected remedy for the
 Site,  this ESD is being issued properly.

 In accordance with Section 117(d)  of CERCLA,  this ESD will become
 part of the Administrative Record which  is available for public
 review at  both the EPA Region I Record Center in Boston/
 Massachusetts and the Washburn Town Hall in Washburn,  Maine.

 DECLARATION

 For the foregoing reasons, by my signature below,  I approve  the
 issuance of an Explanation of Significant Differences for the
 Pinette's  Salvage Yard Superfund Site in Washburn,  Maine and the
 changes stated therein.
.Date                         '^-Linda  M.  Murphy,  Dir«
 '                             Office of Site  Remediation
                              and  Restoration

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              EXPLANATION  OF SIGNIFICANT DIFFERENCES
              PINETTE'S SALVAGE YARD SUPERFUND SITE
                         WASHBURN, MAINE
I.    INTRODUCTION


     A.   Site Name and Location

     Site Name:          Pinette's Salvage Yard Superfund Site

     Site Location:      Washburn, Maine


     B.   Lead and Support Agencies

     Lead Agency:         United States Environmental Protection
                         Agency

     Support Agency:      Maine Department of Environmental
                         Protection


     C.   Legal Authority

     Section 117(c) of the Comprehensive Environmental Response,
     Compensation and Liability Act (CERCLA)  requires that,  if
     any remedial or enforcement action is taken under Section
     106 of CERCLA after adoption of a final remedial action
     plan,  and if such action differs in any significant respects
     from the final plan,  the United States Environmental
     Protection Agency (EPA)  shall publish an Explanation of the
     Significant Differences  and the reasons such changes were
     made.

     D.   summary of Circumstances

     On May 30, 1989 EPA issued a Record of Decision (ROD)  for
     the Pinette1^ Salvage Yard Superfund Site.   The ROD included
     requirements for source  control and management of migration.
     On June 2, 1993,  the  EPA amended the Source Control
     component of the 1989 ROD by changing the remedy for
     contaminated soil from on-site treatment and off-site
     incineration to off-site land disposal and off-site
     incineration.  The ROD required active treatment of
     groundwater as a component of the Management of Migration
     (groundwater).

     Since  the issuance of the ROD and completion of the Source
     Control remedy,  the EPA  has evaluated the new information
     obtained during the remedial pre-design process, has re-
     evaluated the administrative record information supporting

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     the 1989 ROD, and has determined that active groundwater
     treatment is no longer necessary.  Accordingly, EPA is
     issuing this Explanation of Significant Differences (ESD).

     E.   Administrative Record

     In accordance with Section 117(d) of CERCLA, this ESD and
     the new information obtained will become part of the
     Administrative Record which is available for public review
     at both the EPA Region I Record Center in Boston,
     Massachusetts and the Washburn Town Hall in Washburn,  Maine.

II.  SUMMARY OF SITE HISTORY, CONTAMINATION PROBLEMS AND SELECTED
     REMEDY

     A.   Site History

     Pinette's Salvage Yard Site is situated on less than one
     acre in the town of Washburn in Aroostook County, Maine.
     Currently,  the site is fenced and used as an automobile and
     scrap metal salvage' yard.   About 15 persons live within a \
     mile radius of the site.  These persons rely on private
     wells for drinking water.

     In June 1979, three electrical transformers were reportedly
     brought on-site where they ruptured and released about 900
     to 1,000 gallons of dielectric fluid containing
     polychlorinated biphenyls  (PCBs)  and volatile organic
     compounds (VOCs)  directly  onto the ground.

     From October 4,  1983 to November 4,  1983,  under emergency
     removal authority,  the EPA removed about 1,000 tons of
     contaminated soil and debris.   The excavated soils were
     transported to a. hazardous waste landfill  in New York.  In
     1994,  under remedial authority,  the EPA completed the  Source
     Control Remedial Action during which approximately 1,000
     tons of contaminated soil  were excavated and incinerated at
     an off-site incinerator and approximately  5,000 tons of
     contaminated soil were excavated and disposed of at an off-
     site hazardous waste landfill.

     B.   Remedial investigation/Feasibility Study (RI/FS)

     An investigation into the  nature and extent of contamination
     at the Site was conducted  from 1987  to 1989.   The Remedial
     Investigation was performed to characterize the geology,
     hydrogeology, and distribution of contaminants in soil,
     groundwater,  surface water,  and sediments  at the Site.  The
     Remedial Investigation and Feasibility Study dated March
     1989 are included in the Administrative Record.

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Based on the Feasibility Study, EPA proposed  a  remedy called
the "preferred alternative" for the Site  in a Proposed  Plan
dated March 1989.

C.   Summary of the 1989 selected Remedy

On May 30, 1989, the EPA signed a Record  of Decision  (ROD)
for the Pinette's Salvage Yard Superfund  Site.  The selected
cleanup approach for the Site includes two primary
components: Source Control and Management of  Migration.
Only the Management of Migration component is affected  by
this BSD and is summarized below.  The Source Control
component  (as amended in June 1993) has been  completed.  The
Source Control component of the 1989 ROD originally called
for on-site solvent extraction treatment and  off-site
incineration of contaminated soils, but was amended in  1993
for 'off-site land disposal and off-site incineration.   Refer
to the 1989 Record of Decision and the 1993 ROD Amendment
for a complete description of the Source Control and
Management of Migration components.

The Management of Migration component of the  1989 ROD
required that contaminated groundwater containing
concentrations above the following target cleanup goals be
extracted from the ground and treated on site using
filtration and carbon adsorption.

The 1989 Target Cleanup Goals in groundwater  were as
follows:

     Polychlorinated biphenyls (PCBs):  .5 ppb
     Benzene:  5 ppb
     1,4 - Dichlorobenzene: 27 ppb
     Chlorobenzene: 47 ppb
     1,2,4 Trichlorobenzene:  680 ppb
     Chloromethane: 10 ppb
     Lead: 5 ppb

The target cleanup goal for lead was based on a proposed
maximum contaminate level (proposed MCL)  for drinking water
which was never adopted by the EPA.  This BSD adjusts the
site target cleanup goal for lead to the current nationally
accepted MCL of 15 ppb.

The objectives of the Management of Migration component of
the 1989 ROD were l)  to reduce the potential  for off-site
migration of PCBs by reducing the concentration of
associated VOCs that facilitate the transport of PCBs,  2) to
prevent persons from ingesting contaminated water from the
site,  and 3)  conduct five year reviews.   The  1989 ROD did

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not require restoration of the "groundwater to drinking water
quality, but rather explicitly recognized the technical
impracticability of reducing the PCS contamination to drinking
water quality.  In recognizing this treatment limitation, the
1989 ROD waived the legal requirement of achieving the State of
Maine Maximum Exposure Guideline (ME MEG) of 0.5 ppb for PCBs in
groundwater beneath the site.

     The 1989 ROD determined that treatment of groundwater was,
     however, warranted to reduce the mobility of the PCBs by
     reducing the concentrations of certain volatile organic
     compounds.  Volatile organic compounds,  including
     trichlorobenzene, were typically used in transformers to
     decrease the viscosity of PCBs which are naturally waxy and
     not very mobile.   While VOCs were never found in residential
     wells at levels that would pose the need for remedial
     action, it was believed that by reducing the concentration
     of these carrier VOCs in groundwater,  the potential for off-
     site migration of PCBs would be sufficiently prevented.

     0.   Source Control Remedial1Action

     In May 1991,  EPA initiated source control remedial
     activities at the site.   These activities included removing
     junk cars, erecting a fence around the perimeter of the
     site,  excavating, dewatering,  installing concrete pads on
     large portions of the site,  and removing soils contaminated
     with PCBs.  In 1993,  after unsuccessful  attempts to use the
     selected on-site solvent extraction treatment technology,
     the EPA issued an amendment to the source control remedy to
     dispose of contaminated soil at off-site facilities.
     Depending on the concentrations of PCBs,  the contaminated
     soils were disposed of at either a TSCA  landfill or TSCA
     incinerator.   The source control remedial action work was
     completed in 1993,  and grading and revegetation of the site
     were completed in 1994.

     E.   Management of Migration Pre-design  Studies

     In August 1990 and December 1991,  EPA conducted further
     groundwater sampling at the site.   Analytical results of
     this sampling in comparison to earlier rounds of sampling
     conducted in 1987 and 1988 indicated that VOC contamination
     of the groundwater was decreasing over time.   To understand
     the impact the Source Control  remedial activities were
     having on groundwater contamination, -EPA conducted further
     sampling of monitoring wells in March 1993,  July 1993,
     January 1994,  April 1994,  October 1994,  April 1995,  July
     1995,  and October 1995.

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     Residential wells were sampled yearly: November 1987, June
     1988,  August 1990, August/December 1991, March 1993, April
     1994,  and April 1995.  The two residential wells farthest
     from the site were removed from the sampling program after
     the August 1991 sampling round because EPA determined that
     the chemicals detected from these wells during previous
     sampling rounds indicated that they were not at levels of
     health concern and these residential wells were located a
     great distance away from the Site and would not be impacted
     by the site.  Groundwater flow direction is to the
     southeast.  All of the Residential wells are located to the
     northeast and southwest of the site.
III. DESCRIPTION OF SIGNIFICANT DIFFERENCES

     A.    Additional Extraction and Treatment of Groundwater not
          Warranted

     Groundwater sampling data collected during the Management of
     Migration Pre-design studies following the completion of the
     source control remedy indicates that the concentrations of
     VOCs have decreased to below or near the target cleanup
     goals established in the 1989 ROD.  Decrease in VOC levels
     are attributable to the natural attenuation/degradation of
     contaminants,  to the extraction and treatment of over one
     million gallons of contaminated groundwater during source
     control remedial activities, and to improved groundwater
     sampling techniques.

     Unfiltered groundwater samples were analyzed for VOCs,  semi-
     volatile organics, pesticides, PCBs, metals and total
     dissolved solids.  Filtered groundwater samples were
     analyzed for PCBs and metals.  Beginning with the April 1995
     round, EPA began using low flow sampling procedures.  Low
     flow sampling is considered by EPA Region I as the optimal
     groundwater sampling method for evaluating mobility of
     contaminants in groundwater and is also considered most
     representative of human exposure through ingestion of
     groundwater.

     In  monitoring wells, the maximum concentration of lead
     detected in unfiltered samples since EPA began using low
     flow sampling in 1995 has been 14.5 ppb, below the target
     cleanup goal (as amended by this BSD)  of 15 ppb.   The
     maximum concentration of PCBs in unfi-ltered monitoring  well
     •samples detected since the low flow sampling began is 8.5
     ppb,  which is still above the target cleanup goal of 0.5
     ppb.   VOCs for which there are target cleanup goals
     established for the site have not been detected in

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     unfiltered samples above MCLs since low flow sampling began.

     In residential wells, the maximum level of  lead detected in
     unfiltered groundwater sample was at 7.1 in April  1995.
     There is no reason to believe that this lead can be
     attributed to the transformer spill at the site.   None of
     the residential wells are downgradient of the site.  PCBs
     have never been detected in residential wells.  VOCs for
     which target cleanup goals have been established for the
     site have not been detected in unfiltered samples  above MCLs
     in residential wells.

     The results and evaluation of the data are presented in
     "Management of Migration, Summary of Environmental Data and
     Evaluation Report, June 1996."  This report is included in
     the Administrative Record.

     The monitoring results demonstrate that,the primary
     objective of the Management of Migration component of the
     ROD has been achieved—PCS migration has been sufficiently
     reduced.  The 1989 ROD required active groundwater treatment
     to reduce the concentration of VOCs to their cleanup goals
     as a means of reducing the migration of PCBs.  The
     concentrations of VOCs are already below their cleanup
     goals.  Furthermore,  the migration of PCBs has been
     sufficiently reduced; downgradient wells have not  shown any
     contamination.  Consequently,  there is no need to actively
     treat the groundwater.


     B.   Adjusted Target Cleanup Goals

     In the 1989 ROD, the EPA established a cleanup goal for lead
     based on a proposed maximum contaminate level (proposed MCL)
     for drinking water which was never adopted by the EPA.   This
     BSD adjusts the site target cleanup goal for lead to the
     current nationally accepted MCL of 15 ppb.   None of the on-
     site monitoring wells or off-site residential wells have
     lead levels above the 15 ppb level established for drinking
     water.
IV.  SUMMARY OP FUTURE RESPONSE ACTIONS

     A.   Institutional Controls

     As foreseen by the 1989 ROD and based on an evaluation of
     the 1995 low flow sampling data, the groundwater is still
     contaminated with concentrations of contaminants which would
     pose an unacceptable risk if ingested.  Exceedances of MCLs

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     for PCBs, bis(2-ethylhexyl)phthalate,  antimony,  and chromium
     have been detected in unfiltered groundwater  samples  from
     on-site monitoring wells.  Additionally,  the  following VOCs
     were detected, although  below MCLs,  in unfiltered  samples
     from on-site monitoring  wells: chlorobenzene,  1,3-
     dichlorobenzene, 1,4-dichlorobenzene,  1,2-dichlorobenzene,
     1,2,4-trichlorobenzene,  1,2,3-trichlorobenzene,  benzene, and
     xylene.

     To prevent the ingestion and use of  contaminated
     groundwater, institutional controls  (e.g., deed
     restrictions) will be established to prevent  the
     installation of domestic wells on the  site.

     B.   Five Year Reviews

     Five year reviews of the site will be  conducted  to ensure
     that the remedy remains  protective.  At  a minimum,
     groundwater samples will be collected  from the monitoring
     well network during these reviews.  These five year reviews
     will" determine whether the institutional controls  are being
     effective and enforced,  whether residential wells  should be
     sampled, whether site conditions have  changed with respect
     to potential migration which would warrant a different
     remedial approach,  or whether the institutional  controls can
     be removed.

     EPA requested the Agency for Toxic Substances and  Disease
     Registry (ATSDR)  for a recommendation  regarding  future
     residential well sampling.  The ATSDR  has reviewed the
     environmental data and has concluded that contaminants
     detected in groundwater  samples from residential wells are
     not at levels of public  health concern.  This is consistent
     with earlier groundwater sampling of residential wells which
     concluded that contaminants would not pose a health hazard
     to those persons who use it on a daily basis.  Furthermore,
     site related contaminated groundwater does not flow'in the
     direction of the domestic wells.

     ATSDR does not see the need for further residential well
     sampling but recommends  that EPA continue to sample the on-
     site monitoring wells.   If conditions change at the Site,
     ATSDR recommends that EPA reevaluate the need for sampling
     residential wells.
V.   SUPPORT AGENCY COMMENTS

     The Maine DEP acknowledges that the Maine DEP has had an
     opportunity for review and comment and concurs with this ESD-

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      (Attachment  1).


VI.  STATUTORY DETERMINATIONS

     Considering  the adjustment to the selected  remedy  set  forth
     in the  1989  ROD and as described in this  ESD,  the  EPA
     believes that  the remedy remains protective of human health
     and the environment, complies with all Federal and State
     requirements that are applicable or relevant and appropriate
     to this remedial action and is cost effective.
VI.  PUBLIC PARTICIPATION

     In accordance with Section 117(d) of CERCLA, this ESD will
     become part of the Administrative Record which is available
     for public review at both the  EPA Region I Record Center in
     Boston, Massachusetts and the  Washburn Town Hall in
     Washburn, Maine.


                               ###
               FIGURE 1       - SITE LOCATION MAP

               FIGURE 2       - SITE FEATURES MAP

               ATTACHMENT 1   - STATE CONCURRENCE LETTER
                                8

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     FIGURE 1




SITE LOCATION MAP

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REFERENCE:
U.S.G.S. 7.5 Minute Topographic Quadrangle Map
Washbum, Maine, 1984. SCALE 1:24,000
                                             USEPA ARCS I PROGRAM
                                           CONTRACT NO. -68-W9-0034
PINETTE'S SALVAGE YARD SITE

  SITE LOCATION MAP
                                                            FIGURE1

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     FIGURE  2




SITE FEATURES MAP

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           ATTACHMENT 1




STATE OF MAINE CONCURRENCE  LETTER

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                STATE OF MAINE

                DEPARTMENT OF  ENVIRONMENTAL PROTECTION
                ANGUS S KING Jfl                                                        HOWARD 0 SULLIVAN
                                                             JUN 1»
          June 10, 1996
          John DeVillars
          Regional Administrator
          U.S. Environmental Protection Agency
          JFK Building (HBT)
          Boston MA 02203-2211

          Subject: State Concurrence of ESD for Pinette's Salvage Yard Superfund Site

          Dear Mr. DeVillars:

          The Maine Department of Environmental Protection (MDEP) has reviewed the May 30,
          1996 Draft Explanation of Significant Differences (ESD) with regard to the Management
          of Migration for Pinette's Salvage Yard Superfund Site in Washbum, Maine.

          Groundwater samples were collected and analyzed during the Management of Migration
          following the completion of the Source Control remedial activities. The groundwater
          sampling data document a decrease in the concentration levels of Volatile Organic
          Compounds (VOC's) that facilitate the transport of PCB's to within target cleanup goals
          established in the 1989 Record of Decision (ROD). Decrease in the VOC levels are
          attributable to the natural attenuation/degradation of contaminants, to the extraction and
          treatment by carbon adsorption of over one million gallons of water during Source
          Control remedial activities, and to improved groundwater sampling techniques. It was
          not the objective of the Management of Migration component of the  1989 ROD to restore
          groundwater to drinking water quality because it was technically impracticable to remove
          the PCBs. The concentration of PCBs in groundwater have decreased following Source
          Control remedial activities but still remain above the Maine Maximum Exposure
          Guideline (MEG) of 0.5 ppb.

          Since EPA began using low flow sampling techniques in 1995, the maximum
          concentration of lead detected in monitoring wells was 14.5 ppb which is below the
          federal Maximum Contaminant Level (MCL) and the Maine Maximum Exposure
          Guideline (MEG) of 20 ppb for lead.

          The Department concurs with the following changes to The Management of Migration
          components of the 1989 Record of Decision  (ROD).

                       Serving Maine People cV Protecting Their Environment
AUGUSTA                        PORTUWD                   8ANGOB                  PHESOUE ISLH
17 STATE HOUSE STATION                 3i2CA*coflOAO                 KMHOGAMHOAO              1335 CENTRAL Crave, SKYMVAY PARK
AUGUSTA MAINE 0*113-0077               PORTLAND ME 04103               BAWQOJI ME 04401             PHESOUS ISLE. ME 04769
(JOT) 2B7.76M FAX (207) 2B7-7S28           (JOT) 322-«300 FAX (207) E22-S303       (207) 941-4S70 FAX <»7) 941-4J84    (207) 76*-O4T7 FAX 1207) 784.1507
Ofttce LOCATED AT RAYBUILOINQ MOSWTAI. STREET
                                          pniHrd on rtryclrJ pcptr

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A.     Removing the requirement for further extraction and treatment of contaminated
groundwater. Further treatment is not warranted to reduce the potential of PCB
migration.

B.     Adjusting the site cleanup goal for lead in groundwater from 5 ppb to 15 ppb.
The 19X9 ROD selected 5 ppb based on an EPA proposal to change the MCL for lead
from 15 ppb to 5 ppb.  The proposal was never adopted and 15 ppb remains the current
MCL.

Maine DEP accepts 15 ppb as the cleanup level for lead in that it is more restrictive than
the MEG of 20 ppb for lead.

Furthermore, it is the understanding of the Department, that EPA will conduct a review
every five years following the remedial action to ensure that the remedy continues to
provide adequate protection of human health and the environment.

The Department shall receive the analytical results reports from the EPA contractor and
will be awarded reasonable opportunity to review monitoring plans and participate in any
meetings regarding this site.

Institutional controls such as deed restrictions will be implemented to prevent ingestion
and use of PCB contaminated water from the installation of drinking water wells on the
site.

The State will not be responsible for any future Operation and Maintenance at Pinette's
Salvage Yard Superfund Site.

The Department in partnership with EPA is pleased to have cleaned up this Superfund
site.
Sincerely,
              >v
Edward O. SuMvan
cc:  MarkHyland
    Denise Messier

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