[Federal Register: July 28, 2003 (Volume 68, Number 144)]
[Proposed Rules]
[Page 44259-44264]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28jy03-26]
=======================================================================
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 300
[FRL-7534-6]
National Oil and Hazardous Substances Pollution Contingency Plan;
National Priorities List
AGENCY: Environmental Protection Agency.
ACTION: Notice of intent for partial deletion of the Rocky Mountain
Arsenal National Priorities List Site from the National Priorities
List; request for comments.
-----------------------------------------------------------------------
SUMMARY: The Environmental Protection Agency (EPA) Region 8 announces
its intent to delete the Selected Perimeter Area (SPA), encompassing
4,930 acres, of the Rocky Mountain Arsenal National Priorities List
Site (RMA/NPL Site) On-Post Operable Unit (OU) from the National
Priorities List (NPL) and requests public comment on this proposed
action. The NPL constitutes
[[Page 44260]]
Appendix B of 40 CFR part 300, which is the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP), which EPA promulgated
pursuant to section 105 of the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA).
EPA bases its proposal to delete the SPA of the RMA/NPL Site on the
determination by EPA and the State of Colorado, through the Colorado
Department of Public Health and Environment (CDPHE), that all
appropriate actions under CERCLA have been implemented to protect human
health, welfare and the environment and that no further response action
by responsible parties is appropriate.
This partial deletion pertains to the surface (soil, surface water,
sediment), structures, and groundwater media of the Selected Perimeter
Area of the On-Post OU of the RMA/NPL Site. The Surface Deletion Area
of the On-Post OU RMA/NPL Site, composed of the surface and structures
media only within an additional 123 acres, also is being proposed as a
separate partial deletion during the same public comment period. The
rest of the On-Post OU and the Off-Post OU will remain on the NPL and
response activities will continue at those OUs.
DATES: Comments concerning this proposed partial deletion may be
submitted on or before August 26, 2003.
ADDRESSES: Comments may be mailed to: Catherine Roberts, Community
Involvement Coordinator (8OC), U.S. EPA, Region 8, 999 18th Street,
Suite 300, Denver, Colorado, 80202-2466, 1-800-227-8917 or (303) 312-
6025.
Comprehensive information on the RMA/NPL Site, as well as
information specific to this proposed partial deletion, is available
through EPA's Region 8 Superfund Records Center in Denver, Colorado.
Documents are available for viewing by appointment from 8 a.m. to 4
p.m., Monday through Friday excluding holidays, by calling (303) 312-
6473. The Administrative Record for the RMA/NPL Site and the Deletion
Docket for this partial deletion are maintained at the Joint
Administrative Records Document Facility, Rocky Mountain Arsenal,
Building 129, Room 2024, Commerce City, Colorado 80022-1748, (303) 289-
0362. Documents are available for viewing from 12 p.m. to 4 p.m.,
Monday through Friday, or by appointment.
FOR FURTHER INFORMATION CONTACT: Ms. Laura Williams, Remedial Project
Manager (8EPR-F), U.S. EPA, Region 8, 999 18th Street, Suite 300,
Denver Colorado, 80202-2466, (303) 312-6660.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Introduction
II. NPL Deletion Criteria
III. Deletion Procedures
IV. Basis for Intended Partial Site Deletion
I. Introduction
The Environmental Protection Agency (EPA) Region 8 announces its
intent to delete the Selected Perimeter Area (SPA) of the Rocky
Mountain Arsenal/National Priorities List (RMA/NPL) Site, Commerce
City, Colorado, from the National Priorities List (NPL) and requests
comment on this proposed action. The NPL constitutes Appendix B of the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP),
40 CFR part 300, which EPA promulgated pursuant to Section 105 of
Comprehensive Environmental Response, Compensation and Liability Act
(CERCLA), 42 U.S.C. 9605. EPA identifies sites that appear to present a
significant risk to public health 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 (Fund).
This partial deletion of the Site is proposed in accordance with 40 CFR
300.425(e) and Notice of Policy Change: Partial Deletion of Sites
Listed on the National Priorities List (60 FR 55466 (Nov. 1, 1995)). As
described in 40 CFR 300.425(e)(3), portions of a site deleted from the
NPL remain eligible for further remedial actions if warranted by future
conditions.
EPA will accept comments concerning its intent for partial deletion
of the RMA/NPL Site for thirty days after publication of this notice in
the Federal Register.
Section II of this document explains the criteria for deleting
sites from the NPL. Section III discusses the procedures that EPA is
using for this proposed partial deletion. Section IV discusses the
Selected Perimeter Area of the RMA/NPL Site and explains how it meets
the deletion criteria.
II. NPL Deletion Criteria
The NCP establishes the criteria that EPA 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 to protect public
health or the environment. In making such a determination pursuant to
section 300.425(e), EPA will consider, in consultation with the State,
whether any of the following criteria have been met:
Section 300.425(e)(1)(i). Responsible parties or other persons have
implemented all appropriate response actions required; or
Section 300.425(e)(1)(ii). All appropriate Fund-financed response
under CERCLA has been implemented, and no further response action by
responsible parties is appropriate; or
Section 300.425(e)(1)(iii). The remedial investigation has shown
that the release poses no significant threat to public health or the
environment and, therefore, taking remedial measures is not
appropriate.
A partial deletion of a site from the NPL does not affect or impede
EPA's ability to conduct CERCLA response activities for portions not
deleted from the NPL. In addition, deletion of a portion of a site from
the NPL does not affect the liability of responsible parties or impede
agency efforts to recover costs associated with response efforts. The
U.S. Army and Shell Oil Company will be responsible for all future
remedial actions required at the area deleted if future site conditions
warrant such actions.
III. Deletion Procedures
Upon determination that at least one of the criteria described in
Section 300.425(e) of the NCP has been met, EPA may formally begin
deletion procedures. The following procedures were used for this
proposed deletion of the SPA of the RMA/NPL Site:
(1) EPA has recommended the partial deletion and has prepared the
relevant documents.
(2) The State of Colorado, through the CDPHE, has concurred with
publication of this notice of intent for partial deletion.
(3) Concurrent with this national Notice of Intent for Partial
Deletion, a local notice has been published in a newspaper of record
and has been distributed to appropriate federal, State, and local
officials, and other interested parties. These notices announce a
thirty (30) day public comment period on the deletion package, which
ends on August 26, 2003, based upon publication of this notice in the
Federal Register and a local newspaper of record.
(4) EPA has made all relevant documents available at the
information repositories listed previously for public inspection and
copying.
Upon completion of the thirty calendar day public comment period,
EPA Region 8 will evaluate each significant comment and any significant
new data received before issuing a final decision concerning the
proposed partial deletion. EPA will prepare a responsiveness summary
for each significant comment and any significant new data received
during the public
[[Page 44261]]
comment period and will address concerns presented in such comments and
data. The responsiveness summary will be made available to the public
at the EPA Region 8 office and the information repository listed above
and will be included in the final deletion package. Members of the
public are encouraged to contact EPA Region 8 to obtain a copy of the
responsiveness summary. If, after review of all such comments and data,
EPA determines that the partial deletion from the NPL is appropriate,
EPA will publish a final notice of partial deletion in the Federal
Register. Deletion of the Selected Perimeter Area of the RMA/NPL Site
does not actually occur until a final notice of partial deletion is
published in the Federal Register. A copy of the final partial deletion
package will be placed at the EPA Region 8 office and the information
repository listed above after a final document has been published in
the Federal Register.
IV. Basis for Intended Partial Deletion
The following information provides EPA's rationale for deletion of
the SPA of the RMA/NPL Site from the NPL and EPA's finding that the
proposed final deletion satisfies 40 CFR 300.425(e) requirements:
RMA/NPL Site Background
The Rocky Mountain Arsenal was established in 1942 by the U.S.
Army, and was used to manufacture chemical warfare agents and
incendiary munitions for use in World War II. Prior to this, the area
was largely undeveloped ranch and farmland. Following the war and
through the early 1980s, the facilities continued to be used by the
Army. Beginning in 1946, some facilities were leased to private
companies to manufacture industrial and agricultural chemicals. Shell
Oil Company, the principal lessee, primarily manufactured pesticides
from 1952 to 1982. After 1982, the only activities at the Arsenal
involved remediation.
Complaints of groundwater pollution north of the RMA/NPL Site began
to surface in 1954. Common industrial and waste disposal practices used
during these years resulted in contamination of structures, soil,
surface water, and groundwater. As a result of this contamination, the
RMA was proposed for inclusion on the NPL on October 15, 1984. The
listing of RMA on the NPL, excluding Basin F, was finalized on July 22,
1987. Basin F was added to the RMA/NPL Site listing on March 13, 1989.
On February 17, 1989, an interagency agreement--referred to as a
Federal Facility Agreement (FFA)--formalizing the process framework for
selection and implementation of cleanup remedies at the RMA/NPL Site,
became effective. The FFA was signed by the Army, Shell Oil Company,
EPA, U.S. Department of the Interior, U.S. Department of Justice, and
the Agency for Toxic Substances and Disease Registry.
Prior to the selection of remedial alternatives, a remedial
investigation/endangerment assessment/feasibility study (RI/EA/FS) was
conducted for the On-Post OU to provide information on the type and
extent of contamination, human and ecological risks, and feasibility of
remedial actions suitable for application at RMA. The remedial
investigation (RI) completed in January 1992 studied each of the five
environmental media at the RMA/NPL Site, including soils, water,
structures, air, and biota. The feasibility study (FS) was finalized in
October 1995, and a proposed remedial action plan was prepared and
presented to the public in October 1995.
On June 11, 1996, the Army, EPA, and the State of Colorado signed
the Record of Decision (ROD) for the On-Post Operable Unit. The ROD,
which formally establishes the cleanup approach to be taken for the On-
Post OU, specified the remedial actions to be implemented for soil,
structures, and groundwater for the On-Post OU of RMA.
The On-Post OU of the RMA/NPL Site (see map, RMA Selected Perimeter
Area) encompasses 25.5 square miles in southern Adams County, Colorado,
approximately 8 miles northeast of downtown Denver.
Selected Perimeter Area of the On-Post OU
The SPA is an area of approximately 4,930 acres (7.7 square miles)
on the perimeter of RMA. The proposed deletion of the SPA includes the
surface, structures, and groundwater media of portions of Sections 1,
2, 3, 4, 10, 19, 20, 22, 27, 28, 29, 32, and 33; and all of Sections 5,
7, 8, 11, and 12 (see map).
A remedial investigation (RI) for the On-Post OU completed in
January 1992 studied each of the environmental media at the RMA/NPL
Site including soil, sediment, structures, water, air, and biota. Based
upon evidence gathered during the RI, areas with similar soil
contamination were combined into individual projects. This resulted in
four separate soil cleanup projects within the SPA. These include the
Toxic Storage Yards project located in the southeastern area of the
SPA; the Miscellaneous Southern Tier Soil project located in the south-
central portion of the SPA near the south lakes; the Existing
(Sanitary) Landfill--Section 4 project located in the southwestern
portion of the SPA; and the Burial Trenches--Part I project located in
the southwestern portion of the SPA and east of the Sanitary Landfill
project.
The Toxic Storage Yards project incorporated three contamination
areas, one located within the SPA, considered to potentially contain
chemical warfare agent based on use histories and detections of agent
breakdown products. The Miscellaneous Southern Tier Soil project
included eight contamination areas, four located within the SPA,
contaminated with pesticides (aldrin and dieldrin), and heavy metals.
The Existing (Sanitary) Landfill project incorporated five
contamination areas, all within the SPA, which contained trash and
debris, asbestos-containing material, and drums with high
concentrations of styrene. The Burial Trenches--Part I project included
35 contamination areas, five within the SPA, considered to potentially
contain ordnance or explosives, unexploded ordnance, and munition
debris as well as general construction-related debris and trash.
A structures survey identified seventeen structures within the SPA.
Four of these structures have no history of contamination and were
designated to be retained for future use. The contaminants identified
within the other thirteen structures include asbestos, polychlorinated
biphenyls (PCBs), pesticides, herbicides and heavy metals.
Two groundwater plumes below the western portion of the SPA contain
1,1-dichloroethylene, 1,1,1-trichloroethane, and TCE but are not
attributable to the RMA/NPL Site. Because the groundwater does not meet
drinking water standards, the Klein Water Treatment Facility--built in
1989, prior to completion of the RI--treats the groundwater
contamination that is now known to originate from non-RMA/NPL sources.
The Irondale Containment System (ICS) was constructed during
development of the RI/FS as an interim response action (IRA). The ICS
was mostly located on the SPA and installed to extract and treat
groundwater emanating from the Rail Yard--which is primarily
contaminated with dibromochloropropane, and the Motor Pool--which is
primarily contaminated with trichloroethylene. Both of these areas in
the RMA/NPL Site are in close proximity to the SPA. Two additional
groundwater plumes were identified beneath the northwest portion of the
[[Page 44262]]
SPA along the Colorado Highway 2 border. These plumes originate in the
South Plants manufacturing area--which is primarily contaminated with
benzene, chloroform, carbon tetrachloride, and trichloroethylene; and
the historic basins located in the northwest area of the RMA/NPL Site--
which is primarily contaminated with dieldrin, chloroform, and DIMP (a
byproduct of nerve agent production).
A feasibility study (FS) was finalized in October 1995, and a
proposed plan prepared and presented to the public in October 1995. On
June 11, 1996, the On-Post Record of Decision (ROD) was signed by the
Army, EPA, and the State of Colorado. The ROD required the excavation
and consolidation of soil presenting a risk to human health, as well as
munition debris, in a state-of-the-art hazardous waste landfill to be
built within the On-Post OU; and excavation of debris and soil
presenting a risk to biota and placement of those soils in the Basin A
consolidation area which is located in the central portion of the RMA/
NPL Site. The excavated human health exceedence areas were backfilled
with on-post borrow material and revegetated. Unexploded ordnance was
to be transported off-site for detonation or other demilitarization
process, unless the unexploded ordnance was unstable and must be
detonated on-site.
The remedy for structures included the demolition of thirteen of
the seventeen structures identified in the SPA. Four of the seventeen
structures had no contamination history and were not identified for
demolition by the ROD.
The selected groundwater remedy consisted of continued operation of
the groundwater treatment systems, including the ICS to treat the Motor
Pool and Rail Yard plumes and the Northwest Boundary Containment System
to treat the South Plants plumes. Additionally, wells which had the
potential to provide a cross-contamination pathway from the
contaminated, upper groundwater aquifer to the deeper, confined aquifer
were to be closed. The ROD also required continued use restrictions for
the property.
Community Involvement
Since 1988, each of the parties involved with the Arsenal cleanup
has made extensive efforts to ensure that the public is kept informed
on all aspects of the cleanup program. More than 100 fact sheets about
topics ranging from historical information to site remediation have
been developed and made available to the public. Following the release
and distribution of the draft Detailed Analysis of Alternatives report
(a second phase of the FS), the Army held an open house for about 1,000
community members. The open house provided opportunity for individual
discussion and understanding of the various technologies being
evaluated for cleanup of the RMA/NPL Site.
The Proposed Plan for the On-Post OU was released for public review
on October 16, 1995. On November 18, 1995, a public meeting was held,
attended by approximately 50 members of the public, to obtain public
comment of the Proposed Plan. As a result of requests at this meeting,
the period for submitting written comments on the plan was extended one
month, concluding on January 19, 1996. Minimal comments were received
on the alternatives presented for the projects in the SPA of the On-
Post OU. Specifically, the comments requested that excavation of the
western tier landfills be ``complete,'' that the health and safety of
nearby communities be protected from air emissions during excavation
and demolition activities, that additional treatment capabilities or
modification of the existing water treatment systems be considered, and
that potential dioxin contamination of the entire RMA/NPL Site be
evaluated.
The designs for the Miscellaneous Structures, Confined Flow System
Well Closure, and each of the soil projects were provided to the public
for a thirty calendar day review and comment period at both the 30
percent and 95 percent design completion stages (twelve separate public
comment periods). Each design was also presented at the monthly meeting
of the RMA Restoration Advisory Board, composed of community
stakeholders, regulatory agencies, the Army, Shell Oil Company, and the
USFWS. No comments regarding the excavation/demolition approach or the
proposed health and safety controls for each project were received.
Upon completion of the thirty calendar day public comment period
for this NOIDp, EPA Region 8 in consultation with the State and the
Army, will evaluate each comment and any significant new data received
before issuing a final decision concerning the proposed partial
deletion.
Current Status
The Toxic Storage Yards Soil project, completed in 2000, consisted
of three separate cleanup areas including one in the SPA. A total of
4,400 bank cubic yards (bcy) of soils presenting a risk to human health
was removed from this SPA area and disposed in the on-site hazardous
waste landfill. Chemical agent screening was conducted during the soil
excavation and soil ripping activities and three groundwater monitoring
wells were closed. The Miscellaneous Southern Tier Soil project,
completed in 2000, remediated eight areas including three in the SPA. A
total of 12,649 bcy of soil presenting a risk to human health and 8 bcy
of debris were excavated from the three areas within the SPA and
disposed in the hazardous waste landfill. Another 3,325 bcy of soil
presenting a risk to biota was disposed in Basin A. This project also
included the demolition of one structure, Building 863, which was also
disposed in Basin A.
The Existing (Sanitary) Landfill--Section 4 project, completed in
2000, consisted of five separate areas which are all in the SPA. A
small amount of asbestos containing material and 11,975 bcy of soil
presenting a human health risk was disposed in the hazardous waste
landfill. A total of 40,260 bcy of trash and debris was disposed in
Basin A. Ten intact drums containing high concentrations of styrene
were sent to an offsite facility for disposal in accordance with
hazardous waste regulatory requirements. The Burial Trenches Soil
Remediation project, completed in 2002, remediated thirty-five areas
including five in Section 4 of the SPA. All soil presenting a risk to
human health, munition debris and related soil, and asbestos containing
material was disposed in the on-site hazardous waste landfill. All
other material with lesser degrees of contamination, e.g., asphalt
pavement, general construction debris and trash, was disposed in the
Basin A consolidation area.
Demolition and removal of nine of the thirteen structures slated
for removal was completed as part of the Miscellaneous RMA Structure
Demolition and Removal--Phase I project completed in 2002. This project
consisted of the demolition of the structures and foundations; removal
and disposal of structures and foundations, substations, debris piles,
roads and parking areas; removal and disposal or recycling of
underground storage tanks, structural steel and other metal components;
backfilling and grading; and revegetation of the excavated areas. Of
the four remaining structures, one was demolished as part of the
Miscellaneous Southern Tier Soil project, two had been demolished prior
to remedial action, and one structure has been retained for continued
operations of the RMA/NPL Site.
The Northwest Boundary Containment System will continue to
[[Page 44263]]
operate long-term to prevent migration of groundwater plumes offsite.
However, monitoring of the groundwater below the SPA indicates that
contamination in the groundwater has been below all regulatory
standards since 1993. The ICS extraction wells have met the ROD shut-
off criteria and were shut down on October 1, 1997. Extraction wells
for the Motor Pool IRA also met shut-off criteria in March 1998;
therefore, the ICS facility was demolished and removed as part of the
Miscellaneous Structures project on May 7, 2002. A treatment system was
constructed at the Rail Yard to more directly treat the contaminated
groundwater associated with the Rail Yard. The Rail Yard IRA and
Treatment System, and Motor Pool IRA are not associated with the SPA.
Monitoring of the groundwater aquifer for the Northwest Boundary
Containment System and that previously treated through the ICS
extraction wells has been incorporated into the sitewide monitoring
program, as required by the ROD.
The Confined Flow System Well Closure project was completed in
2000. A total of 51 wells, six in the SPA, which extended into the
deeper, confined flow aquifer were closed. Closure was accomplished by
overdrilling the well casing and installing a grout plug. An additional
134 monitoring wells within the SPA are part of the long-term, site-
wide monitoring plan.
Use of the groundwater below the SPA and surface water for potable
drinking purposes is prohibited by the FFA, Public Law 102-402, and the
ROD; and will continue to be prohibited even after the SPA is
transferred to the U.S. Department of Interior or units of local
government. Additional prohibitions imposed by the FFA, Public Law 102-
402, and the ROD include the use of the SPA for residential,
industrial, and agricultural purposes, and for hunting or fishing for
consumptive purposes.
The Army is responsible for ongoing monitoring and maintenance
associated with groundwater wells located on land to be transferred to
the Department of Interior within the SPA. The conduct of long-term
groundwater monitoring required by the ROD is delineated in the Final
Interim Rocky Mountain Arsenal Institutional Control Plan.
Post-ROD Investigations
Since the signing of the ROD on June 11, 1996, three studies have
been conducted that are relevant to the deletion of the SPA. The
Summary and Evaluation of Potential Ordnance/Explosives and Recovered
Chemical Warfare Materiel Hazards at the Rocky Mountain Arsenal (2002)
was conducted in response to the unexpected discovery of six M139
bomblets as part of the Miscellaneous Structures--Phase I project in
the Section 36 Boneyard (central portion of the RMA/NPL Site). Using
state-of-the-art computer imaging, mapping technology, and software
capability which had not existed previously, a comprehensive RMA-wide
evaluation for the potential presence of ordnance and explosives as
well as recovered chemical warfare materiel hazards was completed. The
evaluation identified six additional areas for remedial action (none in
the SPA) and concluded that the future discovery of additional sites
with ordnance/explosives or recovered chemical warfare materiel hazards
is highly unlikely.
In 2001, EPA conducted a four-part Denver Front Range Dioxin Study
which determined that the concentration of dioxins at most of the RMA/
NPL Site, including the SPA, is not statistically different from values
observed in open space and agricultural areas within the Denver Front
Range area. Therefore there is no significant health risk from dioxin
in soils to future Refuge workers, volunteers, or visitors.
As required by the ROD, a Terrestrial Residual Ecological Risk
Assessment was completed in 2002. This report concluded that no
significant excess terrestrial residual risks will remain after the
ROD-required cleanup actions for soil, including additional areas of
excavation and tilling identified as part of remedial design refinement
as required by the ROD, are completed.
Based on the extensive investigations and risk assessment performed
for the SPA of the RMA/NPL Site, there are no further response actions
planned or scheduled for this area. Currently, no hazardous substances
remain at the SPA above health-based levels with respect to anticipated
uses of and access to the site, which are limited under the FFA, Public
Law 102-402, and the ROD. Because the SPA is subject to these
restrictions on land and water use, it will be included in the RMA-wide
five-year reviews. There are no operation and maintenance requirements
for the remedies implemented at the SPA. All completion requirements
for the SPA of the On-Post OU have been achieved as outlined in OSWER
Directive 9320.2-09A-P.
EPA, with concurrence from the State of Colorado, has determined
that all appropriate CERCLA response actions have been completed within
the SPA of the RMA/NPL Site to protect public health and the
environment and that no further response action by responsible parties
is required. Therefore, EPA proposes to delete the SPA of the On-Post
OU of the RMA/NPL Site from the NPL.
Dated: July 16, 2003.
Kerrigan G. Clough,
Acting Regional Administrator, Region 8.
BILLING CODE 6560-50-P
[[Page 44264]]
[GRAPHIC] [TIFF OMITTED] TP28JY03.000
[FR Doc. 03-18741 Filed 7-25-03; 8:45 am]
BILLING CODE 6560-50-C