United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R05-89/104
September 1989
&EPA
Superfund
Record of Decision
Adrian Municipal Well Field, MN
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50272-101
REPORT DOCUMENTATION i. REPORT NO. 2.
PAGE EPA/ROD/R05-89/104
4. Title and Subtitle
SUPERFUND RECORD OF DECISION
Adrian Municipal Well Field, MN
First Remedial Action - Final
7. Authors)
9. Performing Organization Name and Address
12. Sponsoring Organization Nซme and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
3. Redpimf Accession No.
S. Report Data
09/29/89
s.
8. Performing Organization Rept No.
10. Project/Taik/Work Unit No.
11. Contract(C) or Grant(G) No.
(O
(G)
13. Type of Report ft Period Covered
800/000
14.
IS. Supplementary Notes
16. Abstract (Limit: 200 .words) ''
The Adrian Municipal Well Field site is in Adrian, Nobles County, Minnesota, a city
which relies solely on ground water for its municipal water supply. In 1983 the State
detected VOC contamination in two of the six wells at the site, and by 1985 the city had
replaced the VOC-contaminated wells with two new wells. Subsequent ground water sampling
indicated that petroleum releases from underground storage tanks (UST) are sources for
soil and ground water contamination. Although ground water contaminant concentrations
exceed Federal and State drinking water and surface water standards, no further action
will be taken by the Superfund program because the program does not have the authority to
address clean up of petroleum releases. EPA will, however, formally transfer the site to
its UST program in October 1989 for further action. There are no costs associated with
this remedial action.
MN
17. Document Analysis a. Descriptors
Record of Decision - Adrian Municipal Well Field,
First Remedial Action - Final
Contaminated Media: soil, gw
Key Contaminants: petroleum wastes including benzene, xylenes, and lead
b. Identifiers/Open-Ended Terms
c. COSAT1 Reid/Group
18. Availability Statement
(See ANSI-Z39.1S)
19. Security Claw (This Report)
None
20. Security Class (This Page)
None
21. No. ol Pages
34
.22. Price
Sป Instruction, on Reverse . OPTIONAL FORM 272 (4-77)
Department ol Commerce
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RECORD OF DECISION DECLARATION
SITE NAME AND LOCATION
Adrian Municipal Well Field
Adrian, Nobles County, Minnesota
STATEMENT OF BASIS ANP PURPOSE . .....
This decision document presents the selected remedial action for the.Adrian
Municipal Well Field Site in Adrian, Minnesota, developed in. accordance with the
Comprehensive Environmental Response, Compensation and Liability Act of .1980.
(CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986
(SARA), the Minnesota Environmental Response and Liability Act of 1983'.(.MERLA)
and to the extent practicable, the National Oil and Hazardous Substances :;
Pollution Contingency Plan (40 CFR Part 300). '
This decision is based on the administrative record upon which the selectibn of
the remedial action is based. The index of the administrative record is':',
attached. .' / '
The Stat- of Minnesota and the U.S. Environmental. Protection Agency .(U.S.'. EPA)
each and independently, concur and adopt the selected remedy. . . . ' .
DESCRIPTION OF SELECTED REMEDY; NO ACTION . ..'.;
The results of the Remedial Investigation (RI) show that contaminants of .concern
at the Site are excluded from remedial action under MERLA and CERCLA Section .
101. Specifically, the Superfund program does not have the authority tb'address-
cleanup of petroleum releases from underground storage tanks (UST). The '
selected remedy is that "no further action" be taken by the Minnesota Pollution *
Control Agency (MPCA) Site Response Section and the U.S. EPA Office of Superfund
at the Site and that the Site be transferred to the U.S. EPA UST program and the
Hazardous Waste Division (Tanks and Spills Section) at the MPCA, which is acting
under a cooperative agreement with the U.S. EPA.
DECLARATION STATEMENT ..
Pursuant to MERLA and Section 101 of CERCLA, as amended by SARA, U.S. EPA 'and
MPCA do not have the authority to address the Site using Superfund Resources.
The UST program established in Subtitle I of the Resources Conservation and
Recovery Act, as amended by SARA, is the regulatory authority with jurisdiction
over cleanup of releases of petroleum from leaking underground storage tanks.
The Adrian Municipal Well Field Site has been referred to the UST Program for
further action deemed appropriate. Minn. Stat.. ch. 115c (1988) provides
authority for the state underground storage tank program to deal with the Site.
The "no further action" decision does not constitute a finding that the Site is
protective of human health and the environment. .
HA
Vfeddas V. Adamkus . / f\ Date
Regional Administrator
U.S. Environmental Protection Agency
Gerald Lฃ Willet * Date
Commissioner
Minnesota -Pollution Control Agency
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: ADDENDUM
U. S. EPA and MgCA, by this addendum to this declaration, hereby
clarify that at the time funds were expended for remedial
investigation (RI) activities, there was a release or threat of
release of a hazardous substance. Upon-completion of the RI, it
became clear that the nature of the waste was:.petroleum. For
this reason, the agencies are. now transfering authority for
further response action to the UST program. / .. ;
Valdas V. Adamkus
Regional Administrator
N ^
U ;
U. S. Environmental Protection' -Agency
erald L. Willet
Commissioner ':".<.
Minnesota Pollution Control Agency
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RECORD OF DECISION
Summary of Remedial Alternative Selection
Adrian Municipal Well Field
Adrian, Nobles County, Minnesota
I. SITE NAME, LOCATION, AND DESCRIPTION
The city of Adrian (the City) is located in west-central Nobles County in
southwestern Minnesota (T102W, R42W, Sections 18 and 19, and T102N, R43W,
Sections 13 and 24), Figure 1. Located along the Kanaranzi Creek, the City has
a population of approximately 1,336 people (1980 census), with the area of v
investigation (the Site) encompassing a portion of the north-central part of the.
City. Adrian relies solely on ground water for its municipal water supply. The
City operates six water supply wells (Figure 2), five of which produce from the
surficial outwash deposits along Kanaranzi Creek and its tributary outwash
channels, and one of which produces from very thin horizontal sand zones in the
till.
The municipal water supply services approximately 400 connections with an
82 gallon per capita per day consumption. In September 1983, the Minnesota
Department of Health (MDH). reported that City Wells No. 3 and No. 4 contained
detectable concentrations of 1,2-dichloroethane (16 parts per billion [ppb] and
3.8 ppb, respectively). The concentration in City Well No. 3 exceeded the human
health water quality criterion established by U.S. Environmental Protection.
Agency (EPA) for 1,2-dichloroethane (9.4 ppb). Subsequent sampling (January
1984) showed both wells contained benzene at concentrations (130 ppb and 160
ppb, respectively) that also exceeded the human health water quality criterion
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for benzene (6.6 ppb). Prior to the discovery of the ground water problems, the
City used City Wells No. 1, No. 2, No. 3, and No. 4 as their source of drinking
water. On January 16> 1984, the MDH issued a health advisory for the City
recamiending that City Wells No. 3 and No. 4 not be used as a source of drinking
water.
City Wells No. 3 and No. 4 are no longer in use and the City replaced
these wells with recently constructed (1984-1985) City Wells No. 5 and No. 6.
City Wells Nos. 1 and 2 continue to be used as needed. Petroleum-based
contaminants have not been detected in City Wells Nos. 1, 2, 5 and 6.
The area of investigation is underlain by a thick glacial deposit composed
largely of outwash and till of the Wisconsin glaciation during the Pleistocene
i
Epoch. Bedrock is estiinated at 400 to 500 feet below ground surface and
consists of thin.Cretaceous sedimentary units overlying Precambrian granitic *
bedrock. The Precambrian granitic bedrock is not known to be a ground water
source in Nobles County, and only the sandstones within the Cretaceous units are
reported to be adequate as a domestic water supply. The topography/
physiography in the vicinity of' the Site is slightly rolling to flat, and
dominated by glacial features that were formed during pre-Wisconsin and
Wisconsin glaciations. The Eemis and Altamont phases of the Des Jfoines lobe
deposited till across the region. Long, narrow meltwater channels were cut into
the till by peri-glacial streams that drained the front of the ice sheet.. The
channels were subsequently filled with outwash, and are the present day courses
of smaller streams. The Site lies along the southern bank of a channel occupied
by Kanaranzi Creek.
II. SITE HISTORY AND ENFORCEMENT ACTIVITIES
On September 1, 1983, the MDH reported, as part of a state-wide study of
volatile organic compound (VDC) contamination in municipal v^lis, that ground
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water in City Vfell No. .3 contained: 16 ppb of 1,2-dichloroethane. This
concentration exceeded the 9.4 ppb :human health water quality criterion for 1,2
dichioroethane. In addition, City Well No. 4 contained 3.8 ppb
1,2-dichloroethane. The wells were resampled on October 15, 1983, and the MDH
reported concentrations of, 11.0 Jahd .2.7 ppb respectively, of 1,2-dichloroethane
for samples from City Wells. No. 3.and No. 4. Additional samples were collected .
from the wells on January 5 and,-11, 1984. The results of those samples
V .
indicated' that City Wells No;. 3; and No. 4 were contaminated with several VOCs.
Concentrations of benzene ranged, from. 88 ppb to 160 ppb for City Well No. 4, and
from 90 ppb to 130 ppb for City Well No. 3. These concentrations exceeded the
human health water quality criterion of 6.6 ppb for benzene. Concentrations of
1,2-dichloroethane in the samples .ranged from 10 ppb for City Well No. 3 and 15
.'..;'' ป
ppb for City Well No. 4. :. : .. '
Another set of water samples was collected in January 1985. The data
showed high concentrations of'VDCs in monitoring wells MW-3D, MW-7, MW-8, and
MW-8D (see figure 3 for Monitoring Well locations). During March 1985, the
Minnesota Pollution Control Agency (MPCA) conducted an inventory of buried
gasoline tanks to identify possible sources of the municipal well contamination.
All of the tank locations were investigated with flight-auger borings. The
results are listed below:
HIGHEST *
NO. OF NO. OF HI
MPCA '.. NAME
1 . MnDOT Truck Station
2 Adrian Motel
3 Champlin Station
4 Adrian Glass & Sign
6 John'~ - Lonment
NO. OF
TANKS
3
2
3
2
2 .
NO. OF
BORINGS
3
2
1
2
2
HNu READING
(PPM)
500
0
150
70
5
CURRENT
ACTIVE
1
0
3
0
0
STATUS
REMOVED
2
2
2
2
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7 Archer's Rebuilders 3 2 550 0 3
8 Adrian Tile
(Underground) . 1 3 500 0 1
(Above Ground) 4 04
9 Adrian Mini Mart : : ' 3 2 50 3
* The HNu reading is a measure of VDCs present in the soil, like those in
gasoline. The reading.is. generally reported as the equivalent concentration
of isobutylene. The higher the reading, the higher the concentration of
organic vapors .''.',.
\
HNu readings strongly indicated the presence of what was presumed by
investigators to be gaspline at or near the water table in the borings at Adrian
Tile Co., the Champliry (now. Fina) Gasoline Station, the MnDOT Truck Station, and
Archer's Rebuilders.: ,"In\addition, HNu readings suggested the presence of <
gasoline in the borings at. Adrian Glass & Sign, John's Alignment and the Adrian f
Mini Mart. The HNu readings from the borings at the Adrian Motel indicated
little evidence of gasoline. Many of these tanks have been taken out of service
and removed from the ground.
Additional ground water samples were analyzed in October 1987, January
1988, and March 1988, These analyses also showed high concentrations of VDCs in
Wells MW-3D, MW-5D, MW-7, MW-8, and MW-8D.
The history of response actions at the Site is provided below in
chronological order:
. - Samples collected by the MDH on September 1, 1983, indicated that City Well
No. 3 contained 1,2-dichloroethane at 16 parts per billion (ppb). That
concentration exceeds the 9.4 ppb human health water quality criteria for
1,2-dichloroethane. A trace level of chloroform was detected in City Well
No. 2. Peaks were detected for carbon tetrachloride and 1,2-dibromoethane
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for City Wells No. 2 and No. 3, respectively. In addition,
1,2-dichloroethane at 3.8 ppb was detected in City Well No. 4.
MDH confirmation samples collected October 25, 1983, verified levels of
1,2-dichloroethane of 11.0 and 2.7 ppb in City Wells No. 3 and No. 4,
respectively.
Analysis from samples collected on January 5 and 11, 1984, showed that City
Wells No. 3 and No. 4 were contaminated above human health water quality
criteria with several VCCs including 1,2-dichloroethane and benzene.
On January 12, 1984, the City discontinued use of City Wells No. 3 and
No. 4 and began using City Wells No. 1 and No. 2 for their water supply.
MDH issued a health advisory for the City on January 16, 1984,
recommending that City Wells No. 3 and No. 4 not be used for drinking water.
'''' - .ป
On January 16, 1984, MPCA issued a Declaration of Emergency to authorize the
use of MERLA funds at the site.
On January 16, 1984, the MPCA Board authorized the expenditure of funds from
the Minnesota Environmental Response, Compensation and Compliance Fund to:
1. Conduct a remedial investigation to define the release;
2. Conduct a feasibility study to define the best short-term and
long-term alternative water supply; and
3. Develop a temporary water supply for the City.
Barr Engineering Company, under contract with the MPCA, completed the
Feasibility Study on the Temporary Water Supply, Adrian, Minnesota in
March 1984.
Activated Carbon Filtration was installed and operated for City Wells No.
3 and No. 4 from July through November 1984.
MPCA conducted a Soil Boring Investigation at Nobles County Garage, MnDOT
Truck Station, Adrian Motel, Adrian Glass & S;TH, John's M.. ..vnent,
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Archer's Rebuilders, Adrian Tile, and Adrian Mini-Mart in March and
May 1984.
Barr Engineering Company conducted the Hydrogeologic Remedial Investigation
field activities, which included twelve soil boring and six monitoring
wells, from May through September 1984.
The respective landowners removed two inactive underground gasoline tanks
from Adrian Glass & Sign; two inactive underground tanks from Adrian Auto;
and two tanks from the Adrian Motel by September 28, 1984.
The Hydrogeologic Remedial Investigation Report was completed by Barr
Engineering Company in October 1984.
Barr Engineering Company completed a Hydrogeologic Remedial Investigation
Supplement (installation of five monitoring wells) in January 1985.
One inactive underground gasoline tank was removed from Adrian Tile on
August 20, 1985.
The Hydrogeologic Remedial Investigation Supplemental Report was completed
by Barr Engineering Company in November 1985.
Using federal Small Cities Development Grants, the City installed City Well
No. 5 in November 1984, and City Well No. 6 in October 1985.
IT Corporation (IT) was retained by the MPCA to prepare a Work Plan for a
more detailed remedial investigation in early 1986.
IT conducted the field investigation described in their Work Plan between
September 1987 and April 1988.
Malcolm Pirnie, Inc. was retained by the MPCA in July 1988 to complete a
Remedial Investigation Report based on the data from the previous
investigations.
June 1989 - Final RI approved by MPCA and EPA.
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III. COMMUNITY RELATIONS
Public interest-in the Superfund activities at the Site has been limited.
To date, there have been public meetings, fact sheets, and press releases
regarding the activities at the Site. There is an active mailing list of local
citizens interested in the activities at the Site. A public information .
repository has been established at the Adrian Public Library. A Proposed Plan
(attached) was prepared stating MPCA's and EPA's recomiendation for transfer of
the Site from the Superfund Programs to the Federal and State Underground
Storage Tanks (UST) Programs. A chronology of past community relations
activities at the Site is listed in the Responsiveness Summary attached.
A public comment period on transferring the Site began on July 26, 1989, *
and ended on August 25, 1989. The MPCA published a notice in the July 26th
edition of the Nobles County Review, a weekly newspaper published in Adrian, and
also provided a news release to the nearest daily newspaper, the Worthington
Globe. The notice and news release included information on the availability of
the Remedial Investigation Report and Proposed Plan at the Adrian Library, the
dates of the public comment period, and a brief description of the Proposed
Plan. In addition, the MPCA mailed copies of the Proposed Plan to local
officials, state legislators, and tank owners and operators.
One comment was received during the public comment period. The attached
responsiveness summary details the comment received and the MPCA's response.
IV. SCOPE OF RESPONSE ACTION
This declaration of "No Further Action" represents the final action at the
Site under the Federal and State Offices of Superfund. After the Site is
transferred to the Federal UST program, the MPCA's UST program will develop and
implement remedial actions, as is appropriate for sites with only petroleum
i .
contamination.
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V. SITE CHARACTERISTICS
During the 1988" RI activities conducted by IT Corporation, three rounds of
ground water sampling were conducted to determine the nature and extent of
contamination at the Site. The first round included analyses for VDCs of all
samples, and analyses for semi-volatile organic compounds.. (SVs), pesticide/PCB,
and inorganics on selected samples. After the well installation program was
complete, all of the wells were sampled for VDCs, and selected wells for SVs and
inorganics. A third sampling round included only the newly installed wells, and
served as a confirmation round on VDCs for those wells that had only been
sampled once up to that time.
The data indicate one major source and one potentially minor source for
the contaminants. These sources are associated with current or former ; *
underground storage tank locations and are shown in Figure 3. Tank Location 3N
(Figure 3) contains tanks currently in service at a gasoline service station.
Based on the results of the Soil Organic Vapor (SOV) .Survey, analyses of
subsurface soil samples and ground water monitoring (Well MW-7R), .the area
occupied by this source is estimated to be about 40 feet by 100 feet, and
includes about 1,500 cubic yards of soil.
A potentially minor source has been identified at Tank Location 4 (Figure
3). This tank has been removed, but the SOV Survey and analyses of subsurface
soil samples have identified residual contamination in the soil. However, this
location is about 100 feet further from the bank of the channel aquifer than is
Tank Location 3, and the migration of contaiuinants through the glacial till
highland over that distance is doubtful. Consequently, the status of Tank
Location 4 as contributor to the contaminant plume in the aquifer is uncertain.
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A. Ground Water and Surface Water
Ground water at the Site is contaminated with organic compounds and
lead. The compounds found at high concentrations and/or widespread occurrence
are benzene, toluene, total xylenes, ethylbenzene, 1,2-dichoroethane,
1,2-dibrcmoethane, naphthalene, 2-methylnaphthalene, and lead. .This cluster of
compounds indicated that the primary source of contamination is petroleum
products, principally gasoline and possibly fuel oil. Other organic compounds
were found at relatively low concentrations, and in some cases were not found
consistently throughout the sampling program.
The contaminant plume is found in a surficial meltwater channel
aquifer. This is the principal aquifer in the region for large, capacity water
sources such as the municipal system, and no reliable alternative sources are
known. The aquifer generally consists of a zone of shallow, silty sand
overlying a basal unit of coarse sand and gravel. Five of the City's six
municipal water supply wells are completed in the channel aquifer, and four are
screened in the basal unit. The maximum depth of the base of the channel
aquifer is estimated to be 40 feet, and the thickness of the basal unit
supplying the municipal wells is approximately 5 to 10 feet. The water table is
found at depths ranging from about 5 to 20 feet, depending upon surface
elevation.
The contaminant plume is found along the southern bank of the channel
(Figures 4 and 5). It is found in both the shallow sand unit (Zone I) and in
the basal unit (Zone II). The highest concentrations are found at well MW-8,
where the maximum concentrations of the most prevalent compounds were found to
be:
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Contaminant Concen tra t ion
- benzene. 33,000 ug/1
- toluene 50,000 ug/1
- total xylenes 20,000 ug/1
- ethylbenzene 2,400 ug/1.
- 1,2-dichloroethane 1,400 ug/1
- l,2^ฑLbromoethane 700 ug/1
- naphthalene 640 ug/1
- lead ' 525 ug/1
The plume attains its greatest areal extent in the basal unit (Plume Zone II,
Figures 4 and 5). The actual areal extent of the plume.in the western part of
' . J
the Site is uncertain, since the plume extends beyond the monitoring well
network in the basal unit. A conceptual plume shape, based on aquifer
hydraulics and source concentrations, is shown in this portion of Figure 4.
Actual field conditions may differ. As depicted in Figure 4, the plume contains
about two to six million gallons of contaminated ground water.
Ground water flows generally in a north, northwesterly direction,
although it is apparent from the ground water contour maps that the direction of
flow varies somewhat with changes in seasonal recharge conditions. Ground water
velocities also vary with changing conditions, although generally water moves
through the shallow sands and basal unit at a rate of flow less than 1 foot/day.
While water continues to move through the plume at this rate, the plume appears
to be relatively immobile. This apparent immobility may be due to various
degradation processes, including biodegradation at the edges of the plume
keeping pace with flow, resulting in a nearly stationary plume.
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Kanaranzi Creek is the major surface water body in the area, and runs
along the northern part of the study.area. Analytical data collected during .
base flow periods when ground water discharges to the creek indicates that the
' . - *
contaminant plume is not discharging to Kanaranzi Creek at measurable
concentrations...
B. Soil ' ;
Five geologic cross sections were constructed through the Site. The .
Site lies on the southern flank of a glacial meltwater channel incised into Des
Moines lobe till. Channel sediments consist of a basal unit of coarse sand and .'.
gravel to silty, coarse sand overlain by zones of fine to medium sand and silty
sand. The deposits show the effects of changing depositional environments with *
lenses ranging from fine grained material deposited in quiet backwaters to
coarse-grained bar deposits. The glacial till consists of silty clay with some
sand, but contains sand lenses and stringers.
The distribution of soil contaminants was investigated using three
methods. First, the headspace in jars containing soil samples from borings was
scanned using an organic vapor meter equipped, with a photoionization detector,
which provided an estimate of the relative amount of volatile contaminants
present. This technique was used as a basis for selecting soil samples for
laboratory analysis. Second, one sample fron each boring was analyzed using a
gas chromatograph/mass spectrometer (QC/MS) for VDCs. Generally, this was the
sample with the highest headspace reading. This provided actual contaminant
identification and concentration in the. soil. Third, a SOV Survey was
conducted, using vapor probes and a field GC. This provided limited contaminant
identification and concentration in vapors near the water table.
Soil borings were drilled at four tank locations and one background
location. Boring locations are shown'in Figvirs 6. One sample fron each boring
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(two from the background boring) .was submitted for VOC analysis. The highest
levels of contaminants were found in .the vicinity of Tank Location 3N (borings
B-106 to B-108) reaching 79,000 ug/kg total xylenes and 13,000 ug/kg each
toluene and ethylbenzene. Tank Location 4 (boring B-101 and B-102) showed
levels;. almost as high as Tank. Location 3N, reaching 54,000 ug/kg total xylenes,
9,000 ug/kg ethylbenzene, and 7,300 ug/kg toluene. Tank Location 8S (borings
B-104 to Br-105) showed levels that were two orders of magnitude lower, reaching
840 ug/kg total xylenes and 68 ug/kg ethylbenzene in boring B-105. Tank
Location 8N (boring B-103) showed low levels of VDCs. Boring B-109 at Tank
Location 3S showed no detectable VDCs. Boring B-110, the background boring,
showed up to 11 ug/kg total xylenes. Although it was not near any known, tanks,
boring B-110 was located in an unpaved parking lot. The low levels of xylene
present are believed to be due to drips of fuel and lubricants from parked . .;
vehicles. :
A SOV Survey was conducted by IT Corporation in October, 1987. The .:
SOV Survey identified three areas of high vapor concentrations: the vicinity of
Tank Location 3N, the vicinity of Tank Location 4, and the vicinity of Tank
Location 8N. The results of soils analyses from borings at these locations
confirmed the presence of high levels of total xylenes, ethylbenzene and toluene
in the vicinity of Tank Locations 3N and 4. However, only low levels of xylene
were found in the soil at Tank Location 8N (boring B-103). The combination of
high concentrations in the soil gas and low concentrations in the actual soils
.=bove the water table indicate that the soil vapors at Tank Location 8N are
derived from the contaminant plume in the ground water (figure 7).
VI. SUMMARY OF RISKS
An evaluation was performed using monitoring data collected prior to and
during the Rensdial Investigation to estimate the potential impacts to human
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health and the. environment. Contaminant concentrations in ground water in the .
study area exceed federal and state standards and guidelines for drinking water
quality and human exposure. Since city ground water supply wells provide the
sole source of water to Adrian's residents, concern exists for potential adverse
health effects associated with the use of ground water in the vicinity of the
contaminant plume.
A. Health Risk Assessment
The data collected during IT'S remedial investigation describe the
situation where little or no pumping is conducted by City Wells No. 3 and No. 4.
The data show a plume to the south of the city wells, migrating west to
north-westward. Under the non-stressed hydraulic conditions described by this
investigation, the plume appears to be migrating to the west of the city wells,.
and the wells lie outside of the current plume configuration. However, data
collected during investigations while City Wells No. 3 and No. 4 were in regular
service indicate that under those conditions the plume will be drawn directly to
the pumping center of the two wells. Based upon these data and the public
health assessment, the use of City Wells No. 3 and No. 4 for municipal water
supply without treatment could expose people using the water to contaminants.
The primary potential route of human exposure to the contaminants at
the Site is through the use of contaminated ground water (i.e., ingestion,
inhalation, dermal contact, and ingestion of garden vegetables contaminated via
watering.) The compounds of concern selected for this evaluation were chosen
based on toxicological and carcinogenic potentials, and contaminant mobility in
the environment. These compounds are benzene, toluene and xylene (BTX),
1,2-dichloroethane, 1,2-dibromoethane, and lead.
The compounds of concern and their maximum concentration and water
quality criteria are shown on the following table. Maximum contaminant levels
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(MCLs) have been promulgated for benzene, 1,2-dichloroethane and lead.'.. .The MCL
for both organics is.5 ug/1. The MCL for lead is 50 ug/1; In addition.to -MCLs,
EPA has published MCL goals (MCLGs) for benzene and 1,2-dichloroethane. The
MCLG for both benzene and 1,2-dichloroethane is 0 ug/1. The difference between
MCLs and; MCLGs is that while MCLs are enforceable under the Safe Drinking 'Water
Act, MCLGs are not, but remain a goal. In 1989, EPA published proposed MCLs
(PMCLs) and MCLG-S (PMCLGs) for 38 drinking water contaminants. As listed in the
following table., PMCLGs have been published for toluene, xylene and lead. The.
PMCLG for toluene is 2,000 ug/1, for xylene is 10,000 ug/1 and for lead is 0
ug/1. MCLs and MCLGs for benzene and 1,2-dichloroethene have been exceeded at -
the Site. MCLs reflect best available technology (BAT) requirements for public.
drinking water supplies. ป
The MDH has established Recommended Allowable Limits (RALs) for all
the compounds of concern. As shown on the following table, the RALs for all six
compounds of concern have been exceeded. RALs have been developed from two
sources: RALs for noncarcinogens are taken from health advisories published by
the EPA Office of Drinking Water, and RALs for carcinogens are derived from data
published by the EPA Carcinogen Assessment Group. RALs for carcinogens reflect
an estimated lifetime excess cancer of 1 in 100,000. The RAL exceedence by
maximum benzene, 1,2-dibromoethane and 1,2-dichloroethane concentrations
indicate a lifetime incremental cancer risk greater than 1 in 100,000 if the
maximum contaminant levels in ground water were ingested at an average of two
liters of water per day for 70 years.
The following table also lists ambient water quality criteria (AWQC)
for the Site. Benzene, 1,2-dichloroethane, toluene and lead levels in ground
water exceed AWQC. (A summary of all organic compounds found in grc-ur -: vater at
the Site is illustrated in Figure 8). .
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-15-
WATER QUALITY CRITERIA SUMMARY
COMPOUNDS
Benzene
. 1 , 2-Dichloroethane
1 , 2-Dibromoethane
Toluene
Xylene
Lead
Notes:
; MAXIMUM
CONCENTRATION
at SITE
(uq/1)
33000
1400
700
50000
20000
525
ARARs
MCLs
(uq/1)
53
53
.
.. .
50
MCLGs PMCLS
(uq/1) (uq/1)
O3 -* .
O3
. . 05 .
2,000
. . ..10,000 .
: '5:' -.:'
OTHER
PMCLGs
(uq/1)
. .
.: 0.
2,000
.10,000
V 0
CRITERIA
RALs2
(uq/1)
7
3. 8
0 . 005
:': 2420
. . 400
20
AWQC
(uq/1)
0.67
0.94
15000
.50
(1) Data from U.S. EPA except as noted.. . . .
(2) Minnesota Department of Health, 1988. . . ,: ' : .
(3) 1986 Amendments to the Safe Water Drinking Act \ '. . ' '. , : ..
.; (4) indicates no data . ; . ... . *
Key:. ' ..- ' _ \ . .:;. ' ';:. ..-.,.- ''".. ...'-^./V;- /
ARARs Applicable or Relevant and Appropriate Regulatory Requirements
MCLs Maximum Contaminant Levels . . .-..:".
MCLGs Maximum Contaminant Level Goals : . . : . '
PMCLs Proposed Maximum Contaminant Levels . .
PMCLGs Proposed Maximum Contaminant Level Goals . . .
RALS Recommended Allowable Limits
AW2C Ambient Water Quality Criteria . .
In summary, contaminant concentrations in ground water in the study
area exceed federal and state standards and guidelines for drinking water
quality and surface water quality.. Since city ground water supply wells provide
the sole.source of drinking water to Adrian's residents, concern exists for
potential adverse health effects associated with the use of ground water in the
vicinity of the contaminant plume.
B. Environmental Assessment
The channel aquifer is an important natural resource, being the only
reliable aquifer for large water supplies such as municipal systems. A body of
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-16-
contaminated ground water exists in the aquifer, as discussed in Section V of
this Summary of Remedial Alternative Selection.
Ground water discharges to Kanaranzi Creek as base flow. Analyses
of surface water from the creek during a period when base flew was the primary
source of flow in the creek indicates that at this time the ground water
contaminant plume has no discernible effects on the quality of the surface
water. During other periods of the year,.increased flows, due to surface run-off
will reduce the effects of contaminants in the base flow..
Contaminated soils exist in the subsurface. There is no pathway for
direct contact or ingestion of the contaminated soils, but the soils act as a
source of contamination to the.ground water.. Thus, they affect, the environment v
through the ground water pathway. . : .. : ; .
; . . - ";' . '... '...:,' - .;.: i
No flora or fauna populations appear' to be affected.by the contaminant
plume. . . .-'.- - ' ' '- .;:. ' . ;.. ;.: ; .' .
VII. DOOJMENTATION OF SIGNIFICANT CHANGES ': : .
No changes in the selected remedy have been'made since the release of the
Fact Sheet/Proposed Plan. . .
VIII. STATUTORY DETERMINATION.
Pursuant to MERIA and Section 101 of CERCLA, as amended by SARA, U.S. EPA
and MPCA do not have the authority to address the Site using Superfund
Resources. The UST program established in Subtitle I of the Resources
Conservation and Recovery Act, as amended by the Hazardous and Solid Waste
Amendments and as amended by SARA, is the regulatory authority with jurisdiction
over cleanup of releases of petroleum from leaking underground storage tanks.
The Adrian Municipal Well Field Site has been referred to the UST Program for
further action deemed appropriate. Minn. Stat. ch. 115c (1988) provides
authority for the state underground storage tank program to deal with the Site.
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-17--
The "no further action" decision does, not constitute a finding that the Site, is
protective of human -health and the environment. .
IX. SCHEDULE . y. . .,; .. .
The EPA Office of Super fund will formally ..transfer the Site to the EPA UST
program. That transfer -is expected to occur by the end of September 1989.
After the formal transfer, EPA's UST Office will notify the MPCA's Division of
Hazardous Waste (Tanks and, Spills Section), which will then take responsibility
as the lead agency to perform the cleanup. ! . ; .:.. ".
X. DOCUMENTS REVIEWED ''""'""'.':''''-.-
Information for this Record of Decision was obtained .from-the Malcolm
Pimie, Incorporated 1989 Remedial Investigation report- for::the Site, the Barr
Engineering Company's 1984 Hydrogeologic Remedial investigation.and 1985
Remedial Investigation Supplement, and the MDH's August 1989 Health Assessment
for the Site. This decision was based on a review of.information listed in the
Administrative Record Index attached.
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ADRIAN
CITY LIMITS
1 | Meltvaler Channels
SCALE
SHADED AREA INDICATES
MElTWATEH
REFERENCE: 3ARR ENGINEERING :O.. 1984.
'AT I ON OF ADRIAN
.-.,.... . :ZLTWATER CHANNELS
MALCOLM
IMC.
FIGURE 1
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GLACIAL MELTWATEH
CHANNEL
LEGEND
Cw-4 CITY WELL AND ID NUMBER
INDICATES CITY LIMITS
SCALE IN FEET
MADCOLM
PIRNIE
SITE LOCATION
FIGIJF 7. 2
-------
9
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a
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5'
VtLL tOCMM
tOC**MM
Q CUV will iOCAIMM
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TAMH LOCATION* AND ซUซPRCTซP IITIMT
OP CONTAUIMATKO ซOlt
-------
\
'*,
ZONE II
LEGEND
MONITORING WELL LOCATION
CITY WELL LOCATION
SCALE IN FEET
PIRNIE
CONCEPTUAL PLUME CONFIGURATION
Non-Pumping Cpndllloh*.
FIGURE 4
-------
MW-7
(I>MO.IIC 11.11)
CQNIAMINANT
, PI UME
SCREENED INTERVAL
CONTAMINANT
SOURCE
CLAY TILL WITH SAND STRINGERS
AND FRACTURES
ZONE I
APPROXIMATE
VER1ICAI SCAI E 1 INCH = 20 FEE f
IIOI1IZQN1AI SCALE 1 INCH = -10 RET
SCHEMATIC CROSS SECTION OF CONTAMINANT PLUME
MALCOIU MUNIf. IHC
FIGURE 5
-------
Mil tOC AIM
Q CITV 111 iOCAfM
CHM4 MCTHM i
\
MALDOปM
PIRNIE
OMIMQ AND MILL LOCATIONS
-------
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IMMiAHT OF OซOปMIC COMPOUND*
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Responsiveness
Summary
Adrian Superfund
Adrian, Minnesota
*5cr
Minnesota Pollution
Control Agency
This community responsiveness summary has been de-
veloped to document community involvement and con-
cerns during the remedial investigation phase of the
project, and to respond to comments received during the
public comment period. Also included as an attachment
is a summary of the community relations activities
conducted by the Minnesota Pollution Control Agency
(MPCA) since contaminants were discovered in two city
wells in 1984.
OVERVIEW
Based on the findings of the remedial investigation, the
MPCA and the U.S. Environmental Protection Agency's
(U.S. EPA's) Superfund Office have recommended that
the Adrian project be transferred for cleanup to the U.S.
EPA's Underground Storage Tank (UST) program, ad-
ministered by the MPCA. This proposal was announced
to the community through an advertisement in the local
newspaper and a news release. A public comment pe-
riod on the proposal was provided, and the MPCA re-
ceived comments from the city of Adrian during the
comment period.
This responsiveness summary contains the following
sections:
Background Information on the Community's
Involvement
Summary of Comments Received and the MPCA's
Response
Attachment: Community Relations Activities
in Adrian
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BACKGROUND INFORMATION ON THE
COMMUNITY'S INVOLVEMENT
Since the beginning of the Superfund remedial investigation in Adrian, the level of
interest on the part of the general public has been low. Gity officials and tank owners.
however, have expressed continued interest throughout the process.
Under a cooperative agreement with the EPA, the MPCA conducted the community
relations program for the project. The MPCA provided information to the community
on the plans for the remedial investigation through a news release, fact sheet and a
public meeting. Attendance at the meeting was limited to city officials and tank own-
ers. Throughout the two-year remedial investigation, MPCA staff provided periodic
verbal updates on the investigation's progress to city officials.
: At the completion of the investigation, the MPCA announced a 30-day public comment
period (July 26 through August 25, 1989) on its proposal to transfer the project to *
UST. This announcement was made through an advertisement in the local newspaper
and news articles published in both the weekly paper and the daily newspaper serving
the area. Copies of the proposed plan were mailed to city officials, local elected repre-
sentatives and underground storage tank owners and operators, and a copy was made
available at the library. In addition, MPCA staff contacted city officials and tank own-
ers to discuss the proposal.
SUMMARY OF COMMENTS RECEIVED
AND THE MPCA'S RESPONSE
The city of Adrian provided comments on the proposed plan during the comment
period. By letter, the city indicated they understood the reasons for transferring the
project to UST. The city requested a meeting with representatives of the MPCA's UST
program in the near future to discuss UST activities related to the site.
The MPCA has appreciated the city's interest and cooperation throughout the Super-
fund project. MPCA staff are currently working to schedule a meeting between the
city and UST program staff to discuss future cleanup actions.
-------
In addition to the city's comment. U.S. EPA noted that Table 24 in the Remedial Investiga-
tion Report needed correction, based on new information. The table lists guidelines for
contaminant levels in surface and ground water Proposed Maximum Contaminant Level
(PMCL). Proposed Maximum Contaminant Level Goal (PMCLG) and Ambient Water Quality
Criteria (AWQC).
The MPCA made the suggested changes to the PMCL and PMCLG in Table 24, using the
most recent values. The corrected table is as follows:
COMPOUND PMCLG PMCL AWQC
Benzene -- ~ .67
EDC -- -- .94
EDB 0 .05
Toluene 2.000 2,000 15,000
Xylene 10,000 10,000
Lead 05 50
All values in micrograms per liter (ug/1)
-------
COMMUNITY RELATIONS ACTIVITIES CONDUCTED AT THE
ADRIAN SUPERFUND SITE
The MPCA has conducted the following community relations activities for the Adrian
Superfund project:
January 20, 1984
June 12. 1984
April 1986
Summer 1986
September 2, 1987
September 15. 1987
July 26. 1989
Letter mailed to Adrian households explaining muni-
cipal well contamination
Public meeting held in Adrian to provide updated
information on activities related to the well
contamination v
Community relations interviews conducted and infor-
mation repository established at Adrian Public
Library
Community relations plan written and approved by
EPA
News release announcing meeting in Adrian to discuss
beginning of federal Superfund project field work
Meeting held in Adrian; fact sheet provided to resi-
dents and city officials; project work plan placed in
information repository
News release announcing completion of the remedial
investigation, proposal to transfer site, and public
comment period; ad published in Nobles County
Review announcing the same information; remedial
investigation and proposed plan placed in informa-
tion repository
August 25, 1989
Close of public comment period
-------
Proposed Plan/Fact Sheet for the
Adrian Superfund Project
Nobles County
Introduction
This Proposed Plan provides
information on a
recommendation by the
Minnesota Pollution Control
Agencj (MPCA) and the U.S.
Environmental Protection
Agency's (EPA) Office of
Superfund to transfer the Adrian
Superfund site to the
Underground Storage Tank
program. The recommendation
is based on the findings of a
Superfund remedial investigation
conducted by the MPCA, as the
lead agency, with EPA, the
support agency.
Section 117(a) 6f the federal
Superfund law requires that a
plan explaining proposed actions
at Superfund sites be developed
and presented for public review
and comment. The public
comment period, discussed
below, provides an opportunity
for the public to comment on this
plan.
What is the history of the
project?
In early 1984, the MPCA
detected contamination in two of
Adrian's municipal wells. The
contaminants detected, including
benzene and 1,2-dichloroethane,
are chemicals typically
associated with gasoline leaks or
spills. Following discovery of
the contaminants, the city
stopped using the two wells, and
used Small Cities Development
grant funding to install two new
wells in an area not affected by
the contamination.
A preliminary MPCA
investigation of the
contamination delected
petroleum fuels in ground water
near the locations of many
underground fuel storage tanks.
Since that time, all inactive tanks
identified have been removed.
In the fall of 1987, using federal
Superfund money, the MPCA
began a more extensive remedial
investigation of soil and ground
water contamination in Adrian.
This investigation, completed
this summer, was designed to
assess the extent of the soil and
ground water contamination,
identify contaminant sources and
define the characteristics of the
contaminated ground water
aquifer.
\
What did the investigation find?
ป
The remedial investigation
identified a contaminated ground
water plume the pathway
contamination takes as it moves
underground generally
moving to the west/northwest.
WE WANT YOUR OPINION
The MPCA and EPA are
asking for public comments
on the proposed project
transfer between July 26
and August 25,1989,
Comments may be.
addressed to:
"Elizabeth Gelbmann
Public Information Office
V.;.':..;V. .MPCA
'...'.' 520 Lafayette Road
'.St. Paul. Minnesota 55155
. 612/29d-7~r? or toll-free
1-3C"
:-9747
-------
The agencies are proposing this
(transfer because the federal
Superfund law has a petroleum
exclusion that is, the law does
not allow use of Superfund .
money or authority to clean up
sites where the contamination is
from petroleum products.
Because the remedial
investigation verified that the
source of the contamination is
limited to petroleum fuels and
related to underground storage
tanks, Superfund is not the
appropriate program for
continued work at the site.
Specifically, section 101 of
CERCLA, as amended by SARA
-- the federal Superfund laws
provides that the Superfund
program does not have the
Authority to address cleanup of
Ibcroleum spills from
underground storage tanks. The
UST program (established in
Subtitle I of the Resource
Conservation and Recovery Act,
as amended by SARA), is the
regulatory authority with
jurisdiction over the cleanup of
the Adrian site. The proposed
decision to transfer the site docs
not constirue a finding that the
site is protective of human health
and the environment.
What will happen under the
UST program?
Since the Superfund
investigation identified the
source, under the UST program
the MPCA would request that
tresc-r-r -ible parties the
n-c-r: -. .'. operators of the
tank:. -etd with cleaning
up the contaminated soil and
ground water.
Minnesota's UST law allows for
reimbursement of a major
portion of the cleanup costs, if
the responsible parties comply
with requirements in the storage
tank laws. The law provides for
reimbursements to responsible
parties of up to 90 percent of
cleanup costs, up to $250,000. If
a responsible parry is unwilling
or unable to conduct the needed
cleanup, federal Leaking
Underground Storage Tank Trust
funds can be used to clean up the
problem. When these funds are.
used, the MPCA has the
authority to recover its costs
through legal action.
Before the cleanup would begin,
responsible parties will first be
requested to prepare a cleanup
plan for MPCA approval. At
many UST sites, cleanups
involve removal of leaking
tanks, excavation of
contaminated soil to prevent
continuing release of chemicals
to the ground water, and
pumping out contaminated
ground water for treatment to
remove the contaminants.
When will this take place?
The MPCA and EPA's Office of
Superfund are holding a 30-day
public comment period on the
proposal to transfer the site to
the UST program. Following the
comment period, the agencies
will determine whether to
transfer the site, and will notify
the community of the decision.
More questions?
The complete report of the
investigation is available for
review at the Adrian Public
Library. Persons with questions
may call Elizabeth Gelbmann,
MPCA Information Officer, toll-
free at 1-800-652-9747.
Comments on the plan for
transferring the site to the UST
program must be postmarked by
August 25, 1989, and may be
addressed to:
Elizabeth Gelbmann
Public Information Office
MPCA
520 Lafayette Road
St. Paul, Minnesota 55155 >
July 1989
-------
ADMINISTRATIVE RECORD INDEX FOR THE ADRIAN
MUNICIPAL WELL FIELD SITE
* Comprehensive Environmental Response, Compensation and Liability Act (copy of
law)
* Superfund Amendments1 and Reauthorization Act (copy of law)
* Adrian Superfund Project, Remedial Investigation and Feasibility Study Work
Plan
* Adrian Superfund Project, Comrunity Relations Plan
* Adrian Superfund Project (fact sheet)
* Adrian Superfund Project Remedial Investigation, Final Report
* Proposed Plan for the Adrian Superfund Project
* Site Investigation Report for the Adrian Well Field Site, U.S. EPA, March 1,
1984
* Preliminary Assessment Report for the Adrian Well Field Site, U.S. EPA,
February 1, 1985
X
* City of Adrian Hydrogeologic Remedial Investigation, Barr Engineering Company,
1984 . t
* Feasibility Study, Temporary Water Supply, Adrian, Minnesota, Barr Engineering
Company, March, 1984
* City of Adrian Hydrogeologic Remedial Investigation Supplement, Barr
Engineering Company, 1985 :
* Public Notice for the Adrian Well Field Site published in the July 26th, 1989,
issue of the Nobles County Review newspaper
* News release for the Adrian Well Field Site published in the Worthington Globe
July 21, 1989
* Letter from the MPCA to the Adrian Public Library transmitting the Proposed
Plan, July 21, 1989
* Letter from the city of Adrian to the MPCA acknowledging the reasons for the
transfer of the Site to the UST program, August 22, 1989
* Health Assessment for the Adrian Municipal Well Field, Adrian, Minnesota,
Minnesota Department of Health, August 1989
* Memorandum from the U.S. EPA Waste Management Division Director: CERCLA,
RCRA, Water, and Air Overlaps with the UST/LUST Programs, March 29, 1988
* Interim Final Guidance on Preparing Superfund Decision Documents, OSWER
Directive 9355.3-02, U.S. EPA, June, 1989
* Record of Decision for the Adrian Well Field Site
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