[Federal Register Volume 64, Number 180 (Friday, September 17, 1999)]
[Proposed Rules]
[Pages 50477-50482]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-24280]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 300
[FRL-6439-8]
National Oil and Hazardous Substances Pollution Contingency Plan
National Priorities List
AGENCY: Environmental Protection Agency.
ACTION: Notice of Intent to Delete the Tipton Army Airfield portion of
Fort George Meade Site, located in Fort Meade, Maryland, from the
National Priorities List (partial site deletion) and Request for
Comments.
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SUMMARY: The Environmental Protection Agency (EPA) Region III announces
its intent to delete the Tipton Army Airfield portion of the Fort
George Meade Site (Site) from the National Priorities List (NPL) and
requests public comment on this 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 the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA), as amended. EPA and
the Maryland Department of Environment (MDE) have determined that all
appropriate CERCLA response actions have been implemented and that no
further action is appropriate. Moreover, 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.
DATES: Comments concerning the proposed deletion of this Site from the
NPL may be submitted on or before October 18, 1999.
ADDRESSES: Comments may be submitted to Nicholas J. DiNardo, (3HS13),
Project Manager, U.S. Environmental Protection Agency, 1650 Arch
Street, Philadelphia, Pennsylvania, 19103-2029, (215) 814-3365.
Comprehensive information on this Site is available for viewing at
the Site information repositories at the following locations:
(1) Provinces Public Library, 2624 Annapolis Road, Severn, MD
21144, Phone: (410) 222-6280.
Hours: Mondays, Tuesdays and Thursdays--1:00 p.m. to 9:00 p.m.;
Wednesdays and Saturdays--9:00 a.m. to 5:00 p.m.; and Fridays--1:00
p.m. to 5:00 p.m.
(2) U.S. Army, Directorate of Public Works, Attn: ANME-PWE, Bldg.
239, 2-1/2 Street and Ross Road, Fort Meade, MD 20755, Phone: (301)
677-9648.
FOR FURTHER INFORMATION CONTACT: Nicholas J. DiNardo, (3HS13), Project
Manager, U.S. Environmental Protection Agency, 1650 Arch Street,
Philadelphia, Pennsylvania, 19103-2029, (215) 814-3365.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Introduction
II. NPL Deletion Criteria
III. Deletion Procedures
IV. Basis for Intended Site Deletion
I. Introduction
The Environmental Protection Agency (EPA) Region III announces its
intent to delete the Tipton Army Airfield portion of the Fort George
Meade Site, located in Fort Meade, Anne Arundel County, Maryland, from
the National Priorities List (NPL), Appendix B of the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP), and requests
comments on this partial deletion. Releases on the Tipton Army Airfield
portion were located at Inactive Landfill 1, Inactive Landfill 2,
Inactive Landfill 3, Fire Training Area, and Helicopter Hangar Area.
The Army is the DOD component and is responsible for implementing all
response actions at the Fort George Meade NPL Site. In consultation
with EPA and MDE, the Army has completed all required response actions
at Tipton Army Airfield portion of the Fort George Meade NPL Site as
detailed below.
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. Pursuant to Sec. 300.425(e)(3) of the NCP, any site
deleted from the NPL remains eligible for remedial actions if future
conditions at the site warrant such action.
In a December 1998 Record of Decision (ROD), an interim remedial
action decision for Tipton groundwater was made, in addition to a no
further action determination for the soils in the following areas of
concern:
Helicopter Hangar Area (HHA);
Fire Training Area (FTA); and
Inactive Landfill No. 3 (IAL3).
In a June 1999 ROD, a final determination for Tipton groundwater,
which includes continued monitoring, was made in addition to a no
further action determination for the soils in the following areas of
concern:
Inactive Landfill No. 1 (IAL1); and
Inactive Landfill No. 2 (IAL2).
[[Page 50478]]
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 procedures that
EPA is using for this action. Section IV discusses how the Site meets
the deletion criteria.
II. NPL Deletion Criteria
The NCP establishes the criteria that 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, 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;
(ii) All appropriate 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, taking of remedial measures is not appropriate.
In addition to the above, for all remedial actions which result in
hazardous substances, pollutants, or contaminants remaining at a site
above levels that allow for unlimited use and unrestricted exposure,
CERCLA Sec. 121(c), 42 U.S.C. 9621(c), the NCP at 40 CFR
300.430(f)(4)(ii) and EPA's policy, OSWER Directive 9320.2-09, dated
August 1995, provide that a subsequent review of a site will be
conducted by the lead Agency ``no less often than'' every five years
after the initiation of the first remedial action at a site to ensure
that conditions at a site remain protective of public health and the
environment. In the case of a site, the Army will conduct a review
every 5 years to evaluate the frequency and need for continued
monitoring of conditions at the Site. This is to ensure that the no
further action remedies continue to provide adequate protection of
human health and the environment. As explained/discussed below, the
Site meets the NCP's deletion criteria listed above. Five-year reviews
will continue to be conducted at the Site until no hazardous
substances, pollutants, or contaminants remain above levels that allow
for unlimited use and unrestricted exposure.
The NCP further specifies that releases shall not be deleted from
the NPL until the State in which the release was located has concurred
on the proposed deletion. 40 CFR 300.425(e)(2). All releases deleted
from the NPL are eligible for further remedial actions should future
conditions warrant such action. Whenever there is a significant release
from a site deleted from the NPL, the site shall be restored to the NPL
without application of the Hazard Ranking System. 40 CFR 300.425(e)(3).
III. Deletion Procedures
Section 300.425(e)(4) of the NCP sets forth requirements for site
deletions to assure public involvement in the decision. MDE also will
review this document along with all other documents in the
Administrative Record and any public comment that may be received
during the public comments period. During the process of proposing 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
release 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. These items shall be available for public inspection and
copying; and,
(iv) Respond to each significant comment and any significant new
data submitted during the comment period in a Responsiveness Summary
and include this response document in the final deletion package.
If appropriate, after consideration of comments received during the
public comment period, EPA will then publish a notice of final deletion
in the Federal Register and place the final deletion package, including
the Responsiveness Summary, in the Site information 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, Section 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
A. Site History
The following site summary provides EPA's rationale for the
proposal to delete the Tipton Army Airfield portion of the Fort George
Meade Site from the NPL.
Fort George G. Meade (FGGM) is located in Fort Meade, Maryland.
FGGM formerly occupied 13,596 acres of land in the northwest corner of
Anne Arundel County. FGGM is a Base Closure and Realignment Act of 1988
(BRAC) parcel, located east of State Route 198 and south of Highway 32.
It is bounded on the west by the Baltimore-Washington Parkway and by
the Patuxent River to the south. The Amtrak railroad track right-of-way
and State Route 175 form the southeast and northeast boundaries of
FGGM, respectively.
The facility was authorized by Congress in 1917 as a training
cantonment for troops during World War I. The U.S. Government
commandeered 4,000 acres, most of which was then farm land, and named
the installation Camp Meade in honor of Major General George G. Meade.
In January 1941, additional training areas were added within the
installation, expanding the post to 13,596 acres. During the 1940s, the
facility underwent widespread growth to accommodate several regiments
who moved their base of operations to FGGM, including the Second U.S.
Army and the Eleventh Cavalry. Tipton Army Airfield was completed in
1963, replacing a small airstrip which had been in operation since
1928.
In 1988, the Defense Authorization Amendments and Base Closure and
Realignment Act of 1988 mandated the closure and/or realignment of
approximately 9,000 acres, encompassing the southernmost two-thirds of
the installation. In 1991, the Army transferred 7,600 of the 9,000
acres to the Department of the Interior's Patuxent Research Refuge
(PRR), formerly known as the Patuxent Wildlife Research Center. A
second land transfer of approximately 500 acres to the PRR took place
in January, 1993.
Use of the Site as a military range has been documented as far back
as the early 1920s. In Special Military Maps from 1923, the area, later
designated as Tipton Army Airfield, was identified as an artillery
impact area. A 1941 South Cantonment Map shows that two ranges were
located within the future Tipton Army Airfield area; one was an anti-
tank range to the west of Bullard Hill, the other was an anti-aircraft
range to the east of Bullard Hill. In the summer of 1942, 81mm and 60mm
mortars were used in this area for target practice. During the same
timeframe, live high-explosive shells were fired over the heads of
troops for training purposes.
[[Page 50479]]
The investigation of the Tipton Army Airfield portion of the Fort
George Meade NPL Site included the following areas: Helicopter Hangar
Area (HHA), Fire Training Area (FTA), Inactive Landfill #1 (IAL1),
Inactive Landfill #2 (IAL2), and Inactive Landfill #3 (IAL3).
HHA includes Building 90 and adjacent areas located at the
northwest corner of the airfield. The HHA is roughly bounded by the
Little Patuxent River to the west, an unnamed tributary to the Little
Patuxent River to the north, Patuxent Road to the east, and the
helicopter parking area to the south. The HHA is located approximately
800 feet west of the FTA. The HHA covers approximately 5 acres.
During operations, the 97th Army Command performed maintenance and
storage of helicopters at Hangar 90. Typical activities included
washing, disassembly, repair, and painting of aircraft. In addition to
the use of fuels such as aviation and diesel fuel, other materials that
were typically used, handled or stored included hydraulic and
lubricating oils, detergents, and solvents. Hangar 90 was cleared and
taken out of service when it was decommissioned in early 1996.
The FTA is located north of Airfield Road and is about 800 feet
east of the HHA. The FTA covers approximately two acres. The FTA is
flat and sparsely vegetated with grass. A drainage swale and culvert
were located parallel to the gate that drained to wetlands/forested
area just west of the FTA. The northern half of the FTA is fenced off,
enclosing the fire training pit and adjacent training areas. The area
was constructed around 1979 for training purposes by the Fort Meade
Fire Department. Fires were typically set inside the pit or in portable
burn pans by using gasoline or aviation fuel. The fires were then
extinguished with water or aqueous film-forming foam, a synthetic
extinguishing agent. Other emergency response training, such as self-
contained breathing apparatus training and emergency rescues, were
performed at the FTA. The fire training pit was constructed of a
concrete berm about one foot high and twenty feet in diameter, which
was surrounded by a concrete apron. An oil-water separator located on
the south side of the fire training pit was used in draining the pit.
Water from the separator was transported from the site via an
underground pipeline to a sanitary sewer. Both the fire training pit
and the oil-water separator were removed in 1998. During the Final RI
report (USACE, 1998b), contaminants from this area were shown to be
restricted to the two wells nearest the FTA.
IAL3 is located on the Tipton Army Airfield parcel in the eastern
portion of the runway area. According to the Enhanced Preliminary
Assessment (PA) Report (USAEC, 1989), IAL3 was initially used as a sand
borrow area. During the late 1940s and 1950s, the area was used as a
sanitary and ``leaf-dump'' landfill. The Tipton Army Airfield was
constructed over the fill area in 1963. The airfield consists of four
hangars, an operations building, a fire station, taxiways and runway,
and a helicopter training area. A storm water management system is
located under the airfield. The site history indicates that the main
disposal area was under what is now the eastern portion of the runway
area. According to the Enhanced PA, during construction of the airfield
in 1963, much of IAL3 was excavated and the materials were disposed of
off-post. The airfield construction plans, which include both pre- and
post-construction geotechnical soil boring logs, indicate that landfill
materials were removed from beneath all runway construction areas for
structural reasons. However, landfilled materials are still present in
areas subjacent to the runways. The landfill boundary was developed
based on the extent of historical operations, aerial photographs, and
subsequent site investigations.
IAL1 covers 16 acres in the north-central portion of the BRAC
parcel between the Little Patuxent River and Bald Eagle Drive. IAL1 is
considered part of the Tipton Army Airfield parcel although it is
physically separated from the airfield by the Little Patuxent River. A
small concrete blockhouse, formerly used as a communications building,
is present on the northwest corner of the area. This boundary was
developed based on the extent of historical operations, aerial
photographs, and subsequent site investigation activities.
According to the Enhanced PA report (USAEC, 1989), IAL1 was used as
an unlined sanitary landfill from approximately 1950 to 1964. No
information has been found indicating the types of material disposed of
at this location. Select historical aerial photographs of IAL1,
compiled by the USEPA (1990 and 1996), are presented in the Final RI
report (USACE, 1998a). The earliest known aerial photograph (1938)
shows IAL1 as a cultivated field. In subsequent aerial photographs from
1943, 1952, and 1957, IAL1 appears as an open clearing or training
area, with no evidence of ground scarring or landfill activity.
Landfill activities were first indicated in aerial photographs from
1963, which show barren areas and what appear to be trenches, probable
debris, and mounded material presumably associated with landfill
activities (USEPA, 1990). Aerial photographs since 1970 show the area
as inactive. The 1963 treeline, which appears to correspond to the
maximum extent of man-made activities, persists to the present. Areas
of mounded materials located on the north side of IAL1, which were
first observed on the 1970 photographs, also persist to the present. A
possible former burial trench location, corresponding to the mounded
area and an area of strong magnetic responses, was tentatively located
in the northern part of IAL1.
IAL2 is located within the BRAC parcel on approximately 10 acres of
land north of New Tank Road (now Wildlife Loop), approximately 450 feet
north and east of the Little Patuxent River. The bulk of IAL2 is
separated from the PRR by the perimeter fence which runs along New Tank
Road then turns north along the western side of IAL2. A dirt access
road runs north, from a locked gate in the fence, through IAL2 to
Tipton Airfield. Other unnamed tracks provide access to the area
between IAL2 and the Little Patuxent River. No buildings or structures
are present at IAL2. This boundary was developed based on the extent of
historical operations, aerial photographs, and subsequent site
investigations.
Select historical aerial photographs of IAL2 from USEPA photo
compilations are presented in the Final Remedial Investigation (RI)
report (USACE, 1998a). IAL2 was initially operated as a soil borrow
area. Large active excavations are apparent in aerial photographs from
1938 and 1943 (USEPA, 1996). By 1952, the borrow area was mostly
overgrown. According to the Enhanced PA (USAEC, 1989), the area was
subsequently operated as an unlined rubble disposal area. In 1957 and
1963, at its maximum extent, mounded materials and probable fill
material are visible in the southern portion of the area. IAL2 was
little used between 1963 and 1970, with aerial photographs showing the
area being increasingly revegetated. A single north-northwest trending
trench is visible along the east side of the access road in 1970
(USEPA, 1990). Continued disposal activity occurred after 1980 in the
northern portion of IAL2 where graded and disturbed areas are visible
in 1986. During RI fieldwork, piles of rubble material (brush, concrete
and asphalt debris) which appear to be of more recent origin were
observed in a marshy area on the north side of IAL2.
Several environmental investigations have been performed at FGGM
since 1988, including an Enhanced PA
[[Page 50480]]
(USAEC, 1989), a study by the Maryland Department of Natural Resources
(MDNR), an RI (USAEC, 1992a), a Site Inspection (SI) Study (USAEC,
1992b), a Draft SI Addendum (which included an Environmental Impact
Statement (EIS) and a Wetland Identification Study) (USACE, 1991), an
Ordnance and Explosives (OE) Removal Action (USACE, 1997), RI reports
(USACE 1998a and 1998b), and sampling and data evaluation for the
Defense Reutilization and Marketing Office Salvage Yard (DRMO) (USACE,
1999). The Enhanced PA includes a review of all available records
related to air, soil, surface water, and groundwater, and identifies
six areas of concern requiring additional investigation at FGGM: active
and inactive landfills, underground storage tanks, asbestos, unexploded
ordnance, surface water, and burning grounds. These reports either
address totally or in part parcels of Tipton Army Airfield.
Maryland Department of Natural Resources ``MDNR'' conducted an
evaluation of the 9,000-acre BRAC parcel in January 1990, which
includes the Tipton area. The study describes the natural features and
land uses associated with the 9,000 acres to be excessed from FGGM and
discusses the degree of development of the retained land. In January
1991, a wetland identification study was prepared by RGH/CH2M Hill,
Inc. to complete the study of the closure and use/reuse alternatives
for the 9,000-acre parcel at FGGM (USAEC, 1994). The report describes
the methods used to identify wetlands on the parcel and presents a map
of wetlands distribution.
A Final EIS for the comprehensive base realignment and partial
closure for FGGM and Fort Holabird was prepared by the U.S. Army Corps
of Engineers, Baltimore District, in August, 1991. This report focuses
on the environmental and socioeconomic impacts associated with the
planned base realignment and partial closure at FGGM and Fort Holabird.
The EIS covers the 9,000-acre BRAC parcel at FGGM. A Draft SI report
was submitted by EA Engineering, Science and Technology (EA) in
January, 1992. This report discusses conditions at the Helicopter
Hangar Area (HHA), four inactive landfills (IAL1 to IAL4), the DRMO,
the Fire Training Area (FTA), the Ordnance Demolition Area (ODA),
underground storage tanks, and asbestos. The Final SI was submitted in
October 1992 (USAEC, 1992b).
A Draft SI Addendum (SIA) report, prepared by Arthur D. Little,
Inc., addresses data gaps identified in the previous SI report (USAEC,
1994a). The SIA focused on the following six areas of investigation:
DRMO Salvage Yard, the FTA, the HHA, IAL2, the ODA, and Soldiers Lake.
Another study, a Remedial Investigation Addendum (RIA), was conducted
concurrently with the SIA (USAEC, 1993a). The results of the RIA are
reported as a separate document. However, some basewide data, such as
geology, general hydrogeology, and background soil concentrations, are
reported in both reports. An OE Removal was conducted by Human Factors
Applications, Inc. (HFA) over the Tipton Army Airfield parcel in 1996
(USACE, 1997a). With the exception of the interior areas of the
inactive landfill sites and areas beneath water, all unpaved areas of
the parcel were searched for potential unexploded ordnance (UXO) to a
depth of four feet.
RI reports (USACE, 1998a and USACE, 1998b) of IAL1, IAL2, IAL3, the
CFD, the FTA, and the HHA were prepared by ICF Kaiser. In addition, an
ecological risk assessment was performed for the 9,000-acre BRAC
parcel, which included data from the inactive landfills, the CFD, FTA,
and HHA. RI sampling data for the DRMO (USACE, 1999) was recently
approved by EPA and MDE. This RI evaluated the potential for the DRMO
to act as an upgradient source for groundwater contamination in the
Tipton Army Airfield area. The RI data evaluation determined that the
DRMO was not impacting the groundwater at the Tipton Army Airfield.
While other groundwater studies will still be conducted for separate
operable units at the Fort George Meade Site and may still include the
Tipton area, no other upgradient areas are suspected as sources of
groundwater contamination at the Tipton Army Airfield.
B. Other Army Actions and Safety Precautions Taken in the Tipton Army
Airfield Area
Past military training activities resulted in the presence of UXO
at the Tipton Army Airfield parcel. The following is a list of many
actions and safety precautions taken by the Army at the Site:
Ordnance Survey (1994)
The Army commissioned an ordnance survey covering all areas of the
airfield to assess the extent of ordnance remaining at the Site and
surrounding areas. During this survey, ordnance was searched for to a
depth of six inches below the surface, and 10% of the remaining area
was surveyed for ordnance to a depth of five feet. During this action,
a total of 1,400 ordnance items were recovered from the Site and
surrounding areas.
Ordnance Clearance (1995-1997)
The Army searched for ordnance from all accessible areas of the
Site to a four-foot depth. Inactive landfill areas, wetlands, and all
paved surfaces were excluded. During this action, 1,548 ordnance items
were recovered, rendered safe, and disposed of. In addition, more than
33 tons of scrap (concrete, metal, and miscellaneous debris) were
recovered incidental to the ordnance removal. Much of this material was
recycled at local facilities.
Miscellaneous Debris Removal (Summer 1998)
Several items that were identified during previous ordnance
clearance projects were recovered for disposal. Items removed included
several 55-gallon drums and an old vehicle-mounted storage tank.
Ordnance Safety Measures, Inactive Landfill 3 (1998)
The Army performed ordnance survey work in and around IAL3. The
safety plan for this area includes developing a long-term monitoring
plan for the site. The first step in this effort was to identify the
depth of soil cover over any landfill debris at this site. The Army
will now develop a schedule for periodic surface sweeps of the area to
ensure that no ordnance items have migrated to the surface through
frost action.
Ordnance Safety Measures, Inactive Landfill 2 (1998)
IAL2, located at the southern most end of the Tipton parcel, could
not be cleared of suspected ordnance because the area contains large
amounts of rubble debris and is partially composed of wetlands with a
shallow water table. The selected response action for this site was the
installation of a passive engineering control consisting of a seven-
foot high chain link fence with three-strand barbed wire surrounding
the entire site. The fence ties into an existing fence along Wildlife
Loop Road, and encompasses an area of 24.68 acres that will be retained
by the United States as a part of FGGM. IAL2 will not be included in
the Tipton parcel transfer.
Ordnance Safety Measures, Building Debris Site (1999)
The Army took additional ordnance safety measures at a 2\1/2\-acre
area designated as the Building Debris Site. Because of its central
location, this area has been made a priority for reuse. The
[[Page 50481]]
selected response action for the site is a combination of additional
ordnance clearance and construction of a vehicle parking lot.
Ordnance Safety Measures, Inactive Landfill 1 (1998-1999)
The selected response action for IAL1 was a combination of ordnance
clearance to a four-foot depth and construction of a safety cover.
During this action, 54 ordnance items were recovered, rendered safe,
and disposed of. In addition, more than 760 tons of scrap (concrete,
metal, and miscellaneous debris) were recovered incidental to the
ordnance removal, and recycled at local facilities. The area of IAL1
not cleared of suspected ordnance is approximately 5.5 acres. A three-
foot thick safety cover has been constructed over the entire landfill.
In summary, the Army's prior response actions addressed the
explosives risks related to UXO and protect human health and the
environment. The specifics of the Tipton Airfield Decision Document
(July, 1998), and the Decision Document Addendum (November, 1998)
include the establishment and enforcement of land use restrictions,
initially via the FGGM Master Plan and, subsequent to property
transfer, via deed restrictions. Existing land use restrictions include
a prohibition on conducting any surface or subsurface excavations,
digging, well drilling, or other disturbances of soil, or below paved
surfaces, without prior written approval of the U.S. Government. This
approval is also required for the first four feet which was previously
cleared of ordnance items. Exceptions can be made for emergency repair
of existing utilities. Groundwater use at the Site is restricted for
any potable or non-potable purposes except for environmental studies.
Furthermore, the existing land use restrictions prohibit residential
use of the property without evaluation of residential exposure risk.
C. Hazard Ranking Process
On April 1, 1997, Fort George G. Meade (FGGM) was proposed for
inclusion to the National Priorities List (NPL). FGGM was added to the
final NPL on July 28,1998. The initial proposal was based on a Hazard
Ranking System (HRS) Score of 51.44, compiled by EPA. An HRS score of
28.5 has been determined as the cut-off point for inclusion on the NPL;
thus sites scoring below that will typically not be added to the NPL.
None of the areas included in this deletion proposal were used in
compiling the above score. Releases at the following four areas at FGGM
were evaluated by the HRS scoring team;
(1) Defense Property Disposal Office (DPDO) Salvage Yard;
(2) Post Laundry Facility (PLF);
(3) Active Sanitary Landfill (ASL); and
(4) Clean Fill Dump (CFD).
The most significant exposure pathway within the HRS Documentation
Record was the observed releases to the surface water migration pathway
(SWMP) from these areas. Primary contaminants of potential concern
(COPCs) in the SWMP were DDT and Lindane. Atrazine was the primary COPC
in the groundwater migration pathway of the HRS. New information
indicates that none of the private wells in the HRS Documentation
Record are currently being used for drinking water purposes (Phone
record with Amanda Sigillito of Maryland Department of Environment). In
addition to the COPCs identified in the offpost private wells, new and
existing information (Ref. No. 25 and No. 26 in the HRS) indicates that
Atrazine was detected in offpost private wells only and not attributed
to the ASL (``ASL Atrazine Study'', U.S. Army Environmental Center,
June 1995). Atrazine is stored and mixed at the Amtrak rail yard, which
is located between the ASL and the offpost wells. Although Atrazine was
not used for HRS purposes, it is likely to be attributable to sources
other than the ASL.
The Army and EPA issued a Record of Decision in December, 1998
which included an interim remedy for the Tipton area groundwater, and
which included a final remedy of no further action for soils at HHA,
FTA, and IAL3. The Army and EPA issued a Record of Decision in June,
1999 which included no further action as a final remedy for Tipton area
groundwater with continued monitoring, and no further action for soils
at IAL1 and IAL2. Details of the groundwater remedies are discussed in
the following sections. The RI reports provide the basis for the no
further action determinations. These reports, which include the
Baseline Risk Assessment, document the findings associated with the
Site. These findings indicate that contaminants detected in the
environment do not pose an unacceptable risk to human health and the
environment as long as the land use restrictions selected and
established by the Tipton Airfield Decision Document and the Decision
Document Addendum remain in effect. The risk calculated under the
current and reasonably anticipated future land use scenarios for the
Site is within the EPA's acceptable risk range. Previously established
land use restrictions focus on maintaining these land use assumptions.
The RI reports included both ecological and human health risk
assessments to address the potential current and future risks posed to
human health and the environment associated with the Site. The human
health risk assessment was based on exposure to soil, surface water,
sediment, and supplementary evaluations of groundwater. The ecological
risk assessment was based on exposure to soil, sediments, and surface
water. The risk assessment included estimates of the risk posed to
human health and the environment assuming the continuation of the
current industrial (non-residential) land use scenario, as well as risk
in the absence of restrictions, or in the event of contaminant
migration. The establishment of land use restrictions eliminates the
exposure route to the contaminated groundwater and, therefore, protects
human health and the environment. The groundwater assessment supports
the continuation of these restrictions. The current land use scenario
estimates the level of risk posed by Fort Meade's current use of the
land. The current land use scenario is based on the assumption that the
property continues in current or like use remains, remains under U.S.
Government authority to enforce existing land use restrictions, and
assumes that groundwater contaminant migration to off-site receptors
will not occur at unacceptable levels.
The RI report for IAL3 also documents Maximum Contaminant Level
(MCL) exceedances of the volatile organic compound, benzene, in
groundwater sampled from well MW3-2 during two sampling rounds. Benzene
has an MCL of 5.0 g/l. The average benzene concentration
detected during the two sampling events is 9.05 g/l. The RI
investigation did not reveal a likely source area. Although the average
concentration of 9.05 g/l exceeds the MCL, the risks
associated with benzene in the Tipton area groundwater as a whole were
relatively low. Even if the groundwater were used residentially, the
benzene risks would be as follows: for a child, the Hazard Index (HI)
would be 0.04; for an adult, the HI would be 0.07; and the cancer risk
would be 2 x 10-6. Therefore, it has been determined that
benzene is not a risk driver for groundwater.
Health risks are based on a conservative estimate of the potential
carcinogenic risk or potential to cause other health effects not
related to cancer. Carcinogenic risks and non-carcinogenic risks were
evaluated as part of the risk assessment; three factors
[[Page 50482]]
were considered: (1) Nature and extent of chemicals at the Site, (2)
the pathways through which human and ecological receptors are or may be
exposed to those chemicals at the Site, and (3) potential toxic effects
of those chemicals.
Cancer risks are expressed as numbers reflecting the increased
chance that a person will develop cancer, if he/she is directly exposed
(e.g., through working at the Site) to the chemicals found in the
groundwater and soil at the Site over a period of time. For example,
EPA's acceptable risk range for Superfund sites is 1 x
10-4 to 1 x 10-6, meaning there is one
additional chance in ten thousand (1 x 10-4) to one
additional chance in one million (1 x 10-6) that a person
will develop cancer if exposed to a Superfund site. The risk associated
with developing other health effects is expressed as a HI, which is the
ratio of the existing level of exposure to contaminants at a site to an
acceptable level of exposure. Below a HI of 1, adverse effects are not
expected. A HI is also used to evaluate ecological risks.
An isolated detection of 2-amino-4, 6-dinitrotoluene was observed
at 0.522 g/l in well MW3-2. This compound, an explosive's
degradation product, was detected at lower depths (Arundel Confining
Layer) during one of two sampling rounds. This isolated detection
resulted in an HI less than 1 for commercial/industrial use scenarios.
4-amino-2,6-dinitrotoluene was detected in both sampling rounds in well
MW3-2. The average sample concentration is 28.6 g/l resulting
in a HI of 2 (EPA Region 3 risk-based screening concentration = 2.2
g/l; Hazard Quotient of 1). The area-wide evaluation of
groundwater concluded that the contamination was not originating from
an identifiable source area within the Site, but was the result of past
activities at Fort George Meade. There is no known carcinogenic risk
associated with 4-amino-2,6-dinitrotoluene. The aminodinitrotoluenes
(particularly 4-A-2,6-DNT) are associated with HIs greater than 1 for
groundwater use by workers or residents. Because of the land use
restrictions already in effect, it has been determined that no exposure
pathways to the public exist due to this class of contaminants,
provided that the land use restrictions are maintained. This is also
true of metals, bis(2-ethylhexyl)phthalate, and acetophenone, which
could contribute further to risks (both carcinogenic and
noncarcinogenic) if residential receptors were ever exposed to the
groundwater. In addition, a study of groundwater migration does not
indicate expected migration of these chemicals to off-post residential
wells above unacceptable concentrations. Given the relatively low
concentrations of the aminodinitrotoluenes, the lack of a known
carcinogenic risk relating to this class of contaminants, the lack of
an identifiable source of these contaminants within the Site, and the
lack of an exposure route, it has been determined that no active
groundwater remediation is required.
Because of the RI findings, the Army and EPA determined that every
two years after the date of the June 1999 ROD, groundwater will be
sampled from certain wells. Monitoring results will be provided to EPA,
MDE, and the Army. In addition, the Tipton area will be inspected to
assure compliance with the land use restrictions. A review every 5
years will be conducted to evaluate the frequency and need for
continued monitoring. This is to ensure that the remedies continue to
provide adequate protection to human health and the environment. The
five year reviews will be conducted pursuant to OSWER Directive 9355.7-
02. ``Structure and Components of Five-Year Reviews,'' and/or other
applicable guidance.
The remedies selected for this Site will be implemented in
accordance with the two Records of Decision. Human health threats and
potential environmental impacts have been reduced to acceptable levels.
EPA and the MDE, therefore, find that the remedies implemented will
provide adequate protection to human health and the environment.
EPA, with the concurrence of MDE, believes that the criteria for
deletion of the Tipton Army Airfield portion of the Fort George Meade
Site have been met. Therefore, EPA is proposing deletion of the Tipton
Army Airfield portion of the Fort George Meade Site from the NPL.
Dated: September 10, 1999.
Thomas Voltaggio,
Acting Regional Administrator, Region III.
[FR Doc. 99-24280 Filed 9-16-99; 8:45 am]
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