United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R03-93/163
November 1992
SEPA Superfund
Record of Decision:
Dover Air Force Base, DE
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50272-101
REPORT DOCUMENTATION 1. REPORT NO. 2
PAGE EPA/ROD/R03-93/163
4. TO* and Subtitle
SUPERFUND RECORD OF DECISION
Dover Air Force Base, DE
Second Remedial Action
7. Author**)
9. Performing Organization Nam* and Address
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
3. Recipient's Accession No.
& Report Date
11/04/92
e
& PwloniuiiQ OfQuitZsttion Rsipt* Mo.
10 Project Task/Work Una No.
11. Comract(C)orGrant
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EPA/ROD/R03-93/163
Dover Air Force Base, DE
Second Remedial Action
Abstract (Continued)
other containerized or free liquids in an unlined trench that was later filled in and
reseeded. Floating waste has been reported at two areas of DAFB, and oily releases are
known to have occurred from these two onsite landfills. Dark brown oil also has been
observed in the monitoring wells at the site. Both of these areas were investigated as
part of the Air Force Installation Restoration Program (IRP), although no previous or
remedial actions have been conducted at either site. This ROD addresses the floating
wastes at both the WP14 (D-4) and LF18 (D-10) sites, and provides an interim remedy, as
OU2. A future ROD will address remediation of contaminated soil and ground water. The
primary contaminants1, of concern affecting the ground water are organics, specifically
oils.
The selected remedial action for this site includes trenching to collect floating waste;
pumping and/or bailing floating wastes from the monitoring wells; storing the hazardous
wastes onsite at either Building 1306, a hazardous waste storage area, or in drums at
specific sites; testing the waste prior to either RCRA disposal or recycling offsite;
disposing of all ground water from the treatment process to a septic system, drainage
ditch, or infiltration trench; considering other methods to collect the waste; and
developing a monitoring program. The estimated present worth cost for this remedial
action ranges from $140,000 to $150,000.
PERFORMANCE STANDARDS OR GOALS:
This action will reduce the spread of the plume of floating waste and recover the waste,
as practicable. No chemical-specific goals were provided for this interim remedy.
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INTERIM
REMEDIAL ALTERNATIVE SELECTION
RECORD OF DECISION
RECOVERY OF FLOATING WASTE
WP 14 (D-4) AND LF 18 (D-10) SITES
DOVER AIR FORCE BASE, DELAWARE
NOVEMBER 1992
Prepared For:
Headquarters Air Mobility Command
DCS Civil Engineering (HQ AMC/CEVR)
Scott Air Force Base, Illinois 62225-5022
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TABLE OF CONTENTS
1.0 DECLARATION
1.1 SITE NAME AND LOCATION 1
1.2 STATEMENT OF BASIS AND PURPOSE 1
1.3 ASSESSMENT OF THE SITE 1
1.4 DESCRIPTION OF SELECTED REMEDY 1
1.5 STATUTORY DETERMINATION 2
2.0 DECISION SUMMARY
2.1 SITE NAME, LOCATION, AND DESCRIPTION 3
2.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES 8
2.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION 10
2.4 SCOPE AND ROLE OF OPERABLE UNITS 11
. 2.5 SITE CHARACTERISTICS 12
2. 6 SUMMARY OF SITE RISKS 15
2.7 DESCRIPTION OF ALTERNATIVES 17
2.7.1 ALTERNATIVE 1 (No Action) 17
2.7.2 ALTERNATIVE 2 (Bioremediation) 17
2.7.3 ALTERNATIVES (Waste Recovery)' 18
2.8 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 19
2.8.1 Overall Protection 20
2.3.2 Compliance with ARARs 21
2.8.3 Long-term Effectiveness and Permanence . 21
2.8.4 Reduction in Toxicity, Mobility, and
Volume through Treatment 21
2.8.5 Short-term Effectiveness 21
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2.8.6 Implenentability 23
2.8.7 Cost 23
2.8.8 State Acceptance 23
2.8.9 Community Acceptance 23
2.9 SELECTED REMEDY 23
2.10 STATUTORY DETERMINATIONS 24
2.11 EXPLANATION OF SIGNIFICANT CHANGES 26
3.0 RESPONSIVENESS SUMMARY
APPENDIX
APPENDIX A PUBLIC MEETING MINUTES
APPENDIX B STATE OF DELAWARE CONCURRENCE LETTER
USTOFRGURES
FIGURE PAGE
1 AREA LOCATION OF DOVER AIR FORCE BASE 4
2 SITE LOCATION MAP DOVER AIR FORCE BASE 6
3 SITE LOCATION MAPS 7
LIST OF TABLES
TABLE PAGE
1 ESTIMATED THICKNESS OF FLOATING WASTE AT EACH SITE . 16
2 POTENTIAL APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS (ARARs) AND TO BE CONSIDERED (TBCs)
REQUIREMENTS 22
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1.0 DECLARATION
1.1 SITB NAMB AMD LOCATZOH
Dover Air Force Base
WP 14 (D-4) , LF 18 (D-10) , ST 05 (JP-4) ,
and SS 27 (XYZ) Sites
Kent County, Delaware
1.2 STATEMENT OT BASIS AMD PURPOSE
This decision document presents the selected interim remedial
action for the WP 14 (D-4) and LF 18 (D-10) Sites at the Dover
Air Force Base, located in Dover, Delaware. The interim remedial
action for the WP 14 and LF 18 Sites was chosen in accordance
with the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA), 42 U.S.C. Section 9601, et sea., and to
the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (MCP), 40 CFR Part 300. Regarding
Sites ST 05 (JP-4) and SS 27 (XYZ) however, it has been
determined, as more fully discussed in. Section 2.11 (Explanation
of Significant Changes), that CERCLA authorities are not
available to address the floating jet fuel at the present time.
Therefore, response actions at these Sites may proceed under
other, appropriate, authorities, e.g. subtitle I (Underground
Storage Tanks) of the Resource Conservation, and Recovery Act
(RCRA). This decision is based on the administrative record for
these Sites.
The State of Delaware and EPA both concur with the selected
remedy.
1.3 ASSESSMENT OF TBB 8XTB
Actual or threatened releases of hazardous substances from the WP
14 and LF 18 Sites, if not addressed by implementing the response
action selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.
1.4 DESCRIPTION OF TBB SELECTED REMEDY
The selected interim remedy for these Sites addresses the long
term, principal threat, continued ground water degradation,
present at the WP 14 (D-4) and LF 18 (D-10) sites. The principal
components of the selected remedy are as follows;
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* The installation of a pumping unit or bailing of an
existing on-site well to recover and control tha
migration of floating waste under each Site;
* The completion of additional monitoring and/or
extraction wells as needed to effectively withdraw the
floating waste and to ensure protectiveness of human
health and the environment and to control the migration
of groundwater, respectively; and
* The treatment or disposal of the recovered floating
waste and entrained ground water.
1.5 STATUTORY DETBRMXHATXON8
This interim action is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to this
action, and is cost effective. Although this interim action does
not fully address the statutory mandate for permanence and
treatment to the maximum extent practicable, this interim action
does utilize treatment and thus furthers that aspect of the
statutory mandate. Because this action does not constitute the
final remedy for any of the Sites, the statutory preference for
remedies that employ treatment that reduces toxicity, mobility,
or volume as a principal element, although partially addressed in
this remedy, will be addressed by the final response action.
Subsequent actions are planned to address fully all the threats
posed by the conditions at these Sites.
Because this remedy will result in hazardous substances remaining
at the Sites above health-based levels, a review will be
conducted to ensure that the remedy continues to provide adequate
protection of human health and the environment, within five years
after commencement of the remedial action. Because this is an
interim action Record of Decision, review of these Sites and of
this remedy will be ongoing as EPA and the Air Force continue to
develop fiaal remedial alternatives for each separate Site.
william- Welser; III, Colonel, USAF Date
Wing Commander
Edwin B. Erickson Date-
Regional Administrator
EPA Region III
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2.0 DECISION SUMMARY
2.1 8ITB IAMB, LOCATION, DESCRIPTION
The Dover Air Force Base (DAFB) is located in Kent County,
Delaware, approximately 3.5 miles southeast of the city of Dover
(DAFB is within the city limits). Figure 1 presents the regional
location of DAFB. Bounded on the southwest by the St. Jones River
and Little Creek to the northeast, DAFB covers approximately
4,000 acres of gently, rolling uplands, surrounded primarily by
cropland and wetlands. Surface elevations range from 10 feet Mean
Sea Level (MSL) along the St. Jones River to 30 feet MSL along
the Base's western boundary. The maximum local relief is
approximately 12 feet at the St. Jones River.
Delaware has a continental type of climate, marked by well
defined seasons. The average yearly temperature in Dover ranges
from 45.8 to 66.5-F. The wettest months are April and May,
averaging over 4 inches of precipitation each month. The mean
annual precipitation in the Dover area is 44.44 inches.
Land uses in the vicinity of DAFB include single and multifamily
residential areas, industrial zones, commercial land along the-
major highway (U.S. Rte. 113), and extensive areas of open and
agricultural land. Natural resource use in the area includes sand
and gravel quarrying operations south of DAFB and boating and
fishing along the St. Jones River.
DAFB employs approximately 5,000 military personnel and over
1,400 civilians. Base personnel live in large residential areas
across U.S. Rte. 113 and southwest of the Base across the St.
Jones River. The City of Dover is the largest population center
and has the highest percentage of young people, of the population
centers surrounding DAFB. The highest percentage of people older
than 65 are located in the town of Little Creek, 1 mile northeast
of the Base.
The NW/SE runway marks the surface water divide on Base, with
drainage either to the north or south accomplished by overland
flow to diversion structures and then into area surface streams.
The flow to the north is into the Morgan and Pipe Elm Branches of
the Little River. Flow to the south is into small tributaries of
the St. Jones River. Most streams may receive up to 75 percent, of
their base flow from the ground water discharge of the Columbia
Aquifer, the water table aquifer under the Base.
The Cheswold and Piney Point Aquifers are the primary water
supply aquifers in the Dover area, providing approximately 80
percent of the total municipal and industrial water pumped in
Kent County. DAFB uses these two aquifers for its water supply.
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FIGURE 1
AREA LOCATION OF
DOVER AIR FORCI SAS-
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These aquifers show no contamination in the Base area. The
Columbia Aquifer, consisting of fine-to-coarse sand with minor
clays, directly underlays the Base. The water table is shallow
and as mentioned earlier, provides base flow for many streams.
over the past fifty years, DATS has managed and disposed of
hazardous wastes in several different ways. There are 11
landfills on the Base, several storage tanks, one abandoned waste
water lagoon, 12 oil/water separators, and several spill sites.
The actions discussed in this Record of Decision (ROD) cover
releases of oily waste in two landfills. Figure 2 indicates the
locations of the four (4) areas, two of which are covered by this
action.
Floating waste is reported to exist in two areas at the Dover
AFB. These two areas are referenced as the WP 14 (D-4) landfill,
and the LF 18 (D-10) landfill (see Figure 3). Free product is
reported to exist in two areas at the Dover AFB. These two areas
are referenced as the ST 05 (JP-4) Fuel LeaJc, and the SS 27 (XYZ)
Fuel Pump Station (see Figure 3). This Interim Action Record of
Decision (ROD) addresses the floating waste at Sites WP 14 and LF
18. Remediation of Sites ST 05 (JP-4) and SS 27 (XYZ) cannot, at
the present time, proceed under CERCLA authorities because
available information indicates that the waste present at these
Sites (jet fuel) would fall under the "petroleum exclusion*
contained in Section 101(14) and (33) of CERCLA. This issue is
discussed more fully in Section 2.1.1 of this document.
As identified in past investigations, the WP 14 Site is
relatively small, restricted in area to less than 3 acres. The
ground and surface near the WP 14 Site is generally flat, with
gentle undulations and a small drainage swale leading to the
north-northwest. The WP 14 Site is in an area prone to standing
water. A small drainage, the headwaters of the Pipe Elm Branch,
exists to the northwest of the site. Intermittently during the
year Base personnel use this araa for training, including
camping. Personnel may be exposed to ground water discharging
into the swale leading to the Pipe Elm Branch. The nearest non-
military population (a single small residence) is approximately
1/2 mile off-Base*
The LF 18 Landfill underlays six acres presently covered by the
Base golf course. The ground surface is well maintained and
slopes gently to the northwest towards a small drainage and man-
made pond. The surface waters from this pond and drainage are
directed towards the St. Jones River. Residential base housing is
located within 1/2 mile of the LF 18 Site in a northwest
direction beyond the surface water drainage.
The ST 05 Fuel Leak Site is an area of underground fuel supply
lines in the south central portion of the Base. The Site occurs
along the aircraft parking apron between Buildings 500 and 501.
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*- I ~1
/ 1
I
1'WH MAIIGN
i AMI ii ,• i
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Sit* HP 14 (D~t Lnifill)
Site I* 18 (0-10 Landfill)
r*t ri~7 / -. A ,' %,
z ~
Site SI 05 (JP^t Fuel Spill)
Site SS 27 (XXZ Ftel Pu^t Sta.)
FIGURE 3
SITE LOCATION MAPS
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The entire area is relatively flat and paved with asphalt.
Elevations range from 20 to 21 feet above MSL. Surface waters
drain into a storm drain and are discharged from the site into
the North Drainage Ditch and then into the Pipe Elm Branch.
A few Base personnel are stationed in the area during working
hours, otherwise the area is removed from personnel activities.
Because the Site is located in the central portion of the Base,
residential areas are far removed.
The SS 27 Fuel Pump Station is at the northwest end of the Base,
at the farthest extent of the parking and refueling apron.
Underground fuel lines connect the pump station to the X, Y, and
Z refueling hydrants and pads. The area around the SS 27 Site has
controlled grading, with two large drainage ditches located north
and southeast of the Site, respectively. Personnel on Base are
present in the area during limited hours of the day. An off-Base
residential area is located approximately 1/2 mile to the
northwest. Ground water flow is estimated to be towards the St.
Jones River and may be discharging into wetlands along the river
west of the Site.
2.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES
DAFB began operations in December, 1941 when the U.S. Army Air
Corps leased the Dover Municipal Airfield for use by Eastern
Defense -Command as a coastal patrol base. In August 1943, the
mission of the field changed to an operational training base for
combat training and the development of air-launched rockets.
The base was deactivated in September 1946, but was periodically
used by the Air National Guard up to 1950. In July, 1950 the base
was reactivated and designated the Dover Air Force Base. In March
1952, accompanying a transfer of command to the Military Air
Transport Services, the base mission changed froa air and land
defense to cargo operations. The base is at present a member of
the Air Mobility Command and is equipped with C-5 Galaxy aircraft
to provide global strategic airlift capability.
Hazardous wastes have been handled in various manners at the base
since 1941. Froa 1941 through 1963, landfills and/or pits located
along the perimeter of the base were used as disposal sites for
oils, paint, hydraulic fluid, and solvents: combustible chemicals
such as oils, fuels, and solvents were used at fire training
areas: and waste water froa industrial shops, such as the engine
buildup shop and the plating shop, were discharged to a storm
drainage ditch that emptied into a tributary of Little Creek.
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During the 1950's and 1960 's OAFE managed its waste very
differently then it does now. on-site landfills, usually trench-
type or large area fill-type, were used for general trash and
cut-of-dat* or residual maintenance supplies, some areas were
used for the disposal of solvent bath fluids and oils. Previous
investigations have identified several areas where there is oily
waste product floating on the water table.
The WP 14 (D-4) Site was used during the late 1950's for disposal
of waste solvents, hydraulic fluids, waste oils, and other liquid
wastes, both containerized and free, generated by shop operations
taking place in the industrial section of the Base. The waste
oils and materials were disposed of in an unlined trench,
reported to be 20 feet wide, 45 feet long, and 10 feet deep. The
trench was filled in and seeded over sometime during the late
1960's.
The area around the WP 14 Site has been investigated during four
previous studies, starting as early as 1983 under the Air Force
Installation Restoration Program (IRP). More detailed studies
with soil and sediment sampling and groundwater analysis were
undertaken in 1986 and 1989 during later phases of the IRP. The
latest study was prepared in 1990 and provided more detailed
analysis.
Site LF 18 (D-10) is a former landfill used during the 1950s for
the disposal of general Base refuse, spent chemicals, and
industrial shop wastes. The landfill was closed and is currently
covered by the Base golf course. A dark brown heavy oil has been
found in one monitoring well installed to study the area.
The LF 18 landfill has been the focus of four studies by the Air
Force under the IRP and Site Investigation .portion of the CERCLA
programs. The earliest study is dated from 1983 and the most
recent investigation included additional soil sampling in 1991.
No remedial or removal actions have been conducted at either the
WP 14 or LF 18 sites.
OAFB uses pipelines, feeder lines, and storage tanks for all jet
fuel (JP-4) requirements on Base. Delivery, storage, and handling
of this jet fuel has, over the years, led to various spills and
leaks. Previous investigations have identified several areas
where there> is free product floating on the- water table at
presumed leak site*.
The ST 05 (JP-4) Site is related to leaks from the fuel supply
lines along the aircraft apron. The supply lines have been in use
for many years. There is no information concerning leaks from
these lines in the early years. After some repairs were made to
the supply lines and valves in early 1987, there were at least
three leaks reported during pressure testing of the lines.
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All the leaks were repaired, however the residual fuel in the
soil was not cleaned up.
The area around the ST 05 Site was investigated as part of the
Air Force's IRP in 1989. During this investigation, the soil gas
and ground water were analyzed, soil samples were taken, and
surface drainage sediments were tested.
The SS 27 (XYZ) Site is the main pumping unit for the northwest
end of the refueling system. OAFB personnel recall that a fuel
spill did occur in the area in the past, however the quantity
that was spilled is unknown. Additionally, a visual layer of fuel
has been reported on rainwater in nearby manholes. The Site was
constructed in the late 1950's and has always been used as a
refueling area.
The SS 27 Site was investigated two times under the Air Force's
IRP. The first study, in 1986 involved the collection of four
ground water samples, a surface water sample, and two sediment
samples. During the 1989 study a total of eight ground water
samples and two surface water and sediment samples were taken,
and a soil gas survey was undertaken.
No remedial or removal actions have been undertaken at either the
ST 05 or the SS 27 sites.
Enforcement Activities
In early 1989 Dover Air Force Base was listed on the National
Priorities List (NPL). The Air Force, EPA,, and DNREC signed a
Interagency Agreement (IAG) on June 29, 1989, under Section 120
of CERCLA. Additionally, EPA issued a Corrective Action Permit
pursuant to Sections 3004(u) and (v) of RCRA which defers
corrective action under Subtitle C of RCRA to implementation of
Remedial Actions under the IAG.
2.3 HIGHLIGHTS OF COMXDHZTY PARTICIPATIOH
There has been consistent community interest in the Dover Air
Force Base NPL site due to its proximity to and its potential
impact on the nearby city of Dover.
In accordance with Sections 113 (k)(2)(B)(i-v) and 117 of CERCLA,
42 U.s.C. sections 9613 and 9617, Dover AFB and EPA held a public
comment period from June 12, 1992 through July 27, 1992 for the
proposed interim remedy at the WP 14 (D-4), LF 18 (D-10), ST 05
(JP-4), and SS 27 (XYZ) Sites. The Proposed Plan was made
available to the public for review at the Dover Public Library
during the entire comment period.
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The notice of availability of this document, the comment period,
and the announcement of the public meeting were published in the
Delaware state Neva dated June 11, 1992. Additionally, television
coverage of remedial activities at Dover Air Force Base was
provided on June 23, 1992 and an additional newspaper article,
concerning the proposed interim action, was published on June 24,
1992.
A public meeting concerning the proposed remedy for the four
sites was held on June 25, 1992 at the Richardson and Robbins
Building at 89 Kings Highway, Dover, Kent County, DE. The meeting
lasted about one hour and there were six members of the public
and press in attendance. With respect to the proposed remedy for
these Sites, however, there were few questions and little
community concern exists. All the questions from the public were
answered at the meeting. There was a follow-up newspaper article,
covering the Public Meeting, published in the Delaware State News
on June 26, 1992.
The Responsiveness Summary, at the end of this document, provides
the responses to all questions received from the public, either
in writing or during the public meeting.
2.4 SCOPE AND ROLE Of OPERABLE UNIT
This operable unit, floating waste, is one of several management
units for the WP 14 (D-4) and LF 18 (D-10) Sites, and addresses
the floating wastes at each Site. This interim action remedy
addresses the principal threats of the floating waste: its
potential migration or discharge to the interconnecting surface
waters near some Sites; continued degradation of a potential
ground water source; and the discharge of volatile organic
compounds (VOCs) though the surface soils.
The cleanup objective of this interim action is to immediately
reduce the volume of waste floating on the ground water.
The benefits of the interim action include:
Reducing the volume of the floating waste,
Containing: the existing floating waste plume,
Limiting the extent of future migration and additional
contamination, and
Reducing VOC concentrations in soil gases.
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This interim action remedy is consistent with an anticipated
final remedy that will address the restoration of the ground
water operable unit and cleanup the subsurface soils at the wp 14
(D-4), LP 18 (D-10), ST 05 (JP-4), and SS 27 (XYZ) Sites. Data
generated during the implementation of the interim action will be
utilized during the final remedy selection and this data will be
used to evaluate the potential aquifer response to remediation.
2.5 SITS CHARACTERISTICS
WP 14 (D-4)
Site WP 14 was a liquid waste disposal area located in the
northeast area of Dover AFB. It appears to have been a single
trench, probably excavated in the late 1950s to a depth of
approximately 10 feet. The trench was used for disposal of
liquids and waste oils generated during industrial shop
activities at Dover AFB. Most of the liquid wastes were probably
dumped directly into the trench, however metal drums containing
liquids may also be buried in the trench.
An old Liquid Fuel (JP-4) Pipeline is located upgradient from the
WP 14 Site. The pipeline was investigated as a possible source.
Two wells, located between the pipeline and the Site, have not
detected contamination or floating wastes on the water table.
A.brown floating waste oil was found in one monitoring well in
the wp 14 area. Based on one year's (1991) measurements, the
floating waste in the monitoring well varied from just a strong
petroleum odor to a thickness of over two feet. Floating waste
thickness measurements taken in a monitoring well of small
diameter do not represent the potential thickness of the waste on
the ground water in the aquifer. Potential waste thicknesses in
the aquifer are a function of the type of floating waste,
characteristics of the aquifer, and the size of the monitoring
well. In July 1992, a series of measurements and calculations
were made that indicated 0.45 feet of waste floating on the
ground water near this monitoring well. At this time, because the
extent of the floating waste in not known, there is not a firm
estimate of the volume of floating waste at the WP 14 Site.
Ground water analysis of samples from the well containing
floating- waste shoved moderate to low benzene, ethylbenzene, and
toluene concentrations, moderate to high 1,2 dichloroethene (1,2
DCE) levels, and low trichloroethylene (TCE) and
tetrachloroethylene (PCE) concentrations. The last three
compounds are characteristic of solvents and not of a petroleum
product.
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This observation, in conjunction with an analysis of the location
of this Site relative to other areas of contamination at the Base
(WP 14 is far removed from other areas) leads to the conclusion
that the floating waste is a source of hazardous substances
contaminating the underlying groundwater. No analysis of the
floating waste has been performed. However, ground water
collected from the well at this Site contained substances
(benzene, 1,2 DCS, PCE, and TCE) which are toxic and probably
carcinogenic (all three are class B2 carcinogens: Class B2 means
there is sufficient evidence of carcinogenicity in animals to
support an inference that the substance is a probable human
carcinogen).
The floating waste at WP 14 was detected upgradient from the
supposed disposal location. However, an EPA review of aerial
photography in the area found the outline of a trench upgradient
from the contaminated monitoring well. One of the primary
objectives of the ongoing remedial investigation is to determine
the lateral and vertical extent of floating waste at WP 14.
Dissolved contaminants are being discharged with the ground water
into the Pipe Elm Branch leading to environmental degradation and
to potential exposure of base personnel if they were to drink the
waters during field exercises. At the present, the floating waste
does not appear to be migrating on the ground water away from the
Site.
L7 18 (D-10)
Site LF 18 is a former landfill used during the 1950s for the
disposal of general Base refuse, spent chemicals, and industrial
shop wastes. Four trenches, some up to 10 feet deep, may have
been used to dispose of the waste. An early study at this Site
has shown that the trenches may be in excess of ten feet deep.
The landfill was covered during the construction of the Base golf
course.
A dark brown heavy oil was found in one of the monitoring wells
installed to study the area. The thickness of measured oil in the
one monitoring well, varied slightly during the year (1991) of
monitoring from 1.17 to l.SO feet thick. Again, thickness
measurements in the monitoring well do not represent the
potential thickness in the- aquifer. Based on August 1992
measurements and calculations, the waste floating on the ground
water in the aquifer near this well is estimated to be 0.13 feet
thick.
The full extent of floating waste contamination at this Site has
not been determined and therefore the volume cannot be estimated
at this time.
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The ground water in the well containing floating waste has been
analyzed and contains moderate to high levels of TCE, moderate to
low levels of 1,4 dichlorobenzene and low benzene, ethyl benzene,
and toluene concentrations. TCE and 1,4 dichlorobenzene are not
associated with petroleum products. This observation, in
conjunction with an analysis of the location of this Site
relative to other areas of contamination at the Base (LF 13 is
far removed from other areas) leads to the conclusion that the
floating waste is a source of hazardous substances contaminating
the underlying groundwater. Analysis of the floating waste has
not been performed. However, the contaminants dissolved in the
ground water collected from this well (benzene, 1,4
dichlorobenzene, and TCE) are carcinogenic (benzene is a Class A
carcinogen: Class A means there is sufficient evidence from
epidemiological studies to support a causal association between
exposure and cancer in humans. TCE, as described previously, is
a Class B2 carcinogen) and/or toxic.
The floating waste at Site LF 18 is located in an upgradient
position from the former landfill trenches. The floating waste
may be migrating off-Base, considering the base boundary is only
50 feet away. The ground water, with dissolved contaminants, is
discharging to surface water drainages and possibly to the nearby
wetlands .•
ST 05 (JP-4)
ST 05 Fuel Spill Site is located along the aircraft parking apron
in front of, or northeast of, Building 501. Leaks to the supply
pipeline and associated valve were repaired in 1987, but residual
fuel in the soil was not cleaned up.
The movement of the ground water at this Site is reported to be
variable in direction and gradient. This situation arises because
Site ST 05 is located along one of the major ground water divides
that underlays the Base. In June ground water flows to the north,
while in August the flow may be towards the east-southeast.
Toluene, xylene, and total petroleum hydrocarbons were detected
in the soils, sediment, and ground water at the ST 05 Site-. TCE,
1,2-OCE, 1,1-DCA, and carbon tetrachloride (CCL4) along with high
concentrations of total purgeable hydrocarbons were detected in
the ground water. There are two wells, close to the fuel lines,
which detected floating product. No analysis of the floating
product was performed, but because it is near the fuel lines that
were reported to have leaked in the past, the floating product at
this Site is assumed to be JP-4 jet fuel.
Based on one year's (1991) measurements, the thickness of the
floating jet fuel varied from approximately one foot to over 2.8
feet in both wells. No measurements were made of the potential
thickness of the floating waste hydrocarbon in the aquifer.
14
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At this time there is not a good estimate of the total volume of
waste jet fuel floating beneath the ST 05 Site. This floating
product is? however, very mobile and contains hazardous
substances, such as benzene and toluene.
As discussed in Sections 1.2 and 2.11, the remediation of Site ST
05 is not addressed in this ROD. Remediation of this Site must
proceed, initially, under other statutory authorities, such as
subtitle I of RCRA.
S3 27 (ZY2)
SS 27 site is the main fuel pumping station in the refueling
hydrant system on the Base.
The ground water at the SS 27 Site is contaminated with a
dissolved plume containing elevated levels of benzene, 1,4-
dichlorobenzene, ethylbenzene, and xylene that exceed applicable
or relevant and appropriate requirements, such as the maximum
contaminant levels promulgated under the Safe Drinking Water Act.
Free-product was detected in two of the sampling points, with a
maximum thickness in the shallow monitoring well of over 11.0
feet of waste jet fuel. The thickness of the floating product in
one monitoring well varied from 6.3 to 11.1 feet over one year's
(1991) monitoring. No measurements or calculations of the
potential floating waste thickness-in the aquifer near this Site
were made. The extent of the floating waste jet fuel plume is not
known at this time and therefore the volume of the fuel to be
recovered has not been estimated.
The free product at the SS 27 Site is spreading under the Site
and has been detected in manhole areas. Additionally, the
dissolved plume from the floating product may be migrating off-
Base in the direction of the wetlands along the St. Jones River.
As discussed in Sections 1.2 and 2.11, the remediation of Site SS
27 is not addressed in this ROD. Remediation of this Site must
proceed, initially, under other statutory authorities, such as
Subtitle I of RCRA.
2.6 StnOORT 07 SZTB RISKS
For the Sites WP 14 and LF 18, hazardous substances in the
floating waste are acting as a source of hazardous substances
causing ground water contamination. Control and recovery of the
floating waste in turn will reduce continued contamination of
these ground waters.
15
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For the Sites ST 05 and SS 27, underground pipeline leaJca and jet
fuel spills during aircraft refueling have resulted in the
development of a floating waste layer beneath the sites. This
floating layer of waste is acting as a source of ground water
contamination'. Reduction and control of the floating product in
turn will reduce continued contamination of these ground waters.
Table 1 summarizes the information developed for one sampling
round of the floating waste thickness at each Site.
TABLB 1 ESTIMATED THICKNESS OF FLOATING WASTE AT EACH SITE
Estimated
Monitoring Floating Waste
Site w?ll PMHffr Date Thickness Comment
WP 14 13 8/8/91 0.4 feet (Brn. oil)
LF 18 07 J 8/9/91 0.3 feet (Brn. Oil)
ST 05 55 P 8/8/91 0.5 feet Piezometer
68 S 8/8/91 0.5 feet (Jet Fuel)
SS 27 59 S 8/8/91 1.6 feet (Jet Fuel)
The soils immediately above the water table have been saturated
with floating waste at the WP 14 and LF18 Sites. This soil
contamination will continue to act as a source of leachable
constituents for future ground water contamination, even after
the floating waste is removed.
This interim action remedy will control the migration potential
of the floating waste thereby reducing the development of
additional soil contamination at Sites WP 14 and LF18.
Actual or threatened releases from Sites WP 14 and LF 18 of
hazardous substances associated with the floating waste, if not
addressed by implementing the interim action selected in this
Record of Decision, may present an imminent and substantial
threat to public health, welfare, or the environment.
In summary, the removal of floating waste will reduce a principal
threat of continued ground water degradation, and a potential
threat of subsurface soil contamination at Sites WP 14 and LF 18.
16
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2.7 DBSCRX9TXOV OF ALTERATIVE*
CERCLA requires that each selected Site remedy be protective of
human health and the environment, comply with applicable or
relevant and appropriate requirements (ARARs), utilize permanent
solutions and alternative treatment technologies or resource
recovery technologies to the maximum extent practicable, and be
cost effective.
As discussed previously, it has been determined that CERCLA
authorities are not available at Sites ST 05 (JP-4) and SS 27
(XYZ) at the present time. Therefore, the following discussion
does not apply to these Sites.
This section summarizes the three alternatives reviewed for
analysis and fulfillment of applicable or relevant and
appropriate requirements. The selected alternatives for the
removal of floating waste at the identified Sites include:
* Alternative 1: No Action
* Alternative 2: Bioremediation
* Alternative 3: Pumping/Bailing with off-Base
Disposal
2.7.1 ALTERATIVE 1
The Superfund program requires that a "no action*
alternative be evaluated at every site to establish a
baseline of comparison. If this alternative is selected
then, as the name implies, no remedial action would be
undertaken at this time. The site conditions would remain as
they are and the qualitative risks discussed above would
continue. The threat to human health and the environment
would not be reduced.
2.7.2 ALTERATIVE 2
Alternative 2, bioremediation, is the process of using
microorganisms to convert the hazardous chemicals into
harmless materials. The process requires suitable microbes
that can biodegrade or transform the wastes and a "good*
growth environment for the microbes. The growth environment
includes such factors as a favorable temperature range, a
supply of inorganic nutrients, the proper pH range, and the
'reduction of competitor or predator microorganisms.
17
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The advantage of bioremediation, if it could work at the
Sites, is that it is a destruction technology or treatment
which eliminates the hazardous waste and leaves only
harmless substances. Two other advantages of bioremediation
are that it requires only minimal site disruption and that
there are low costs associated with the treatment of the
waste on site, if the soils are not saturated- with
hydrocarbons.
Bioremediation, as an alternative for these Sites would
require increasing the number of microbes adapted to the
existing Site conditions and the installation of at least
two new wells to provide oxygen and inorganic nutrients to
the microorganisms. This process would require above ground
pumping and storage systems for these materials. The start-
up time for this process would be lengthy. Additionally, a
major drawback for bioremediation at the Sites is that the
microbes are not effective when the hydrocarbons saturate
the soils and exist as a separate phase.
2.7.3 ALTERNATIVE 3
Under Alternative 3, floating waste would initially be
recovered from the existing monitoring wells, using a pump
or hand bailer on at least a weekly basis. Floating waste
recovered at Sites LF 18 and WP 14 would be taken to the
RCRA permitted storage area (Bldg. 1306). The waste would be
analyzed for hazardous constituents/substances and
suitability for energy recovery/ and then disposed of in
accordance with applicable regulations. If the test results
indicate that hazardous waste or hazardous constituents are
present then the material would be disposed of in accordance
with RCRA. If the test results do not indicate the presence
of hazardous wastes or hazardous constituents, then the
waste would be utilized in an energy recovery (heat)
facility.
All produced ground waters would be either discharged to a
constructed septic system (an infiltration trench),
permitted by the State/ or into a drainage ditch if the
contaminant concentrations are below the limits required by
a NPDES permit. Appropriate consideration will be provided
to control the escape of volatiles from the recovered ground
water during its disposal. A control mechanism might involve
a cover over the infiltration trench.
As additional information is developed during the next phase
of the remedial investigation, other mechanisms for
collecting the floating waste at each Site would be
considered.
18
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These method* might include trenching to collect the
floating- waste, followed by skimmer pumping to an oil/water
separator and then off-Base disposal of the waste at a
permitted facility and discharge of the recovered ground
water as outlined above. If the field data indicate that a
new, separate pumping well would be more effective, then a
dual pump or single pump recovery well may be installed to
optimize removal of the floating waste. Under this method,
the recovered fluids would be handled the same way as the
oil and water removed from the above-described trench.
2.8 SUMMARY OF COMPARATIVB AHALYSIS OF ALTERH&TXYZS
The proposed remedial action alternatives described above were
evaluated under the nine criteria in the NCP, 40 CFR
300.430(e) (9) . These nine criteria can be further categorized
into three groups: threshold criteria, primary balancing
criteria, and modifying criteria, as follows:
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• Short-Term Effectiveness
This criterion covers how fast a remedy may achieve its
goals and if a remedy potentially can create adverse human
health and environmental impacts during implementation of
the remedy.
• Implementabilitv
This criterion references the technical and administrative
feasibility and practicability of the remedy.
• Cost
This criterion covers capital and operation and maintenance
costs and can be discussed in a comparative fashion.
MODIFYING CRITERIA
• Community Acceptance
This criterion insures that the public was informed and
provided comment on the proposed plan or RI/FS report.
• State Acceptance
This criterion indicates that the State and support agencies
have reviewed, commented on, and concur with the proposed
plan or RI/FS report.
These evaluation criteria, which measure the overall feasibility
and acceptability of the remedy, relate directly to requirements
in Section 121 of CERCLA, 42 U.S.C. Section 9621. Threshold
criteria must be satisfied in order for a remedy to be eligible
for selection. Primary balancing criteria are used to weigh
major.trade-offs between alternatives.
State and community acceptance are modifying criteria formally
taken into account after public comment is received on the
Proposed Plan.
The comparative evaluation of alternatives follows.
2.8.1 overall Protection. Alternatives 2 and 3 will provide
an acceptable level of protection of human health and
environmental safety by eliminating the principal threats through
contaminant source reduction and treatment.
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Because the "no action" alternative is not protective of human
health and the environment, it is not considered further in this
analysis as an option for these sites.
2.8.2 Compliance vith ARARs. All acceptable alternatives
would meet their respective applicable or relevant and
appropriate requirements of Federal and state environmental laws.
Table 2 identifies the list of ARARs that were reviewed as part
of this criterion.
2.8.3 Long-term Effectiveness and Permanence. Alternative 3
will greatly reduce the risks presented by the continuation of a
floating layer of waste beneath the sites.
The reduction in the volume of waste and in the physical
(hydraulic gradient) control of the spread of the contaminant
layer will have long-term effects at each Site. However, this is
only an interim remedial action to effect the source of the
potential risks and t:he final remedy selected at the Sites will
provide a more permanent reduction in overall risks. Alternative
2, after full implementation, would maintain a reliable measure
of overall protection. However, Alternative 2 does not provide a
physical control on the gradient of the floating waste.
2.8.4 ~ Reduction in Toxicity, Mobility, or Volume Through
Treatment. Alternative 3 reduces toxicity and mobility of the
floating waste by volume reduction.' Alternative 2 would reduce
toxicity, mobility, and volume by in-situ treatment.
2.8.5 Short-term Effectiveness. Alternative 2 will require
the disruption of present surface operations over a longer period
then Alternative 3. The overall effectiveness of Alternative 2 is
only realized after removal of the free product and the microbes
have become acclimated after the addition of oxygen and other
nutrients. Since the soils are saturated with floating product,
bioremediation (Alternative 2) is not an appropriate technology
at this time.
Alternative 3 will produce an immediate reduction in the volume
of free product. However, this alternative may increase the risk
to human health and the environment over the short term because
of the increase in handling and disposal of the hazardous
materials.
This increase in short term risk will be managed by close
monitoring of personnel involved in the removal process,
inspection of storage and transfer facilities, and the use of
appropriate equipment.
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TABLB 2
APPLICABLE OR RELEVANT AHD APPROPRIATE REQUIREMENTS
(ARABS)
TYPE OF ARAR
CHEMICAL-SPECIFIC
LOCATION-SPECIFIC
ACTION-SPECIFIC
No Action
Biotreatment
Removal of
Floating Waste
Transport and
Disposal of
Floating Wast*
Disposal of
Effluent-
Recovery Well
Installation
Ground Water
Pumping Over
100,000 6PO
None
None
None
None
Delaware UST
Act (7 Del.
Code Ch. 74)
Safe Drinking
water Act
Delaware
Hazardous
Waste Manage-
ment Act (7 Del.
Code Ch. 63)
REQUIREMENT
Risk-based soil action level
based on worker exposure.
Soil concentrations which will
not result in leachate or
ground water concentrations
greater than MCLs.
None
None
None
Delaware UST Regulations
Part B, Section 4
MCLs and MCLGs (40 CFR Part
141)
Protection of ground
water (Del. Haz. Waste Rules
Parts 264, 265)
Clean Water
Act NPDES
Del. Haz. Waste Rules
Parts 262, 263, 264, 265
and 268)
Del. Water Pollution
Control Regulations
Delaware Water Well permits, submittal of
Well construction/abandonment
Construction records, licensing drillers,
(January 1987) and prevent ground water
pollution.
Delaware River Del. River Basin Commission
Basin Comm. Water Quality Regulations
Compact (7 Del.
Code S 6501)
22
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2.8.8 Implementability. Alternative 3 requires a minimum of
equipment and supplies to operate. The existing wells at each
Site could be utilized, the waste will be stored while undergoing
tests, and would be disposed of off-Base by the Base waste and/or
hazardous waste contractors. RCRA permits are in place for
storage of the waste and manifests would be used for all off-Base
shipment^. Contaminated ground water recovered with the floating
waste would be discharged under State permit, to a constructed
septic system (infiltration tranch) or, if allowed, discharged to
a drainage ditch.
Alternative 2 is more difficult to implement because of the new
wells and the required above ground delivery system.
Additionally, Alternative 2 would require the enhanced growth of
microorganisms acclimated to the existing Site wastes and
environment.
2.8.7 Cost. Costs have been compared on a relative,
qualitative basis for the limited options considered. Alternative
2 would be the most costly, because it involves the installation
of new wells; development of a storage, supply, and delivery
system for oxygen and nutrients, and continued monitoring. Total
costs estimated for implementation of Alternative 2 are $300,000
to $600,000. Alternative 3 is generally considered to require
less capital investment and operation and maintenance costs
(Total estimated costs - $150,000 to $400,000).
2.8.S State Acceptance. The State of Delaware, after review
of the Proposed Plan, concurs with the preferred alternative.
2.8.9 Community Acceptance. Community acceptance of the
preferred alternative was evaluated after comments received
concerning the Proposed Plan. Community' acceptance is outlined in
the Responsiveness Summary of this Record of Decision.
2.9 81L1CTBO
Based on the above analysis of alternatives and the limited scope
of this interim remedial action, the Air Force has determined
that Alternative 3 (Recovery of Floating Waste) is the most
effective and appropriate option at the HP 14 and LF 18 Sites.
The EPA and DMREC concur with this determination.
Alternative 3 involves recovery of floating waste from the HP 14
and LF 18 Sites and off-Base disposal of this waste. Initially,
the floating waste will be pumped and/or bailed from existing
monitoring wells. The recovered waste material will either be
stored at Building 1306, the hazardous waste storage area, or in
drums at specific Sites. After testing of the floating waste, it
will be disposed of off-base either for energy recovery or
according to RCRA regulations.
23
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This alternative appears to provide the best balance of tradeoffs
among the listed evaluation criteria and the mandate for
permanence and alternative treatment.
This alternative calls for the design and implementation of an
interim remedial action as a source control to protect human
health and the environment. The goals of this interim action are
to reduce the spread of the plume of floating waste, to recover
as much floating waste as is practicable through pumping, and to
collect data on aquifer and contaminant response to these
remedial measures.
The ultimate level of remediation to be attained will be
determined in a final remedial action for source control at these
Sites. This remedial action will be monitored carefully to
determine the feasibility and practicability of recovering
floating waste hydrocarbon and to ensure that the floating plume
is contained. After the period of time necessary, in the Air
Force's, and EPA's judgment, to arrive at a final decision for
the Sites, a final Record of Decision for source control, which
specifies the ultimate goal, remedy, cleanup levels for the soils
at each Site, and anticipated time-frames will be prepared.
Upon completion of the remedial investigation/feasibility study,
this interim system may be incorporated into the design of.the>
site remedy specified in the final action Record of Decision.
A monitoring program shall be developed to evaluate the extent to
which the floating waste extraction under this interim remedial
action performs. ' .
2.10 STATUTORY DETERMINATIONS
To meet the statutory requirements of CERCLA Section 121, the.
selected remedy must;
• Be Protective of Human Health and the-Environment;
. Comply with ARARs;
» Be Cost Effective;
• Utilize Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable; and
« Satisfy: the Preference for Treatment. That Reduces
Toxicity, Mobility, or Volume as a Principal Element.
/
The description of how the selected Alternative fulfills these
requirements follows.
24
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This selected Alternative will implement an interim remedial
action that is protective of human health and the environment.
The recovered floating waste will also be handled, stored, and
treated in a protective manner. Waste recovery by pumping or
bailing at these Sites will require that personnel be outfitted
in full protective gear including full face air purifying
respirators. When pumping is employed, explosion proof pumps will
be used.
CQttPlv With
The interim remedial action will comply with Federal and State
applicable or relevant and appropriate requirements.
Cost Effective
The selected interim remedial action is cost effective and in
terms of time for effective reduction of the potential threat at
the Sites, it is a very reasonable value. The cost of
implementation of the selected alternative is estimated to be
between $150,000 and $400,000.
'as Alternative ^
The goals of this interim remedy are to remove waste floating on
the water table, to remove some contaminant mass, and to reduce
the spread of contamination.
This interim remedial action will be monitored carefully to
determine the feasibility of achieving an optimal level of
reduction of floating waste. These actions are in furtherance of
the mandate for permanence and treatment to the maximum extent
practicable.
APAiiaA for 9v«*feBAitfe ttiafe TtmAnc.** Vavi.ai.tar. Mobi.li.fev
This interim remedial action is of limited scope and addresses a
specific component for contaminant source control at the HP 14
and LF 18 Sites. The Alternative will reduce the mobility and
volume of the floating waste. The ultimate level of remediation
to be attained at these Sites will be determined in a final
remedial action.
25
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The statutory preference for remedies that employ treatment, that
reduce toxicity, mobility, or volume, although partially
addressed in this interim remedial action, will be addressed by
the final response action. Upon completion of the next phase
RI/FS, this .interim system may be incorporated into the design of
the site remedy specified in the final action ROD.
2.11 EXPLANATION OF SIGNIFICANT CHANGES
Only one significant change from the proposed plan has been made.
Jet fuel, detected floating on the water table at the ST 05 and
SS 27 Sites is subject to the "petroleum exclusion" under CERCLA.
CERCLA response actions are limited to releases of hazardous
substances and/or pollutants or contaminant3. The definitions of
these terms do not include "petroleum, including crude oil or any
fraction thereof re.a. jet fuel] which is not specifically listed
or designated as a hazardous substance under [CERCLA]." Section
101(14) and (33) of CERCLA. Although hazardous substances have
been detected in ground water beneath the ST 05 (JP-4) and SS 27
(XYZ) Sites, on the basis of information presently available, it
cannot be determined that the jet fuel released at these Sites
contains levels of hazardous substances which would remove the
jet fuel from the petroleum exclusion of CERCLA. Therefore,
remediation of jet fuel contamination at these Sites may not
proceed, initially, under this ROD but must take place under
other statutory authorities, e.g. Subtitle I of RCRA (Underground
Storage Tanks).
Also, reflecting the above discussion, the name of the selected
remedy has been changed from FREE PRODUCT RECOVERY WP 14 fD-41.
LF 18 fP-101. ST 05 (JP-4) AND SS 27 fXYZl SITES to RECOVERY OP
FLOATING WASTE WP 14 fD-41 AND LP 18 fD-101 SITES.
Remediation of the ground water and soil at these Sites will be
the subject of a subsequent ROO(s).
26
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> ^ i»j £>: U =. kL=>S
SUMMARY
A responsiveness sumnary is required to provide a summary of the
citizen comments and concerns about the sites, raised during the
public comment period, and the responses to those concerns. All
comments summarized in this document have been considered in
evaluating the final decision of the interim remedial action for
the Sites.
This responsiveness summary for the waste recovery at four Sites
on Dover Air Force Base is divided into the following sections:
Section As overview - A description of the selected remedy and
community reaction to the selected remedy.
Section Bs Background of Community Involvement and concerns - A
brief history of community interest in the Free Product Recovery
project and Dover Air Force Base.
section Ct Summary of Public Comments and Air force Responses -
Replies to public comments.
Section Dt Remedial Designs/Remedial Action Concern* - Discussion
of public concerns which have a bearing on the remedial action.
A. overview
The Proposed Interim Remedial Action Plan (IRAP) was released to
the public for review and comment on June 12, 1992. This date
marked the opening of the public comment period on the
alternatives detailed in the Proposed Plan. A public notice was
published June 12, 1992 which identified Alternative 3 as the
preferred remedial alternative. This alternative is described on
Page 12 of the proposed IRAP. It includes the pumping and/or
bailing of the floating free product from the ground and
recycling of recovered fuel and disposal of other recovered
products.
The limited comments received from the public suggest that area
residents do not object to the preferred alternative. However,
there is concern that the preferred interim remedial action does
not address* the> possibility of contaminated groundvater or
surface* water* migrating of f site. The Air Force conducts
quarterly monitoring of surface water and is continuing an
investigation of base-wide groundvater to address this concern.
27
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B. Background of Community Involvement and Concerns
Sites WP14 (D-4) and LF18 (D-10) were trenches which were used
for the disposal of waste solvents, waste petroleum, and other
shop wastes during the 1950's. After disposal activities ceased
at these sites they were filled with local soil and seeded with
grass. LF18 is now part of the base golf course. The hydrant
fueling system for refueling of the jet aircraft at the base was
installed at the site ST05 (JP-4) in 1957 and at the XYZ fuel
pumping station (site SS27) in 1960. Those systems are still in
use and are planned for replacement starting in 1993.
In 1982 the United States Department of Defense (DOD) implemented
the Installation Restoration Program (IRP) to identify and
evaluate environmental contamination and associated public health
hazards at DOD facilities resulting from past operations and
waste handling/disposal. An Installation Assessment (Phase I -
Records Search) was completed for Dover AFB in 1983. This study
indicated a potential for contamination from past and/or current
facility operations at a number of sites, including the four
sites of concern in this interim remedial action. Two successive
Remedial Investigation (RI) Studies were completed in 1986 and
1989 by Science Applications International Corporation (SAIC) and
E. C. Jordan. These RI's confirmed the presence of contamination
in the soil and groundwater.
The interim remedial action was proposed to reduce the current
contamination level and prevent the spread of the contamination.
A proposed interim remedial action plan was developed which
recommended selection of Alternative 3 (See Overview, Paragraph
A, above).
In addition, a public meeting was conducted on June 25, 1992 and
a public comment period was established from June 12, 1992
through July 27, 1992.
The Public Affairs Office at Dover AFB issued press releases
detailing IRP progress. Coverage in the two daily newspapers
serving the Dover area has usually been front page, but the
issues tend to dissipate within a few days due to a relatively
low level of community concern. The start of remedial activities
at Dover AFB could increase community concern.
C. Summary of Public Comments and Air Force Responses
The majority of the comments revolved around surface water and
groundwater conditions. Additional questions concerned efforts
to identify all possible contamination sources on the base and
the funding source used by the base for clean up. (See Public
Meeting Minutes attached). No written comments were received.
28
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D. R«a«dial Oesign/Reaedial Action Concerns
The only comment regarding implementation of the remedial action
was about the disposal of the recovered floating waste.
Air Force Response: The waste removed from the monitoring wells
will be stored and analyzed to determine if the floating waste
contains other toxic materials. If the floating waste contains
other toxic materials, it would be disposed of as hazardous waste
by Dover Air Force Base through a licensed contractor. If the
floating waste does not contain hazardous wastes or constituents
then it can be disposed of through recycling.
29
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APPENDIX A
PUBLIC MEETING MINUTES
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Public Halting Minutes on tha-
Interim Action Propacad Plan for
Fra* Product Sacovary at Sitaa
WPU (04), LF18 (010), ST05 (J?-4), »nd S827 (XYZ)
Oov«r Air Pore* ••••, D«law*r«
Datai 25 Jun* 1992
tiius 1900
Location! Richardton and Robbing aidg Auditorium
89 Kings Highway
Oov«r DC 19903
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PUBLIC MRTIHG MXNUTIS
capt 4eif*U Chi*f of tn* 436th Airlift Wing Public Affairs office of Dover
Air Fore* Baa*. I would Ilka Co weicom* you ail hare tonight. Tonight we're
her* to diacuaa the interim Action for four fitte for sftt ranwval of 5z*e
product and if that' • not why you' ?» her* tonight your at th* wrong meeting
and we'll give you th* chance to leave right now - what we'll do it ••I'll
introduce Col Cappa in just a moment and we'll have a briefing we'll
introduce our panel to answer - then we'll have a queation ana anawer
period. And that'a pretty much hew we'll do thing*...At thia time I'd like
to introduce col Tom Cappa who'a the Baae civil Engineer, we'd like to have
•ome welcoming comment* from him.
col Cappet Let me Ju*t echo Capt aeicel's welcome to everyone who is here
tonight. A* the Baae Civil Engineer, col Mike Moffitt the commander of the
Airlift Wing of cover haa invited me to come and repreaent him. And tonight
we want to make the public presentation of the plan the baae haa for four of
the aitee on the baae that w» want to clean up and to give everyone an
opportunity to ask questions and ta make input*. Dover ie taken the lead in
environmental cleanup and we're really proud of what we've accomplished in
the laat year or ao. About a year and a half ago we had one maybe two
people in the Environmenta1 Office and new we have aeven and we loolc to have
cloae to thirteen people working in our Environmental Engineering Office
within a year. So we take it very aerioualy. we've been identified aa the
Model Environmental Inatallation for the Air Mobility Command, and aa the*
model installation we are taking efforta to do thing* right and teach other
Baae* throughout the Air Force how to do thing* right* So it i* my pleaaure
to be here and rapreaent Col Moffitt. We'd really like to encourage your
input* and your queation*. Thank you.
Capt Ceiaeli At thi* time I'd like) to introduce Matt Parker who 1* the
Chief of the environmental Planning Branch at Dover Air Force Baae who'll
brief ua on the propoaed aite.
Matt Parkeri Oood Evening my name is Matt Parker, Z'a Chief of
Environmental Planning at Dover Air Force Baae. Thi* evening Z'd like to
take about fifteen minutee to give you a brief introduction and to explain*
the propoaed plan we have initiated for aa interim remedial action at four
aite* on the baae. Thi* evening I'll be going through theae subject at Baae
Hi*tory-cover aome of tha> contaminant aource* that have reeulted in what
we're cleaning up; Environmental Hiatory-we'll go through the propoaed plan
and the reaaea we're; her* thi* evening and we'll alto introduce th* third
alternative)-of thi* project and finally I'll diacuaa futur* environmental
issue* that will ba> undertaken at Dover. Juat e littl* bit about th* Baa*,
in Dee 1941 the •«•*> wa* initiated from th* Dover Municipal Airport. Zt wa*
initiated beeau** of th* war and eoaatal defense. Free) 1943 till the ead e*
the war it wa* P4T training baa* and alao uaad to develop air launch rocket*
and moat of th*** over th* courae of tim* hav* contributed ta acme of our
contamination aource* that you'll •*• later in th* program. Zn 1946 th*
Ba** wae deactivated' and th*n reactivated in 1950. sine* 19S2 th* Bat* ha*
been primarily a cargo Air Force Baae.
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A lot of th* Acronym* hav* changed - -vhat th* ba«* w«a called, and since i
June w* er* Air Mobility Conrad to -- you hear MAC or MATS we are Air
Mobility command.
Our contaminated aourcaa hav* reeulted from aircraft speratloaa and
nai.-.ranaac*. ~ everybody at the baaa ia there for or.* raaaon and cnat la to
support th* aircraft Lei th* Mlaeion that thoa* aircraft support. ft* had
landfill* throughout tha> court* of tin*, in tha early SO'a 60'» and even
into the mid 70'a landfilla were a common diapoaal practice throughout tha
united statee. we've alao had apUla and laaJca and moats of thaea hava> been
in our jee fuel ayatem. Aa you oan aa* tha next four itana ar« tha prime
contaminant aoureaa. of theae four/ petroleum producta are tha major
•oureaa that wa'll ba addraaaing ia our propoaad plan. Jat fual la tha
primary contaminant that wa do hava. w* do about SO million gallona p«r
yaar of Jat fual buainaaa — Moat Buainaaaaa conaidar if thay hav« 1% arror
race, tftay hava good arror rata. 1% of 60 million gallona ia a larga
problaa. Wa don't avan look at 1% work, wa addraaa a tanth of a parcant.
w* hava routine maintananea chacka to maka aura tha intagrity of tha
tightnaaa of tha fual li.-taa and tanka ia alao taatad. Wa'va had «oma
•olvanta that hava baan diapoaad of in aoaa of tha landfilla aa w* diaeuaaad
about in a faw minutaa. wa alao hava aavaral aitaa that hava aoma haavy
matala for plating oparatiana. Our plating oparation war* eloaad in 1985
and wa finally diapoaad o£ tha laat aoureaa laat yaar. Wa alao had aoma)
paatieidaa and thaaa wara uaad to control inaaeta on baaa.
A littlo bit about our anvironmontal historyt In Oetobar 1983 w* bagan
what waa callad a praliminary aaaaaaaant through tho Suparfund proeaaa. In
tha Air Rare* w* hara our own acronym, it'a callad. tha Znatallatioa
Raatoration Program bacauaa it'a fundad aaparataly and than ia not aubjact
to ua* of flup«*fund moniaa. Cn 1964 th« laa« waa nominatad for H?t acatua
that waa baaad on EPA "a avaluation of our preliminary aaaaaamont. Tha naxt
major itama you aaa on tha alido addraaa acudlaa that hava baan undartakan
ainca than. Wa'v* had major ait* invaatigationa and ramadial invaatigationa
at a numbar of sitaa and coapilad a fairly aignifioant amount of analytical
data. All of thia data, waa rollad ovar into on* product in Jun* 1991 in a
product w* call th* Curr*nt situation Xaport. Sine* that wa* initiated
we've identified date, gap* in the) data that w*'d collected previoualy.
we've initiated a final atudybaa* a Baaavid* atudybaae and we'll be
undertaking that within th*next aeveral month*.
The final itaai on h*r* i* an action we'r* undertaking right now thia ia a
remedial deeign that he* been completed and remedial action i* underway in
rtre Training; Are* 3 and if I could juat take a few minute* to put through
aoffi* alid*a> X can ahow you aome of what we're doing out there. Thi* i* what
th* ait* looked lik* originally* Thar* war* dumpatera that were aet up in
the ahap* of *, croa* ua*d to aimulate an aircraft burning. That'a * oloae
up you aee that'* a banned • burned are* that fuel wa* introduced to and an
ignition aource wee provided and it wae aet on fir*. Th* fir* department
practiced putting it out. Thia i* aome of th* contamination that over the
courae of about fifteen yeara leached into the aoil and thia i* what we have
removed. Thi* ia where ttt* aoiL had been atockpiled on plaetic before it
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was transported: to tho- industrial incinerator in Virginia. All the tim«
that ws> wero excavating wo were* continually faepiing to make euro that we
adhered to the> criteria thae had been established in the same; kind of
document the* we're presenting today and a proposed plan and a ROD. Thla is
a picture of a underground storage tank .that had been on site, used to store
the fuel. Thla la after we toetad the soil and found out chat we'd removed
all contamination. ... The backfill ... compacted the loll ... and finally
got back ton established grade, we'll end up putting a cover of copaoil on
it, reseeding it, and then we- will have cleaned up the soil at the site.
The proposed plan la really why we are here thla evening thla is an issue
toe public comment. The publie comment period la 12 June through 27 July.
That'e why we're here tonight, to tee if there la any Input* front you and
the community. Thle will remove floating preducte from four sites and I'll
diacuaa thie In just a second. Thie la th« interim remedial action and that
ia •omething Z want to make clear. This la not a final action this la just
a first step. We're going to remove the product and once we've done that
we''re going to look at remediation of soil and remediation of ground water.
The four sitee that we're looking at arei WP14 we'll call 0-4, this was a
landfill tha« wae developed in the 1950*s for liquid waste disposal
material. You can see there ia nothing obnoxious there, no drums sticking
up out of the ground, this waa covered up and landfllled. we've have about
forty wells in that area that we. use to characterise the groundwater. We-
have reported product in ieee than two wells there, the next site 0-10 ie
also a 1950's landfill, aa you can see now it's a golf course/ it's number 9
fairway at Dover Air Force Base. This waa used for municipal refuse and
also industrial shop waste. It waa generated through the maintenance and
operational aetivitiee of the aircraft, C-S's and 141's. Again we have a
number of wells on thie eite to characterise the product, we've detected
the product from 3 to 4 inches eo about a foot and a half.
The third site la called JP-4 eite ia the result of jet fuel leake in the
hydrant system and valve failures. That ia we've- a jet fuel delivery system
so the aircraft can be refueled on aite and they've been a number of leaks
and breaks in there and ae X ge* into the future initiatives one of the
thing* that we have) right now is an approved product, project for IS million
dollar* to replace the) hydrant fuel system. The aito ie just off the
parking apron ae you can seo the) aircraft . They're largo enough that you
have to take the fuel, to theev you caa't move them to the pump. The final
site ie xrt and again this ie a eito of jet fuel leak* during the 1960's
through they 19tO'a. Thin ie the pump atation, it has eight (8) SO thousand
gallon tanks ia the- ground and a number of valves in here, several of which
have failed over the) coure* of 20 years at various timee.
The objective* of this project is to remove floating product and to n
the potential, for migration of this product thereby contaminating additional
soil and groundwater . wo will aample and analyse the product that is
removed, and will alao uae> the data to evaluate and select futuro
groundwater and soil cleanup teehnologiee. Thie is a site map of the Base
that shows you where- the four sitee are. You aeo that ST 5 and SS 27 are at
or near the aircraft-parking apron these are where the general fuel leake
were. W? 14 and LF 18 were landfills. Lf 18 'a off the- golf course and the
other one*a at the hammer head.
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we looked at three) different alternativee for selecting one for the
proposal. The) first alternative we looked at wa» no action. Thie
alternative) ie required by law to be evaluated and wae not selected because
there is free product there and scne action had to be taken. The next
alternative we> looked at wae Bio-remediation, this is where we introduce
microorganism* that will destroy the hydrocarbons . This was not selected
again because floating product was not the ideal situation where you want to
remove the floating product before you introduce the microorganisms or
bacteria. The third area we looked at was to pump or hand bail the
monitoring wells, this is the area we've selected to present as our propossd
plan for removal of hydrocarbon product. The reason we know the hydrocarbon
product is there is because we detected it by our monitoring wells.
I'd like to cover a few future environmental initiatlvee. As X said before
we're getting ready to undertake a base wide remedial investigations and
feasibility study, we hope to be underway by August of this year. Xn
addition to that we're doing quarterly monitoring well surveys to determine
elevations of water over a period of time that will tell ue the direction
the ground water is flowing, we're doing ecological assessments,
archaeological assessments, and a number of other activitlee . This is all
leading to remediation — culmination of a number of projects some of those
are listed below here. We're looking at groundwater remediation program at
a site called Tl. we expect to be started en that in September of 1992 and
continue at a steady pace. Looking at a soil remediation project for a
drainage ditch at 00-1. we have the 2 million dollar- the approved 2
million dollar Underground Storage Tank Replacement project which will also
have a contaminated soil project associated with it in case there is any
encountered. The jet-fuel hydrant system Z told you about earlier that's an
approved project for IS million dollars to replace that hydrant system. And
we're working on a landfill remediation at an additional four sitee and this
ia to cap and remove contamination at other landfills. That concludes my
briefing and at thie time X'm going to turn back over to Capt Ceisel who'll
Introduce the panel and open it up to questions. •
Capt Oeiselt Before Z ask the panel to come up let me juet explain how we
do this; we'll have a panel...who'11 answer your queetione and so forth on
the remediation of these other sitee. If you could if you have a question
X'd like to hear you state your name and if you're representing an
organisation pleaee also state that organisation and if you could we'd like
you to go to the mik* we need to provide a public record of thie meeting and
we are recording it will enable ue to make sur* we have an accurate record
of the meeting. So if Z could aek you to do that - state your name, th*
organisation if in fact your are representing an organisation, and go ahead
and aek your gjueetion. Additionally Z'd like to also have you limit it to
one question at e tia* baaed on the number of people in here you can
probably ask if yea have a several queetione stay at the mike and aek those
questions. At thi* tin* Z'd like th* panel to com* forward pleaee. Take
your seate. At thi* time I'll introduce the panel - to my far right is or
Milton Beck he ie the Dover Air Force Base Project Manager, we have Mr Bruce
Beach he ie the 1PA project officer and we have Mr Robert Allen who Ie the
Oept of Natural RcatfUrcee and Environmental control OSJUtC officer here
tonight and Z guess Matt you will be also able to aek questions - if you
have specific queetione about the briefing or something Matt Sarker brought
up he will also be available to answer, so at this time we'll open it up to
questions and if uh we'll start.
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Chris fimermani My nam*- i* Chris Zinmerman Z liv* n*ar Magnolia and you
spofca.of th* pumping or bailing out of th* monitoring w*lie. where does the
wat*r go frosy th*r*f
capt o*it*li . You mean th* bailed out product?
Chris Zl«m*rman« Right.
Capt ceiselt okay.
or Milton Becks Th* product when it is removed from th* monitoring wells
will b* stored and analyzed to determine if th* product contains other toxic
materials. If th* fre* product contains other toxic materials, which is a
possibility especially at the two landfills, if indeed it doee contain toxic
materiale it would be dieposed of ae hasardous waat* by Dover Air force Base
through a licensed contractor . If th* petroleum product doee not contain
hazardous materiale theft it can b* disposed of, through a contractor, for
recycling and w* anticipate that th* majority of th* product which will come
from th* two sit** near th* hydrant fueling aystem will b* primarily jet
fuel. And w* do not believe that it will contain hazardous materials tout it
will b* analyzed also to make sure. If it is not coneidered hazardous it
will b* sold - uh - disposed of through a contractor for recycling.
Capt oeiaeli Any further questions?
Chris Zimmerman! Yes. of course as you know there ie a iarg* gravel pit
across th* highway. Ha* there any contamination been detected in that large
lak* of fleorg* « Lynch?
Or. Milton Becki W* hav* not sampled the water ia that gravel pit. But we
do have monitoring wells between th* gravel pit oa th* Baat aid* of Rt 113
and we would b* abl* to detect .if material* ar* migrating from th* Baa*
toward* that highway.
Chris Zimmermant Any contamination detected in th* - Z gueee it'* th*. first
major aquifer below th* base*
Or. Miltoa Beokt That would b* th* unconfined aquif*r, th* Columbia aquifer
and ia som* area* on th* Bae* yoe* w* hav* found contamination.
Chria rinawjmini. Z gu*** ay laat gu*etion for now i* the) contamination, ha*
any of it r*aoh*d any of th* tributaries, wetlande of thai St Jonee or th* st
Jon** ftlv*r it**lff
Or. Miltoa B**k» We) hav* detected low level* of so**) solvent* ia th* small
tributary on th* golf coure* which emptiee into the) Bt Jon** Xiv*r. Th*
level* a* Z recall that war* detected ar* well below Leval* that ar* within
th* Surface Water standard* for th* State of Oelawar*. Th*r*'a probably
been som* diaeharg* to th* Worth drainag* ditch whioh in turn emptiee into
Little Creek or Pipe- Blm Branch of th* Little Cree* . Z don't think that
th* levele that havrf *b**n found th*r* exceed any surfac* wat*r standard*.
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Cnri* siam*nuut X can think of a faw mor*, but I'll ...
Capt Gaiaalt Okay well than please com* back up her* than.
Chria Zifflmermaai you mentioned several landfilled aitee. TO the beat of
your xnowledo* haa an effort baan mada co identify every conceivable lite on
the Base?
Dr. Milton Seckt Yes, efforts have been mad* by going through racorda,
interviews of amployeea that worked on base in years past, there has been a
rather extensive effort to try and locata every possible source of
contamination that could be identified on the Baa*. Hav* we identified
everything? That remain* to be seen. In tha course of the remedial
investigation that ia going to b* undergoing or starting this summer, we
will be looking ac ground water throughout the entire Base. And one of the
big efforta ia looking at tha ground water that would be migrating off the
Base to make sure contamination ia not leaving the Baa*. In th* course of
thia.investigation, it ia possible that we would locate or identify
additional sources of contamination. If we find contamination that seems to
be coming from an area that we are unaware of, we will investigate that
further to see if there ia or what the source might b*.
Chria Zimmerman* Initially you mentioned that th* funding for thia project
la a separata line item from your operation*.
Or. Milton Beckt That ia correct.
Chria Zimmerman* Ia th* funding for thia cleanup - can th* funda ba
utilized by either the county or other Superfund cleanupa for inatanee
wildcat Landfill or the Landfill at Houston?
Or. Milton Beckt No. Th* funda that ar* being uaed to clean up Dover Air
Force Baa* ar* funda that hav* been appropriated by Congreaa to th*
Department of Defense under what ia called Th* Defenae Environmental
Restoration Aeoount. DUtA money ie ueed only for oleenup of paat
contamination problema or contamination problame that originated prior to
1984 and it will be used only on aetlv* Military Baa**, Air Fore*, Army,
Navy, whatever.
Chris Simmermant Sots* of you hav* been named aa a contributor to a
hasardoua waato ait* on privat* property or county property. X* there a
mechanism that Congreeo ha* a*t aaid* funding for that cleanup!
Or. Milton- B*ck» Ye*. A* a matter of fact X think there's two there may b*
more but X knew that there'a two ait** that Dover Air Tore* Baa* ia
considered third party PR*, which Dover Air Fore* Base through th* Air
Force ia contributing to th* investigation and oleanup of those eite*. Now
ae to th* exaet mechanism of that funding X don't knew. I'm not awar* of it
because someone alae handle* that. Xt isn't even handled at Dover Air Force
Base.
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Mat* Parker* That'e • apecial pot of money, it ia tlao DSRA money. That
cornea off and ia handled, in our caae by Airataff, and aa Air Fore* Baaaa,
whether it ia Dover or any ethar Air Porca Baa*/ ara identified aa ?*?»,
thoaa funds ar« allocated for the investigation and cleanup of thoae aitaa.
Capt Geiaal: Ara there any other queatione?
cape Oeiael: Par thoae of you who are more baahful and choa* not to 90 so
the mike but night have acme queationa to aak on a peraonal note, the panel
will be available *a well aa Mate ?arke* fallowing the meeting for 15-20
ainutee or whatever ia required to maybe anawer aome queatione that you
might have that you didn't want to bring up in the public forum. If there
are no further queaticne, and again I'll aak again Z don't wane to - W«T«
not trying to cut thia ahort by any neana. w«'re here to anawar che
quaatione thae you might hav«, but if there are no queationa, it'a atlll
daylight outaide and go outaide and enjoy the evening. We'll go ahead and
adjourn thia public meeting and like Z aaid the panel will be available to
anawer aone queetione you might have. No further queationa?
Dr. Milton Baefes It might be mentioned that if you have conmenta that you
wiah to make in writing they can be Accepted by Dover Air Force Baae up
until July 21.
capt Geiael: And they can be directed to either Or. Milton Beck than ia in
the Environmental Planning Office of Oovar Air Force Baae and the sip code
for that ia 19901...02 -I'm aorry 19902. And that wea ia the public notice
will appear in the newapaper and a record of thia meeting will be placed in
our depoaitory. No further queationa? Thia public meeting ie adjourned.
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APPENDIX B
STATE OF DELAWARE CONCURRENCE LETTER
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STATE OF DELAWARE
DEPARTMENT OF NATURAL RESOURCES
a ENVIRONMENTAL CONTROL
DIVISION OF AIR & WASTE MANAGEMENT
89 KINGS HIGHWAY
P.O. BOX I4O1
OFFICE OF THE DOVER. DELAWARE I 99O3 TELEPHONE: (3O2) 739 • 4764
DIRECTOR
September 30, 1992
Mr. Edwin B. Erickson (3RAOO)
Regional Administrator
U.S EPA Region III
841 Chestnut Building
Philadelphia, PA 19107
Dear Mr. Erickson:
This letter is to officially express DNREC's concurrence with the
Record of Decision for recovery of floating waste at sites WP 14
(D-4) and LF 18 (D-10) at Dover Air Force Base. As you know, DNREC
has provided review and comment on the drafts of this document.
We look forward to the implementation of this interim remedial
action, which we believe is an important first step in remediating
the ground water problems at the base, and in providing effective
protection of human health and the environment.
Director, Division of Air and Waste Management
PGR:RJA:rja
RJA2202
pc: N.V. Raman
Robert Allen
Bruce Beach
Milton Beck
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