DuPont/Pompton Lakes Works site

Summer 2012 Update

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www.epa.gov

Cleanup to date

More than 200,000 tons of contaminated soil and sediment
has been removed from Acid Brook and Wanaque River.
Within these projects, more than 150 properties were cleaned
up and approximately 10 acres of wetlands were replanted.

Thirty areas on-site have been cleaned up from former
manufacturing operations.

SITE HISTORY

The DuPont Pompton Lakes Works site is located at 2000
Cannonball Road in Pompton Lakes and Wanaque, New
Jersey. The site encompasses approximately 570 acres. DuPont
manufactured explosives on site from 1902 to 1994. DuPont
ceased operations in April 1994 and began the closure and
cleanup of the site. Past operations and waste management
practices contaminated surface water, soil, sediment and
ground water both on and off site. Primary soil and sediment
contaminants are lead, mercury and copper. Primary ground
water contaminants are the volatile organic compounds
tetrachloroethene (PCE), trichloroethene (TCE) and their
degradation products.1

FEDERAL AND STATE CLEANUP
PROGRAMS

The DuPont Pompton Lakes Works site is regulated under the
federal Resource Conservation and Recovery Act or RCRA,
which requires facilities that have stored, treated or disposed of
hazardous waste to clean up any releases of hazardous materials
regardless of when they occurred. The "hazardous materials"
can be the waste itself as generated, or hazardous components
of other discarded materials. If such releases are suspected
or confirmed at RCRA-regulated facilities, EPA requires the
investigation and cleanup of the contamination under the RCRA
Corrective Action program. DuPont is required to clean up the
facility under a RCRA permit, which is still in effect even though
it ceased operations in 1994.

1 Vinyl Chloride, 1,1-DCA, 1,1-DCE, Carbon Tetrachloride, 1,2-DCA, Trans - 1,2-DCE,
CIS -1,2-DCE, 1,1,1 -TCA

U.S. Environmental Protection Agency

Region 2

DuPont also has cleanup obligations under New Jersey law
resulting from a 1988 Administrative Consent Order that the
company entered into with the New Jersey Department of
Environmental Protection (NJDEP). The order requires the
company to conduct an investigation of all contamination on or
emanating from the site.

DuPont is responsible for conducting the necessary
investigations and cleanups with oversight by EPA and NJDEP.
EPA and NJDEP follow similar procedures for site assessments,
investigations, evaluations and remediation. The agencies share
information and coordinate oversight of the cleanup. NJDEP
has primary responsibility for the investigation and cleanup of
the former manufacturing facility, while EPA is the lead agency
for the investigation and cleanup of the Acid Brook Delta. EPA
and NJDEP are jointly managing studies of the ground water
aquifer and the actions to reduce the intrusion of vapors from
the ground water into people's homes.

Restored shooting pond


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Figure 1. DuPont/Pompton Lakes Works Site

LEGEND

0

Former Western Valley
Manufacturing Area

f)

Former Eastern Valley

w

Manufacturing Area



Former Northern

©

Manufacturing Area

o

Acid Brook

0

Off site Wanaque River Area

0

Pompton Lakes Delta Area

Of f s ite G ro u n dwate r Area

/ v*.

• f-i

¦ . >

OVERVIEW OF CLEANUP AREAS AND ACTIVITIES

Site cleanup areas are organized into on-site areas and
off-site areas as shown in Figure 1. Cleanup of the former
western, eastern arid northern on-site manufacturing areas
(areas 1 through 3) will address soil and ground water
contamination.

intrusion. Within these areas, multiple site cleanup activities
are taking place concurrently. A summary of the current
status of the cleanup areas is shown in Table 1.

Cleanup of the off-site Acid Brook, Wanaque River and Acid
Brook Delta, which includes lake and uplands areas (areas
4 through 6) will primarily address contaminated soil and
sediment. Cleanup of the off-site ground water area (area
7) will address both ground water contamination and vapor

Investigations to characterize the nature and extent of the
contamination have been conducted in various areas of the
site. Remedial Investigation Reports, called RIRs, have been
submitted by DuPont to EPA and NJDEP. Areas requiring
immediate attention have been addressed as interim actions.
Sampling to further delineate areas of contamination is
ongoing.

Table 1. Status of the DuPont Pompton Lakes Works Site Cleanup

Cleanup Areas

Status



Investigation

Cleanup
Technology
Assessment

Remediation
(Cleanup)

On-site

Soil

O

O

O

Ground water

O

O

O

Off-site

Acid Brook

•

•

•

Wanaque River

o

o

o

Acid Brook Delta and Uplands (Lake Remediation)

•

o

o

Ground water (shallow aquifer)

•

•

o

Ground water (intermediate aquifer)

•

o

o

Symbols

# Complete
O Ongoing
O Not started

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ON-SITE CLEANUP AREAS

Soil Remediation

DuPont is expected to complete the investigation of on-site soil for
the western, eastern and northern manufacturing areas by the end of
2012. DuPont will then submit a supplemental report that describes
the findings. DuPont will submit the Remedial Action Selection
Report /Corrective Measures Study 90 days after the approval of the
report. These reports will identify and evaluate cleanup alternatives.

EPA and NJDEP will conduct public outreach on them, and will
propose final cleanup plans for these areas as part of a RCRA permit
modification, which will also be subject to a public comment period.

Following issuance of the permit modification, DuPont will submit
work plans to perform the work to EPA and NJDEP for approval.

Cleanup is expected to begin in late 2013 and continue until 2015.

In response to concerns raised by community members about
possible contamination in on-site blasting tunnels in the former
eastern manufacturing area, EPA, NJDEP and community
representatives viewed the tunnels during a site tour. The tunnels
were formerly used for metal cladding (bonding dissimilar metals
with dies or pressing or rolling sheets together under high pressure).

The tunnels were also videotaped by DuPont during the site
investigation. EPA and NJDEP have no evidence of contaminants in
the tunnels that pose a risk to people's health or the environment.

Ground Water Cleanup

On-site ground water monitoring has been conducted since the 1980s. Primary on-site ground water contaminants are the
volatile organic compounds PCE and TCE. The ground water contaminant plume has been delineated and Classification
Exception Areas that provide notice that a ground water remediation project is ongoing, have been established with NJDEP.

In 1998, DuPont installed a system to keep ground water contamination from moving off-site and to remove volatile organic
compounds. Ground water is pumped from the shallow and intermediate aquifer on site, treated to remove volatile organic
compounds, then discharged into the shallow aquifer through a series of infiltration basins downgradient along the southern
boundary of the site.

OFF-SITE CLEANUP AREAS

Acid Brook

Past operations at the site resulted in discharges of copper, lead and mercury to soil and sediment in the Acid Brook, which in
turn impacted the surrounding upland area leading into Pompton Lake. The contaminated sediment also affected residential
properties along the Acid Brook. In 1991, DuPont began cleaning up contaminated Acid Brook sediment and floodplain
soil. The interim cleanup also covered affected residential properties. Cleanup activities included excavating impacted soil/
sediment, backfilling with clean soil, upgrading embankments and installing geotextile, rip-rap (permanent cover of rock
used to stabilize stream banks) and silt curtains to reduce the potential for recontamination. The cleanup of this area was
completed in 1997.

Wanaque River Area

Cleanup activities for the Wanaque River area will address potential impacts from plant operations in the former northern
and western manufacturing areas. DuPont has collected surface water and sediment data and compiled it in a report. It is
expected that future evaluations and selection of proposed cleanup plans for this area could begin as early as late 2013
and continue through 2015.

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Acid Brook Delta and Uplands (Lake Cleanup)

Investigations from 2003 to 2009 identified metal contamination including
lead and mercury in soil and sediment where Acid Brook discharges to
Pompton Lake (the Acid Brook Delta). DuPont submitted reports in 2009 that
identified and evaluated cleanup alternatives. EPA proposed a draft RCRA
permit modification to incorporate cleanup of the lake. EPA held a public
hearing on the proposed permit modification in January 2012.

The proposed cleanup approach includes excavation of contaminated soil
from the upland area to meet appropriate cleanup standards, and dredging
of sediment from the Acid Brook Delta to meet qualitative cleanup objectives
selected to reduce mercury uptake in fish and wildlife. After the cleanup is
completed, the area will be restored. EPA expects to make an announcement
on the next steps for the lake cleanup during fall 2012.

Mercury Bioaccumulation

Some forms of mercury accumulate in organisms - specifically,
organisms higher on the food chain such as fish - as they ingest it.
This makes the fish hazardous for human consumption.

Ground Water Contamination

Off-site ground water is contaminated with the volatile organic compounds PCE,TCE and their degradation products. Under
certain environmental conditions, these contaminants follow a natural process that breaks them down into ethene, a harmless
end product. The ground water underneath homes in the plume area of Pompton Lakes is contaminated at two levels with
volatile organic compounds.

Shallow Aquifer

Since 1998, DuPont has been treating on-site contaminated ground water
with a pump and treat system. Treated ground water is discharged into the
shallow aquifer zone through a series of infiltration beds located along the
property boundary. The primary purpose of this system is to contain the on-
site ground water plume from migrating off-site.This system has also resulted
in improved conditions in the eastern portion of the shallow ground water
plume.

DuPont is now preparing to conduct a pilot study to perform hydraulic
surcharging using horizontal wells to inject treated ground water into the
western part of the shallow ground water plume. If successful, the process
would then be adopted as an interim remedial measure. DuPont expects to
submit the pilot study work plan during summer 2012, with a pilot test report
expected in early 2013.

Pilot Study

A small-scale study performed to
evaluate the effectiveness of a specific
remediation treatment.

Bioremediation

The use of naturally occurring bacteria
to break down contaminants in
soil and water. The bacteria can be
"enhanced"through the addition of
food sources.

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Intermediate Aquifer

DuPont is conducting a ground water pilot study to determine
if bioremediation would be beneficial in treating ground water
contaminants in the plume. DuPont will continue to gather additional
data through fall 2012 to further evaluate the effectiveness of
implementing bioremediation.

Vapor Intrusion

Vapor intrusion results from the volatile organic compound
contamination in the shallow ground water underneath homes.
The volatile organic compounds in the ground water vaporize and
migrate building foundations. Vapor mitigation systems installed
on houses are effective in intercepting the vapors and diverting the
vapors above house rooflines.

EPA encourages all residents with homes above the contaminated shallow ground water plume to install one. Homeowners
have a choice of having DuPont install the vapor mitigation systems or arranging to have their own contractor install a vapor
mitigation system. Eligible property owners or residents may contact EPA, NJDEP or DuPont for more information. Information
on hiring a contractor to install a vapor mitigation system is available at: http://www.nj.gov/dep/srp/community/sites/
dupont_pomptonJakes/contractor_info. Currently, more than 70 percent of the homes located above the ground water
plume have vapor mitigation systems installed or the vapor mitigation system installation process is underway. For more
information about vapor mitigation systems see: http://www.state.nj.us/dep/srp/community/sites/dupont_pompton_lakes/
faqs.htm

COMMUNITY INVOLVEMENT

EPA and NJDEP are committed to providing meaningful community
involvement throughout the DuPont Pompton Lakes Works site cleanup
process. EPA will be providing the community with regular site updates
through quarterly fact sheet mailings and public information sessions.

RESOURCES

EPA Region 2 DuPont Pompton Lakes Works RCRA Site Web page:
http://www.epa.gov/region2/waste/dupont_pompton/index.html

NJDEP Site Web page:

http://www.state.nj.us/dep/srp/community/sites/dupont_pompton_
lakes

FOR MORE INFORMATION

Please contact:

EPA Region 2

Pat Seppi, Community Involvement Coordinator

(212) 637-3679

seppi.pat@epa.gov

NJDEP

Mindy Mumford, Community Relations Coordinator
(609)777-1976

mindy.mumford@dep.state.nj.us

This document has been funded in whole or
partly through the EPA's TASC program.

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