[Federal Register Volume 61, Number 63 (Monday, April 1, 1996)]
[Proposed Rules]
[Pages 14280-14284]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-7745]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR PART 300
[FRL-5448-8]
National Oil and Hazardous Substances Pollution Contingency Plan;
National Priorities List
AGENCY: Environmental Protection Agency.
ACTION: Notice of intent to delete the Washington County landfill from
the National Priorities List; request for comments.
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SUMMARY: The United States Environmental Protection Agency (U.S.
[[Page 14281]]
EPA) Region 5 announces its intent to delete the Washington County
Landfill Superfund Site from the National Priorities List (NPL) and
requests public comment on this action. The NPL constitutes Appendix B
of 40 CFR part 300 which is the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), which U.S. EPA promulgated pursuant
to section 105 of the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA) as amended. This
action is being taken by U.S. EPA, because it has been determined that
fund-financed responses under CERCLA have been implemented and U.S.
EPA, in consultation with the State of Minnesota, has determined that
no further response under CERCLA is necessary. U.S. EPA and the State
have determined that remedial activities conducted at the Site to date
have been protective of public health, welfare, and the environment. In
addition, based on the results of a five-year review of the remedial
action completed in January 1994, the existing remedy is being upgraded
to improve long-term protectiveness. The State of Minnesota will
undertake any further response actions that may be necessary, using
funds provided under the Minnesota Landfill Cleanup Law.
DATES: Comments concerning the proposed deletion of the Site from the
NPL may be submitted on or before May 1, 1996.
ADDRESSES: Comments may be mailed to Gladys Beard (SR-6J) Associate
Remedial Project Manager, Superfund Division, U.S. EPA, Region 5, 77 W.
Jackson Blvd. (SR-6J), Chicago, IL 60604. Comprehensive information on
the site is available at U.S. EPA's Region 5 office and at the local
information repository located at: Minnesota Pollution Control Agency
Public Library, 520 Lafayette Rd., St. Paul, MN 55155-4194. Requests
for comprehensive copies of documents should be directed formally to
the Region 5 Docket Office. The address and phone number for the
Regional Docket Officer is Jan Pfundheller (SMR-7J), U.S. EPA, Region
5, 77 W. Jackson Blvd., Chicago, IL 60604, (312) 353-5821.
FOR FURTHER INFORMATION CONTACT: Lawrence Schmitt, Remedial Project
Manager at (312) 353-6565, Gladys Beard (SR-6J) Associate Remedial
Project Manager, Superfund Division, U.S. EPA, Region 5, 77 W. Jackson
Blvd., Chicago, IL 60604, (312) 886-7253 or Don de Blasio (P-19J),
Office of Public Affairs, U.S. EPA, Region 5, 77 W. Jackson Blvd.,
Chicago, IL 60604, (312) 886-4360.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Introduction
II. NPL Deletion Criteria
III. Deletion Procedures
IV. Basis for Intended Site Deletion
I. Introduction
The U.S. Environmental Protection Agency (EPA) Region 5 announces
its intent to delete the Washington County Landfill Site from the
National Priorities List (NPL), which constitutes Appendix B of the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP),
and requests comments on the proposed deletion. The EPA identifies
sites that appear to present a significant risk to public health,
welfare, or the environment, and maintains the NPL as the list of those
sites. Sites on the NPL may be the subject of remedial actions financed
by the Hazardous Substance Superfund Response Trust Fund (Fund).
Pursuant to Section 300.425(e)(3) of the NCP, any site deleted from the
NPL remains eligible for fund-financed remedial actions if the
conditions at the site warrant such action.
The U.S. EPA will accept comments on this proposal for thirty (30)
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 procedures that EPA is using for
this action. Section IV discusses the history of this site and explains
how the site meets the deletion criteria.
Deletion of sites from the NPL does not itself create, alter, or
revoke any individual's rights or obligations. Furthermore, deletion
from the NPL does not in any way alter U.S. EPA's right to take
enforcement actions, as appropriate. The NPL is designed primarily for
informational purposes and to assist in Agency management.
II. NPL Deletion Criteria
The NCP establishes the criteria the Agency uses to delete Sites
from the NPL. In accordance with 40 CFR 300.425(e), sites may be
deleted from the NPL where no further response is appropriate. In
making this determination, U.S. EPA will consider, in consultation with
the State, whether any of the following criteria have been met:
(I) Responsible parties or other persons have implemented all
appropriate response actions required; or
(ii) All appropriate fund-financed responses under CERCLA have been
implemented, and no further response 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, remedial measures are not appropriate.
III. Deletion Procedures
Upon determination that at least one of the criteria described in
300.425(e) has been met, U.S. EPA may formally begin deletion
procedures once the State has concurred. This Federal Register notice,
and a concurrent notice in the local newspaper in the vicinity of the
Site, announce the initiation of a 30-day comment period. The public is
asked to comment on U.S. EPA's intention to delete the Site from the
NPL. All critical documents needed to evaluate U.S. EPA's decision are
included in the local information repository and the deletion docket.
Upon completion of the public comment period, the U.S. EPA Regional
Office will prepare a Responsiveness Summary to evaluate and address
each significant comment that was received. The public is welcome to
contact the U.S. EPA Region 5 Office to obtain a copy of this
responsiveness summary. If U.S. EPA then determines the deletion from
the NPL is appropriate, final notice of deletion will be published in
the Federal Register.
IV. Basis for Intended Site Deletion
The Washington County Landfill site is located within the city
limits of Lake Elmo in Washington County, Minnesota. Lake Elmo is
approximately nine miles northeast of St. Paul. The site occupies a 110
acre parcel, and the landfill covers 40 acres of the site. The area
adjacent to the site is predominantly residential with a small amount
of farming. Residences are directly adjacent to the site on the north,
west, and south. There is a city park to the east of the site.
Approximately 3000 people reside within a three mile radius of the
site. A recreational lake, Lake Jane, is located 250 feet north of the
site.
The landfill is located in a gently sloping area and is underlain
by sand and gravel deposits. Ground water flow in the sand and gravel
aquifer below the site is generally to the south away from Lake Jane.
The site was extensively mined for sand and gravel prior to its use as
a sanitary landfill during the years 1969 through 1975. The landfill
was operated jointly by Washington and Ramsey Counties (``the
Counties''), which accepted approximately 2.6
[[Page 14282]]
million cubic yards of solid waste. The solid waste is estimated to be
73% residential waste, 26% commercial waste, and 1% demolition waste.
Following landfill closure, ground water at the site was found to
contain elevated levels of organic and inorganic substances in wells on
and off-site, including residential wells. Volatile organic compounds
(VOCs) found in residential wells were the most serious concern. The
site was proposed for the NPL July 8, 1983. The listing was finalized
in September 21, 1984, 49 FR 37070.
Operable Unit 1
Remedial planning activities began under the authority of the
Minnesota Pollution Control Agency (MPCA) prior to finalization of the
site on the National Priorities List. In 1982, MPCA requested that the
Counties begin investigating the need for remedial action at the site.
On October 24, 1984, the Counties and MPCA signed a Response Order
by Consent which required the following:
Installation and operation of a ground water gradient control
system, which captured contaminated ground water and prevented further
movement of contaminants off-site;
Installation and operation of a spray irrigation system for VOCs in
the captured ground water;
Monitoring of the landfill and area ground water to ensure the
effectiveness of the gradient control system and the protection of
residential wells; and
Provision of safe drinking water supplies to residents whose
private wells contained substances in excess of Minnesota private
drinking water well criteria. An interim water supply was required
immediately upon effect of the Order and a permanent supply was to be
developed.
Construction of monitoring wells, a gradient control well, and the
air stripping system was accomplished in sequence with the Phase I thru
Phase IV investigations during 1982 and 1983. The gradient control
system began full operations on December 12, 1983. The system consisted
of one gradient control well near the southwest corner of the landfill,
designed to extract 200 gallons per minute, and a spray irrigation area
in the southeast portion of the site. The spray irrigation area
consisted of an area of 1.9 acres with sandy soils. This area was
believed to be contained within the capture zone of the gradient
control system. Twenty-seven monitoring wells were installed and an
additional 25 residential wells were being monitored for the presence
of contaminants.
The Phase V report in February 1984 provided the first evaluation
of the performance of the system. Regular evaluations, modifications,
and improvements to the system continued after 1984. During that time,
the gradient control system was expanded to include 4 wells capable of
extracting a maximum of 400 gallons per minute, berms were constructed
and other improvements were made to increase infiltration of treated
ground water at the treatment area, and an off-site discharge was added
for some extracted ground water. A backup treatment area was added and
used while the primary treatment area was down for maintenance. The
backup treatment area is not currently in use. Finally, the number of
monitoring wells was expanded to 38.
The interim alternative water supply consisted of bottled water for
4 residences, which was implemented immediately after the Response
Order was effective in 1984. Planning for a permanent water supply for
affected residents resulted in the report: ``Long Term Drinking Water
Supply Plan for Washington County Sanitary Landfill No. 1'' dated
October 1985. On July 7, 1986, MPCA issued a Minnesota Enforcement
Decision Document (MEDD) which approved the use of activated carbon
filters for the residences with drinking water well advisories issued
by the Minnesota Department of Health. The activated carbon filters for
the 4 affected residences were installed immediately after the MEDD was
effective in 1986.
Operable Unit 1 is a containment remedy, with treatment of the
extracted ground water. The reports provided by the Counties documented
the results of regular sampling of monitoring wells and residential
wells, which indicated that the gradient control system adequately
contained the ground water contamination on site. Remedial action
implementation for Operable Unit 1 ground water and drinking water
measures was conducted by the Counties under MPCA authority and
oversight prior to the issuance of U.S. EPA's Unilateral Administrative
Order on January 16, 1992. U.S. EPA's Unilateral Administrative Order
required the Counties to continue the implementation of MPCA's previous
requirements. Under the requirements of MPCA's terminated Response
Order by Consent, there were no cleanup levels or termination
provisions for this operable unit at the site.
Quality Assurance/Quality Control (QA/QC) measures for ground water
sampling and analysis were specified in MPCA's Response Order by
Consent. U.S. EPA adopted these same measures in its Order. QA/QC for
all other activities was monitored by MPCA, and all documentation is
contained in correspondence between the Counties and MPCA or in
internal MPCA memos and reports.
In September 1992, a soil gas survey conducted at the site by the
MPCA discovered explosive levels of landfill gases in soils at the
western boundary of the site. After further investigation confirmed
that there was significant off-site migration of explosive gases, U.S.
EPA issued a First Amended Unilateral Administrative Order on February
17, 1993. This Order required the Counties to control landfill gas
migration so that explosive levels are not exceeded at the property
boundary.
A barrier extraction vent system was constructed along the west
side of the landfill to intercept migrating gases; this system was
completed in December 1993. The system consisted of 11 extraction vents
connected to a blower system. The gas control system effectively
controlled gas migration from the western portion of the site
immediately. The mixture of air and landfill gases collected by the
system was found to be safe for discharge to the atmosphere without
treatment. Off-site areas which contained elevated levels of explosive
gas in soils were monitored and gas levels were found to slowly
dissipate. Monitoring of basements in nearby residences for gas
accumulation was initiated shortly after discovery of the gas, and no
exceedences of safe levels occurred.
Remedial action implementation for Operable Unit 1 explosive gas
control measures was conducted by the Counties under U.S. EPA authority
and MPCA oversight. QA/QC measures for landfill gas sampling and
analysis were specified in the approved work plans. U.S. EPA approved a
Remedial Action Report documenting the QA/QC for completion of
construction activities for explosive gas control in March 1995. This
report describes the activities completed pursuant to the First Amended
Unilateral Administrative Order.
Operable Unit 2
Based on the results of residential well sampling conducted during
1988 and 1989, MPCA requested the Minnesota Department of Health (MDH)
to reassess the health risks to residents. As a result, the MDH issued
drinking water well advisories to 10 residences. MPCA subsequently
requested the Counties to re-evaluate the long-term drinking water
supply needs of affected residences. The Counties submitted the report
``Long-Term Drinking Water Supply Plan, Washington County
[[Page 14283]]
Sanitary Landfill No. 1'' dated June 30, 1990. This report constitutes
the Remedial Investigation/Feasibility Study for Operable Unit 2. MPCA
executed a Record of Decision (ROD) requiring the construction of a
public water supply system to serve the 10 residences on September 27,
1990. U.S. EPA concurred with this ROD on November 15, 1990.
Although not required by the ROD, the Counties elected to provide
the alternate water supply to 73 additional residences within a service
area which surrounds the site. The service area was developed to
include all residences which might possibly be affected by the site.
The additional work also includes the abandonment and sealing of 68
residential wells within the service area, since continued use of these
could possibly contribute to further movement of contaminants away from
the site. Construction of the water supply system was initiated in June
1991 and connection of the 10 residences with drinking water advisories
to the system was completed in December 1991. Connection of 72 of the
remaining 73 residences was completed by June 1992.
A Remedial Action Report dated September 1992 documents
construction activities for Operable Unit 2. The report describes both
the activities required by the ROD and the additional work performed by
the Counties in order to increase the protectiveness of the remedy.
Community relations activities conducted by MPCA for Operable Unit
2 began on July 27, 1990, when the RI/FS and Proposed Plan were
released to the public. The documents were placed in an information
repository at the Lake Elmo Branch of the Washington County Public
Library, 3459 Lake Elmo Avenue, Lake Elmo, MN and notices published in
local newspapers. A public comment period was open from July 31, 1990
thru August 31, 1990, and a public meeting was held on August 14, 1990.
A responsiveness summary was included with the ROD.
Remedial action implementation for Operable Unit 2 was conducted by
the Counties under MPCA authority and oversight. The MDH reviewed plans
and specifications for the installation of the public water supply
system and the sealing of residential wells. Documentation of QA/QC for
this operable unit is contained in the Remedial Action Report.
Operable Unit 2 is an alternate water supply, and there are no
cleanup levels for this activity. The Remedial Action Report documents
that the system was properly installed and tested, and is functioning.
The water supply system is connected to the City of Oakdale's
distribution system. Lake Elmo and Oakdale are jointly responsible for
maintaining the distribution system and assuring the quality of the
drinking water delivered to the residents. Operable Unit 2 is completed
and there are no operation and maintainance (O&M) requirements for the
alternate water supply system. Responsibility for routine operation of
the water supply system has been assumed by the local municipalities.
The QA/QC program utilized throughout this remedial action has been
sufficiently rigorous and adequately complied with to enable the
determination by U.S. EPA that all activities have been correctly
carried out and all results accurately reported. U.S. EPA is thereby
assured of the satisfactory execution of the remedial action consistent
with MPCA's Response Order by Consent, MEDD, and Record of Decision, as
well as U.S. EPA's 1992 and 1993 Unilateral Administrative Orders.
Five-Year Review
Hazardous substances will remain on-site above levels that will
allow unrestricted use and unrestricted exposure, and CERCLA Section
121 provides that reviews will be performed every five years for
remedial actions which result in hazardous substances, pollutants, or
contaminants remaining at the site above levels that allow for
unlimited use and unrestricted exposure. The first Five-Year Review was
completed in January 1994. U.S. EPA and MPCA concluded that the remedy
has been reasonably effective in limiting further uncontrolled releases
of contaminants to the environment. However, the inadequacies
documented in the review indicated the need for modifications to the
remedy. The remedy was not found to be sufficiently protective of human
health and the environment and as operated unlikely to be cost-
effective for the long-term. Specific recommendations follow:
Long-Term Water Supply
U.S. EPA and MPCA recommended that the long-term water supply
system remedy continue as it currently exists. The public water supply
along with well abandonment continued to provide an alternative safe,
long-term source of water to the owners of residences near the landfill
who were issued drinking water well advisories by the State.
Ground Water Remedial Action
The long-term need for a ground water remedial action was found to
be related to recommendations for closure and post-closure as described
below. A final landfill cover combined with a long-term landfill gas
extraction and treatment system, if necessary, would reduce long-term
reliance on the current gradient control well and treatment system.
However, in the short-term, a ground water gradient control well and
treatment system would continue to be necessary at the Site. The need
for a gradient control system should be evaluated at least on an annual
basis.
U.S. EPA and MPCA recommended that the ground water and treatment
system be modified to utilize either an air stripper or granular
activated carbon filtration system prior to spray irrigation. Winter
spraying will be halted and storage capacity of effluent will be
provided if the effluent cannot be properly treated.
Ground Water Monitoring Well Network
U.S. EPA and MPCA recommended that the existing ground water and
ground water monitoring plan used to evaluate the performance of the
system be maintained, with the addition of several monitoring wells.
Landfill Closure and Post-Closure Requirements
U.S. EPA and MPCA recommended that a final landfill cover be
installed to current MPCA standards. A final landfill cover should
limit infiltration of precipitation into the fill and help to reduce
leachate production. The reduction of leachate should in turn reduce
the amount of loading to ground water at the landfill site. Reduction
of the moisture in the fill should also help to reduce the
bacteriological activity in the fill, thus reducing the rate of methane
production.
Minnesota Landfill Cleanup Law
In 1994, the Legislature of the State of Minnesota enacted the
Landfill Cleanup Law, Minnesota Laws 1994, ch. 639, codified at
Minnesota Stat. Sec. Sec. 115B.39 to 115B.46 (the Act), authorizing the
Commissioner of the MPCA to assume responsibility for future
environmental response actions at qualified landfills that have
received notices of compliance from the Commissioner. Additionally, the
Act established funds to enable the MPCA to perform all necessary
response, operation, and maintenance at such landfills.
A notice of compliance was issued by MPCA for the Washington County
Landfill Site on November 21, 1995. MPCA has since assumed all
responsibility for the Washington County Landfill under the Act. This
includes operating the ground water gradient control and gas control
systems
[[Page 14284]]
as well as the implementation of the recommendations of the Five-Year
Review. Therefore, no further response actions under CERCLA are
appropriate at this time. Consequently, U.S. EPA proposes to delete the
site from the NPL.
Dated: March 18, 1996.
David A. Ullrich,
Acting Regional Administrator, U.S. EPA, Region 5.
[FR Doc. 96-7745 Filed 3-29-96; 8:45 am]
BILLING CODE 6560-50-P
