Final Permit Modification Issued for
DuPont/Pompton Lakes Works Site
Pompton Lakes, New Jersey

Community Update

January 2013

Major changes between
the proposed and final
permit modifications:

1.	An expanded area of
Pompton Lake will be
dredged; it encompasses
approximately 40 acres
as compared to the
originally proposed 26
acre dredging area.

2.	The cleanup requires
DuPont to perform
additional sediment
sampling to identify
potential "hot spots"
outside of the Acid
Brook Delta; and

3.	A post cleanup, long-
term monitoring program
and ecological risk
assessment will be
performed to confirm the
effectiveness of the
dredging/restoration
project.

This summary describes the key differences
between the proposed November 2011 permit
modification and the final permit modification
which was issued by the EPA in December 2012
(http://www.epa.gov/region2/waste/dupont_pompto
n/additionaldocs.html). The cleanup of the Acid
Brook Delta and uplands requires a modification of
the permit under the federal Resource Conservation
and Recovery Act. The final permit modification
will become effective on February 4, 2013 pending
any requests for appeal submitted prior to that date.
Most work plans relating to the changes in the
permit modification will be submitted to EPA for
approval within 30 days of the permit effective date.

Expanded Acid Brook Delta Sediment Removal

All sediment will be removed down to the peat
layer in an expanded area from the mouth of the
Acid Brook Delta to a line closer to the Ramapo
River channel, running approximately north-south,
and coinciding with the 2 ppm surficial mercury
concentration contour line. A revised Corrective
Measures Implementation Workplan addressing the
modified permit conditions must be submitted by
DuPont to EPA for approval within 30 days of the
effective date of the permit modification.

Pompton Lake Sediment Sampling Plan

Sediment sampling will be performed outside the
40-acre dredge area to delineate mercury
concentrations in sediment outside of the dredging
area. The objective is to identify "hot spots" within
the rest of the lake which may require removal.
Potential impacts from lake sediment on
downstream areas will also be evaluated from the
Pompton Lake dam downstream to Riverside Park,
a distance of approximately three miles.

www.EPA.gov/region2/waste/dupont_pompton/index.html


-------
Community Update

January 2013

If you would like additional
information, please contact:

Pat Seppi

Community Involvement

Coordinator

(212)637-3679

seppi .pat@epa. gov

Visit EPA's Web Site at:

http://www.epa.gov/region2/waste
/dupont pompton/index. html

Post Cleanup Long-Term Monitoring Program
and Ecological Risk Assessment

A post cleanup, long-term monitoring program of
the lake system will be performed to confirm the
effectiveness of the dredging/restoration project.
Baseline conditions of the Pompton Lake system
will be established prior to dredging to help
determine the effectiveness of the
dredging/restoration project and the potential need
for further dredging.

Two years after completion of dredging and re-
establishment of the bio-layer, an updated
Ecological Risk Assessment will be conducted
using updated risk data, bioaccumulation factors,
and relevant, newly gathered site information. This
work will be conducted in close coordination with
the U.S. Fish and Wildlife Service.

Uplands Restoration Program

A revised Uplands Restoration Program will be
prepared. This plan must ensure that the potential
pathways for exposure of wildlife to mercury-
contaminated soil are eliminated.

Site Background:

From 1902-1994, DuPont manufactured explosives
on a 570-acre site located at 2000 Cannonball Road
in Pompton Lakes and Wanaque, New Jersey. Past
operations and waste management practices have
contaminated surface water, soil, sediment and
ground water both on- and off-site. The primary soil
and sediment contaminants are lead, mercury and
copper. Primary ground water contaminants are
volatile organic compounds which can cause vapor
intrusion in areas where the shallow ground water
contaminant plume extends beneath homes. The
DuPont Pompton Lakes Works site is regulated
under the federal Resource Conservation and
Recovery Act. DuPont is responsible for conducting
the necessary cleanup with oversight by the EPA
and the New Jersey Department of Environmental
Protection.

www.EPA.gov/region2 /waste/dupont_pompton/index.html


-------