| A drainage structure referred to as a French drain also
existed north of former Building 3694 and a dry well, located approximately 10 feet
northeast of Building 3693, was identified during Phase I of the Sump Removal Action
Program. After the completion of the 1993/1994 RI, the USTs, the fuel pump island, and
associated Building 3693 were removed as part of the MMR Fuel Upgrade Program. Additional
structures removed after the RI included the foundations of former Buildings 3692 and 3694
(along with the vehicle repair bays), the leaching well, the dry well, and the French
drain. These structures were removed as part of the MMR Drainage Structure Removal Program
(DSRP). The DSRP involves a systematic basewide investigation and cleanup effort to
address drainage sumps that were used historically at MMR, including those at FS-17 and
FS-19. Removal activities conducted under the DSRP are described more completely in the Drainage
Structure Removal Program Remedial Action Workplan (Jacobs Engineering Group 1995). FS-19
 FS-19 is located in the south-central portion of MMR (see Figure 1) and was
operated as a World War II vehicle fuel storage and distribution facility. The site
consists of two separate areas about 200 feet apart designated as Areas I and II (see
Figure 3). The northern portion of the site is the location of former Building 3493 (Area
I). Base personnel reported that hazardous wastes were stored in Building 3493. The
concrete building foundation was removed in 1993, and the former building site is now a
grass-covered area approximately
20 feet by 40 feet mostly surrounded by paved roads and driveways. The southern portion of
the site is the location of the former vehicle fueling facility (Area II). This facility
used six 10,000-gallon USTs that were installed in 1941 and operated until 1958. Between
1958 and 1965, the six USTs were used for the storage of hazardous waste. The quantity of
fuel and the type and quantity of waste that was stored and that may have leaked or been
spilled during operational history of the USTs is unknown. In 1965, the six USTs were
reportedly emptied and the fill pipes capped. In May 1985, however, it was determined that
the USTs still contained approximately 7,000 gallons of a waste fuel/solvent mixture. The
Defense Property Disposal Office issued a contract for removal of the waste mixture, and
in October 1989, the USTs were removed and found to be in good condition and the
excavation was backfilled. During the RI, a concrete slab believed to be a remnant of the
former control building located east of the USTs was encountered just below surface and
adjacent to the UST excavation (see Figure 3). The dry well located below the former
control building and 21 cubic yards of soils were excavated and removed during the DSRP.
The DSRP activities will be summarized in the Drainage Stucture Removal Program
Remedial Action Summary Report (ABB-ES 1998) currently under regulatory review. Area
II is currently an open grassy area approximately 60 feet long and 40 feet wide mostly
bounded by paved roads and driveways.
History of Environmental Investigations at FS-17 and
FS-19
A number of investigations have been conducted at FS-17 and FS-19 to assess the potential
impact of these sites on human health and the environment. The results of these
investigations are reviewed below in chronological order for each site.
FS-17
Site Investigation—1990
A SI was undertaken in 1990 to assess the presence or
absence of contamination resulting from fuel spills or leaks associated with the fuel pump
island, USTs, and vehicle repair bays at FS-17. The SI included a soil-gas survey, a
limited soil investigation, sampling of the leaching well and French drain associated with
the vehicle repair bays, and a limited groundwater investigation. Based on SI activities,
it was recommended that additional soil and groundwater data be collected to evaluate
possible leaks and spills associated with waste sources, as well as past and present
fueling activities. Subsequent to the completion of the 1993/1994 RI, the leaching well,
French drain, dry well and foundations of former Buildings 3692 and 3694 (along with the
vehicle repair bays) and associated soils contamination were removed as part of the MMR
DSRP. A total of 568 cubic yards of soil was removed and the sites had a clean closure.
The DSRP activities will be summarized in the Drainage Structure Removal Program
Remedial Action Summary Report (ABB-ES 1998) currently under regulatory review.
Remedial Investigation Activities—1993-1994
The RI for FS-17 was designed to further characterize
potential soil and groundwater contamination, evaluate site hydrogeology, and determine
potential risks to human health and the environment posed by contaminants present at the
site. The 1993/1994 RI field program for FS-17 included Geoprobe™ soil sampling in 13
locations, surface soil sampling at 5 locations, advancing 3 test borings, installing 5
new groundwater monitoring wells, and collecting 7 groundwater samples. The hydrogeologic
investigation included measuring depths to static groundwater and performing in situ
hydraulic conductivity tests on all existing and newly installed wells. Soil and
groundwater samples were analyzed by an on-site mobile laboratory and an off-site
fixed-base laboratory. The mobile laboratory was used to provide real-time screening data
to select soil samples for off-site laboratory analysis and to guide the placement of
groundwater monitoring wells. The fixed-base laboratory was used to confirm screening
results and to provide data necessary to conduct the Preliminary Risk Assessment (PRA),
which is the component of the RI that evaluates potential human health and ecological
risks.
Supplemental Groundwater and Soil
Investigations— 1997/1998
Supplemental groundwater investigations conducted in
October and November of 1997 included the installation and sampling of four additional
monitoring wells to confirm that there were no significant impacts associated with
potential contaminant releases from three source areas (i.e., the fuel pump island and
USTs, the former leaching well, and the former motor pool fence line) identified by MADEP
as areas of concern requiring further investigation. Supplemental soil investigations
conducted in February 1998 involved resampling previous RI surface and subsurface soil
locations and analyzing these samples using MADEP’s extractable petroleum
hydrocarbons (EPH)/ volatile petroleum hydrocarbons (VPH) methods.
Nature and Extent of Contamination—FS-17
Field observations and analytical results obtained for
soils during the 1993/1994 RI showed that contamination was generally limited to petroleum
releases in localized areas as a result of previous uses associated with vehicle repair
and maintenance activities. Specific areas affected by stained soil conditions showing TPH
levels exceeding the MMR soil target cleanup level STCL of 500 mg/kg included (1)
former vehicle repair Building 3694 at sampling points located to the north, east and
south; (2) former Building 3692 at one sampling point near the western end; and (3) the
former motor pool fence line at two sampling points along the edge of the existing
pavement. However, based on the 1998 supplemental soil investigations, no significant
impacts to these areas remain; resampling of the 1993/1994 RI sampling points did not show
evidence of stained soil conditions or the presence of petroleum hydrocarbons, as measured
by MADEP’s VPH/EPH methods.
In addition, an elevated lead level (769 mg/kg) was also
found in surface soil along the former motor pool fence line at a single sampling location
along the edge of the existing pavement. However, this result is not considered indicative
of a hot spot because it is well within the typical range of lead levels observed in fence
line soils at other MMR motor pool areas and is less than an order of magnitude above the
mean lead level observed at FS-17. Furthermore, this result is not considered significant
based on the September 19, 1995 ecological site survey in which it was determined by USEPA
and MADEP that this location is not an ecologically important habitat.
With respect to former Building 3693, the USTs, and
associated pump island, no significant impacts to surface or subsurface soils were
observed; TPH levels were found below the MMR STCL, and only trace levels of organic fuel
constituents were found. In addition, removal of Building 3693, the USTs, and associated
pump island subsequent to completion of the 1993/1994 RI field investigations did not
reveal subsurface contamination. AFCEE therefore concluded that significant fuel releases
associated with these structures did not occur.
Based on the results of the RI groundwater investigations
conducted in 1994, no significant impacts to groundwater quality were observed associated
with past site uses and activities. Contaminant concentrations were found below federal
and state drinking water standards, except for one location (MW-2), where total lead (40
µg/L) exceeded the Massachusetts standard of 15 µg/L. In addition, the supplemental
groundwater investigations conducted in 1997 confirmed that no significant impacts to
groundwater quality have occurred associated with either the fuel pump island and USTs,
the former leaching well, or the former motor pool fence line area; contaminant levels
found in monitoring wells located downgradient of these areas are below federal and state
standards.
FS-19
Site Investigation—1985-1986
In September 1985, the U.S. Army Environmental Hygiene
Agency installed a water table monitoring well immediately downgradient of the USTs at
Area II. Although sampling in April, May, and June 1986 showed the presence of volatile
organic compounds (VOCs), levels were generally below federal and state drinking water
standards.
Site Investigation—1989-1990
Between October 1989 and March 1990, ABB-Environmental
Services, Inc. (ABB-ES), conducted a two-phase SI. The SI activities included drilling
three soil test borings and installing two monitoring wells. Based on sampling results, RI
activities were recommended for FS-19.
Remedial Investigation Activities—1993-1994
The RI for FS-19 was designed to further characterize
potential soil and groundwater contamination in two suspected source areas depicted on
Figure 3 as Area I and Area II, to evaluate site hydrogeology, and to determine potential
risks to human health and the environment posed by contamination present at the site. The
field exploration program for FS-19 included soil sampling with Geoprobe equipment in 17
locations, surface soil sampling at 3 locations, drilling 2 soil test borings, installing
2 groundwater monitoring wells, and collecting groundwater samples (all sampling locations
are shown in Figure 3). The hydrogeologic investigation included measuring depths to
static groundwater and performing in situ hydraulic conductivity tests on all existing and
newly installed wells.
Soil and groundwater samples were analyzed by an on-site
mobile laboratory and an off-site fixed-base laboratory. The mobile laboratory was used to
provide real-time data to guide the placement of groundwater monitoring wells and further
investigations. The fixed-base laboratory was used to confirm the screening results of the
mobile laboratory and to provide data necessary for conducting the PRA.
Supplemental Soil Investigations—1998
The 1998 supplemental soil investigations for FS-19
involved the resampling of two RI boring locations in the former UST grave to characterize
petroleum hydrocarbons using MADEP methods for analysis of VPH and EPH.
Nature and Extent of Contamination—FS-19
The 1993/1994 RI analytical results obtained for FS-19
soils in the vicinity of former Building 3493 showed detectable concentrations of VOCs,
semivolatile organics, including PAHs, pesticides, polychlorinated biphenyls, metals, and
TPH. However, none were found at levels exceeding respective MMR background values for
metals, or the MMR STCL for TPH (500 mg/kg). Similar results were found for soils located
within the approximate limits of the former UST grave except for two isolated subsurface
sampling points that showed elevated TPH levels. However, resampling of these two sampling
points as part of the 1998 supplemental soil investigations showed detectable
concentrations of petroleum hydrocarbons, as measured by MADEP’s VPH/EPH methods, in
only one of nine samples submitted for analysis. This detection was reported well below
MADEP’s S-1/GW-1 risk characterization standard. These findings indicate that there
are no significant impacts to subsurface soils located within the limits of the former
USTs. The impacts to groundwater at FS-19 are minimal; study area wells generally do not
show contaminant concentrations above regulatory standards. One exception was detected in
the monitoring well located within the former UST area. At this location, an original and
a duplicate analysis of groundwater were analyzed. Although laboratory analysis of the
original sample showed no total lead or bis(2-ethylhexyl) phthalate (BEHP), the duplicate
analysis collected simultaneously did indicate total lead concentrations of 18.5 µg/L and
BEHP at 13 µg/L.
Results of the Risk Assessment for FS-17 and FS-19
As part of the RI, a PRA was conducted to evaluate potential adverse effects of site
contaminants on human health and ecological receptors in the vicinity of FS-17 and FS-19.
Contaminated soil and groundwater that might serve as exposure media for human or
ecological receptors were evaluated. Human health and ecological potential contaminants of
concern (COCs) were identified for each environmental medium. VOCs, SVOCs, pesticides and
inorganic constituents were identified as COCs (for FS-17 see Tables 8-4 through 8-9 in
the RI Report; for FS-19 see Tables 8-4 through 8-9 in the RI Report). For the human
health PRA, the following current and future use exposure scenarios were selected for
evaluation at FS-17 and 19: current utility workers and child trespassers; and future
utility workers (FS-17 only), future child residents, and adult residents. For the
ecological PRA habitat-specific terrestrial and aquatic receptors were assessed.
Human health noncarcinogenic effects and carcinogenic risks
were characterized using maximum and mean detected concentration data at each site for the
exposure scenarios and media under evaluation. For surface and subsurface soil using
maximum concentration data, the results of the human health risk assessment establish that
noncarcinogenic and carcinogenic risks (as measured by the noncarcinogenic HI and
carcinogenic incremental excess lifetime cancer risk) estimated for current land use
exposure scenarios are below U.S. EPA and MADEP risk management regulatory criteria. These
results indicate that remediation of soil based on these potential exposure conditions is
not warranted.
The FS-17 and 19 human health risk assessment results for
future land use exposure scenarios, also based on maximum COC concentration data,
establish that noncarcinogenic risks related to surface and subsurface soils for adult and
child residents are below U.S. EPA and MADEP risk management regulatory criteria.
Carcinogenic risks, based on maximum COC concentration data, for adult and child future
residential scenarios at FS 17 and 19 range from 10-5 to 10-6. These risks range from
slightly above to slightly below the MADEP risk management regulatory criteria, but fall
within or below the U.S. EPA target risk range for remediation. Risks within or below
EPA’s target risk range generally do not require further action based on protection
of human health; therefore, for FS 17 and 19, remediation of soils based on these
potential exposure conditions is not warranted.
The results of the human health risk assessment for FS-17
and 19 for noncarcinogenic risks based on maximum COC concentration data (unfiltered
groundwater sample) for residential exposure to groundwater under future land use indicate
a potential for adverse effects from manganese (HI FS-19 = 2.6; HI FS-17 = 1.7). These
maximum levels of manganese exceed the secondary federal drinking water standards.
Secondary standards control drinking water contaminants that affect aesthetic qualities of
water. These maximum data include analytical results for inorganics that include
inorganics associated with the solids in the groundwater. However, results based on
dissolved data (filtered groundwater sample), expected to be more representative of
exposure concentrations, indicate that noncarcinogenic risks for manganese are below
EPA’s and MADEPs HI threshold of 1.0. In addition, manganese is present at a maximum
dissolved concentration below MMR maximum background and below the federal drinking water
standards. Carcinogenic risks based on maximum COC concentration data for residential
exposure to groundwater under future land use are above the MADEP risk management
regulatory criteria, but within the U.S. EPA target risk range. These maximum data include
analytical results for inorganics that include inorganics associated with the solids in
the groundwater. Results based on dissolved data, expected to be more representative of
exposure concentrations, indicate that carcinogenic risks are below both the MADEP risk
management regulatory criteria and below EPA’s target risk range. These results
indicate that remediation of groundwater based on these potential exposure conditions is
not warranted.
The potential for exposure to lead in groundwater and soil
by residential children under future land use was assessed for both FS-17 and FS-19. Lead
analyses based on maximum lead concentrations at FS-17 indicated that 65.98% of the
exposed child population (0- 48 Mo.) would be expected to have a blood lead level less
than the EPA and MADEP benchmark of 10 ug/dL (micrograms/deciliter). However, an analysis
based on mean soil and groundwater concentrations, which are expected to be more
representative of potential exposures, indicates that 96.95% of potentially exposed
children (aged 1-48 Mo.) would be expected to have a blood lead level less than the EPA
and MADEP benchmark of 10 ug/dL indicating that remediation of groundwater and soil based
on lead exposure is not warranted. At FS-19 lead analyses based on both maximum and mean
lead concentrations indicated that 96.33% and 99.94% respectively, of potentially exposed
children (aged 0-48 Mo.) would be expected to be below the EPA and MADEP benchmark,
suggesting that remediation of soil and groundwater based on lead for these exposure
conditions is also not warranted.
The ecological risk assessment for each site addressed
hypothetical risks to terrestrial vertebrates and plants and to semiaquatic and aquatic
receptors. The evaluation of risk to terrestrial wildlife and plants concluded that
because of the relatively small size of these sites and the limited area of viable
habitat, an unacceptable risk is unlikely. With regard to semiaquatic and aquatic
receptors, no surface water bodies exist at the FS-17 and FS-19 sites, so no direct
exposure route occurs locally. Furthermore, data indicate that groundwater below these
sites (which occurs at depths of 75 to 80 feet below surface) is unlikely to discharge
into the nearest downgradient surface water bodies (e.g., Edmunds Pond at FS-19). AFCEE
therefore concluded that risk to aquatic and semiaquatic receptors is remote as well.
Summary of No Further Action Recommendation for FS-17
and FS-19
Recommendations—FS-17
Based on the findings and conclusions resulting from the
1993/1994 RI activities and the 1998 supplemental soil investigations, including the
conclusions of the PRA, No Further Action is recommended for soils at FS-17 because no
unacceptable risk to human health and the environment was found. In addition, although
levels of manganese found in site groundwater pose a slightly elevated human health risk
under a future residential scenario, No Further Action is recommended for groundwater
because the presence of manganese is not considered to be related to historic site
activities or uses. The 1997 supplemental groundwater investigations also support No
Further Action for site groundwater, because the results verify that no significant
impacts have occurred associated with the areas of concern identified by MADEP. The
existing wells will be resampled in November 1998 using the EPA low flow method and
analyzed for metals. These results will be used to confirm that no risk is posed by lead
and other inorganics in groundwater. This evaluation will be completed before issuance of
the ROD.
Recommendations - FS-19
Based on the findings and conclusions resulting from the
1993/1994 RI and the 1998 supplemental soil investigations, including the conclusions of
the PRA, No Further Action is recommended for soils at FS-19 because no unacceptable risk
to human health and the environment was found. Although levels of manganese found in site
groundwater pose a slightly elevated human health risk under a future residential
scenario, No Further Action is recommended for groundwater at FS-19 because the presence
of manganese is not considered to be related to site activities. The existing wells will
be resampled in November 1998 using the EPA low flow method and analyzed for metals. These
results will be used to confirm that no risk is posed by lead and other inorganics in
groundwater. This evaluation will be completed before issuance of the ROD.
What Is a Formal Comment?
During the formal public comment period, AFCEE will accept formal written comments on the
Proposed Plan and will hold a public hearing to accept either verbal or written comments.
It is important to note that there is a distinction between formal comments received
during the public comment period and informal comments received outside of the comment
period. While AFCEE will respond to all comments no matter when they are received, only
formal comments postmarked by January 8, 1999 and AFCEE's responses will be documented in
the Responsiveness Survey.
You can submit a formal comment in any of the following
ways:
- Offer verbal or written comments during the public hearing
on January 5, 1999 from 6-8 pm.
- Send written comments, during the public comment period that
will extend from December 9, 1998 through January 8, 1999, to
HQ AFCEE/MMR
Attn: FS-17 and FS-19 PP
322 E. Inner Road
Otis ANG Base, MA 02542-5028.
Submit comments by fax at (508) 968-4673.
- Send an electronic mail message to: doug.karson@mmr.brooks.af.mil
- Send a message by Internet at http://www.mmr.org.
Why Submit Formal Comments?
Your comment will become part of the official public
record, a crucial element in the decision-making process. AFCEE will consider all formal
comments received at the public hearing and all written comments received during the
public comment period before making the final selection of remedial alternatives for
cleanup at the FS-17 and FS-19 sites. A transcript of all formal comments and AFCEE's
written responses will be issued in a document called a Responsiveness Summary that will
accompany the Record of Decision for the FS-17 and FS-19 sites. AFCEE expects to complete
review of all comments, select a remedial alternative for the FS-17 and FS-19 sites, and
issue the Record of Decision documenting AFCEE's choice in February 1999. At that time,
copies of the Responsiveness Summary will be mailed to everyone who submitted a formal
comment and copies will also be placed in local libraries. In addition, AFCEE will
announce the decision through the local news media and site mailing list.
GLOSSARY
Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA): This law, commonly known as Superfund, authorizes the federal
government to respond directly to releases of hazardous substances that may endanger
public health or the environment.
Drainage Structure Removal Program: A comprehensive
program to identify, characterize, and remove underground drainage structures, sumps, and
associated soils at various sites across MMR.
Feasibility Study (FS): A study for identifying and
evaluating options for remedial action to reduce risk to human health and the environment.
Federal Facility Agreement: An agreement between
USEPA and individual federal facilities that establishes a procedural and legal framework
for investigating and performing remedial actions at Superfund sites.
Inorganics: Metals and all compounds except
hydrocarbons.
In Situ Hydraulic Conductivity Test: A groundwater
monitoring well test method which determines the conductivity of the aquifer.
Installation Restoration Program (IRP): The
Department of Defense program implemented at military bases to identify, investigate, and
clean up contamination resulting from past operations.
MADEP S-1/GW-1 Risk Characterization Standard: Risk
based soil values calculated to be protective of human health and the environment.
National Priorities List (NPL): USEPA’s list of
uncontrolled or abandoned hazardous waste sites that are priorities for long-term remedial
evaluation and response. NPL sites are eligible to receive federal funds for investigation
and cleanup under the Superfund program.
Proposed Plan: A document that summarizes for the
public the preferred remedial action for a site and presents the rationale for the
preference.
Remedial Action: Action taken to reduce or eliminate
the long-term risks to human health or the environment from exposure to contaminants.
Remedial Investigation (RI): An investigation to
gather and analyze the data necessary to determine the nature and distribution of
contamination at a site and to provide information for performing a feasibility study.
Risk Assessment: An evaluation of human health and
ecological risk resulting from exposure to a chemical or pollutant.
Site Investigation (SI): An initial investigation
involving field assessments sampling and laboratory analysis as a precursor to an RI.
Soil Target Cleanup Level (STCL): MMR-specific
risk-based and leaching-based concentrations of contaminants in soils developed for the
protection of human health and the environment under the MMR Drainage Structure Removal
Program.
Acronyms |
USEPA placed MMR on the National
Priorities List in 1989 for investigation under CERCLA. A Federal Facility
Agreement, signed in 1991 and updated in 1997, requires AFCEE to take the lead in
cleanup activities at MMR, including FS-17 and FS-19. AFCEE’s activities to date,
carried out under the Installation Restoration Program, include performing a Site
Investigation (SI) and a Remedial Investigation (RI) at these sites to
characterize the nature and distribution of contamination. Risk assessments were performed
as part of the RIs to identify potential risks from exposure to contaminants. The risk
assessments evaluated the present and future risks to human health and the environment
posed by existing conditions, assuming no remedial action is taken. Cancer and
noncancer risks were evaluated. Because the risk assessments concluded that no
unacceptable risk exists at FS-17 and FS-19, a Feasibility Study (FS) was not
prepared, and the No Further Action alternative is being proposed by AFCEE as the most
appropriate action for these sites. AFCEE believes this alternative will protect human
health and the environment and will comply with environmental laws and regulations. Those
who seek more detailed technical information for FS-17 and FS-19 should consult the RI
reports available in the Administrative Record for MMR (see page 10 - For Further
Information). Those reports provide the basis for the findings summarized in this Proposed
Plan.
