Natural Attenuation of Chlorinated Solvents
at Ashumet Valley
Cape Cod, Massachusetts
by
Hilary J. Eichler, P.E.
B.S., Civil Engineering
University of California at Berkeley, 1990
Submitted to the Department of Civil and Environmental Engineering
In Partial Fulfillment of the Requirements for the Degree of
MASTER OF ENGINEERING
in Civil and Environmental Engineering
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
June 1997
© Hilary J.Eichler. All rights reserved.
The author hereby grants to MIT permission to reproduce and to distribute publicly paper and electronic copies of this thesis
document in whole and in part.
Signature of the Author__
- _, _
D9 aent of Civil and Envirofmental Engineering
May 9, 1997
Certified by
.
-
Philip M. Gschwend
Professor of Civil and Environmental Engineering
Thesis Supervisor
/")
Accepted by
V
Professor Joseph M. Sussman
Chairman, Departmental Committee on Graduate Studies
01
',.
JUN 2 41997
Natural Attenuation of Chlorinated Solvents
at Ashumet Valley
Cape Cod, Massachusetts
by
Hilary J. Eichler, P.E.
Submitted to the Department of Civil and Environmental Engineering
on May 9, 1997, in partial fulfillment of the
requirements for the degree of
Master of Engineering
ABSTRACT
This study defines the source of trichloroethylene (TCE) and perchloroethylene
(PCE) contamination in the Ashumet Valley Plume, and evaluates the potential for
natural attenuation of these compounds. TCE and PCE, putative carcinogens, were
chosen for study because previous studies have shown that the estimated risk for
household consumption of groundwater on the Upper Cape, based on exposure to
maximum allowable contaminant levels, exceeds USEPA guidelines.
Natural attenuation has been shown to be a viable bioremediation strategy under
certain conditions. This study uses a mass balance approach to show that the TCE and
PCE input masses are approximately equal to the mass of contaminants still found in
groundwater at Ashumet Valley. Therefore, although it can be argued that some
biodegradation is occurring, it is not significant enough to justify a full scale natural
attenuation strategy.
Thesis Supervisor: Philip M. Gschwend
Title: Professor of Civil and Environmental Engineering
ACKNOWLEDGEMENTS
I would like to take this opportunity to acknowledge the following people who
have guided me through this project:
Professor Phil Gshwend for his endless energy, enthusiasm, and technical guidance for
this project, which helped me to stay focused and motivated; for his patience. when I was
ready to throw it all out the window; and for his advice for when I felt overwhelmed with
work.
Dr. Peter Shanahan, my project group advisor for his professional perspective and
technical advice.
Professor David Marks and Shawn Morrissey for listening to me when I needed it
most.
The Thirsty Ear Staff for their companionship, support, and cheap beer.
My Project Group and Master of Engineering Colleagues for their suggestions and
support.
Finally, I would like to thank my family members and close friends in California who
kept their faith in me long distance.
TABLE OF CONTENTS
LIST OF FIGURES ......................................................................................................... 6
LIST OF TABLES ..........................................................................................................
LIST OF UNITS AND ABBREVIATIONS .....................
6
...............
1. INTRODUCTION AND BACKGROUND.................................
..............
1.1 MMR Site Description .......................................................................................
8
1.2 Population and Demographics .............................................
8
..........................
2. ASHUMET VALLEY ...............................................
2.1 Site Location and Description.............................
..................
2. 1.1 Meteorological Conditions................................................. ..
2.1.2 Geology ..........................................................
2.1.3 Hydrogeology..............................
10
.........
10
............................................. 10
........................................
12
2.1.4 EnvironmentalSetting ofAshumet Pond.......................................................
13
3. SOURCES OF CONTAMINATION ..............................................
3. 1.1 Fire TrainingArea (FTA-1) .........................................................
14
3.1.2 Sewage Treatment Plant (STP) ....................................................................... 15
4. PROBLEM STATEMENT AND OBJECTIVES ............................................. 16
4.1 Problem Statement...........................................
..................................
.. 6
4.2 Research Objectives .....................................................................
.17
4.3 Natural Attenuation ..........................................................................
17
4.3.1 BiodegradationMechanisms..........................................................................
5. METHODOLOGY ..................................................................................
6. RESULTS ...............................................................................
.
.
18
2
.....
22
6.1 Mass Balance Calculations .......................................................
........
6.1.1 Source Function...................................................
....... ................................ 22
6.1.2 Sensitivity Analysis .............................................................................
............... 25
6.1.3 Existing Mass Estimates ...............................................................................
6.2 Boron, Specific Conductance, and Dissolved Oxygen ...........
.
26
3
6.3 Cis-1,2-DCE ..................................................
...
.....................
3
7. DISCUSSION AND CONCLUSIONS ....................................................... . 39
7.1 Discussion ...........................
.............................................................................. 39
7.2 Biodegradation Potential ..............................................
7.3 Conclusions ..................................
...................................
39
..................................................................... 40
8. REFERENCES.......................................................................
........................
41
GLOSSARY ..........................................................................................
45
APPENDIX A SOURCE FUNCTION AND SENSITIVITY ANALYSIS
CALCULATIONS ........................................................................................................
48
APPENDIX B EXISTING MASS ESTIMATE CALCULATIONS ........
......
56
LIST OF FIGURES
Figure 2-1. MMR Site Location Map ................................................... 9
Figure 2-2. Ashumet Valley Plume Location Map .......................................................... I 1
Figure 6-1. Production Quantities of PCE and TCE in the United States ........................
23
Figure 6-2. Yearly Estimated Concentrations of TCE and PCE Discharged................24
Figure 6-3. Yearly STP Discharge Flow Rates................................................................24
Figure 6-4. Plan View of Ashumet Valley Plume with Cross Section Locations (adapted
from ABB, 1995)....................................................... 27
Figure 6-5. Cross Section A-A' (adapted from ABB, 1995) .....................................
28
Figure 6-6. Cross Section B-B' (adapted from ABB, 1995)...................................
29
Figure 6-7. Cross Section C-C' (adapted from ABB, 1995)..................................
30
Figure 6-8. Plan View of Ashumet Valley Plume with Cross Section Locations (adapted
from OpTech, 1996) ......................................................... 32
Figure 6-9. Cross Section A-A' (adapted from OpTech, 1996)........................................33
Figure 6-10 . Cross Section B-B' (adapted from OpTech, 1996) .................................... 34
Figure 6-11 . Boron, Specific Conductivity, and Dissolved Oxygen ............................. 35
Figure 6-12 . TCE, PCE, and cis-1,2-DCE Distributions ..................................................
37
LIST OF TABLES
Table 6-1. Input Function Mass Estimate Sensitivity ..................................................
Table 6-2. TCE and PCE Mass Estimates .....................................
..... 26
.......... 31
LIST OF UNITS AND ABBREVIATIONS
UNITS
'C - degrees Centigrade
ýpg/L,- micrograms (10'6 grams) per liter
ft - feet
kg- kilograms
L/day - liters per day
lbs/ acre-year - pounds per acre per year
lbs/year - pounds per year
m - meter
mgd - million gallons per day
ppb- parts per billion by mass
pS/cm - microsiemens per centimeter
ABBREVIATIONS
AFCEE- Air Force Center for Environmental Excellence
BTEX- benzene, toluene, ethylbenzene, and xylene
DCE- dichloroethylene
DEP- Massachusetts Department of Environmental Protection
FTA-1- Fire Training Area 1
HAZWRAP - Hazardous Waste Remedial Actions Program
MCL- maximum contaminant level
MMR- Massachusetts Military Reservation
NDPES- National Pollutant Discharge Elimination System
PCE- perchloroethylene
STP- sewage treatment plant
TCE- trichloroethylene
USEPA- U.S. Environmental Protection Agency
USGS- United States Geological Survey
VC- vinyl chloride
1. INTRODUCTION AND BACKGROUND
1.1 MMR Site Description
The Massachusetts Military Reservation (MMR) is located on the upper, western
portion of Cape Cod, Massachusetts. The MMR covers 22,000 acres within the towns of
Bourne, Mashpee, and Sandwich (Figure 1-1). It abuts the town of Falmouth and is
bordered on the west by State Route 28 and on the north by U.S. Highway 6. Since 1991,
the MMR has hosted various branches of the Armed Forces.
At its peak, the MMR was the primary staging ground for World War II and home
to over 10,000 soldiers. The industrial and military activities associated with the MMR
have had far-reaching impacts upon the environment of Cape Cod. In 1989, as a result of
widespread groundwater contamination in the area, the MMR was placed on the National
Priority List of Superfund sites.
1.2 Population and Demographics
The MMR has a year round population of approximately 2,000. Additionally,
there are approximately 800 non-resident employees of the MMR. The population of the
four towns that border the MMR fluctuates between the winter (29,000) and the summer
(70,000) due to the large number of summer vacationers that visit Cape Cod. The
Western, or Upper, Cape registered a population growth of 35% between 1980 and 1990.
However, this area is still considered to be sparsely populated in relation to the rest of
Cape Cod. The median age of residents of Barnstable County, which encompasses the
entire Cape, is 39.5 years. This county has the highest percentage of residents over age.
65 (22%) of any county in Massachusetts (Choi, et al., 1997).
2. ASHUMET VALLEY
This study focuses on the wastewater plume in the Ashumet Valley (Figure 2-41).
In particular, the health of Ashumet Pond and the eventual fate of the contaminants
downgradient relative to drinking water sources are of concern.
0
CROOKED
POND
COON4MESSETT
POND
RUNWAY
AL ItI ABB Environmental
AJUnlP Services. Inc.
NOT TO SCALE
WNSTALLATION
RESTORATION PROGRAM
MASSACHUSETTS MLITARY RESERVATION
ASAUMT
R
Figure 1-1. MMR Site Location Map (adapted from ABB, 1995)
2.1 Site Location and Description
The Ashumet Valley area of Falmouth, Massachusetts, is located near the
southern boundary of the MMR, downgradient of the two source areas (Figure 2-1). To
the east, the plumes exfiltrate into Ashumet Pond. Sandwich Road runs along the
approximate western boundary of the plume. Much of the area is forested or residential.
A golf course is located between Sandwich Road and the southwest corner of Ashumet
Pond.
Ashumet Pond is an example of one of the many "kettle-hole" ponds on Cape
Cod. The pond is formed by the intersection of the groundwater table with a kettle
depression formed by a melted glacial ice block (K-V Associates, 1991). Aside from the
groundwater feed, Ashumet Pond has a small inlet from drained cranberry bogs and no
noticeable surface outlet.
2.1.1 MeteorologicalConditions
The climate in the Ashumet Valley region is considered to be humid continental
that is modified by close proximity to the ocean. The mean annual rainfall is around 50
inches per year. Net precipitation (total rainfall minus evaporation and other runoff) is
around 20 inches per year (ABB, 1995). During a normal year, rainfall is fairly evenly
distributed among the months. However, as much as five to six inches may fall during
single 24-hour rainfall events, which are produced by occasional tropical storms
intersecting the Cape.
Prevailing winds are from the northwest in the winter months, and from the
southwest during the remainder of the year. Wind velocities range from a mean value of
nine miles per hour from July through September to an average of twelve miles per hour
during the fall and winter months (ABB, 1995).
2.1.2 Geology
Ashumet Valley is located on what is known as Inner Cape Cod. This region was
primarily formed by glacial deposits. These deposits are composed of sands and gravels
washed from three different glacial lobes during the Wisconsinian period, 7,000 to 85,000
I.
MMR
/
/
.
Location
Crooked
Pond
i
COONAMESSETT RIVER
LEGEHD
i(
OOV
• 1,6uz
YALLEY
'ATEROPERABLE
h-i.
l
Asnume[ vaiIey ?lume Location Map (adapted
from ABB, 1995)
11
years ago (ABB, 1995). A fan-shaped concave plain called the Mashpee pitted plain
covers the Ashumet Valley. This is formed mostly of gravely sand and pebbly-to-cobbly
gravel. A few boulders may also be found in the area.
The Inner Cape consists of moraines formed by the melting and advancing of
glaciers. These moraines are predominantly composed of till. Subsequent advancing and
retreating of glaciers around the Cape led to the development of kettle hole ponds by ice
that remained and later melted (ABB, 1995). Ashumet Pond is one such kettle hole pond.
Soil profiles in the pond watershed show sandy topsoils with sandy loam to
gravely sand underlain by sand or gravel. The topsoil, which extends roughly 2 to 4 ft
below ground surface, is predominantly composed of Agawam and Enfield sandy loams.
The Agawam soils are well-drained and are capped by a sandy loam surface about 3 to 6
ft in depth. The appearance of gravel is common in the topsoil. The Enfield sandy loam
is distinctly more crumbly and silty than the Agawam loam. Beneath the topsoil lies
approximately 150 ft of generally well sorted, light brown, medium to very coarse sand
with some presence of gravel. Below this layer exists approximately 100 ft of very fine
sand with some silt. These unconsolidated deposits, which are highly permeable, sit on a
crystalline bedrock that is predominantly granodiorite. The bedrock elevation dips in a
southeast direction towards Ashumet Pond.
2.1.3 Hydrogeology
The groundwater flow system ofwestern Cape Cod is unconfined. Groundwater
flows radially outward from a water table mound located to the north of the study area.
This water table mound has a maximum hydraulic head of about 70 ft above sea level. In
the study area, groundwater flow is southward and water table elevations range from 44
to 49 ft above sea level. During periods of increasing pond stage, hydraulic gradients in
the area between the infiltration beds and the pond increase and groundwater flow
directions shift eastward toward the pond. Groundwater flow upgradient from the pond, is:
predominantly horizontal. Vertical gradients near the pond shore are significantly higher
because of the strong local effect of the pond.
Water levels in the sand and gravel aquifer and in Ashumet Pond fluctuate
seasonally; both are higher in the spring and summer months than in the autumn and
winter months. Ashumet Pond is hydrologically well connected with the aquifer, and the
pond is an expression of the local water table. Ashumet Pond has no significant surface
inlet or outlet. The pond exhibits a flow-through condition in which groundwater
discharges to the northern, or upgradient, part of the pond. This discharge occurs
primarily along the pond shore, and pond water recharges the aquifer from the southern or
downgradient part of the pond.
Precipitation is the sole source of natural recharge to the aquifer, and groundwater
discharges to streams and coastal embayments. Groundwater flow occurs primarily
within the coarse grained sediments. The saturated thickness of these sediments is about
120 ft in the study area.
2.1.4 EnvironmentalSetting ofAshumet Pond
Because of heavy recreational use, the welfare of Ashumet Pond is a high priority
for the many year-round and seasonal residents of Cape Cod. Ashumet Pond has two
public landings, one in Falmouth and one in Mashpee. The Falmouth Landing lies on the
western side of the pond and opens up to Fisherman's Cove, while the Mashpee Landing
lies on the northeast corner of the pond. Both landings provide access for residents to the
beaches and for recreational activities such as swimming, power boating, sailboating,
canoeing, and fishing.
Ashumet Pond is managed as a fisheries resource by the Massachusetts Division
of Fisheries and Wildlife. Since the 1930's, the pond has been stocked with different
species of fish. Before 1956, Ashumet Pond was stocked with smallmouth bass,
bullheads, catfish, Chinook salmon, white perch, yellow perch, chain pickerel, sunfish,
rainbow trout, brown trout, and brook trout (Choi, et al., 1997). Currently the pond is
stocked with rainbow trout, brook trout, yellow perch, and smallmouth bas& Other fish
species currently living in Ashumet Pond are largemouth bass, banded killifish, golden
shiners, eastern brook trout, and brown bullheads. In addition, a number of
phytoplankton and zooplankton live in Ashumet Pond, which are relatively sensitive to
infiltration of contaminants (Choi, et al., 1997).
3. SOURCES OF CONTAMINATION
The Ashumet Valley area is one of the areas most affected by activities on the
MMR. There have been two major sources of contamination to the Ashumet Valley
Region. The first source is known as Fire Training Area Number I (FTA-1). Through
the use of FTA- for military fire training activities, there is a plume emanating from this
site that is composed of hydrocarbons from jet fuel, including benzene, toluene,
ethylbenzene, and total xylenes (BTEX), and chlorinated organic compounds such as
trichloroethylene (TCE) and perchloroethylene (PCE). Previous studies predict the
southern toe of the plume will reach Green Pond by about the year 2015 (OpTech, 1996).
The second major source of contamination to Ashumet Valley is the MMR
Sewage Treatment Plant (STP), located approximately 1600 ft upgradient of Ashumet
Pond. Wastewater disposal from the STP began at this site in the 1930's. Since that time,
it is estimated that nearly 10 billion gallons of wastewater have infiltrated to the
groundwater that eventually flows towards Ashumet Pond. As a result of this wastewater
disposal, there is now a plume originating from the wastewater disposal beds that
contains high levels of dissolved solids, chloride, sodium, boron, detergents, and various
forms of nitrogen and phosphorus. Chlorinated solvents and arsenic have also been
detected in the wastewater plume at levels above maximum contaminant level (MCL)
guidelines for drinking water published by the U.S. Environmental Protection Agency
(USEPA). Groundwater samples taken at Fisherman's Cove reveal elevated
concentrations of phosphorus and other sewage chemicals, demonstrating that the sewage
plume intercepts the groundwater flow discharging into Ashumet Pond.
3.1.1 Fire TrainingArea (FTA-1)
Former Fire Training Area 1 (FTA-I) is located 500 ft north of Kitfedge Road:
near the southern boundary of the MMR (see Figure 2-1). It consists of a level, cleared
area of approximately three acres of land that was used by the MMR fire department for
fire training exercises from 1958 to 1985. The area was closed in November 1985 due to
air emissions permitting difficulties.
Six to 16 fire training exercises per year were conducted in designated areas of
FTA-1. Flammable waste liquids from the flightline area were burned and extinguished
with water, foam, or dry chemicals. The residual mixture was allowed to infiltrate
overnight and then burned off the next day to eliminate any remaining fire hazard. The
materials burned include jet fuel, aviation gasoline, motor gasoline, diesel fuels, waste
oils, solvents, paint thinners, transformer oils, and spent hydraulic fluids. Substances
used to extinguish the fires include carbon dioxide, protein foam, aqueous film-forming
foam, a bromine-based dry powder, and liquid chlorobromomethane.
Several previous investigations have been performed by ABB (1995), Operations
Technology (1996), and others to document site history and the nature and extent of
contamination. These studies concluded that, although several chemicals impacted soils
and groundwater downstream of FTA-1, the estimated risks are within or below the
acceptable USEPA target Hazard Index. Consequently, the effects of the contaminants
associated with the FTA-1 plume are discussed in this study only as they pertain to
containment issues.
3.1.2 Sewage Treatment Plant (STP)
The STP on the MMR was built in 1936 to treat, on average, a capacity of 0.9
million gallons per day (mgd). In 1941, the plant was expanded to an average capacity of
3 mgd, with a peak capacity of 6 mgd (Shanahan, 1996). The sewage treated at this plant
was alternately disposed of in 20 half-acre sand infiltration beds. The original design
called for only eight beds to be operational at any given time, with occasional rotation of
the beds. However, from 1977 to 1984 only the four infiltration beds nearest to Ashumet
Pond (Figure 2-1) were used (LeBlanc, 1984b). In order to dispose of treated wastewater,
the infiltration beds were flooded with wastewater, which then slowly percolated to the
groundwater.
Following World War II, the number of troops stationed at the MMR decreased.
Consequently, flow to the treatment plant decreased significantly as well. In fact, the
average flow during the 1980s and 1990s was less than 0.3 mgd (Shanahan, 1996). As a
result of the large amount of unused capacity, as well as the aging of the plant, the plant
was decommissioned in December, 1995. A smaller plant was then brought online next
to the location of the old plant, and use of the infiltration beds ceased.
The first recognition that groundwater was being contaminated by the wastewater
occurred in the 1970s. At this time, the Town of Falmouth closed a public water supply
well located 9,000 ft downgradient of the wastewater treatment plant because water
coming from the well was foaming. The foaming was determined to be a direct result of
detergents that had entered the groundwater from the wastewater infiltration beds. In
1977, the U.S. Geological Survey (USGS) conducted a study which showed that the
plume of contaminated groundwater originating from the wastewater treatment plant
extended more than 11,000 ft downgradient of the disposal beds and had a width of 2,500
to 3,500 ft (LeBlanc, 1984a). Currently, the Ashumet Valley plume, as defined by waterquality characteristics such as boron, pH, specific conductance, sulfate, nitrate,
phosphorous and dissolved iron, extends more than 17,000 ft from the wastewater
treatment plant (Walter, 1995).
4. PROBLEM STATEMENT AND OBJECTIVES
4.1 Problem Statement
Since there are two sources identified for the Ashumet Valley Plume, some debate.
has ensued over the source of PCE and TCE in the plume. This portion of study will
examine the two sources and make a preliminary determination for which source has
more significantly contributed to PCE and TCE contamination. Previous studies (ABB-,
1994, ABB, 1995, OpTech, 1996) have shown that the estimated risk for household
consumption of groundwater on the Upper Cape, based on exposure to MCLs, exceeds
USEPA guidelines. The contaminants of concern in drinking water include TCE and
PCE, which have been shown to be carcinogenic (EPA, 1985; National ToxicolJog
Program, 1988; Encyclopedia of Chemical Technology, 1991).
Some contaminants can be reduced in concentration by natural processes such as
dispersion. Additionally, studies have shown that TCE and PCE are susceptible to
biological degradation under conditions described in Section 4.3.1 (Hinchee, 1995b;
Hinchee, 1995c; Weidemeier et al., 1996a). These natural processes are known as natural
attenuation. Indicators for natural attenuation include the presence of intermediate
degradation products. A strong indicator at Ashumet Valley is the presence of cis-1,2dichloroethylene (cis-1,2-DCE) (Bouwer, 1994), a product of TCE reduction, which has
been detected at significant levels in several of the monitoring wells.
4.2 Research Objectives
The objectives of this study were to (1) define the source of PCE and TCE
contamination in the Ashumet Valley Plume, and to (2) evaluate the potential for natural
attenuation of TCE and PCE. Initial studies performed in the early to mid-1980's (E.C.
Jordan, 1986; E.J. Flynn, 1985; Metcalf& Eddy, 1983) concluded that the sewage
treatment plant was the main source of contamination. More recent studies do not
differentiate between sources, but discuss analytical data without consideration for the
two sources (ABB, 1995; OpTech, 1996). The plumes can be separated by comparing the
treatment plant effluent constituents with the spatial distribution of TCE and PCE in the
plumes.
Field studies have shown that PCE and TCE can be biologically degraded in an
anaerobic environment (Hinchee, 1995c; Weidemeier et al., 1996b) under conditions
discussed in Section 4.3.1. Because there are anoxic zones within the STP plume, in
addition to an abundance of nutrients, natural attenuation of TCE and PCE in the STP
plume appears likely. Consequently, this portion of study include a discussion of the
degree to which natural attenuation will remediate these contaminants.
4.3 Natural Attenuation
Before a meaningful discussion of natural attenuation can be undrtaken,
some understanding of the mechanisms and conditions under which it can be applied
must first be achieved. The Air Force Center for Environmental Excellence (AFCEE) has
distributed a protocol (Weidemeier, et al., 1996b) for evaluating the feasibility of natural
attenuation, should other indicators suggest significant biodegradation. Three lines of
evidence are used to demonstrate that degradation of site contaminants is occurring at
rates sufficient to be protective of human health and the environment. These lines of
evidence are:
1) Documented loss of contaminants at the field scale
2) Contaminant and geochemical analytical data, and
3) Direct microbiological evidence.
If analysis of collected data shows that these criteria cannot be met, then it is
unlikely that natural attenuation can be used as a remedial strategy.
4.3.1 BiodegradationMechanisms
Biodegradation of fuel hydrocarbons has been well documented as a viable
remediation approach in recent years (Hinchee, et al., 1994; Hinchee, 1995b; Hinchee,
1995c; Weidemeier et al., 1996a; EPA, 1996; Madsen, 1991). The process is mainly
limited by the availability of electron acceptors. Biodegradation of compounds such as
benzene, toluene, ethylbenzene, and xylenes (BTEX) generally proceeds until all the
contaminants are destroyed. However, in the case of chlorinated solvents, biodegradation
under natural conditions occurs via reductive dechlorination, a process which requires
both electron acceptors, which include chlorinated aliphatic compounds, and an adequate
supply of electron donors (Weidemeier, et al., 1996b). Murray and Richardson (1993)
showed that micro-organisms are believed to be incapable of growth using TCE and PCE
as a primary substrate. It is common for fuel hydrocarbons or other types of carbon, such
as organic carbon in sewage, to serve as electron donors (Weidemeier, et al., 1996b).
Biodegradation of chlorinated compounds occurs through three different
pathways: (1) use as an electron acceptor, (2) use as an electron donor, or (3) cometabolism. Co-metabolism is a process where the contaminant is degraded as a byproduct of other biodegradation processes and has no known benefit to the
microorganism (Weidemeier et al., 1996b). Evaluation of electron acceptors and donors
and their distribution can provide evidence for whether and how chlorinated compounds
are being degraded. For example, co-metabolism often occurs during biodegradation of
BTEX in aerobic environments. Therefore, the amount of oxygen present in the
subsurface coupled with the presence of BTEX and a significant loss of chlorinated
compounds could suggest that biodegradation of the chlorinated compounds is occurring.
Reductive dechlorination is the fastest process for degrading chlorinated
compounds. Compared to biodegradation of fuel hydrocarbons, whereby the
microorganisms degrade the fuel compounds to obtain carbon, chlorinated compounds
are used as electron acceptors. Reductive dechlorination occurs as a sequential process.
PCE degrades to TCE as the first chlorine atom is replaced by a hydrogen atom.
Theoretically, all three isomers of Dichloroethylene (DCE) are produced by
dechlorination of TCE, however, cis-1,2-DCE is the most common intermediate product
than trans-1,2-DCEand 1,1-DCE (Bouwer, 1994). Cis-1,2-DCE is degraded to vinyl
chloride (VC), which is degraded to ethylene.
Weidemeier, et al. (1996a) estimated a rate constant for reductive dechlorination
of TCE under reductive dechlorination conditions of 1.2 per year. Wilson, et al. (1996)
show that rate constants for TCE of up to 3.7 per year can be achieved in microcosm
studies. These rates are relatively rapid compared to co-metabolism of the more highly
chlorinated compounds. DuPont, et al. (1996) estimated a rate constant for
dechlorination under co-metabolism conditions of TCE at Eielson Air Force Base of 0.18
per year, and Ellis, et al. (1996) estimated a rate constant for TCE at Dover Air Force
Base of 0.25 per year and 0.29 per year for PCE, where processes other than reductive
dechlorination account for the majority of degradation.
Studies have shown that the rate of biodegradation via reductive dechlorination
decreases as the degree of chlorination increases (Weidemeier, et al., 1996b; Ellis, et al.,
1996). It follows that PCE has been shown to be the most susceptible to dechlorination
because it is the most chlorinated, and VC the least susceptible. In addition, the most
rapid biodegradation rates affecting the widest range of compounds occur under
methanogenic conditions (Bouwer 1994).
The second pathway for degrading chlorinated compounds is their use as electron
donors (Weidemeier et al., 1996b). In contrast to first pathway, only chlorinated
compounds which are less chlorinated, such as cis-1,2-DCE and VC, can be used as a
primary substrate for microorganism growth. In this situation, the microorganisms
facilitate a redox reaction between electron acceptors, such as dissolved oxygen or nitrate,
and the chlorinated compound, obtaining energy from the degraded chlorinated
compound. This reaction is similar to that for biodegradation of fuel compounds (e.g.,
BTEX). Studies in this area have shown that VC will degrade under aerobic conditions,
and that cis-1,2-DCE will degrade under aerobic or anaerobic conditions (Weidemeier et
al., 1996b).
A third mechanism for biodegradation of chlorinated compounds is cometabolism. In this case, enzymes or other factors produced by the organisms for other
purposes act as catalysts for the degradation of chlorinated compounds. This process has
been documented more often for aerobic environments, although it can occur under
anaerobic conditions as well (Murray and Richardson, 1993; Vogel, 1994; McCarty and
Semprini, 1994). Co-metabolism often occurs under an environment in which BTEX are
the primary substrates undergoing direct biodegradation. Chlorinated compounds that are
present in this environment are fortuitously degraded at the same time as the BTEX
compounds. Generally, it has been observed that the co-metabolism rate increases as the
degree of chlorination decreases (Weidemeier et al., 1996b).
These three approaches for the degradation of chlorinated compounds produce
three different types of plume behavior under field conditions. Weidemeier et al. (1996a)
discuss three types of behaviors for chlorinated compounds that have been observed and
documented in the field. Type 1 behavior occurs when the primary substrate is
anthropogenic carbon such as BTEX or landfill leachate. In this case, the carbon is the
limiting factor driving biodegradation rates. This type of behavior results in the most
rapidly observed degradation rates for the highly chlorinated constituents including PCE,.
TCE, and cis-1,2-DCE (Weidemeier, et al., 1996b).
Type 2 behavior occurs in areas characterized by high concentrations of
biologically available natural organic carbon, which drives the rate of dechlorination.
This type of behavior generally results in slower degradation rates ofPCE, TCE, and cis1,2-DCE.
A third type of behavior is dominant in areas with low concentrations of either
organic or anthropogenic carbon and by dissolved oxygen (DO) concentrations greater
than 1.0 milligrams per liter. Under these aerobic conditions, reductive dechlorination
will not occur. Physical transport mechanisms such as advection, dispersion, and
sorption are the primary mechanisms for attenuation in this case. However, VC can be
rapidly oxidized under aerobic conditions (McCarty and Semprini, 1994).
A plume containing chlorinated compounds may exhibit all three types of
behavior at different locations. Ideally, more than one type of plume behavior is desired
to biodegrade both the source contaminants and daughter products. The most favorable
situation is one in which PCE, TCE, and cis-1,2-DCE are reductively dechlorinated near
the source (type 1 or 2 behavior) and VC is oxidized downgradient (type 3 behavior). In
this situation, VC does not accumulate, since it is oxidized relatively rapidly into carbon
dioxide. A less ideal scenario involves reductive dechlorination of the chlorinated
compounds via type 1 or type 2 behavior. In this situation, VC is reduced to ethylene
instead of carbon dioxide at a slower rate than PCE and TCE degradation, and may tend
to accumulate.
5. METHODOLOGY
A mass balance approach was used to determine whether all the existing TCE and
PCE masses in the groundwater can be explained by the STP source. Mass resulting
from source inputs were compared to existing plume mass to determine whether a loss of
contaminants could be documented.
Source inputs were estimated using a number of assumptions about usage of TCE
and PCE at the MMR. To compare input contaminant mass with existing mass in the
groundwater, a reasonably reliable estimate of the contaminant mass input over time, or
source function, must be made. This estimate was based on several assumptions: (1) the
TCE and PCE mass infiltration rates over time were continuous, (2) TCE and PCE
discharge rates were proportional to the rates of production for these chemicals (in the
United States), (3) the STP discharge concentrations of TCE and PCE are similar to other
secondary treatment effluent discharge concentrations, and (4) the sewage treatment plant
was the primary source of discharge as opposed to the FTA-1 source. Concentrations
over time were multiplied by flow rates to obtain mass discharge over time. The mass
discharge values were then summed to yield an estimate of the total mass discharged
from the STP. Source mass estimates were compared to historical data to verify the
accuracy of the estimates.
Existing contaminant mass in the plume was estimated from isoconcentration
contours, which can be generated from analytical data. The most abundant data were
available for the period from 1993 through 1995 (Operations Technology, 1996; ABB,
1995; USGS, 1995). Iso-concentration contours were plotted on a cross-section or plan
view. Cross-sectional areas within each contour were measured and multiplied by plume
width to estimate a volume within each contour. These volumes were multiplied by
isoconcentration contour values and summed to obtain an estimate of total contaminant
mass.
In addition, non-degradable constituents, such as boron, were discharged from the
wastewater treatment plant (Walter et al., 1995 and 1996). If the distribution of TCE and
PCE corresponds to the distribution of boron, then it can be concluded that the source of
these contaminants is the STP. Specific conductivity of groundwater was also shown to
increase in the presence of wastewater discharge (Walter et al., 1995 and 1996).
Therefore, a significant increase in specific conductivity corresponding to the distribution
of TCE and PCE is another indicator that the STP is the source of these contaminants.
6. RESULTS
6.1 Mass Balance Calculations
6.1.1 Source Function
In order to estimate the source function, three pieces of information were used.
First, production curves for TCE and PCE over time were tabulated (Chemical
Encyclopedia, 1991). Figure 6-1 shows TCE and PCE production carves for the United
States from 1950 to 1990. Intermediate points were linearly interpolated to obtain values
___ _
350.0
300.0
8 250.0
" 200.0
8
-- e-TCE
*
PCE
150.0
100.0
50.0
0.0
1950
1955
1960
1965
1970
1975
1980
Year
Figure 6-1. Production Quantities of PCE and TCE in the United States
(adapted from Chemical Encyclopedia, 1991)
for each year between 1952 and 1980 (source function calculations can be found in
Appendix A).
Second, estimates of TCE and PCE discharge concentrations were based on the
assumption that discharge concentrations of TCE and PCE from the STP could be
compared to average discharge concentrations for comparable treatment sewage treatment
plants. For TCE, Helz and Hsu (1978) showed that effluent concentrations for nonchlorinated effluent from secondary treatment plants were between 8.5 ppb (1974 data)
and 30 ppb (1978 data). For 1974, a value of 8.5 was matched to the production curve for
that year, and, assuming linear proportionality to production, concentration values for
each year were extrapolated to estimate concentrations discharged over time. Similarly,
this calculation was performed for 30 ppb in 1978 to produce a second estimate of the
time varying concentration curve. A similar analysis can be made for PCE, using values
between 3.8 ppb (1974 data) and 60 ppb (1978 data). Figure 6-2 shows the resulting
concentration curves for TCE and PCE based on the 1978 data.
The third piece of information needed for estimating the source function is sewage
flow rates, which were documented by the USGS (LeBlanc, 1984b). Figure 6-3 shows
~___
70.00
60.00
50.00
-e--TCE 30 ppb in
1978
• 40.00
-4- PCE 60 ppb in
1978
30.00
. 20.00
10.00
S00n
.1950
1950
1955
1960
1980
1975
1970
1965
Year
Figure 6-2. Yearly Estimated Concentrations of TCE and PCE Discharged
from the STP
volumes of sewage treated at the STP between 1936 and 1980 as a function of sewage
flow in million gallons per day (mgd). Concentrations were multiplied by flow rates over
the time period from 1952 through 1980. Total mass discharge per year was then
summed to yield a total mass discharged from 1952 to 1980. Mass estimates using the
process described above for TCE are between 190 and 870 kg, and for PCE are between
50 and 760 kg.
I
I
I
I
Measured value
* Estimated from w .ter-supply records
a
5
II
0.
ce CL3
w
z3z
Inferred from base history
Wate pumped for supply
'SI
1.0
I'
-I
ZI
02
---
II 8
SIlr
I I'I
|
S.I.
-I
0.5
'--
I
n
W-
I -I I - I - I1
ItO
O
S
no
om
mOm
I
- --I
I
Om
97
Figure 6-3. Yearly STP Discharge Flow Rates
(adapted from LeBlanc, 1984b)
These values can be compared to historical records that show approximate
quantities sent to the STP from various operations (Metcalf & Eddy, 1983). Historical
discharge estimates show that approximately 300 kg of total chlorinated solvents were
sent to the STP. This estimate falls within the range of discharged mass estimated above.
Records from the Massachusetts Department of Environmental Protection (DEP)
indicate that after 1982, there were no discharges of TCE or PCE detected during annual
sampling. These permits show that the effluent discharge was analyzed for volatile
organic compounds as early as 1982. TCE and PCE were not detected above 0.2 ppb in
these effluent samples. Subsequent annual monitoring required by the STP National
Pollution Discharge Elimination System (NPDES) permit, which was issued in 1986
(DEP, 1984), also shows TCE and PCE at non-detect levels for samples collected in
1985. However, PCE was detected at 6 ppb in one of five samples in 1986, at 9.8 ppb in
one of five samples 1987, and at 6.6 ppb in one of five samples 1988 (DEP, 1985; DEP,
1986; DEP, 1987; DEP, 1988). However, these samples were not collected as effluent.
Rather, they were collected in wells located in the disposal beds, which have 40 foot
screens. Concentrations detected in these wells are integrated over long intervals of the
aquifer and may not accurately represent concentrations at the well locations (Hess,
1997). Since the FTA-1 source is located directly upgradient from the STP, it cannot be
determined whether these concentrations are from STP effluent or from the FTA-1 source
without additional data.
6.1.2 Sensitivity Analysis
A sensitivity analysis that uses peak discharge concentrations of 10 ppb, 50 ppb
and 100 ppb shows the range of reasonable discharge amounts for PCE and TCE to the
groundwater (Table 6-1). The first three estimates were made by assuming PCE and TCE
discharges were proportional to national production. The fourth estimate was made by
comparing PCE and TCE discharge concentrations to MMR usage, as described below.
Historical data agree with source input discharge concentrations closer to 10 ppb,.
although 50 ppb as a peak discharge concentrations are also plausible. However,
maximum concentrations found in groundwater wells are 120 ppb of TCE (Well MW581B) and 130 ppb of PCE (Well 271).
Table 6-1. Input Function Mass Estimate Sensitivity
Variable
Peak Effluent Conc.
Value
10 ppb
based on production
Peak Effluent Conc.
50 ppb
Contaminant
TCE
Mass (Kg)
140
PCE
120
TCE
680
based on production
PCE
600
Peak Effluent Conc.
TCE
1400
PCE
1200
TCE
160
PCE
160
100 ppb
based on production
Peak Effluent Conc.
based on usage
10 ppb
One initial assumption was that the PCE and TCE usage at the MMR varied
temporally in a manner proportional to national production rates. However, it is possible
that a more accurate picture could be seen if TCE and PCE usage were tied to MMR
population or activity fluctuations instead. These population fluctuations are best
reflected in the variations in STP discharges, as shown in Figure 6-10. TCE and PCE
mass estimates were accordingly matched to the flow discharge, again assuming linear
proportionality. Accordingly, Table 6-1 also compares a mass estimate that was based on
concentration curves that are proportional to the flow shown in Figure 6-3. For this
analysis, it appears that the peak effluent concentration chosen is more important than
whether the concentration over time is compared to overall United States production of
TCE and PCE or to MMR usage as reflected by the effluent discharge flow.
6.1.3 Existing Mass Estimates
Under contract to the Hazardous Waste Remedial Actions Program (HAZWRAP),.
ABB (1995) completed iso-concentration contours for total solvents in the plume, as
shown in Figure 6-4 through Figure 6-7. Since total solvents in the plume consist
primarily of TCE, PCE, and cis-1,2-DCE (LeBlanc, 1984a; ABB 1995; USGS, 1995),.
estimating TCE plus PCE from these contours is reasonable. Additionally, Operations
i2
3C
.-
7~
=A2N~
sow-
vww--
S%
I6*7ýJ KF3W6
-
/Y
/s -34
X
FSWSV-4
a:
FSW
SW" rý-SW-I .
"S
-,3
. )
:
s1
Mv
rv
FS-384
4-1. 419,
. - .- ---426
MW.
Fs
W-j
,u-'
/
/
0W32AZ
-0
l~7'
74.-
N D]
Z,
AS-UC P
I
=
NRAPOND
C0N~.
IN ppn
---
0
500
1000
2000
rFE
PilEU
ASZA
8909% BO.V
r
;,,
SCA,-:
1"=
=000'
Sevr:es
INS7ALAý,ICN:OS'-ZRAT CN
MASSACH.S-S
W.*
ý7AD
no.a
R03.AM
EvAi3
,
YOC GKXOLDWATER PLUME
993
ASHUMFT
v•--V
FIGURE 4-2
Figure 6-4. Plan View of Ashumet Valley Plume with Cross Section Locations (adapted from ABB, 1995)
Figure 6-5. Cross Section A-A' (adapted fom ABB, 1995)
om
Cr
:zL-2O
cuav
B
100
B'100
-J
N)
z
2C _
IEErDN
INTERVAL
WELL SCREEN
-20
T
A
T
OR 048 -
SCREENED-
WELLOESICNATION
AUGERINTERVAL
SCREENED - AUGER SAMPLE
VALUEIN ppb
WATERTABLE
-40
Fol
5P-5-
O
;r
100
200
CLP SAMPLEVALUE
PLUM CONTOURIN Dob
400 FEET
':I
Figure 6-6. Cross Section B-B' (adapted from ABB, 1995)
Figure 6-7. Cross Section C-C' (adapted from ABB, 1995)
Technology completed iso-concentration contours for TCE and PCE separately, as shown
in Figures 6-8 through 6-10.
Figures 6-4 and 6-8 show plan views of the location of the cross sections used for
the existing mass estimates. Areas obtained from the cross sections within each contour
were multiplied by plan view plume lengths and applicable concentrations. (Mass
calculations can be found in Appendix B). Volume (and thus mass) estimates were also
obtained from iso-concentration contours for TCE plus PCE concentrations (Barber et al.,
1988). A third estimate was made from separate iso-concentration contours for TCE and
PCE that were generated by Operations Technology (1996). A summary of these mass
estimates is presented in Table 6-2. Note that ABB (1995) does not separate solvents but
shows iso-concentration contours for all solvents in the plume (Figures 6-4 through 6-7)
Table 6-2. TCE and PCE Mass Estimates
Data Source
OpTech, 1996
OpTech, 1996
L. Barber, 1988
ABB 1995
Contaminant Mass inkg
TCE
PCE
TCE + PCE
Total Solvents
170
220
75
250
6.2 Boron, Specific Conductance, and Dissolved Oxygen
Since the Ashumet Valley plume originates from two different sources, some
understanding of how much mass came from each source is necessary. In order to
characterize the separation of the two sources, the spatial distribution of boron and
specific conductivity were used to define the boundaries of the STP plume. Barber, et al.
(1988) discuss correlations between boron, a non-degradable product from the STP, and
its relationship to TCE and PCE. Walters and Bussey show that boron concentrations
were in excess of 400 pg/L (ppb by mass) as far downgradient as 1,800 feet, and specific
conductances were greater than 400 iS/cm (at 25*C) as far as 1,200 feet downgradient
Figure 6-11 shows cross sections generated by ABB (1995), with boron and
specific conductivity plotted at each well in an effort to separate the plumes. The boron
and specific conductivity spatial distributions clearly delineate the interface between the
I
· · i';'
."
.
.
4%I
,I
9%
:
,L
''···..
''·
5
·
I
-1·..
I
· ·.
/
i
"
IS- 1-4
.
'4W-4
.. 17CLý-L7
· ··-
"
, • ..•,.
"< <;7!
Ii ,'
,
I)-Z5
· ·
(
y-'2/
"-
'
-
`·.
Y
'···:. '··
-."
-
"..
~ 41S1~
SW-42
.
.
"'--M
.--
,,
. t..
'
,iii'
,: .. .,,, .
" 'i
i\s
"_
.
-i
• , \'t -T':
,·- -
.i•
\" ','.
......"
·
I
#
7- -
_, •
,
_.
I•..
.
\
•
. ;.
.
-
~·
.·:·-~
'·I
gilL.
K
/'
/
/'
.
-
EXISTING
SOURCE
AREA
S
I
'-V
LEGEND
LEGEND
MONITORING
WELL
n BASE BOUNDARY
+
A'
A'
CROSS-SECTION
DATA GAP
MONITORING WELL
PRIMARY
ROAD
PROPOSEDPERCOLATION
TEST BORING
RIVER'PON/STREAN
-5
TCE MCL EXCEEDANCE
PROPOSED
RUNWAY/TAXIWAY/APRON GEOTECHNICAL BORING
SECONDARY
ROAD
O)'RCEIIZA7WiP.
AYEN•EDBY OPMI. 1995
SIGU
DRAFT
I
9
0
800
CRANBERRY BOG
SCALE IN FEET
TCE NICL EXCEEDANCE BASED ON
DATA GAP AT ASHUMET \'ALLEY
LOL
E=
TECHNOLOGIEs
OPERATIONAL
Massachusetts Military Reservation
o01••.
.•~,19r
cASI
Cape Cod, Massachusetts
199
ruFBRUVRY
Figure 6-8. Plan View of TCE Plume Exceeding MCL Limits with Cross Section Locations
(adapted from OpTech, 1996)
I
SOUTH
NORTIII
-110
100
90
- 80
-SW- FIW40
443
FSW411
-_0
FSW-
•3
0
LEGEND
6o
WATERTABLE
Mw
271
WELL SCREEN ID
0
3550FW
5'NS
1
137
4
20
ND
NS
50 WELLSCREENID
EXISTING
WELL
MONITORING
d20
WELL
MONITORING
3 ND
5 4010
SCREENED AUGER
S2D
5 ND.
N
1 5
6 5 :3 .
r
51.2
:-?
129,NS
-60 -
62
tJ .
2
*
"
*
1 69 ND
. . .
74
.
1 d4bS.
-
-4u
2
ND
6 4.9
*N
'"
...
1 NO.- N
ND
n
-30
-
.
ICBO D
ND
i
0.64
2
80
90
L
1
110 -
20
BELOW QUANTITATION
LIMIT
MONITORING
WELL SAMPLE
RI DATA
FINE TO COARSEjGRAINED SAND
SILTYSAND
DENSE. FINE TO COARSE
SAND WIT SILT AND
0
30
140
N
NCENTRATIO
ISOCO
CONTOUR
NOT DETECTED
NOT SAMPLED
NS
BQL
·
·~C
-70
5/
-20
-
NZ
L
SAMPLES
-10
ND
CONCENTRATIONS IN pg/l,
1500
-
SCALE IN FEET
DRAFT
TCE ISOCONCENTRATION
C 0 11P tl
k
CROSS-SECTION
DAFT
. .).
'RE
FIG
B-H' AT ASIHUMET VALLEY
MassaChusetts Military Resrvati1"(1
NT
Cape Cod,
1096
FEBRUARY
~iF;·r
C*~n
6
u
assahuse s
of
re
-
.
ross
F-221 TMASI -B
'
^L-
TCE
1996)
P
,
from
A-A
g
OTIS
1.1 I
d
(adapte
Section
Limits
MCL
ing
lume
Exceed
OpTech
NO/ATH
SOUTHWEST
tio
110
--
1 0 SDW-90
W
343
80
4411
422
a
70 60 -
FSW -
50 -
-
rn
27127
LEGEND
40
ANS
.sjB
3 S45 S
130 -S1,75
0
I07.
6NS
- NSA
20 -
z0
F
'
40o
N3NSN
_jjo.
330
S6910
o-40
F452
-50 -
*
4-60
70
S
I
145JS
20
-
-20 -
19.NS
-
_ND
*64
1
30
Y
..
.
8422
O 51061
o
L
2.5
ASl
"NN '' 604
4
151.104 a
A~s
m
0go
ND
Ni)
EXISTING
MONITORING WELL
DATA GAP
MONITORING WELL
1
on
1105
-
30
WELL SCREEN ID
S90
WELL SCREEN ID
ND
SCREENED AUGER SAMPLES
5c5- ISOCONCENTRATION CONTOUI
50
- -60
--
70
- -80
_ND
- -g
-
100
-110
-120
-130
--
110
-
120
-140
--
140
-150
--
150
.,.
SA
-- 20
-1.9
40
-80
0
-10
-- 40
21
-
-80
-100
WATER TABLE
65 ND5
10 -!
10 -
.
-
ND
NOT DETECTED
NS
NOT SAMPLED
NR
NO RECOVERY
BQL
BELOW QUANTITATION LIMIT
15
2
MONITORING WELL SAMPLE
RI DATA
MINE TO
SAND
SILl,SAND
- -130
DENS
:. FINE TO COARSE
SAND WITH SILT AND
GRASFI.
CONCEN RATIONS IN pg/L
0
- 1•n
,16
- 160
COARSE-GRAINED
1500
SCAILE IN FEET
O
ECH--E-CE
c0o P 09R A T
.0 N
TCE ISOCONCENTRATION
CROSS-SECTION A-A' AT ASHUMET VALLEY
DRAFT
FIGVRE 5.1.13
Massachusetts Milifarv ReservationI
,wM
Cod,
Cape
w
.
Massachusetts
I-
"S
EM -221 T'd •H-A
Figure 6-10. Cross Section B-B' of TCE Plume Exceeding MCL Limits (adapted from OpTech, 1996)
>4
U
z
-•,F; ~4REL
SS'
SV)
0
ai
l i
V.
M, C4 C
I
1
z
m0
U-aim
*
m
It Vs
D'
Ln.e)
120
co
1
o
•-t
I
(i5
o;
I
(NM NM NM)Tf
9.
(NM. NM. NM)
p
(20. NM,
(NM. NM. NM)T
,(29fr
10.4)
(80230.001)
148, O I)
.0
1 a2)0.(20,
(29.
.(_40.
(NM. NM, NM)
321. 01)
021
460.
(380,
.(320, 355. ND)
422.
ND)
L.J
z
IL 2)
(30. NM. II'Z:)
(50 S156, NI))+
"(•0,'
(80. 169,
3
379, NI))-
I)-"
.(230, 271,0.2)
-40
(30,. 136.
(NM. NM. NM)
W
(50. 197.4 7)-"
FINE TO
COARSE SAND
(OUTWASH)
(10. 68. 10 2) t
(2)0. 76, NM)
76,NM)
(20, 81. 10.2) A(20.
-80
(lo. 92. NM)
-120
FINE SILTY SAND
(NM. NM. NM)
I
wEL
ý!--W
•
-
4
(20. 180,2)
:0
49
•
D
E. -r N w.
IIJt-.PVA!
C26 -
WELL DrSIONA11ON
- dissolved boron (tig/L as B).
specific condcIctivity (US/cn)
anddissolved oxygen (mg/l.)
- approximate interface between
STP plume and FTA-I plume
1
400
""
4)
H'
-
S' ARn
•.:O, AR'wC tI.SLO;ict
(NI))
(NM)
- not detecled
- not measured
Figure 6-11. Boron, Specific Conductivity, and Dissolved Oxygen (adapted from ABB, 1995)
sewage plume and the FTA-1 plume. Furthermore, an anoxic zone can be seen to
correlate within the core of the sewage plume at a downgradient location corresponding
to cross section C-C' (Figure 6-4). If the length of the plume shown in plan view from
Figure 6-4 is compared to the length shown in plan view from Figure 6-8, it appears that
ABB only plotted iso-concentration contours for about half the plume. Therefore, it is
likely that the error for mass estimates calculated from the ABB cross sections may be
half as much mass as is actually in the STP plume. This factor of two is plausible when
the ABB mass estimates are compared to the mass estimates made from the OpTech isoconcentration contours (Figures 6-5 through 6-7).
Figure 6-12 shows TCE, PCE and cis-1,2-DCE spatial distributions. Comparison
of the TCE and PCE 1994 analytical data with the boron distribution shows that the TCE
and PCE exist at greater depths than the boron. This agrees with remedial investigation
findings that the solvent plume is descending within the aquifer, but not because it is
descending from the STP surface location. Rather, the plume appears deeper because the
plume is actually the product of two plumes, where the deeper plume from the FTA-1
only consists of solvents.
Although it would be reasonable to assume that only flammable substances were
used at the FTA-1, the historical evidence suggests otherwise. According to historical
usage records at the MMR, waste solvents, which were leftover from cleaning machine
parts and aircraft, were often disposed of in an unknown manner, or just dumped on the
ground near the site where they were used (E.C. Jordan, 1986; Metcalf and Eddy, 1983).
Since flammabilities for TCE and PCE are classified as slight and none, respectively
(OSHA 1997), it is not expected that these chemicals were useful at the FTA-1.
However, mixing TCE and PCE with other chemicals such as jet fuel may
increase their flammability. Large quantities ofjet fuel were used in the same locations
as TCE and PCE (E.C. Jordan, 1986; Metcalf and Eddy, 1983), which supports the
plausibility that jet fuel and solvents were mixed in the disposal process. It has been
postulated that the solvents used at the FTA-1, which is directly upgradient of the STP
contribute additional mass of TCE and PCE in the plume, and may be a more significant
source than contaminants discharged from the STP. However, plume mass estimated in
S,-F
1)
4RAz
0
I
120
tn
Ol
In
cr*
In
I*
-AS- '4ME~
POID.
FINE
SILTY
0F=
80
a
SAND
o.
(N
r
(0•2.
ND, NI)
(0 1.0.
ND)
r
oND)
(NM. NM, NM)'
o0,ND)
T
I
(ND.
(NI)D,0
(2.0,2. NI))
NI))
. NI))
(
0
0
4, ND)
(0.7,0.5. 350)
FINE TO
COARSE SAN
(OUTWASH)
(ND. ND. ND)
FINE SILTY SAND
""'
-U A.'
4) ,
4=£
OC
, p_:
7.
T
-
Figure 6-12. TCE, PCE, and cis-1,2-DCE Distributions (adapted from ABB 1995)
this study from the FTA-1 after the STP boundaries were defined do not support this
conclusion. Using methods described in Section 6.1.3, the mass contribution from the
FTA-1 plume was estimated to be 10 kg for PCE plus TCE, which is small compared to
the mass of the sewage plume.
6.3 Cis-1,2-DCE
Existing site data at Ashumet Valley documents the presence of cis-1,2-DCE at
concentrations as high as 197 ppb (LeBlanc, 1984b). Although there is no evidence to
support that cis-1,2-DCE was discharged directly to the STP, it may be a degradation
product from other processes. However, its presence is a strong indicator for
biodegradation (Weidemeier et al., 1996b, and Bouwer, 1994). In addition, areas with
low concentrations of TCE and PCE appear to correspond with areas of high
concentrations of cis-1,2-DCE.
From Figures 6-11 and 6-12, a high cis-1,2-DCE occurs in areas of high specific
conductivity and boron. This indicates that the cis-1,2-DCE is located within the sewage
plume, where there is an abundance of nutrients. In addition, dissolved oxygen (DO)
concentrations, shown on Figure 6-11, demonstrate that areas of low DO generally appear
to have high cis-1,2-DCE concentrations with low PCE or TCE concentrations. These
preliminary indications suggest that biodegradation is occurring within the anoxic zones
in the sewage plume.
Close inspection of the areas where high cis-1,2-DCE occurs, however, shows a
"pocket" of potential degradation in the middle of the plume at the C-C' cross section.
An estimate (using methods described in Section 6.1.3) of the mass of cis-I,2-DCE was
only 30 kg. Although this is a significant enough amount to conclude that biodegradation
is occurring in the anoxic core of the STP plume, it is not enough tojustify a full scale
natural attenuation remediation strategy, since the cis-1,2-DCE represents degradation of
only about 10% of the original TCE discharged to the subsurface.
7. DISCUSSION AND CONCLUSIONS
7.1 Discussion
It should be noted that the small amounts of mass estimated to be discharged
during the time period of interest (see Section 6.1.1) could be a result of several one-time
discharges from the STP without a continuous concentration in the effluent.
Consequently, if effluent discharge concentrations were documented annually or monthly
during the entire operational period of the STP, it is likely that pulse discharges would
not be detected. Therefore, an initial assumption that the discharge of TCE and PCE is
continuous over time may not reflect actual conditions.
7.2 Biodegradation Potential
The results of this study show that the first line of evidence for natural attenuation
(Section 4.3.2), that is, documented loss of contaminants at the field scale, cannot be
clearly supported. From the mass estimate comparisons in Section 6.3, it appears that the
source mass estimate of about 200 kg for either compound (TCE or PCE) is not
significantly different from the mass estimated to be in the groundwater of about 400 kg
of total compounds. Therefore, if the estimates are accurate, the contaminant mass is not
substantially decreasing.
The presence of BTEX in the plume (Metcalf & Eddy, 1983), shows that fuels
may have been discharged to the STP, which suggests that co-metabolism may have been:
a mechanism for biodegradation in the past. Presently, however, the absence of a BTEX
substrates might cause biodegradation rates to be slower compared to rates achieved
during co-metabolism. However, dissolved oxygen levels in the plume are low and may
not have been high enough for biodegradation of BTEX. Additionally, although cis-1,2DCE generally degrades to VC, none of the analytical data shows detections for VC.
In the absence of sufficient data, additional analysis is required to determine the
importance of biodegradation to the TCE and PCE mass balances. Existing data have
proved insufficient for use in the BIOSCREENTM model, which is recommended by
AFCEE (Weidemeier et al., 1996) for use as an initial screening tool. If additional
samples were collected according to the AFCEE protocol, which specifies number of
samples and analytical tests to be performed, sufficient data could be obtained to use the
BIOSCREENTM model as an assessment tool. The evidence presented here suggests that
limited biodegradation is occurring in the anoxic zones of the STP plume.
7.3
Conclusions
Mass estimate comparisons show that the source mass is not significantly
different from the mass estimated to be in the groundwater at the present time. Therefore,
if the estimates are accurate, the contaminant mass is not substantially decreasing.
Although cis-1,2-DCE, a product of biodegradation, is present in the groundwater, it is
not present in large enough amounts to support the claim that the plume will remediated
with natural attenuation.
8. REFERENCES
ABB Environmental Services Inc., 1994. PreliminaryRisk Assessment Updatefor the
Leading Edge of the Ashumet Valley Plume, Hazardous Waste Remedial Actions
Program (HAZWRAP), U. S. Department of Energy.
ABB Environmental Services Inc., 1995. Ashumet Valley GroundwaterOperable Unit
Remedial InvestigationReport, Hazardous Waste Remedial Actions Program
(HAZWRAP), U. S. Department of Energy.
ABB, 1995., Ashumet Valley GroundwaterOperable Unit Remedial InvestigationReport,
Draft, Volumes I-VI, April 1995, Under Contract to the Hazardous Waste
Remedial Actions Program (HAZWRAP), Number DE-AC05-840R21400.
Barber, L.B., Thurman, E.M., Schroeder, M.P., 1988. Long Term Fate of Organic
Micropollutantsin Sewage-ContaminatedGroundwater,Environmental Science
and Technology, February 1988, Vol. 22, No. 2, pp. 205-211.
Bouwer, E.J., 1994. Bioremediationof ChlorinatedSolvents UsingAlternate Electron
Acceptors. In: Norris, R.D., Hinchee, R.E., Brown, R., McCarty, P.L., Semprini,
L., Wilson, J.T., Kampbell, D.H., Reinhard, E.J., Bouwer, E.J., Borden, R.C.,
Vogel, T.M., Thomas, J.M., Ward, C.H., Handbook of Bioremediation, Boca
Raton, FL, Lewis Publishers, Boca Raton, FL., 1994.
Choi, J., Eichler, H., Morange, A., Salipsip, D., Schneider, S. J., 1997, Fate, Transport,
and Containmentof Nutrients and Contaminants,Ashumet Valley, Cape Cod,
Massachusetts Institute of Technology, Master of Engineering Team Project, May
1997.
Committee on In Situ Bioremediation, Water Science and Technology Board,
Commission on Engineering and Technical Systems, National Research Council,
1993. In Situ Bioremediation, When Does it Work?, National Academy Press,
Washington D.C.
Department of Environmental Quality Engineering (DEQE), Masa
Discharge Permit.
1986.
DuPont, R.R., Goder, K., Sorensen, D.L., Kemblowski, M.W., Haas, P, 1996,
Remediation Technology Development Forum IntrinsicRemediationProject at
Dover Air Force Base, Delaware,EPA 1996, Symposium on Natural Attenuation
of Chlorinated Organics in Groundwater, Hyatt Regency, Dallas, TX, September
11-13, 1996, EPA/540/R-96/509, pp. 104-109.
E.C. Jordan, 1986. U.S. Air Force Installation RestorationProgram,PhaseI: Records
Search, Air National Guard,Camp Edwards (ANG), U.S. Air Force, and Veterans
AdministrationFacilitiesat MassachusettsMilitary Reservation, Task 6, prepared
for Oak Ridge National Laboratory, Oak Ridge, Tennessee, December 11, 1986.
E.C. Jordan Co., 1988a. InstallationRestorationProgram:Ashumet Pond Trophic State
& EutrophicationControlAssessment, Hazardous Waste Remedial Actions
Program (HAZWRAP), U. S. Department of Energy.
E.C. Jordan Co., 1988b. InstallationRestorationProgram,Ashumet Pond Trophic State
and EutrophicationControlAssessment, FinalReport: Task 1-4, prepared for
Hazardous Waste Remedial Actions Program, Oak Ridge, Tennessee. E.C.
Jordan Co., Portland, Maine. March, 1988.
E.J. Flynn Engineers, 1985. Ashumet Well Study, Falmouth, Massachusetts,prepared for
the Board of Public Works, August, 1985.
Eganhouse, R.P., Dorsey, T.F., Phinney, C.S., Westcott, A.M., 1996. ProcessesAffecting
the Fate of MonoaromaticHydrocarbonsin an Aquifer Contaminatedby Crude
Oil, Environmental Science and Technology, Vol. 30, No. 11, pp. 3304-3312.
Ellis, D.E., Lutz, E.J., Pardieck, D.L., Salvo, J.J., Heitkamp, M.A., Gannon, D.J., Mikula,
C.C., Vogel, C.M., Sayles, G.D., Kampbell, D.H., Wilson, J.T., Maiers, D.T.,
1996, Remediation Technology Development Forum IntrinsicRemediation
Projectat Dover Air ForceBase, Delaware,EPA 1996, Symposium on Natural
Attenuation of Chlorinated Organics in Groundwater, Hyatt Regency, Dallas, TX,
September 11-13, 1996, EPA/540/R-96/509, pp. 93-97.
Encyclopedia of Chemical Technology, 1991. Volumes 5 and 6.
EPA, 1985, Final Report EPA/600/8-83/0005F.
EPA, 1996, ChlorinatedSolvents Biodegradation.Groundwater Curnts, September,
Issue No. 16, EPA-542-N-96-005.
Helz and Hsu, 1978. Anthropogenic C1 and C2 Halocarbons:PotentialApplicationsas
Coast Water-Mass Tracers, Proceedings of the International Symposium.on the
Analysis of Hydrocarbons and Halogenated Hydrocarbons in the Aquatic
Environment, Ontario, Canada, May 23-25, 1978, Afghan, BK., Mackay, D.,
Editors, Plenum Press, NY, pp. 435-444.
Hess, Kathryn M., 1997, Hydrogeologist, USGS, Marlborough, Massahusetts, personal
communication on Wednesday, 26 March, 1997.
Hinchee, R.E., Hoeppel, R.E., Anderson, D.B., 1995a. BioremediationofRecalcitrant
Organics,Batelle Memorial Institute, Batelle Press.
Hinchee, R.E., Leeson, A., Semprini, L., 1995b. Bioremediationof ChlorinatedSolvents,
Batelle Memorial Institute, Batelle Press.
Hinchee, R.E., Wilson, J.T., Downey, D.C., 1995c. IntrinsicBioremediation,Batelle
Memorial Institute, Batelle Press.
Hinchee, R.E., Leeson, A., Semprini, L., Ong, S.K., 1994. BioremediationofChlorinated
and PolycyclicAromatic Hydrocarbon Compounds, CRC Press, Lewis
Publishers.
K-V Associates, Inc., 1991. Ashumet Pond: A Diagnostic/FeasibilityStudy, Volume 1,
Diagnostic,prepared for Towns of Falmouth and Mashpee, Massachusetts and
Massachusetts Clean Lakes Program. K-V Associates, Inc., Falmouth,
Massachusetts and IEP Inc., Sandwich, Massachusetts. January, 1991.
LeBlanc, D.R., 1984a. Movement and Fate ofSolutes in a Plume of SewageContaminatedGround Water, Cape Cod, Massachusetts: U.S. GeologicalSurvey
Toxic Waste Ground-Water ContaminationProgram,Toxic Waste Technical
Meeting, Tucson, AZ, March 20-22, 1984, U.S.G.S. Open-File Report 84-475.
LeBlanc, D.R., 1984b. Sewage Plume in a Sand and GravelAquifer, Cape Cod,
Massachusetts, Water Supply Paper 2218. U.S. Geological Survey, Denver,
Colorado.
Madsen, E.L., 1991. DeterminingIn Situ Biodegradation,Environmental Science and
Technology, Vol. 25, No. 10, pp. 1663-1672.
Metcalf and Eddy, Inc., 1983. InstallationRestoration Program,PhaseI - Records
Search, Otis Air National Guard Base, Massachusetts, January 1983.
McCarty, P.L., Semprini, L., 1994, Groundwater Treatmentfor ChlorinatedSolvents,
Handbook of Bioremediation, Lewis Publishers, Boca Raton, FL., 1994.
Murray, W.D., Richardson, M., 1993, ProgressToward the BiologicalTreatment ofC1
and C2 HalogenatedHydrocarbons,Critical Reviews in Environmental Science
and Technology, v. 23, no. 3, p. 195-217.
National Toxicological Program (NTP), 1988. ToxicologicalandCarinogenesisof
Trichloroethylene in FourStrainsofRats, NTP TR 273, NIH Publicattion No. 882529, Research Triangle Park, North Carolina.
Occupational Health and Safety Administration, 1997. gopher://gopher.chem.utah.edu:
70/00/MSDS, March 5, 1997.
Operational Technologies Corporation, 1996. InstallationRestorationProgram,Plume
Containment Design Data Gap Field Work Technical Memorandum, Volumes IVI, February 1996.
Shanahan, Peter, 1996. Effect of the MMR Sewage Plume on the Presentand Potential
Future Health ofAshumet Pond, prepared for Ashumet-Johns Pond TAG
Coalition Committee, Falmouth and Mashpee, Massachusetts. HydroAnalysis,
Inc., Acton, Massachusetts. November 1993; revised February, 1996.
USGS, 1995. Ashumet Valley Plume, Results of 1994 Sampling, Water Resources
Division, March 1995.
Vogel, T.M., 1994, NaturalBioremediationof ChlorinatedSolvents, Handbook of
Bioremediation, Lewis Publishers, Boca Raton, FL., 1994.
Walter, D.A., B.A. Rea, K.G. Stollenwerk, and J. Savoie, 1995. Geochemical and
Hydrologic Controlson PhosphorusTransport in a Sewage-ContaminatedSand
and Gravel Aquifer Near Ashumet Pond,Cape Cod,Massachusetts. WaterResources Investigations Report 95-381. U.S. Geological Survey, Marlborough,
Massachusetts.
Walter, D.A., Bussey, K.W., 1996. Spatial and Temporal DistributionofSpecific
Conductance,Boron, and Phosphorous in a Sewage-ContaminatedAquifer Near
Ashumet Pond,Cape Cod, Massachusetts,U.S. Geological Survey, Open-File
Report 96-472.
Wilson, B.H., Wilson, J.T., Luce, D., Design and Interpretationof Microcosm Studiesfor
ChlorinatedCompounds, EPA 1996, Symposium of Natural Attenuation of
Chlorinated Organics in Groundwater, Hyatt Regency, Dallas, TX, September 1113, EPA/540/R-96/509, pp. 21-28.
Weidemeier, T.H., Benson, L.A., Wilson, J.T., Kampbell, D.H., Hansen, J.E., Miknis, R,
1996a. Patternsof naturalattenuationof chlorinatedaliphatic hydrocarbonsat
PlattsburghAir Force Base, New York. EPA 1996, Symposium of Natural
Attenuation of Chlorinated Organics in Groundwater, Hyatt Regency, Dallas,. TX,
September 11-13, EPA/540/R-96/509, pp. 74-82.
Weidemeier, T.H., Swanson, M.A., Moutoux, D.E., Gordon, E.K., Wilson, .T., Wilson,
B.H., Kampbell, D.H., Hansen, J.E., Haas, P., Chapelle, F.H., 1996b. Technical
Protocolfor EvaluatingNaturalAttenuation of ChlorinatedSolvents in
Groundwater,Air Force Center for Environmental Excellence, Technology
Transfer Division, Brooks Air Force Base, San Antonio, TX, November 1996.
GLOSSARY
aerobic - containing oxygen and/or nitrate
advection - a mechanism contaminant movement through groundwater via hydraulic
groundwater flow
algae - type of phytoplankton
anaerobic-containing no oxygen or nitrate
anisotropy - directional differences in aquifer properties
anoxic - containing no oxygen
anthropogenic- originating from human activity
biodegradation- degradation of chemicals via microbial activities (microbial
metabolism)
chlorinatedorganic compound - an organic compound that contains one or more chlorine
molecules in its molecular structure
chlorinatedsolvent - a solvent that contains one or more chlorine molecules in its
molecular structure
dilution - an increase in the ratio of water mass to chemical mass, resulting in an apparent
decrease in overall concentration
dispersion - a transport mechanisms of chemical mass via movement of molecules
through diffusion processes resulting in an apparent decrease in chemical concentration
degradation- a decrease in chemical concentration caused by chemical or biological
reactions, often accompanied by breakdown products
downgradient- in the direction of decreasing hydraulic head
electron acceptor - a molecule that gains one or more electrons during
reduction/oxidation reactions
electron donor - a molecule that loses one or more electrons during reduction/oxidation
reactions
glacialmoraine - loosely packed soils deposited after the retreat of a glacier
granodiorite- bedrock beneath Cape Cod consisting of granite that has been partially
metamorphosed to diorite
hydraulichead - the level to which water will rise, due to potential and kinetic energy of
ground water, in a piezometer that is placed in an aquifer
hydraulicgradient- the change in hydraulic head over distance
hydraulic residence time - the time, on average, in which a particle of water spends in a
particular water body
hydrocarbon- a chemical with a molecular structure that includes hydrogen and carbon
hydrodynamics - the study of water movement
infiltrationbeds - sandy areas where the treated groundwater is discharged and can
rapidly infiltrate in the soil
ionic - having a net electrical charge
isotherm - measurement made at constant temperature
isoconcentrationcontour - A map contour delimiting the boundaries of a single
concentration value
limiting nutrient - the element required for organism growth that is present in the least
amount relative to the organism's needs
microorganism- a microscopic organism that (in the context of this report) can be found
living in the pore water of the subsurface environment
methanogenic - a condition of ground water whereby, in the absence of other (preferred)
electron acceptors, carbon dioxide is used as an electron acceptor to produce methane via.
biologic activity
naturalattenuation- a remediation technology which utilizes natural microbial activity to
degrade groundwater contaminants
nutrient - elements and compounds necessary for biological processes to occur
organic - containing the elements carbon and hydrogen
oxide - pure specie associated with one or several oxygen
oxidized - during reduction/oxidation reactions, the loss of one or more electrons
plume - an area of pollution in any environmental medium
pump and treat - a remediation method whereby ground water is pumped from one or
several wells and treated at the surface
reduced - during reduction/oxidation reactions, the gain of one or more electrons
reductive dechlorination- a degradation process whereby a chlorinated organic
compound is reduced via the removal of one or more chlorine atoms from molecular
structure
remediation - clean-up or restoration of contaminated site
respiration- consumption of oxygen for biological processes
retardation- physical phenomenon where the transport of a chemical specie in the soil is
retarded
substrate - nutrients and organics substances utilized by microorganisms for growth
steady state - when conditions are not significantly changing over time
stratigraphy- layering of subsurface
substrate - nutrients and organics substances utilized by microorganisms for growth
till - densely packed glacial deposits
unsaturatedzone (vadose zone) - zone situated above the water table
verticalgradient - a hydraulic gradient in the vertical direction
volatile organic compound - an organic compound (see definition above) that also has a.
high tendency to exist in the gaseous phase
APPENDIX A
SOURCE FUNCTION
AND SENSITIVITY ANALYSIS
CALCULATIONS
Est Source Function 1974
1
Scurce per yr in Moles
FloetP
Total Prod (tons x 1000) Effluent Conc (ppb)
-tp So! rce per yr in kg
PCE
TCE
TCE
PCE
PCE
TCE
MGD
Year
TCE
PCE
1.75
1940
1940
1.00
1945
1945
0.25
1950
1950
19.29
2.53
0.25
7.1
1952
1952
135.3
21.22
2.78
0.25
1953
1953
161.7
7.81
27.00
3.54
1954
0.25
1954
196.6
9.94
2.57
3.34
0.43
25.46
1955
0.30
1955
7.81
89.0
158.1
3.00
0.50
35.10
4.60
1956
1956
92.8
9.23
0.35
173.1
0.63
1.1
37.03
3.77
1957
0.40
4.85
1957
168.9
98.3
8.52
0.64
3.86
1958
0.45
4.78
36.45
1958
1.2
93.7
147.6
7.455
7.88
6.17
1959
1.02
60.18
1959
180.1
101.5
9.23
0.60
1.2
19602
7.28
55.55
6.17
1960
0.60
1.02
168.4
104.7
8.52
1961
8.49
7.80
1961
1.3
1.30
64.81
0.70
154.6
112.6
8.52
1962
1962
70.21
9.00
178.0
1.5
129.6
9.23
0.70
9.20
1.49
19633
1963
1.7
146.6
184.5
0.70
9.48
1.69
72.37
10.20
9.514
19643
1964
1.9
191.0
163.6
0.70
9.76
1.89
74.53
11.41
9.798
1965
1965
197.5
180.6
2.1
0.70
9.90
2.09
75.61
9.94
12.61
1966
1966
2.3
0.70
64.81
213.5
197.6
8.52
8.49
13.81
2.29
19673
1967
229.5
9.95
214.6
75.92
0.60
11.644
12.86
2.5
2.14
19683
1968
245.5
81.47
12.496
231.6
2.7
0.60
10.67
2.31
13.89
1969
1969
261.5
13.348
79.77
2.9
248.6
0.55
10.45
2.27
13.68
1970
1970
277.6
265.6
14.2
3.1
69.44
0.45
9.10
1.99
11.96
19713
1971
282.6
248.7
12.78
3.3
0.45
8.19
2.11
62.49
12.73
19723
1972
219.8
299.6
11.36
3.5
0.4
6.47
1.99
49.38
12.01
19733
1973
190.9
316.6
9.94
3.7
0.4
5.66
12.69
2.11
43.20
1974
1974
162.0
333.1
3.8
0.25
8.52
3.03
1.35
23.15
8.15
1975
1975
133.0
318.3
7.1
3.7
2.53
19.29
0.25
1.32
7.93
1976
1976
130.6
303.4
3.6
6.958
0.45
4.46
2.31
34.02
13.89
19773
1977
128.2
318.3
3.7
6.816
0.45
4.37
2.37
33.33
14.28
1978
1978
125.8
333.4
3.8
6.674
0.45
4.28
2.43
32.64
14.66
19793
1979
123.4
340.3
6.532
3.9
0.70
6.51
3.89
49.69
23.41
1980
1980
347.1
121.1
6.39
4
6.37
0.70
3.99
48.61
24.01
19813
1981
112.8
306.2
5.893
3.5
1982
1982
104.5
5.396
265.3
3
3
1982
1982
96.2
262.7
4.899
3
1984
1984
87.9
260.0
4.402
3
1985
1985
79.5
223.9
2.5
3.905
1986
1986
77.3
187.8
3.905
2
1987
1987
88.6
206.8
4.615
2.45
1988
1988
225.8
1989
1989
218.3
1990
1990
132.3
TOTAL
189
287
48
1,442
moles
moles
Kg
Kg
'LeBlanc, Movement and Fate of Solutes... open file report 84-475, Figure 3
2
Average value for TCE from two different estimates
3
Inferred values
Est Source Function 1978
Year
1940
1945
1950
1952
1953
1954
1955
1956
1957
1958
1959
19602
1961
1962
19633
19643
1965
19663
1967
19683
19693
1970
19713
19723
1973'
1974
1975
1976
1977'
1978
19793
1980
19813
1982
19823
1984
1985
1986
1987
1988
1989
1990
1LeBlanc,
2
1940
1945
1950
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1982
1984
1985
1986
1987
1988
1989
1990
Total Prod (tons x 1000) Effluent Conc (ppb)
Source per yr in Moles
Flow Rates' Source per yr in kg
TCE
TCE
PCE
TCE
PCE
MGD
PCE
TCE
PCE
1.75
1.00
0.25
135.3
0.25
11.44
32.15
87 34
161.7
35.37
0.25
12.59
96.09
196.6
45.01
16.02
0.25
122.27
158.1
35.37
89.0
15.93
0.30
15.10
6.80
115.30
40.97
173.1
41.80
92.8
15.93
0.35
20.83
7.93
158.98
47.80
168.9
38.58
98.3
17.52
21.97
0.40
9.97
167.69
60.09
147.6
93.7
33.76
15.93
0.45
10.20
21.63
61.45
165.08
180.1
41.80
101.5
19.11
0.60
272.53
35.70
16.32
98.32
168.4
104.7
38.58
19.11
0.60
32.95
251.54
16.32
98.32
154.6
38.58
112.6
20.70
38.44
0.70
20.63
293.46
124.27
178.0
129.6
41.80
23.89
0.70
41.65
317.95
23.80
143.39
184.5
146.6
43.08
27.07
0.70
327.69
42.93
26.98
162.51
191.0
163.6
44.37
30.26
0.70
44.21
337.50
30.15
181.63
197.5
180.6
45.01
33.44
0.70
44.85
33.32
342.37
200.75
213.5
197.6
48.87
36.63
0.70
48.70
36.50
371.73
219.86
229.5
214.6
52.73
39.81
0.60
45.04
34.00
343.79
204.84
245.5
231.6
56.58
43.00
0.60
48.32
36.72
368.89
221.23
261.5
248.6
60.44
46.18
0.55
36.16
47.32
361.22
217.82
277.6
265.6
64.26
49.37
0.45
41.16
31.62
314.22
190.50
248.7
282.6
57.83
52.55
0.45
37.04
33.66
282.78
202.79
219.8
299.6
51.44
55.74
0.4
31.74
29.29
223.59
191.19
190.9
316.6
45.01
58.92
0.4
25.63
33.55
195.64
202.11
162.0
333.1
38.58
60.52
0.25
13.73
21.54
104.81
129.73
133.0
318.3
32.15
58.92
0.25
11.44
20.97
87.34
126.32
130.6
303.4
31.51
57.33
0.45
20.18
36.72
154.08
221.23
128.2
318.3
30.86
58.92
0.45
19.77
37.74
150.90
227.38
125.8
333.4
30.22
60.52
0.45
19.36
38.76
147.77
233.52
123.4
340.3
29.58
62.11
0.70
29.47
61.89
225.00
372.81
121.1
347.1
28.94
63.70
0.70
28.84
63.47
220.13
382.37
112.8
306.2
26.68
55.74
104.5
265.3
24.43
47.78
96.2
262.7
22.17
47.78
87.9
260.0
19.93
47.78
79.5
223.9
17.68
39.81
77.3
187.8
17.68
31.85
88.6
206.8
20.90
39.02
225.8
41.41
218.3
38.22
132.3
25.48
TOTAL
866
757
6,608
4,563
moles
Kg
moles
Kg
Movement and Fate of Solutes... open file report 84-475, Figure 3
Average value for TCE from two different estimates
3
Inferred values
Est Source Function 10 ppb
Year
1940
1945
1950
19.52
1953
1954
1955
1956
1957
1958
1959
19602
1961
1962
1963'
19643
1965
19663
19673
1968,
19693
1970
1971
1972'
1973
1974
1975
1976
1977'
1978
1979
1980
1981,
1982
1982
1984
1985
1986
1987
1988
1989
1990
Flow Rates' Source per yr in kg - - Source per yr inMoles
Total Prod (tons x 1000) Effluent Conc (ppb)
PCE
TCO
TCE
PCO
MGD
PCE
TCE
PCE
.......
- -. -. E-:÷1.75
1940
1.00
1945
0.25
1950
13.58
1.78
0.25
5
1952
135.3
14.94
1.96
0.25
5.5
161.7
1953
19.02
2.49
0.25
7
1954
196.6
17.93
6.43
1.07
2.35
0.30
2.5
5.5
89.0
1955
158.1
7.50
24.72
1.25
3.24
0.35
2.5
92.8
6.5
1956
173.1
26.08
9.43
1.57
3.42
0.40
2.75
6
98.3
1957
168.9
9.65
25.67
1.60
0.45
3.36
2.5
5.25
93.7
1958
147.6
15.44
42.38
2.56
5.55
3
0.60
6.5
101.5
1959
180.1
15.44
2.56
39.12
5.12
0.60
3
6
104.7
1960
168.4
19.51
45.64
5.98
3.24
0.70
3.25
6
112.6
1961
154.6
22.51
49.44
3.74
6.48
0.70
3.75
6.5
129.6
1962
178.0
25.51
50.96
4.23
6.68
0.70
6.7
4.25
146.6
1963
184.5
28.51
52.48
4.73
0.70
6.88
4.75
6.9
163.6
1964
191.0
31.51
53.25
6.98
5.23
0.70
7
5.25
180.6
1965
197.5
34.52
57.81
5.73
7.57
5.75
0.70
7.6
197.6
1966
213.5
32.16
53.46
5.34
0.60
7.00
6.25
8.2
214.6
1967
229.5
57.37
34.73
7.52
5.77
0.60
6.75
231.6
8.8
1968
245.5
56.18
34.19
5.68
7.36
7.25
0.55
9.4
248.6
1969
261.5
48.90
29.91
4.96
6.41
7.75
0.45
10
265.6
1970
277.6
44.01
31.84
5.77
5.28
0.45
9
8.25
282.6
1971
248.7
30.01
34.77
4.98
4.56
8.75
0.4
8
299.6
1972
219.8
31.73
30.43
3.99
5.27
7
0.4
9.25
316.6
1973
190.9
16.30
20.37
3.38
2.14
0.25
6
9.5
333.1
1974
162.0
13.58
19.83
1.78
3.29
0.25
5
9.25
318.3
1975
133.0
23.96
34.73
5.77
0.45
3.14
9
303.4
4.9
1976
130.6
23.47
35.69
5.93
0.45
3.07
4.8
9.25
318.3
1977
128.2
36.66
6.09
22.98
0.45
3.01
4.7
9.5
333.4
1978
125.8
34.99
58.53
9.72
0.70
4.58
4.6
9.75
1979
123.4
340.3
34.23
60.03
4.48
9.96
0.70
4.5
10
347.1
1980
121.1
4.15
8.75
1981
112.8
306.2
3.8
7.5
1982
104.5
265.3
7.5
3.45
262.7
1982
96.2
7.5
260.0
3.1
1984
87.9
2.75
223.9
6.25
1985
79.5
5
187.8
2.75
1986
77.3
3.25
6.125
1987
88.6
206.8
225.8
1988
218.3
1989
132.3
1990
716
135
119
1,028
TOTAL
moles
moles
Kg
Kg
'LeBlanc, Movement and Fate of Solutes... open file report 84-475, Figure 3
2
Average value for TCE from two different estimates
3
Inferred values
Est Source Function 50 ppb
Year
1940
1945
1950
1952
1953
1954
1955
1956
1957
1958
1959
19602
1961
1962
19633
19643
1965
19663
19673
1968
19693
1970
19713
19723
19733
1974
1975
1976
19773
1978
19793
1980
19813
1982
19823
1984
1985
1986
1987
1988
1989
1990
1
Total Prod (tons x 1000) Effluent Conc (ppb) Flow Rates' Source per yr inkg Source per yr in Moles
PCE
PCE
TCE
TCE
PCE
MGD
TCE
PCE
TCE
1.75
1.00
..
0.25
8.90
67.92
0.25
135.3
25
74.71
9.79
27.5
0.25
161.7
95.08
0.25
12.46
196.6
35
11.74
5.34
89.65
32.16
158.1
27.5
12.5
0.30
89.0
6.23
123.61
37.52
16.19
173.1
92.8
32.5
12.5
0.35
152.13
47.16
19.93
7.83
168.9
98.3
35
13.75
0.40
16.82
8.01
128.36
48.24
147.6
12.5
0.45
93.7
26.25
211.90
77.18
15
0.60
27.76
12.81
180.1
101.5
32.5
77.18
25.62
12.81
195.60
168.4
104.7
30
15
0.60
29.89
16.19
228.19
97.54
154.6
112.6
30
16.25
0.70
247.21
112.55
178.0
32.38
18.68
129.6
32.5
18.75
0.70
184.5
0.70
33.38
21.17
254.82
127.56
146.6
33.5
21.25
142.56
191.0
0.70
34.38
23.67
262.42
34.5
23.75
163.6
0.70
197.5
34.88
26.16
266.23
157.57
180.6
35
26.25
213.5
0.70
37.87
28.65
289.05
172.58
197.6
38
28.75
160.79
26.69
267.31
229.5
214.6
41
31.25
0.60
35.02
245.5
44
33.75
0.60
37.58
28.83
286.87
173.65
231.6
261.5
0.55
36.80
28.38
280.90
170.97
248.6
36.25
277.6
0.45
32.03
24.82
244.49
149.53
265.6
38.75
248.7
0.45
28.83
26.42
220.04
159.18
282.6
45
41.25
219.8
299.6
40
43.75
0.4
22.78
24.91
173.86
150.07
190.9
316.6
46.25
35
0.4
19.93
26.33
152.13
158.64
162.0
47.5
0.25
10.68
16.90
81.50
101.83
333.1
30
133.0
318.3
25
46.25
0.25
8.90
16.46
67.92
99.15
130.6
28.83
119.80
173.65
303.4
24.5
45
0.45
15.69
128.2
117.36
178.47
15.37
318.3
24
46.25
0.45
29.63
114.91
125.8
333.4
23.5
47.5
0.45
15.05
30.43
183.30
123.4
340.3
48.75
0.70
22.92
174.95
292.63
23
48.58
121.1
347.1
50
22.42
49.82
171.15
300.14
22.5
0.70
112.8
306.2
20.75
43.75
104.5
265.3
19
37.5
96.2
262.7
37.5
17.25
87.9
260.0
15.5
37.5
79.5
223.9
13.75
31.25
77.3
187.8
13.75
25
88.6
206.8
16.25
30.625
225.8
32.5
218.3
30
132.3
20
TOTAL
676
595
5,160
3,582
moles
moles
Kg
Kg
LeBlanc, Movement and Fate of Solutes... open file report 84-475, Figure 3
'Average value for TCE from two different estimates
3
lnferred values
Est Source Function 100 ppb
Year
1940
1945
1950
1952
1953
1954
1955
1956
1957
1958
1959
19602
1961
1962
19633
19643
1965
19663
19673
19683
19693
1970
19713
19723
19733
1974
1975
1976
19773
1978
19793
1980
19813
1982
19823
1984
1985
1986
1987
1988
1989
1990
1
Total Prod (tons x 1000) Effluent Conc (ppb) Flow Rates' Sour ce per yr inkg Source per yr inMoles
PCE
PCE
TCE
TCE
MGD
TCE
PCE
TCE
PCE
1.75
1.00
0.25
135.83
17.79
135.3
0.25
50
149.41
19.57
161.7
55
0.25
190.16
196.6
24.91
0.25
70
158.1
23.49
179.30
64.31
55
25
10.68
0.30
89.0
173.1
247.21
75.03
12.46
32.38
92.8
65
25
0.35
168.9
260.79
94.33
60
0.40
34.16
98.3
27.5
15.66
147.6
16.01
256.72
96.47
93.7
52.5
25
33.63
0.45
180.1
423.79
154.36
101.5
65
30
55.52
25.62
0.60
168.4
104.7
60
30
391.19
154.36
51.25
25.62
0.60
154.6
112.6
0.70
59.79
32.38
456.39
195.09
60
32.5
178.0
494.42
65
64.77
129.6
37.5
0.70
37.37
225.10
184.5
67
146.6
42.5
0.70
509.63
66.76
42.35
255.12
191.0
163.6
69
68.76
47.5
0.70
47.33
524.85
285.13
197.5
180.6
70
532.45
52.5
0.70
69.75
52.31
315.14
213.5
197.6
76
57.5
0.70
75.73
578.09
57.30
345.16
229.5
214.6
82
62.5
0.60
70.04
53.38
534.63
321.57
245.5
231.6
0.60
75.16
57.65
88
67.5
573.75
347.30
261.5
248.6
0.55
73.59
56.76
561.79
341.94
94
72.5
277.6
265.6
100
77.5
0.45
64.06
49.64
488.99
299.06
248.7
282.6
0.45
57.65
52.85
90
82.5
440.09
318.36
219.8
299.6
80
87.5
0.4
45.55
49.82
347.73
300.14
190.9
316.6
70
92.5
0.4 39.86
304.26
52.67
317.29
162.0
333.1
60
95
21.35
163.00
0.25
33.81
203.66
133.0
318.3
50
92.5
0.25
17.79
32.92
135.83
198.30
130.6
303.4
49
90
0.45
31.39
57.65
239.60
347.30
128.2
318.3
48
92.5
0.45
30.75
59.25
234.71
356.95
125.8
333.4
47
95
0.45
30.11
60.85
229.82
366.59
123.4
340.3
46
97.5
0.70
45.84
97.15
349.90
585.26
121.1
347.1
45
100
0.70
44.84
99.65
342.29
600.27
112.8
306.2
41.5
87.5
104.5
265.3
38
75
96.2
262.7
34.5
75
87.9
260.0
31
75
79.5
223.9
27.5
62.5
77.3
187.8
27.5
50
88.6
206.8
32.5
61.25
225.8
65
218.3
60
132.3
40
10,277
1,346
7,164
TOTAL
1,189
moles
Kg
moles
Kg
LeBlanc, Movement and Fate of Solutes... open file report 84-475, Figure 3
Average value for TCE from two different estimates
3
Inferred values
2
Est Source Function Using Flow
Year
1940
1945
1950
1952
1953
1954
1955
1956
1957
1958
1959
19602
1961
1962
19633
19643
1965
19663
19673
19683
19693
1970
19713
19723
19733
1974
1975
1976
19773
1978
19793
1980
Source per yr in Moles
Flow Rates' Effluent Conc (ppb) Source per yr in kg
PCE
TCE
PCE
TCE
PCE
TCE
MGD
1.75
1.00
0.25
13.58
1.78
5
0.25
14.94
1.96
5.5
0.25
19.02
7
2.49
0.25
17.93
11.06
4.3
2.35
1.84
0.30
5.5
5
3.24
2.49
24.72
15.01
0.35
6.5
3.25
3.25
24.78
19.55
0.40
5.7
5.7
24.70
4.10
31.30
6.4
4.10
0.45
6.4
55.42
43.73
8.5
8.5
7.26
7.26
0.60
0.60
8.5
8.5
7.26
7.26
55.42
43.73
0.70
10
10
9.96
9.96
76.06
60.03
0.70
10
10
9.96
9.96
76.06
60.03
0.70
10
10
9.96
9.96
76.06
60.03
0.70
10
10
9.96
9.96
76.06
60.03
0.70
10
10
9.96
9.96
76.06
60.03
0.70
10
10
9.96
9.96
76.06
60.03
0.60
8.5
8.5
7.26
7.26
55.42
43.73
0.60
8.5
8.5
7.26
7.26
55.42
43.73
0.55
7.9
7.9
6.19
6.19
47.21
37.26
0.45
6.4
6.4
4.10
4.10
31.30
24.70
0.45
6.4
6.4
4.10
4.10
31.30
24.70
0.4
5.7
5.7
3.25
3.25
24.78
19.55
0.4
5.7
5.7
3.25
3.25
24.78
19.55
0.25
3.6
3.6
1.28
1.28
9.78
7.72
0.25
3.6
3.6
1.28
1.28
9.78
7.72
0.45
6.4
6.4
4.10
4.10
31.30
24.70
0.45
6.4
6.4
4.10
4.10
31.30
24.70
0.45
6.4
6.4
4.10
4.10
31.30
24.70
0.70
10
10
9.96
9.96
76.06
60.03
0.70
10
10
9.96
9.96
76.06
60.03
TOTAL
164
156
1,249
941
Kg
Kg
moles
moles
'LeBlanc, Movement and Fate of Solutes... open file report 84-475, Figure 3
2
Average value for TCE from two different estimates
3
lInferred values
STP Discharge Estimates from Historical Data
I
Area
Current Maint Shop
Former West Truck
Former USAF Main Motor Pool
CAMS Shops
Bldg 156 Degreaser
Engine Shops
AGE Shops
Hangars 124, 126, 128
Operating
Years
Number of
Vehicles
1974-1990
1954-1958
215
100
1955-1970
Perm Field Site Training Hangar
1958-1990
1955-1970
1958-1971
Former NDI Lab
1955-1970
Former Refueling
Former Refueling
Road/ANG Motor
Road/ANG Motor
Maint Shop
Maint Shop
Pool
Pool
Current Maint Shop
Hangars 192 and 194
BOMARC
Former ANG Motor Pool
Former USAF Civil Eng./Roads
Engine Rebuild Area
Former NDI Lab
PMEL
200-400
1954-1967
1955-1990
1955-1990
45 (aircraft)
Gallons/
Contaminant(s)
Halog. solventsHalog. solvents
Halog. solvents
TCE, PCE, other
PCE
Halog. solvents
Solvents
18-21 (aircraft) Solvents
2?
Solvents
TCE
1955-1974
1955-1974
1958-1966
20-25
Halog. solvents
20-25
1958-1966
120
JP-4
Halog. solvents
120
1967-1974
1955-1970
1962-1990
1966-1973
1950-1973
1958-1990
1970-1978
JP-4
600
??
Halog. solvents
90
300
TCE, PCE
Unk. solvents
Halog. solvents
Solvents
Halog. solvents
TCE
TCE
1955-1990
r
TCE-
Year
Disposal
50DRMO or contract disposal
30Dumped along back fence of site
92 Dumped On Site
600 Dumped On Site or DRMO disposal
10 To leaching pit adjacent to Hangar 156
500 Dumped On Site or to Storm Drains1320 To Storm Drain System
233 Dumped On Site or to Storm Drains1500 Aquafarm storm drainage system
TCE
Density
(mg/L)
1.46
PCE
Density
(mg/L)
1.62
|
Estimated
Mass of
Solvents
(kg)
Avg.
Solvent
Density
(g/mL)
1.46
1.46
1.62
1.62
1.62,
1.62
1.62
1.62
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.50
1.46
1.62
1.50
173.35
1.46
1.62
1.50
2.37
1.46
1.62
1.50
1.46
1.46
1.46
1.46
1.62
1.50
1.50
55.41
1.50
1.50
8.31
27.31
1.46
1.46
1.46
1.62
1.62
1.46
1.46
1.46
1.46
1.46
1.46
1.62
1.62
19.79
11.87
36.41
237.47
4.27
197.89
522.43
92.22
593.67
bldg. or to aquafarm storm drainage
system
6 Dumped On Site
6 ??
28 Dumped along back fence of site
3125 Dumped along back fence of site
140 ??
Unknown
Unknown
69 ,??
300 Sanitary Sewer and DRMO disposal
450 Sanitary Sewer
0.25 Sanitary Sewer
1.62
1.62
1.62
1.62
1.62
1.50
118.73
173.35
0.10
1.50
1 t 292.18
i
292.18
APPENDIX B
EXISTING MASS ESTIMATE
CALCULATIONS
Plume Integrations
Plume Integration, ABB, 1995
Cross -C -Sectional
Average
Area for A-A' Length for
(ft2 )
5 ppb
50 ppb
100 ppb
5375
2500
1500
Mass
A-A' (ft) contribution
1500
1.14165
1500
5.31
1500
6.372
Cross
Sectional
Average
Cross
Average
Area for B- Length for
Mass
Sectional Area Length for C
Mass
contribution
C' (ft)
B-B' (ft) contribution for C-C' (ft2)
B' (ft2)
17900
2000
5.06928
9250
5000
6.549
1250
2000
3.54
12750
5000
90.27
1000
2000
5.664
9750
5000
138.06
FTA-1 mass
STP mass
Total Mass
(kg)
12.75993
99.12
150.096
261.97593
7.9
254.07593
Plume Integrations
I
TCE Plume Integration, OpTech, 1996
))
VOLUME 1, Well 422-Well 271 (Figure
6-9
•
v
Section
Length (ft) Width (ft)
750
1012
750
1350
750
750
750
750
750
750
750
750
750
1575
Depth (ft)
28
40
44
46
VOLUME 2, Well 271-Well 594 (Figure 6-9)
Volume
(cu. ft.)
21252000
40500000
51975000
62100000
67433250
72900000
80175000
92947500
-1.06E+08
Section
C)epth (ft)
Width (ft)
Volume (cu. ft.)
1260
40
3.8E+07
1485
36
4.0E+07
1710
32
4.1 E+07
1395
28
2.9E+07
1035
26
2.0E+07
720
16
3.7E+06
Total Vol.
1.7E+08
VOLUME 3, Well 271-Well 596 (Figure 6-10)
Section
Volume (cu. ft.)
Width (ft)
)epth (ft)
Length (ft)
1
750
855
36
2.3E+07
2
750
2250
6.1E+07
36
3
750
2880
30
6.5E+07
4
750
2160
3.7E+07
5
750
1395
2.0E+07
Total Vol. (cu. ft.) =
2.1E+08
1
2
3
4
5
6
1800
1913
47
2025
48
2138
50
2295
54
2565
55
2880
54 1.17E+08
3150
46 1.09E+08
Total Vol. (cu. ft.)=
8.2E+08
Mass (kg) = (Total vol.) x (conc) x (unit conversion factors) =
j 16681
96168413
Length (ft)
750
750
750
750
750
325
(cu. ft.) =
Plume Integrations
PCE Plume Integration, OpTech, 1996
VOLUME 2,Well 271-Well 594 (Figure 6-9)
VOLUME 1, Well 422-Well 271 (Figure 6-9)
Volume
Section
1
2
3
4
5
6
7
8
9
10
11
12
13
Length (ft) W idth (ft)
Depth (ft)
(cu. ft.)
1170
750
23 20182500
750
1620
36 43740000
750
1800
40 54000000
750
1890
42 59535000
2025
750
44 66825000
2160
47 76140000
750
2295
750
52 89505000
2475
57 1.06E+08
750
750
2610
61 1.19E+08
2790
750
63 1.32E+08
750
2790
62 1.3E+08
750
3330
58 1.45E+08
355
325
48 55458000
5
Total Vol. (cu. ft.) -= 1.1•E+09
Mass (kg = (Total vol.) x (conc) x (unit conversion factors) =
Section
Length (ft)
750
750
750
750
750
325
• IJ*•
I II
·rI
P
1
271-Well
Length (ft)
750
2
750
3
4
5
6
750
VULUME 3, VVWell
Section
750
750
325
223.20447
I
VVidth (ft)
V )lume (cu. ft.)
Depth (ft)
4.3E+07
42
1350
5.0E+07
39
1710
4.5E+07
32
1890
3.0E+07
22
1800
18
1.9E+07
1440
11
2.6E+06
720
1.9E+08
(cu. ft.) =
Total Voi.
(Figure
6-10)
_1
Volume (cu. ft.)
Width (ft) Depth (ft)
3.1 E+07
51
810
46
1890
6.5E+07
42
8.2E+07
2610
6.6E+07
2520
35
3.8E+07
27
1890
18
6.8E+06
1170.
2.9E+08
Total Vol. (cu. ft.)
4
Plume Integrations
Total Solvent Plume Integrations, Barber (1988)
Applicable Assi imed
Area
-10,000 ng
- 1000 ng
- 100 ng
Approx.
Total Area
Approx.
Height (m) Length (m)
(sq. ft.)
20000
20
1000
20
66000
3300
92500
25
3700
Area
Average
(sq. ft.)
Widt h(m)
20000
300
46000
300
46500
300
TOTAL MASS (kg)=
.
.J.....
. ..
I
.
.
Mass (kg)
60
13.8
1.395
75.195