United States
                  Environmental Protection
                  Agency
                   Solid Waste and
                   Emergency Response
                   (5502G)
EPA520-F-93-015
   Summer 1993
  EPA     Su perf u nd  At Work
                  Hazardous Waste Cleanup Efforts Nationwide

 Site Description:
 A former sand and gravel quarry
 located two miles southwest of
 New Castle, Delaware
 Site Size:  47 acres
 Primary Contaminants:
 Volatile organic compounds (VOCs),
 and heavy metals including chro-
 mium, iron, mercury, and zinc
 Potential Range of Health Risks:
 Long-term consumption of contami-
 nants could lead to gastrointestinal
 disorders, liver and kidney damage
 Nearby Population Affected:
 130,000 people within three miles
 Ecological Concerns:
 High-quality wetlands, aquatic
 creatures and other wildlife
 Year Listed on NPL: 1983
 EPA Region: 3
 State: Delaware
 Congressional District: 1
High quality wetlands surrounding Army Creek Landfill were contaminated with
hazardous substances.
Success In Brief

Environmental Victory

At Army Creek Landfill
  Through the efforts of the Superfund enforcement program, the U.S.
Environmental Protection Agency (EPA) successfully negotiated with
waste contributors to clean up the Army Creek Landfill site. Both
public water supplies and fragile wetlands were at risk from hazard-
ous waste dumping in the 1960s. With the cooperation of New Castle
County, EPA:
   Negotiated a $25 million cleanup of the landfill, ground water,
    and surface water;                                     ,
   Employed the latest technologies to reduce the risk of contamina-
    tion of local drinking water;
   Facilitated negotiations for an $800,000 settlement for restoration
    of wetlands affected by dumping in nearby Army Creek and
    Army Creek Pond; and
   Settled with 18 parties to recover $1 million in past cleanup costs.
The Army Creek settlement conserves Superfund dollars for hazard-
ous waste sites where viable parties cannot be found to compensate for
environmental damage. The use of private resources for cleanup
demonstrates EPA's commitment to the environment through fair and
equitable enforcement.

                            The Site Today
                               Early installation of ground water
                            recovery wells substantially reduced
                            the immediate threat of contamina-
                            tion to public water supply wells. To
                            permanently control the source of
                            contamination, waste contributors
                            began building a multi-layer cap'
                            over Army Creek landfill in the
                            spring of 1992.
                               In addition, workers started
                            construction of a water treatment
                            plant to decontaminate discharge
                            from the recovery wells. EPA super-
                            vises all work performed at the site.

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                Superfund At Work
     Army Creek Landfill, New Castle, DE    Summer 1993
  The Army Creek Landfill,
a former sand and gravel
quarry, lies approximately
two miles southwest of New
Castle, Delaware. The aban-
doned landfill is bordered by
Army Creek, which discharges
into the Delaware River
approximately one mile east
of the site.
  The residential community
of Llangollen Estates, and a
public supply well field
operated by the Artesian
Water Company, are located
less than a mile south of the
site. An estimated 130,000
people live within three miles
of the site and rely on ground
water for household use.
                             A Site Snapshot
Fortunately, drinking water
supplies have not been contami-
nated.
  Next to the landfill is the Dela-
ware Sand and Gravel Landfill,
another Superfund site. New

       Volatile organic
        compounds
      and  heavy metals
     have contaminated
      the ground water

Castle County owned and oper-
ated the 47-acre Army Creek
Landfill between 1960 and 1968,
when it was filled to capacity with
two million cubic yards of indus-
trial and municipal wastes. A
variety of chemicals also were
haphazardly discarded in the
landfill.
  Volatile organic compounds
(VOCs) and heavy metals such
as chromium, mercury, and
zinc have contaminated the
ground water.
  The surface water is also
degraded. High levels of these
contaminants were detected in
Army Creek and Army Creek
Pond, a small body of water
located southeast of the landfill.
  Mercury and chromium
have detrimental effects on
aquatic creatures inhabiting the
creek and wildlife frequenting
the high-quality wetlands near
the pond.
 Army Creek Landfill
 Timeline
                                          Superfund legislation enacted

                County installs wells to protect public drinking water
                                              County and state sample ground water
                                                1 Contamination detected in
                                                   nearby residential well
                                         1 Landfill closed
                       1
            Municipal and industrial waste disposal
                                           1
      1960
                        1968
       1971  1972  1973
                                         Page 2

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                      Superfund At Work    Army Creek Landfill, New Castle, DE      Summer 1993
    Hazardous Substances Leak into Ground Water
   County Attempts
   To Curtail Pollution
     Ground water contamination
   first became apparent in 1971
   when a local resident reported
   that his well water had gone bad.
   In response, the State of Delaware
   and New Castle County began
   sampling the ground water in

        Contamination from
     two neighboring landfills
         was seeping into
           local aquifers

   1972. The County's studies sought
   to identify and define the extent
   of the contamination.
     Investigations revealed that
   leakage originating from the two
   neighboring landfills was seeping
   underground and contaminating
                             local aquifers, potentially affect-
                             ing 5,000 residents. In response,
                             the County installed a series of
                             ground water recovery wells in
                             1973. This prevented the contami-
                             nants from reaching public sup-
                             ply wells belonging to the Arte-
                             sian Water Company.
                               The recovery wells created an
                             underground water divide be-
                             tween the landfills and the Arte-
                             sian well fields. Contaminated
                             ground water was pumped and
                             brought to the surface for dis-
                             charge into Army Creek and
                             Army Creek Pond.

                             Army Creek
                             Becomes  Superfund Site
                               The Superfund program was
                             created by Congress in 1980. This
                             program gave EPA the authority
                             to allocate federal funds to clean
                                      Army Creek Landfill
                                      New Castle, Delaware
                                           up hazardous
                                           waste sites across
                                           the nation. In 1983,
                                           the Army Creek
                                           Landfill site was
                                           included on the
                                           first National
                              Priorities List (NPL), EPA's roster
                              of sites eligible for cleanup.
                                At this time, EPA reviewed the
                              County's studies, and determined
                              their investigations were complete
                              enough to serve as the first step in
                              a Superfund cleanup: an official
                              evaluation of the nature and
                              extent of contamination at a site.
                                New Castle County agreed to
                              go one step further by performing
 \  Site listed on NPL
 /  EPArevi
EPA reviews county studies

               County submits cleanup alternatives, proposes corrective measures
                r
                          Protective cap design completed
                           r
                          EPA studies Army Creek and Army Creek Pond
                          EPA selects surface water cleanup approach
                          Settling parties agree to conduct cleanup

                                /  Construction of cap and water treatment plant begins

                                              Construction complete (planned)
                                                                Five-year evaluation of
                                                                selected cleanup activities
                                                                (planned)
1983
         1986  1989  1990
1992
1995
1999
                                                Page 3

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                    Superfund At Work
     Army Creek Landfill, New Castle, DE
  Summer 1993
an analysis of potential cleanup
alternatives, including corrective
measures for the site. Their analysis
was completed in September 1986.
  That summer, EPA identified
over 20 corporate entities as

 Twenty corporate entities
      were identified as
   potentially responsible
           parties

potentially responsible parties
and requested that they partici-
pate in carrying out the remedy
selected for the site. The identified
parties failed to reach an accept-
able agreement: therefore, EPA
continued with the cleanup.

EPA Chooses Remedy
to Protect Ground Water
  In 1986, on the basis of the
county's analysis, EPA chose a
remedy to control the source of
ground water contamination.
Phase one of the cleanup involved
installing a protective cap to cover
the landfill to prevent rainfall
from infiltrating the hazardous
waste. The cap would minimize
any further migration of the
ground water contaminants.
  The recovery well network
installed by the county to capture
contaminated ground water
would continue operations. In
addition, the recovery wells also
would be used to monitor the
effectiveness of the cap over a
five-year period.
A worker smooths newly delivered soil for the protective cap, part of phase one of
the cleanup.
  During phase two of the
cleanup, EPA will use the results
of this five-year evaluation to
determine whether additional
pollution controls will be neces-
sary. Monitoring and evaluation
of the recovery well system will
accompany its long-term opera-
tion and maintenance.

EPA Protects
Natural Resources
  Once the landfill cap was
designed, EPA shifted its attention
to the contamination of Army
Creek and Army Creek Pond.
  Surface water samples indi-
cated that the creek and pond had
been partially degraded by dis-
charge from the recovery wells.
In January 1989, EPA asked the
waste contributors to cooperate in
conducting a focused study of
surface water contamination.
  Once again, the notified parties
refused to perform the study, and
so EPA evaluated Army Creek
and Army Creek Pond in Febru-
ary 1990.
  Resulting data indicated el-
evated concentrations of chro-
mium, cadmium, iron, mercury
and zinc exceeding surface water
quality standards, but only iron
could be directly linked to the
recovery well discharge. The
other contaminants were believed
to originate from Army Creek
leachate or off-site surface runoff.
              continued on page 5
                                              Page 4

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                  Superfund At Work
    Army Creek Landfill, New Castle, DE
Summer 1993
       Environmental Trustees to

       Restore Damaged Habitat

    Federal and state natural resource trustees played a prominent
  role in the cleanup of the environment surrounding Army Creek
  Landfill. Settling parties agreed to pay an additional $800,000 to
  environmental trustees at the National Oceanic and Atmospheric
  Administration, the Department of the Interior, and the State of
  Delaware. The natural resource trustees will use this money to
  improve wetlands in the vicinity of the site.
    This part of the settlement was intended to offset injury to wet-
  lands and aquatic life resulting from the release of hazardous
  substances from the landfill and contaminated ground water
  discharged into Army Creek and Army Creek Pond.
   Funds for improving nearby wetlands were part of the settlement
Hazards Leak into Ground Water
continued from page 4
  In June 1990, EPA selected a
cleanup remedy for the surface
water, which involved construc-
tion of a water treatment plant.
The treatment plant purifies the
ground water brought up by the
recovery wells prior to its dis-
charge into Army Creek.
  To track the level of contami-
nants, EPA will undertake a long-
term monitoring program of
ground water, surface water,
sediments, and associated wet-
lands affected by the site.
  Following extensive negotia-
tions with EPA, the waste con-
tributors began construction of
the selected remedies in the
spring of 1992.
        EPA's

     Pursuit of

        Waste

  Contributors

     Pays Off
   In September 1990, EPA
 reached a formal cleanup
 agreement with 18 waste
 contributors who were
 willing to enter into a mixed-
 funding agreement.
   Under mixed funding,
 EPA settles with fewer than
 all of the responsible parties
 at a site for a substantial
 portion of the cleanup. The
 remainder of the costs can be
 contributed by EPA, or
 obtained from other finan-
 cially viable waste contribu-
 tors. In the settlement with
 EPA, 18 parties agreed:
  To conduct a $25 million
   cleanup that involves
   building the cap, monitor-
   ing the pumping systems,
   and constructing and
   operating the wastewater
   treatment plant according
   to EPA specifications;
  To compensate EPA's
   Superfund program for $1
   million in past costs; and
  To fund future EPA
   oversight costs, estimated
   at another $1 million.
   This settlement provides
 recovery of approximately
 71% of past response costs.
 In addition, the settling
 parties will undertake the
 remedies selected to address
 soil, ground water,  and
 surface water contamination.
                                         Page 5

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                   Superfund At Work
Army Creek Landfill, New Castle, DE     Summer 1993
                    Success at Army Creek Landfill

    By promptly addressing the immediate risk of   design and conduct a $25 million cleanup, and
  ground water contamination, the Superfund       reimburse EPA for $1 million of previously
  program reduced the threat to drinking water      incurred response costs.
  supplies posed by the Army Creek Landfill. EPA      In addition, federal and state natural resource
  also responded to immediate
  environmental concerns by
  orchestrating comprehensive
  cleanup'actions for the site.
    EPA Successfully con-
  cluded negotiations with 18
  parties Responsible for con-
  taminants at the site. Under
  the terms of the settlement,
  the waste contributors will
      The safety of the
      drinking water
      supply was greatly
      enhanced by prompt
      actions at the Army
      Creek Landfill site
trustees have received
$800,000 to help them
counteract damages to
wetlands and aquatic life.
  Although construction
activities are scheduled to
be completed in the spring
of 1995, the potential for
exposure to contaminants at
this site has been eliminated.
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Superfund At Work(5502G),
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For additional copies of this or other Superfund At Work updates,
contact the National Technical Information Service,
U.S. Department of Commerce,
5285 Port Royal Road, Springfield, VA 22161,
telephone (703) 487-4650.

     EPA
United States Environmental Protection Agency
5502G
Washington, D.C. 20460

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