PB97-963111
EPA/541/R-97/035
March 1998
EPA Superfund
Explanation of Significant Difference
for the Record of Decision:
United Heckathorn Company
Richmond, CA
11/29/1996
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
V 75 Hawthorae Street
».«<" Sa« Francisco, CA 94105
United Heckathorn NPL Superfund Site
Richmond, California
Explanation of significant Differences
November 29, 1996
I. Introduction
Pursuant to Section 117 (c) of the Comprehensive Environmental
Response, Compensation and Liability Act, as amended, (CERCLA), the
United States Environmental Protection Agency (EPA) is issuing this
explanation of significant differences (ESD) for the United
Heckathorn Superfund Site located in Richmond, California (the
Site). This explanation of significant differences will be added
to the Administrative Record for the Site. The Site Administrative
Record is available for review by members of the public from 8 a.m.
to 5 p.m. Monday through Friday at the U.S. EPA Region 9 Superfund
Records Center, 95 Hawthorne Street, Suite 403S, San Francisco,
California. Appointments to review the Site Administrative Record
can be made by calling the U.S. EPA Region 9 Superfund Records
Center at (415) 536-2000.
II. summary of Site History, Contamination Problems and Selected
Remedy
From 1947 to 1966, portions of the United Heckathorn Superfund
Site (located in the Port of Richmond on San Francisco Bay) were
occupied by a pesticide formulation business. Site soils and
sediments in Richmond Harbor were contaminated by chlorinated
pesticides, particularly DDT and dieldrin, released from the
formulation activities.
EPA listed the Site on the CERCLA National Priorities List in
March 1990. EPA's investigation of the Site found unacceptable
levels of DDT and dieldrin in marine sediment in the Lauritzen
Channel and Parr Canal.' EPA concluded that DDT and dieldrin
contamination in these two areas if not addressed by cleanup
actions "may present an imminent and substantial endangerment to
public health, welfare, or the environment." Most importantly, DDT
-and dieldrin were found at unhealthy levels in fish'in Richmond
Harbor and. . despite posted warnings and a state advisory,
subsistence and recreational fishing occurs in Richmond Harbor.
On October 26, 1994, EPA issued its CERCLA Record of Decision
which selected the following cleanup and other response actions for
the Site:
dredging of all young bay mud from the Lauritzen Channel and
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Parr Canal, with offsite disposal of dredged material;
placement of clean material in the dredged areas of the
Lauritzen Channel and Parr Canal after the completion of the
dredging;
construction of a cap around the former formulation area
to prevent soil erosion;
a deed restriction limiting use of the property to
non-residential uses; and
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marine monitoring to verify the effectiveness of the remedy.
• Pursuant to a court-approved Consent Decree with EPA, the
Montrose Chemical Corporation of California, Inc. (Montrose) has
agreed to conduct the dredging of the Lauritzen Channel and Parr
Canal as veil as the placement of clean material in the Channel and
Canal following conclusion of the dredging.
.Since August of this year, contractors hired by Montrose have
been conducting the dredging activities in the Parr Canal and
Lauritzen Channel and shipping the dredged sediment offsite, by
rail, to a permitted disposal facility. Initial dredging
activities have been completed in the Parr Canal. However, as of
today, despite on-going dredging in the Lauritzen Channel since
mid-September, a substantial portion of the Lauritzen Channel,
containing some of the highest concentrations of DDT and dieldrin,
has not yet been dredged.
III. Description of Significant Differences and the Bases for
those Differences
As part of the public comment received prior to EPA's issuance
of the CERCLA Record of Decision in 1994, the U.S. National Oceanic
and Atmospheric Administration (NOAA), a federal agency authorized
under CERCLA to protect certain natural resources, recommended that
the dredging of the Lauritzen Channel and Parr Canal not be
conducted during the period from December 1 to March 1 in order to
protect the herring spawning season in San Francisco Bay. In the
Response to Comments portion of the EPA 1994 Record of Decision,
EPA agreed to abide by NOAA's request and EPA stated that "[EPA]
will ensure that the remedy is not implemented between December 1
and March 1."
By this ESD, EPA is now authorizing and allowing marine
response actions, including dredging and related activities, in the
Lauritzen Channel and Parr Canal, to be conducted on and after
December 1. This decision is based on the following
considerations. First and foremost, NOAA, having been apprised of
the situation, including the status and progress of dredging in the
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Lauritzen Channel, supports continuing the dredging and related
activities in order to complete the marine remedial actions as soon
as possible. Second, the areas being dredged are physically
isolated from the rest of Richmond Harbor and San Francisco Bay by
means of a silt curtain and daily turbidity testing is conducted to
confirm that the silt curtain 1m functioning properly. EPA
believes these safeguards will continue to prevent the release of
dredged sediments into the larger ecosystem of Richmond Harbor
during dredging -activities. Third, if weather conditions or
testing results suggest dredging activities could or vould result
in a release of sediment outside the dredging area, EPA has full
authority to order the dredging activities to cease until favorable
conditions return or are restored. . And fourth, given that a
substantial portion of the Lauritzen has been dredged already,
significant and costly response actions may have been required to
stabilize sediment conditions in the Lauritzen Channel if further
dredging had been postponed until March 1.
IV. Support Agency Comments
In addition to comments from NOAA, the U.S. Department of the
Interior, another federal CERCLA natural resource trustee agency,
has indicated that it supports continuation of dredging and related
activities on and after December 1 in order to complete the marine
remedial actions as soon as possible.
V. Determination
Considering the change to the selected remedy described in
this ESD, EPA believes that the remedy remains protective of human
health and the environment, and also complies with state and
federal requirements that are applicable or relevant and
appropriate to this remedial action, and is cost effective.
John/Wise * Date
Deputy Regional Administrator
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