[Federal Register Volume 61, Number 56 (Thursday, March 21, 1996)]
[Proposed Rules]
[Pages 11597-11599]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-6561]
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ENVIRONMENTAL PROTECTION AGENCY
[FRL-5443-4]
40 CFR Part 300
National Oil and Hazardous Substances Pollution Contingency Plan
National Priorities List
AGENCY: Environmental Protection Agency.
ACTION: Notice of Intent to Delete the New Castle Spill Site from the
National Priorities List (NPL).
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SUMMARY: The Environmental Protection Agency (EPA) Region 3 announces
its intent to delete the New Castle Spill Site (Site) from the National
Priorities List (NPL) and requests public comment on this proposed
action. The NPL constitutes Appendix B of 40 CFR part 300 which is the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP).
EPA promulgated the NCP pursuant to section 105 of the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) of
1980, as amended. EPA and the Delaware Department of Natural Resources
and Environmental Control (DNREC) have determined that all appropriate
CERCLA actions have been implemented and that the Site poses no
significant threat to public health, welfare, or the environment.
Therefore, further remedial measures pursuant to CERCLA are not needed.
DATES: Comments concerning the proposed deletion of the Site from the
NPL may be submitted on or before April 22, 1996.
ADDRESSES: Comments may be submitted to Stephanie Dehnhard (3HW23),
Remedial Project Manager, U.S. Environmental Protection Agency, 841
Chestnut Building, Philadelphia, Pennsylvania, 19107, (215) 597-3167.
Comprehensive information on this Site is available for viewing at
the Site information repositories at the following locations:
U.S. EPA, Region 3, Hazardous Waste Technical Information Center,
841 Chestnut Building, Philadelphia, PA, (215) 597-6633. Delaware
Department of Natural Resources and Environmental Control, 715 Grantham
Lane, New Castle, DE, (302) 323-4540.
FOR FURTHER INFORMATION CONTACT: Stephanie Dehnhard (3HW23), U.S. EPA
Region 3, 841 Chestnut Building, Philadelphia, PA, 19107, (215) 597-
3167.
SUPPLEMENTARY INFORMATION:
I. Introduction
II. NPL Deletion Criteria
III. Deletion Procedures
[[Page 11598]]
IV. Basis For Intended Site Deletion
I. Introduction
The Environmental Protection Agency (EPA) Region 3 announces its
intent to delete the New Castle Spill Site, New Castle, Delaware, from
the National Priorities List (NPL), Appendix B of the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR Part 300,
and requests comments on this decision. EPA identifies sites that
appear to present a significant risk to public health, welfare, or the
environment and maintains the NPL has the list of those sites. As
described in Section 300.425(e)(3) of the NCP, sites deleted from the
NPL remain eligible for remedial actions in the unlikely event that
conditions at a site warrant such action in the future.
EPA will accept comments on the proposal to delete this Site from
the NPL for thirty calendar days after publication of this notice in
the Federal Register.
Section II of this notice explains the criteria for deleting sites
from the NPL. Section III discusses the procedures that EPA is using
for this action. Section IV discusses the New Castle Spill Site and
explains how the Site meets the deletion criteria.
II. NPL Deletion Criteria
Section 300.425(e) of the NCP provides that sites may be deleted
from, or recategorized on the NPL where no further response is
appropriate. In making a determination to delete a site from the NPL,
EPA considers, in consultation with the state, whether any of the
following criteria has been met:
(i) Responsible parties or other parties have implemented all
appropriate response actions required;
(ii) All appropriate Fund-financed response under CERCLA has been
implemented, and no further action by responsible parties is
appropriate; or
(iii) The remedial investigation has shown that the release poses
no significant threat to public health or the environment and,
therefore, taking of remedial measures is not appropriate.
Sites may not be deleted from the NPL until the state in which the
site is located has concurred on the proposed deletion. EPA is required
to provide the state with 30 working days for review of the deletion
notice prior to its publication in the Federal Register.
Pursuant to the NCP, 40 CFR 300.425(e)(3), all sites deleted from
the NPL are eligible for further Fund-financed remedial actions should
future conditions warrant such action. When there is a significant
release from a site deleted from the NPL, the site can be restored to
the NPL without application of the Hazard Ranking System.
III. Deletion Procedures
Section 300.425(e)(4) of the NCP sets forth requirements for site
deletions to assure public involvement in the decision. During the
proposal to delete a site from the NPL, EPA is required to conduct the
following activities:
(i) Publish a notice of intent to delete in the Federal Register
and solicit comment through a public comment period of a minimum of 30
calendar days;
(ii) Publish a notice of availability of the notice of intent to
delete in a major local newspaper of general circulation at or near the
site that is proposed for deletion;
(iii) Place copies of information supporting the proposed deletion
in the information repository at or near the site proposed for
deletion; and,
(iv) Respond to each significant comment and any significant new
data submitted during the comment period in a Responsiveness Summary.
If appropriate, after consideration of comments received during the
public comment period, EPA then publishes a notice of deletion in the
Federal Register and places the final deletion package, including the
responsiveness summary, in the Site repositories.
Deletion of a site from the NPL does not itself create, alter, or
revoke any individual's rights or obligations. As stated in Section II
of this Notice, Sec. 300.425(e)(3) of the NCP provides that the
deletion of a site from the NPL does not preclude eligibility for
future response actions.
IV. Basis for Intended Site Deletion
The following site summary provides EPA's rationale for the
proposal to delete the New Castle Spill Site from the NPL.
The Site is a former manufacturing plant of the Witco Corporation
(Witco) located 0.5 miles west of the Delaware River and 0.5 miles
north of the City of New Castle, Delaware. Surrounding the Site is a
mixed commercial and residential area. The Site is bordered on the west
by a marsh and on the east by a dual highway.
Among the chemicals Witco used in the production of plastic foams
was the semi-volatile organic compound tris(2-chloropropyl) phosphate
(Tris). Sometime before 1977 it is estimated that approximately 4-5
drums of Tris, stored on the Site, were spilled on the ground
contaminating the soil and shallow ground water beneath. Under the
direction of DNREC, the ground water was pumped and discharged into the
adjacent marsh. Numerous investigations of the soil and ground water
followed, including an EPA Site Inspection in 1981. EPA proposed the
Site for inclusion on the NPL on December 30, 1982 and finalized the
listing on the NPL on September 8, 1983.
Pursuant to an Administrative Order on Consent with DNREC, Witco
conducted a remedial investigation (RI) and feasibility study (FS) from
February 1988 to June 1989. These studies determined the extent of
contamination, the risks to human health and the environment posed by
the contamination, and cleanup alternatives to address those risks. The
RI included sampling of soils, ground water, surface water, and marsh
sediments.
Results of the RI showed that the ground water in the shallow
Columbia aquifer was contaminated with the organic compounds Tris,
trichloroethylene (TCE), and 1,2-dichlorethene. Only Tris was
determined to be present at levels that presented a significant risk to
human health. TCE was determined to be from another source upgradient
of the Site and was addressed through a separate State action. No Tris
contamination was found in the deeper Potomac aquifer. Tris and several
other organic compounds were found in soil samples but at levels that
would not threaten human health or the environment and were no longer
considered a source of contamination to the ground water. Contaminant
levels found in the marsh area were well below levels that would
threaten the wetland habitat or environmental receptors.
Using the RI data, an endangerment assessment was performed to
evaluate the risks that contaminants detected at the Site posed to
human health and the environment. Of the numerous exposure pathways
evaluated, only potential future exposure to ground water used as a
potable water supply was determined to present a risk to human health
that exceeded acceptable levels as defined by the NCP. As no one was
using the Columbia aquifer in the area for a potable water supply,
natural attenuation was determined to be the most appropriate means by
which to reduce the Tris concentrations to acceptable levels. EPA
developed a health-based drinking water cleanup level of 4.4 mg/l for
Tris and estimated that it would take approximately four years for Tris
to reach this level by natural attenuation.
To document this cleanup approach, EPA and DNREC issued a Record of
Decision (ROD) on September 28, 1989 which included the following
[[Page 11599]]
components: (1) Monitoring of the Columbia aquifer on a quarterly basis
for Tris to ensure the effectiveness of the natural attenuation
process; (2) monitoring of the Potomac aquifer on an annual basis for
Tris to ensure that contamination has not migrated from the Columbia
aquifer; (3) monitoring of the surface water and sediments of the
adjacent wetlands on an annual basis for Tris, with further evaluation
and bioassay testing required if trigger values of 100 ug/l Tris in
surface water, or 1000 ug/kg Tris in sediments were reached; (4)
institutional restrictions on the placement of wells in the Columbia
aquifer in the vicinity of the Site; and, (5) a five year effectiveness
review of the remedy.
Public participation was encouraged in the remedy selection
process. Prior to issuing the ROD, EPA and DNREC had released a
proposed plan outlining the cleanup alternatives developed in the
feasibility study and the preferred remedy. A public comment period
followed the proposed plan's release from August 22, 1989 to September
22, 1989. A public meeting was held on September 6, 1989 to discuss the
proposed plan. All public comments were addressed and documented in the
responsiveness summary which is part of the ROD.
In April 1991, EPA and Witco entered into a Consent Decree whereby
Witco agreed to implement the remedy selected in the ROD. Witco began
quarterly ground water, surface water, and sediment monitoring in July
1992 which continued through September 1995. Tris levels in the surface
water and sediment samples were consistently well below the trigger
levels specified in the ROD or not detected at all; therefore, no
further evaluation or bioassay testing was necessary in the marsh. Tris
was not detected in the Potomac aquifer in any sampling event.
Of the 13 monitoring wells screened in the Columbia aquifer that
were included in the monitoring program, only two wells showed
concentrations of Tris above the ground water cleanup level of 4.4 mg/l
during the entire monitoring period. By natural attenuation, Tris
concentrations decreased with time in these two wells until they were
below the cleanup level for the last several sampling events. During
the last sampling event in September 1995, Tris concentrations ranged
from approximately 1 to 2 mg/l. A statistical analysis of the data
confirmed that there is very little chance that the Tris concentration
will exceed the cleanup level in the future.
In November 1990, pursuant to the ROD, DNREC instituted a Ground
Water Management Zone (GMZ) in the vicinity of the Site to restrict
installation of drinking water wells in the area. Now that the Tris
cleanup level has been achieved in the area of the Site and there is no
longer a need to prevent exposure to the ground water, DNREC will
retract the GMZ following the deletion of the Site from the NPL.
Based on the information presented above, EPA has determined that
Witco, the responsible party for this Site, has implemented all
response actions required and that no further action is appropriate.
Thus, the required NPL deletion criteria presented in Section II,
above, have been met. DNREC has concurred on this determination.
Correspondence documenting this concurrence is included in the
supporting documentation.
The ROD stated that EPA would conduct a five-year effectiveness
review to reevaluate the Site. The evaluation made to determine if the
NPL Deletion criteria have been met serves as that review. In addition,
EPA reviewed the most recent toxicological information available for
Tris and determined that the cleanup level of 4.4 mg/l in ground water
remains protective. Therefore, EPA has determined that the Site poses
no significant threat to public health or the environment.
The NCP at 40 CFR 300.430 states that EPA shall review remedial
actions every five years if hazardous substances, pollutants, or
contaminants remain at the site above levels that allow unrestricted
exposure and unlimited use. Since neither of these conditions exists at
this Site, further five-year reviews are not warranted and will not be
conducted.
EPA, with the concurrence of DNREC, believes that the criteria for
deletion of the Site have been met. Therefore, EPA is proposing
deletion of the Site from the NPL. Documents supporting this action are
available in the site repositories of information.
Dated: March 8, 1996.
Alvin R. Morris,
Acting Regional Administrator, U.S. EPA Region 3.
[FR Doc. 96-6561 Filed 3-20-96; 8:45 am]
BILLING CODE 6560-50-P
