Record of Decision Decision Summary Hastings Ground Water Contamination Well Number 3 Hastings Nebraska


RECORD OF DECISION DECLARATION
INTERIM SOURCE CONTROL OPERABLE UNIT

SITE NAME AND LOCATION
Well Number 3

Hastings Ground Water Contamination
Hastings, Nebraska

STATEMENT OF BASIS AND PURPOSE

This decision document presents the selected response action
for the Well Number 3 subsite 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), 42 USC §9601 et. sea, and
consistent with the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP) to the extent practicable.

This decision is based upon the contents of the
administrative record for the Well Number 3 subsite.

In accordance with CERCLA Section 121(f)(1)(E) and (G), the
state of Nebraska reviewed and commented on the Engineering
Evaluation and Cost Analysis; for an Expedited Response Action for
Soil and Soil Gas (EE/CA) Well Number 3 Subsite. The state
concurs in the selected action for this operable unit and
has determined, through a detailed evaluation, that the selected
action is consistent with its laws and regulations.

ASSESSMENT OF THE SITE

Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare or the environment.

DESCRIPTION OF THE ACTION

This interim source control operable unit was developed to
protect public health and the environment by controlling and
reducing the migration and volume of contaminants present in the
soil-gas which overlies the aquifer. The operable unit is fully
consistent with all planned future activities. Future activities
will be addressed in subsequent Records of Decision and will
include a decision on possible remediation of contaminated ground
water.

1

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The major components of the selected action are as follows:

-	Soil vapor extraction (SVE) and treatment of air
emissions by granular activated carbon (GAC)

GAC will be transported off-site to an approved
treatment facility for regeneration or incineration

Monitoring contaminants in the soils above the aquifer;

-	Monitoring ground water contamination at the site;
and

Monitoring of the air system emissions.

DECLARATION

This interim action is protective of human health and the
environment, attains federal and state requirements that are
applicable or relevant and appropriate to this action and is
cost-effective. This action satisfies the statutory preference
for actions that employ treatment that reduces toxicity, mobility
or volume as a principal element, and utilizes permanent solutions
and alternative treatment technologies to the maximum extent
practicable. This action will mitigate future releases to the
ground water; however, this action will not address other
contaminant source areas. Due to its limited scope of migration
control, this action does not address remediation of the ground
water. Subsequent remediations are planned for the site that
will address all remaining concerns.

?- 9-7

Date	/tao^ris/Kay

Regional Administrator

Attachments: Index to Administrative Record
Decision Summary
Responsiveness Summary

2

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RECORD OF DECISION
DECISION SUMMARY
HASTINGS GROUND WATER CONTAMINATION
WELL NUMBER 3
HASTINGS, NEBRASKA

Prepared By:
U.S. Environmental Protection Agency
Region VII
Kansas City, Kansas
September, 1989

1

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Record of Decision
Decision Summary
Contents

Section



Paae

I.

Site Description

3

II.

Site History

4

III.

Enforcement History

10

IV.

Community Relations

10

V.

Site Characteristics

11

VI.

Risk Assessment

17

VII.

Scope of Operable Unit

20

IX.

Summary of Alternatives

20

X.

Evaluation of Alternatives

21

XI.

Comparison of Alternatives

25

XII.

Selected Alternative

28

XIII.

Cleanup Levels

28

XIV.

Operation and Maintenance

28

XV.

Future Action

28

XVI.

State Role

29

2

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DECISION SUMMARY
WELL NUMBER 3 SUBSITE
HASTINGS GROUND WATER CONTAMINATION

SITE DESCRIPTION

The Hastings Ground Water Contamination site is located in
south central (Adams County) Nebraska. The location of Adams
County and Hastings is shown by Figure 1. Hastings has an
estimated population of 23,000. This site consists of several
source areas which are referred to as "subsites." These subsites
are identified with various volatile industrial chemicals. The
Well Number 3 subsite consists of a carbon tetrachloride ground
water plume which extends eastward from a former grain storage
facility. This subsite is located in the west central part of
Hastings. The affected area lies between B Street and Second
Street in the north-south direction, and between Maple Avenue
and Kansas Avenue in the east-west direction (see Figure 2).

The Well Number 3 Subsite is located in the Central
Industrial Area of the city which contains commercial and
industrial properties situated along the Burlington-Northern
Railroad right-of-way. Well Number 3 source area is located on
property that was formerly used as a grain storage facility.
Records indicate that the property was previously owned by the
Burlington Northern Railroad. In 1959, the property was leased
by the railroad to Farmers Grain Storage, Inc., and later, in
1972, purchased by Farmers Grain Storage, Inc. The current
owner, W.G. Pauley Lumber Co., purchased the property in 1975.

Hastings Public Water Supply Well Number 6 is located four
blocks west of the source area. Well Number 11 is located four
blocks north-east of the source area. Wells Number 9, 10 and 20
are all downgradient of this site. Well Number 3 is one mile
downgradient from the identified source area. This well was
taken out of service in 1985. The municipal wells, shown on
Figure 2, were sampled by the state of Nebraska; the data are
presented in Table 1.

SITE HISTORY

The Hastings Groundwater Contamination site consists of
an aquifer contaminated with industrial chemicals, primarily
chlorinated volatile organics. Due to this contamination, the
City of Hastings decommissioned several of its wells and the CMS
public supply system operating east of Hastings decommissioned
one well.

3

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Figure 1

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WELL LOCATIONS WELL «3 AREA

mn mi^	^ 11 |

M-20

"I

0 _S00 FEET
JULY 1989

CW-1, MW-12, SHALLOW
MONITORING WELLS

-$>¦ MW-23, MONITORINO -4- M-10, CITY WELL

WELL SCREENED	M-3 DECOMI8SIONED

FULL DEPTH

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TABLE 1

Range of Concentrations of Volatile Organic Compounds
City of Hastings, Nebraska.

1983 - 1984
Municipal Wells
Concentrations in micrograms per liter (ug/1).

PARAMETER	M-3 M-6 M-9 M-10 M-ll

Carbon

27.1 -

NA

ND

ND

NA

Tetrachloride

46.4









(CC14)











Chloroform

ND

ND

ND

ND

0.15

1,l-Dichloroethene

ND

NA

ND

ND

NA

(DCE)











Trans-1,2-

ND

NA

ND

ND

NA

Dichioroethene











Tetrachloroethene

ND

NA

ND

ND

NA

(PCE)











Trichloroethylene

ND

ND

ND

19.6 -

0.42

(TCE)







46.5



1,1,1-

ND

NA

ND

ND

NA

Trichloroethane











(TCA)











Ethylene Dibromide

ND

NA

NA

ND

NA

(EDB)











Notes

Ground water data (1983-1984) presented here reflect data
from two wells (M-3 and M-10) which have since been taken
out of regular service and/or disconnected from the
distribution system. The highest contaminant
concentrations were found in 1983 when the wells were in
use.

Data was obtained from state of Nebraska data reports and
the REM II - Ground Water Evaluation, Hastings Groundwater
contamination Site, Hastings, Nebraska, May 7, 1987.
Samples analyzed by EPA's Lab in September, 1984 were
consistent with the above data.

NA - parameter not analyzed.

ND - compound not detected.

1983 and 1984 analyses were reported by the state of
Nebraska.

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In 1983, the Nebraska Department of Health (NDOH) sampled
the public water supply system of Hastings in response to citizen
complaints of taste and color in the drinking water. That same
year, NDOH and the Nebraska Department of Environmental Control
(NDEC) began investigating wide-spread ground water contamination
in the Hastings area. During this investigation, samples
collected from Well Number 3 indicated that the well was
contaminated with carbon tetrachloride (CC14).

In 1984, the state of Nebraska installed five pairs of
monitoring wells in the City of Hastings to define the extent of
the contamination. The Environmental Protection Agency (EPA)
began to sample wells on a quarterly basis in 1985. -Results of
the production wells are given in Table 2.

Several locations on the west side of Hastings upgradient
of City Well 3 were suspected as source areas for the CC14
contamination. Between 1986 and 1989 EPA performed a field
investigation to identify and characterize these suspected source
areas. Analyses of soil gas samples were used to identify and
define the source areas. The results of the data, which are
presented in the EE/CA, indicated that the former grain storage
facility was the area from which the CC14 found in Well Number 3
emanated. No other sources of contamination were indicated by
the data. Results of the soil-gas sampling taken from depths of
20. to 22 feet at the Well Number 3 subsite are shown in Figure 3.
These results indicate the CCl^ source is located in an area at
the east corner of the old gram storage building.

The contamination found in the water at the Well Number 3
subsite is believed to be a result of accidental spills of grain
fumigants that occurred at the former grain storage facility
prior to purchase by the current owner. During the 1960's when
there were large grain crop surpluses, extensive amounts of grain
were stored for long periods of time while waiting for market.
Fumigants were used on the grain in an effort to keep the grain
in good condition. A primary ingredient of the liquid grain
fumigants that were used in the 1960's and 1970's was CC14. The
presence of volatile organic compounds in the ground water
downgradient from the former grain storage facility is consistent
with liquid fumigants, having been released into the soil at the
former grain storage facility, migrating downward and entering
the ground water.

7

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TABLE 2

Range of Concentrations of Volatile Organic Compounds
City of Hastings, Nebraska
1985-1989
Municipal Wells
Concentration in micrograms per liter (ug/1).

PARAMETER	M-3	M-6	M-9	M-10 M-ll *M-20

Carbon

22.0 -

ND

ND

ND

ND

ND

Tetrachloride

32.0











(CC14)













Chloroform

ND

ND

ND

ND

ND

ND

1,1-Dichloroethene

ND

ND

ND

ND

ND

ND

(DCE)













Trans-1,2-

ND

ND

ND

ND

ND

ND

Dichloroethene













1,2-Dichloroethene

ND

ND

ND

ND

ND

ND

(Total)













Tetrachloroethene

ND

ND

ND

ND

ND

ND

(PCE)













Trichloroethylene

ND

ND

ND

ND -

ND -

ND -

(TCE)







21.0

2.0

5.0

1,1,1-

ND

ND

ND

ND -

ND

ND

Trichloroethane







0.3





(TCA)













Ethylene Dibromide

NA

ND

ND

NA

ND

ND

(EDB)













*M-20 is a new well constructed in 1987 and initially sampled by
the EPA in May, 1988.

NOTES:

Ground water data presented here reflects data found in M-3
and M-10 which have since been taken out of regular service
and/or decommissioned. CC14 concentrations were higher when
these wells were in service.

-NA - parameter not analyzed.

~ ND - compound not detected.

Data were obtained from the REM II - Ground Water Evaluation,
Hastings Groundwater Contamination Site, Hastings, Nebraska,
May 7, 1987; and from EPA laboratory reports.

- The above analyses were reported by EPA Labs and EPA
Contract Labs.

8

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Second St.

CARBON TETRACHLORIDE
SOIL-GAS CONCENTRATION

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An Engineering Evaluations and Cost Analysis for an
Expedited Response Action for Soil and Soil Gas Well Number 3
Subsite (EE/CA) dated July 24, 1989 was released by EPA for
public comment on July 31, 1989. The public comment period for
this subsite was closed on August 28, 1989. The EPA has prepared
a responsiveness summary which addresses the comments received
(Attachment A).

The EPA has no information indicating that hazardous
substances were ever generated at the site. Therefore, no onsite
burial of wastes is suspected.

Public access to the subsite is not restricted at this
time; however, the owner of the subsite has been advised by EPA
that precautions should be taken when response activities are
underway so that soils that might be contaminated are not
disturbed.

ENFORCEMENT HISTORY

History of this site indicates that this property was leased
to the Farmers Grain Storage, Inc. in the 1960's and later sold
to its current owner, W.G. Pauley Lumber Co. in 1975.

Information request letters were sent to W.G. Pauley Lumber Co.
and one of the past owners to determine use of grain fumigants at
the site. The current owner uses the former grain storage
buildings as warehouses for lumber. It has been determined,
through EPA's investigation, that CC14 was used by Farmers Grain
Storage, Inc. Additional information requests are being prepared
for former shareholders of Farmers Grain Storage, Inc. to further
determine, among other things, the past use of CC14 and
chloroform at this site. Farmers Grain Storage, Inc., was
dissolved in 1978 and no successor corporations are known to
exist. The investigation of potentially responsible parties
(PRPs) is ongoing; EPA has not yet notified anyone of their PRP
status at this subsite.

COMMUNITY RELATIONS

Community relations activities for the Hastings Ground Water
Contamination site were initiated by the EPA in 1984 with the
development of a Community Relations Plan. Since December 1984,
EPA has conducted meetings periodically with Hastings city
officials to update them regarding site work and findings.

The EPA Region VII Public Affairs Office has written several
Fact Sheets and provided them to parties who have expressed an
interest in the Hastings Ground Water Contamination Site. The
public affairs office also responds to inquiries from news media
and members of the public regarding this site. The most recent
Fact Sheet was prepared in July, 1989.

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A public meeting was held on August 10, 1989 to provide the
public an opportunity to comment on the EE/CA. Concerns
regarding the environmental impacts of contamination and the
relative merits of alternative response actions were voiced. A
responsiveness summary, which addresses the comments and
questions raised, is attached to this ROD as Attachment A. This
summary also addresses comments made during the course of the
remedial investigation.

SITE CHARACTERISTICS

Investigations conducted by EPA during 1987-1989 show that
the highest levels of CCl^ contamination in the soils and soil-
gas occur in the area defined by the soil-gas contours
illustrated in Figure 3, which depicts the levels of CC14
contamination in shallow borings at depths of 20-22 feet. Figure
3 also indicates that the CC14 contamination is concentrated
within a small area near the outside wall of the eastern
warehouse at the subsite. The highest CC14 concentration in deep
borings, as indicated by Figure 5, is 1200 parts per million by
volume (ppmv), found at a depth of 110 feet.

Data presented in the EE/CA also show high levels of CC14
and chloroform in the ground water at the subsite. As indicated
in Table 4, analyses of samples taken from CW-1, the monitoring
well installed at the subsite, revealed the presence of CC14 at
levels ranging from 110 parts per billion (ppb) to 270 ppb and
chloroform ranging from non-detect to 68 ppb. These samples
confirmed the results from borehole water samples taken during
the remedial investigation which indicated the presence of CC14
and chloroform.

Pursuant to the authority of the Safe Drinking Water Act
(SDWA), 42 USC §300(g), EPA has established a Maximum Contaminant
Level (MCL) for CC14. MCL refers to the maximum permissible
level of a contaminant in water which is delivered to any user of
a public water system. The MCL of 5 ppb has been established for
CC14. As indicated in this document, the MCL for CC14 has been
exceeded. The MCL for chloroform is 100 ppb; analyses of samples
collected indicate this MCL has not been exceeded.

CC14 and chloroform, as members of the volatile organic
compounds (VOC) family, readily form vapors because of their low
boiling points. These vapors move through soil by the processes
of diffusion and dispersion. VOC's have a tendency to migrate
through porous regions. Due to their density and to
gravitational effects, these VOCs will move through deeper soils
and then enter ground water. When a sufficient concentration of
CC14 and chloroform are present, phase separation will occur and
the pure liquid will tend to be located in the lower regions of
the aquifer or above clay lenses, if such lenses are present.
Because these natural processes of diffusion and dispersion are
continuous, as long as the CC14 and chloroform remain in the
soil-gas, they will continue to move through the soil and into

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the ground water.

The continuous movement of the CCl^ is indicated by the
data. For example, prior to the decommissioning of public supply
well M-3 in 1985, CC14 was present in M-3 at a concentration
ranging from 27 to 46 ppb. Since M-3 was taken out of service
and is no longer drawing CC14 from the source area, the presence
of CCl^ has been noted in MW-23, a downgradient monitoring well.

CCI4 and chloroform have been classified by EPA as probable
human carcinogens, based on animal studies. The potential for
carcinogenic risks is evaluated by estimating excess lifetime
cancer risks, that is, the incremental increase in probability of
developing cancer during one's lifetime, generally 70 years,
compared to the probability of getting cancer where there is no
exposure to contaminants. Based on the highest detected
concentration of CC14 and chloroform found in the ground water
sampled onsite at CW-1, the excess lifetime cancer risk for a
person who ingests two liters of such water per day for a
lifetime of 70 years is 3 X 10~3 which is greater than 1
increased cancer case in an exposed population of 1000. See
Table 5.

The level of CC14 contamination present in the ground water
and in soil gas above the water table necessitates a response
action at the Well Number 3 subsite to reduce the potential
risks to human health and to reduce further significant releases
of contaminants to the sole source aquifer.

Ground Water Contamination

Ground water at the subsite is found at a depth of
approximately 120 feet. The subsite is underlain by a sand and
gravel aquifer, having a saturated zone approximately 100 feet in
depth. This aquifer is the sole source of drinking water and is
used extensively for industrial and irrigation purposes. The
lateral flow in the aquifer has been found to be generally
eastward from the subsite. However, the potentiometric surface
map of the area indicates the direction of flow east of the
subsite is influenced by the regional east-southeast gradient.
The sand and gravel aquifer is underlain by thick deposits of
clay and shale. Depths to the clay/shale formations range from
200-220 feet.

Analyses of samples from Well M-3, taken between 1983 and
1985, have shown CC14 contamination (Table 3). M-3 is
approximately 4,500 feet downgradient from the source area.

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TABLE 3

Range of Concentrations of Volatile Organic Compounds in
Ground Water WELL NUMBER 3, Hastings, Nebraska

1983-1985

Concentrations in micrograms per liter (ug/1)
Parameter 4/83 5/83 4/85 9/85 12/85

CC14 27.1 31-46 22 26 32

Chloroform ND ND ND ND ND

Notes

Data were obtained from the REM II Ground Water Investigation
Report for Hastings Ground Water Contamination, May 7, 1987,
and quarterly ground water sampling data

, - M-3 is located 4,500 feet east of the former grain storage
facility

Key: ND - not detected

In addition to the contaminants of concern,trichloro-
ethylene (TCE) also has been detected in the ground water at this
subsite. TCE is a contaminant of concern at other portions of
the Hastings Ground Water Contamination Site, but it was not
detected in the soils or soil-gas samples taken at the Well
Number 3 source area.

Ground water samples were collected from the monitoring well
located at the subsite (CW-1) and from monitoring wells located
downgradient from the subsite. The highest detected contaminant
concentrations of CC14 and chloroform were seen at well CW-1
which is screened in the shallow portion of the aquifer (120-140
ft.). As indicated in Table 4, CC14 is present not only in the
ground water onsite, but is also present in monitoring well MW-23
downgradient from the subsite. Table 4 also indicates that CC14
is not present in MW-12, a well northeast of the source area.
Table 1 indicates CC14 is not present in public supply wells M-6,
M-10, M-9 and M-ll, which are downgradient of the source area.

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TABLE 4

Range of Concentrations of Volatile Organic Compounds
City of Hastings, Nebraska
1986-1989
EPA Monitoring Wells
Concentration in micrograms per liter (ug/1).

PARAMETER MW-3 MW-11 MW-12 MW-23 CW-1

CC14

ND -

110.0 -

3.0 M

8.0

270.0

Chloroform

ND -

68.0

1,1-Dichloroethene

(DCE)

Trans-1,2-

Dichloroethene

1,2-Dichloroethene

ND -

(Total)

7.0

Tetrachloroethene

ND -

(PCE)

4.0 M

3.0 M

Trichloroethylene

81.0 -

ND -

(TCE)

130.0

11.0

7.0

70.0

1,1,1-

Trichloroethane

(TCA)

Ethylene Dibromide

ND -

(EDB)

0.088

NOTES:

- Ground water data presented here for well MW-3 reflects data
collected from 1986 to 1989. Ground water data presented
for wells MW-11, MW-12, MW-23 and CW-1 were collected during
1988 and 1989.

- M - the value indicated is below the quantification limit
but above the detection limit.

NA - parameter not analyzed.

ND - compound not detected.

Data were obtained from the REM II - Ground Water Evaluation,
Hastings Groundwater Contamination Site, Hastings, Nebraska,
May 7, 1987; and from EPA laboratory reports.

- The above analyses were reported by EPA Labs and EPA
Contract Labs.

EDB reported in CW-1 was not confirmed in June, 1989 re-
sampling

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Soil and Soil-Gas Contamination

Soil sampling and soil-gas sampling were performed in 1988
and 1989 in order to better define zones with the highest
concentration of volatiles in the soils. Results of this
sampling, which is reported in the EE/CA, showed high levels of
contamination in the soil-gas and localized areas of
contamination. Figure 3 depicts the area where the highest
levels of CC14 in soil-gas have been detected. The action
selected in this document will reduce the potential for future
releases of CC1* and chloroform to the ground water by removing
the CCI4 and chloroform from the unsaturated zone above the
ground water.

The results of the soil-gas analyses located the highest
levels of contamination at a depth of 80 to 120 feet (Figures 4
and 5), which is in the unsaturated zone directly above the water
table. Historical data indicates that the water table level has
receded 20 feet in the past 20 years. The contamination is
therefore located in an area that was once an aquifer which
produced large volumes of water.

FIGURE 4

SOIL-GAS SAMPLING LOCATIONS WELL NUMBER 3 SUBSITI

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SAMPLING RESULTS
Well No. 3 Subsite

CCI4 in Soil-Gas (ppm)

14
8.9
34

160

120

0.2
11.0

•50'

¦100'

0.4
3

9.6
85

310
430

350
410
830
1100

1200

50'

¦Coo-

¦130'

13
26

8.1
110

140
120

150
0.2

130'

FIGURE 5

Depth of borings shown in feet

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The levels of CC14 in soil-gas, as shown in Figure 5, pose a
potential health threat to users of ground water downgradient
from the source area.

RISK ASSESSMENT

A risk assessment has been conducted for two purposes:

1. to determine the likelihood that people who are exposed to
CC14 and chloroform known to be present at the subsite
will be adversely affected by that exposure; and

2. to characterize the nature of the effects such persons may
experience from exposure.

The risk assessment consisted of the evaluation of the toxic
properties of CC14 and chloroform and the conditions of human
exposure to them. This risk assessment has been based only on
exposure to the contaminants of concern and has not taken into
account other factors such as genetics, lifestyle habits, and
other environmental exposures.

Exposure Pathways

The likelihood of human exposure to high levels of CC14 and
chloroform contained within the soil-gas at the subsite is remote
as the high levels of these contaminants are located 40 feet
below the surface, depths greater than would normally be
encountered during typical excavation activities. Any risks
associated with human exposure to low levels of CC14 and
chloroform contained in thie surface soils at the subsite is
likely to be minimal due to the dilution of the contaminants when
in contact with the atmosphere.

In contrast, the potential exposure pathways associated with
ground water contamination does present a potential threat to
human health. Potential exposure pathways include ingestion of
ground water, direct dermal contact with ground water, and
inhalation of contaminants released during use of contaminated
ground water. Persons potentially at risk of exposure to the
contaminants in ground water include users of private and
industrial wells downgradient from the site and customers who
depend on the public water supply within the City of Hastings.

Carcinogenic Effects of CC14 and Chloroform

As discussed earlier in this document, the contaminants of
concern, CC14 and chloroform, have been identified by EPA as
probable human carcinogens, which, if ingested daily in high
enough doses over a lifetime, could elevate a person's cancer
risk. Excess lifetime cancer risks are determined by multiplying
the intake level by the cancer potency factor which is the
quantitative estimate of cancer risk due to ingestion of water.
These risks are probabilities that are generally expressed in
scientific notation (e.g., 1 X 10~6). An excess lifetime cancer
risk of 1 X 1(T6 indicates that, as a plausible upper limit, an

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individual has a one in one million chance of developing cancer
as a result of site-related exposure to a carcinogen over a 70-
year lifetime under the specific exposure conditions at a site.

An assessment has been done of the risk associated with
ingestion by a 70 kilogram adult of two liters of water on a
daily basis over a lifetime of 70 years from CW-1, the
contaminated well at the subsite. The results of this baseline
risk assessment indicate that the risk of cancer to those who
ingest CW-1 well water, using the above-stated assumptions (2
liters /day /70kg /70 years), is approximately : 3 additional
cancers in a population of 1000 for CC14; 2 additional cancers in
a population of 100,000 for chloroform. This risk exceeds the
risk range that EPA considers protective of human health.
Extrapolations from animal studies indicate that the liver is the
organ at risk for developing cancer as a result of ingesting CC14
or chloroform, assuming 2 liters/day/70 kg/70years.

TABLE 5

Health Assessment Based on CW-1 Water Ingestion Exposure

Excess Lifetime Cancer Risk

EPA Carcinogenic Highest Detected Excess

Carcinogen Potency Factor Concentration Lifetime
Chemical Classification fmq/kq/dav) (ppb) Cancer Risk

CC14 B2 0.13 700 3 X 10

Chloroform B2 0.0061 120 2 X 10

-3

-5

Overall 3 X 10~3

Notes: EPA's carcinogen classification scheme:

B2 = Probable human carcinogen on the basis of animal data

Source: Table 2-4, EE/CA for an Expedited Response Action for
Soil and Soil Gas Well Number 3 Subsite, July 24, 1989
citing Superfund Public Health Evaluation Manual,
U.S. EPA, 1986 and the Integrated Risk Information System
(IRIS), U.S. EPA, 1988. IRIS is a catalog of risk
assessment and risk management information designed
especially for federal, state and local environmental
health agencies as a source of the latest information
about Agency health assessments and regulatory decisions
for specific chemicals.

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Noncarcinogenic Effects of CC14 and Chloroform

An assessment has also been done of the noncarcinogenic
risks associated with ingestion of these contaminants.
Noncarcinogenic risk is determined by comparing the daily intake
of the contaminants to their reference dose (RfD), which is an
estimate of the daily exposure to the human population that is
likely to be without appreciable risk of harmful effects during a
lifetime. RfDs are reference points for gauging potential effects
of other doses. Therefore, doses less than RfDs are not likely
to be associated with any health risks but a clear conclusion
cannot be drawn that all doses below the RfDs are acceptable and
that all doses above the RfDs are unacceptable. RfDs are
expressed in units of milligram per kilogram per day. Estimated
intakes of the contaminants, if ingested from the ground water,
can be compared to the RfDs. RfDs are derived from human
epidemiological studies or animal studies, to which uncertainty
factors have been applied. These uncertainty factors help ensure
that the RfDs will not underestimate the potential for adverse
noncarcinogenic effects to occur. Table 6 indicates RfDs for
CC14 and chloroform.

TABLE 6

Reference Dose milligrams per kilograms per day

Water from CW-1

COMPOUND Critical Effect Highest Level Hazard Index RfD

CCI4 Liver lesions 270 ug/1 11.0 0.007

Chloroform Fatty cyst form- 68 ug/1 0.196 0.01

ations in liver

Hazard Index is the daily intake divided by the reference
dose. A hazard index value greater than 1 indicates a
potential human health risk.

Environmental Risks

No threatened or endangered species or critical habitats
have been identified in or near the site. However, there is a
potential threat to the environment and to wildlife if source
control measures are not taken to prevent the release of the
contaminants into the ground water.

Conclusion

Because of the carcinogenic and noncarcinogenic risks to
human health associated with ingestion of ground water
contaminated with chloroform and CC14 at the levels found onsite
in CW-1, response action alternatives were developed to reduce
the potential for human exposure to contaminated ground water.
This response action selected will minimize the volume of
contaminated ground water which will migrate from the Well Number
3 subsite.

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SCOPE OF OPERABLE UNIT

This response action is an interim source control operable
unit and is consistent to the maximum extent practicable with
Section 300.68(c) of the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP). This interim source control
operable unit is being implemented to protect public health and
the environment by controlling the migration and reducing the
volume of contaminants from the subsoils to the ground water.
The operable unit addresses known areas of contamination in the
sands and silts which overlie the aquifer. Future actions may
involve expansion of the response action or modification in the
design of the system being used. Based upon EPA's
investigations, the operable unit contains approximately 400
pounds of VOC's. This area is shown on Figures 3 and 5.

This interim action, by reducing the volume and controlling
the migration of contaminants, is fully consistent with all
future site work, including the ongoing ground water
investigations at the Hastings site. In addition, this action
will affect the costs of the final remedy by limiting the amount
of ground water that is likely to become contaminated from this
source.

The following are the key milestones for implementation of
the response action:

Approve Response Action (Execute ROD) September 1989

Initiate Response Design (Funding) November 1989

Initiate Response Action (Operational April 1990

Testing)

SUMMARY OF ALTERNATIVES

Response alternatives have been developed in order to meet
the objectives of CERCLA and, to the maximum extent practicable,
the NCP. The process used to evaluate alternatives for this site
is detailed in the EE/CA and is addressed briefly here.

The first step in the evaluation of alternatives was to
investigate technologies and determine which technologies may be
feasible. The technologies were then screened based on
effectiveness, implementability, and overall comparative cost.
The technologies that are applicable to the response action at
the subsite were then evaluated individually.

Based on this initial screening, response action
alternatives were identified for development and evaluation of
their ability to meet environmental laws and standards. This
interim action will be consistent with Section 121 (d) of CERCLA
which requires that remedial actions comply with applicable or
relevant and appropriate requirements or standards (ARARs) under
Federal and State environmental laws. Two of 3 alternatives
presented win the EE/CA in addition to the No Action alternative

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were further evaluated.

EVALUATION OF ALTERNATIVES

CERCLA and the NCP require that each alternative developed,
including the no-action alternative, be evaluated with respect to
two major criteria: overall protection of human health and the
environment and compliance with applicable or relevant and
appropriate environmental requirements. Seven additional
criteria are considered as a means to compare the alternatives.
These include:

- Long-term effectiveness;

- Reduction of toxicity, mobility or volume;

- Short-term effectiveness;

- Implementability;

- Cost;

- State acceptance; and

- Community acceptance.

Each alternative must be evaluated for the degree of onsite
and offsite protection required (and thus, to be provided) by the
actions involved, as part of the overall effectiveness.

Since this response action is an interim measure, two
alternatives will be compared and evaluated. These are, in
addition to the No-Action Alternative, Soil-Vapor
Extraction with Granular Activated Carbon Treatment of Air
Emissions and Soil-Vapor Extraction with incineration of air
emissions.

No-Action Alternative

The Agency has evaluated the no-action alternative for
source control. If the no-action alternative were selected, it
would be necessary to closely monitor the downgradient wells of
the public water supply system. This monitoring would identify
the wells with water that exceed the MCLs, but would not prevent
continued migration and would not assure availability of
alternate water supplies to users. Based on downgradient water
quality data and the high levels of contamination in the soil-
gas, the no-action alternative would not reduce migration of
contaminants and may permit the level of risk to increase due to
the amount of contamination present in the soils. Consequently,
neither on-site nor off-site protection would be achieved by this
alternative.

Another reason the no-action alternative is not viable is
that the long-term reliability of monitoring would decrease with
the passage of time and with distance from the site. In
addition, there would be no reduction of mobility, toxicity or
volume; therefore, the no-action alternative would create the
highest likelihood for future releases of hazardous substances to
the environment. Because hazardous substances are known to exist
in the soil-gas above the aquifer, the no-action alternative

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would not protect the ground water from further degradation.

Short-term costs associated with the no-action alternative
relate to the costs of monitoring the drinking water supply
system in Hastings. The frequency of this monitoring would
depend on the level of contamination found, with increased
frequency where high levels are found in the public supply
system. Additional wells would have to be installed in order to
properly monitor the movement of the plume. Further
investigations would be required to determine proper placement of
wells. Alternate water supply systems would have to be installed
or alternate treatment technologies would have to be implemented
in the case of high levels of contamination.

In-Situ Soil Vapor Extraction(SVE) and Treatment by Vapor Phase
Granular Activated Carbon (GAC) Adsorption

This alternative involves removing the contamination from
the soil-gas without excavation and subsequently treating the
vapor. This alternative would provide permanent removal and
destruction of contaminants from the soil-gas and, thereby, achieve
a reduction in mobility, toxicity and volume of contaminants and
impede their movement to the ground water. Human health and the
environment would be protected both on-site and off-site to the
extent that this response action would prevent the spread of
further contamination into the ground water. Further, as part of
the SVE process, the air emissions would be controlled.

A vapor extraction system enables VOCs to be removed from the
soil-gas by applying a vacuum and using a conventional industrial
blower and standard valving, piping and instrumentation. This
equipment is readily available, thus the SVE is an implementable
response action. Vacuum extraction has been used successfully in
full-scale operations for removing many types of VOCs found in
soils ranging from fine-grained silts to coarse-grained sand and
gravels. This alternative proposes that the extracted vapor
would be treated by a vapor phase activated carbon system, if
significant air emissions were to result from implementation of
this response alternative. The GAC filters would be replaced, if
necessary, and '•spent" carbon would be transported off-site to an
approved treatment facility for regeneration or incineration (if
regeneration is not available). Any liquid generated from the
soil vapor process would also be treated with GAC. These liquids
would be disposed on-site when the MCLs for CC14 and chloroform
are reached.

The need for direct action was stressed in public comments
submitted to the Agency. This alternative is acceptable to the
community. The EPA and the state of Nebraska prefer the less
costly action alternative.

One of the characteristics of the SVE process is that it
immediately withdraws the contaminants. This response action
would therefore provide both short-term and long-term
effectiveness.

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An engineering calculation for the capital costs for this
response action was estimated to be $874,000, based upon a gas
extraction system of 19 extraction wells. The first year
operation and maintenance costs were $154,000. Details of this
calculation are set forth in the EE/CA.

Applicable, Appropriate, and Relevant Requirements (ARARs)

Regulations governing the transportation of hazardous
materials are applicable, relevant and appropriate to this
interim action. Therefore, transportation of the "spent" carbon
offsite will be done in compliance with regulations found in 49
CFR Part 107 promulgated pursuant to The Hazardous Materials
Transportation Act, 49 U.S.C. §1801 et. sea.

It is possible that the carbon used in the SVE system and
the subsequent treatment of the air emissions would become
contaminated, requiring its disposal as a hazardous
waste. Regulations governing the disposal of hazardous wastes
are therefore applicable, relevant, and appropriate. Disposal
would be in compliance with Sections 3002, 3003 and 3004 of the
Resource Conservation and Recovery Act, as amended (RCRA), 42
U.S.C. §6922, §6923, arid §6924 and the regulations found at 40 CFR
Parts 262, 263, and 264. These statutes and regulations govern
the standards applicable to generators, transporters, and owners
and operators of hazardous waste treatment, storage, and disposal
facilities. These regulations require, among other things,
proper recordkeeping, reporting, and management of hazardous
wastes. Disposal of the "spent" carbon would also be consistent
with EPA's off-site policy which requires that hazardous wastes
disposed off-site as part of a remedial action would be taken to
a facility in compliance with RCRA.

The Occupational Safety and Health Act (OSHA), 29 USC §651
et. sea.. is legally applicable to this interim action. This law
regulates worker health and safety in the work place. The
regulations found at 20 CFR Part 1910 et. sea, are relevant to
this response action. These regulations protect health and
safety of workers at hazardous waste sites performing remedial
actions.

Estimated Time for Implementation

It is estimated that an SVE system could be implemented at
this subsite within 9 to 18 months.

Treatment Goal

The goal of the SVE implementation is to remove the VOCs
known to be contained in the soil-gas directly above the aquifer.
The current engineering estimate of 400 pounds of VOCs in the
soil-gas at the sub-site contains uncertainty. Monitoring of the
SVE system for VOC removal and monitoring of the soil-gas within
the unsaturated zone above the aquifer will direct the
implementation and will determine the duration of the response
action.

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In-Situ Soil Vapor Extraction and Treatment bv Incineration

This alternative involves removing the contamination from
the soils and treating the vapor. This alternative is similar in
design to the second alternative except that the vapor phase
emissions would be treated using incineration instead of GAC.
Incineration is a proven technology for treating VOC emissions.
An incinerator consists of a refractory-lined vertical
cylindrical vessel containing a bed of inert, granular materials.
Air is injected at the bottom of the vessel through a distributor
plate. Contaminated gases are injected above the bed.

Auxiliary fuel is also injected at this point. This equipment,
while costly, is readily available and therefore this response
action is implementable. This alternative would provide
permanent removal and destruction of contaminants and achieve a
reduction in mobility, toxicity and volume. Human health and the
environment would be protected both on-site and off-site to the
extent that this response action would prevent the spread of
further contamination into the ground water. Further, as part of the
SVE process, the air emissions would be controlled. Incineration
could achieve an overall VOC removal efficiency of over 99
percent if operating temperatures of 1880°F are achieved. Pilot
tests would be conducted for system design that would achieve the
level of destruction required at this site.

The need for direct action was stressed in public comments
submitted to the Agency. This alternative is acceptable to the
community. The EPA and the State of Nebraska prefer the less
costly action alternative.

One of the characteristics of the SVE process is that it
immediately withdraws the contaminants. This response action
would therefore provide both short-term and long-term
effectiveness.

An engineering calculation for the capital costs for this
response action was estimated to be $954,000, based upon a gas
extraction system of 19 extraction wells. The first year
estimated operation and maintenance costs were estimated to be
$213,000. Details of this calculation are set forth in the
EE/CA.

Applicable, Appropriate, and Relevant Requirements (ARARs)

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Since the SVE process will capture the contaminants within
the soil-gas, the air to be burned within the incinerator will
contain hazardous waste, as defined in the RCRA regulations, 4 0
CFR Part 261 "Identification and Listing of Hazardous Waste."
Pursuant to Nebraska Environmental Protection Act Section 81-
1501 et. sea, regulations were promulgated. These regulations
found at Chapter 16 of Title 128 adopted RCRA regulations found
in 40 CFR Part 264 Subparts 0 Sections 264.340 through 264.351
concerning the proper operation of incinerators and are legally
applicable.

Estimated Time for Implementation

It is estimated that an SVE system could be implemented at
this subsite within 9 to 18 months.

Treatment Goal

The goal of the SVE implementation is to remove the VOCs
known to be contained in the soilrgas directly above the aquifer.
The current engineering estimate of 400 pounds of VOCs in the
soil-gas at the sub-site contains uncertainty. Monitoring of the
SVE system for VOC removal and monitoring of the soil-gas within
the unsaturated zone above the aquifer will direct the
implementation and will determine the duration of the response
action.

COMPARISON OF ALTERNATIVES

The no-action alternative is not a viable option because it
is not protective of human health and the environment. Of the
two action alternatives, both are protective of human health
and environment. Both are implementable; both would reduce
toxicity, mobility and volume of contaminants. The effectiveness
of both alternatives, short-term and long-term, are equal. The
degree of on-site and off-site protection is the same for both
alternatives. Both action alternatives are acceptable to the
community of Hastings. However, the only significant distinction
between the two action alternatives is cost effectiveness the SVE
alternative that utilizes GAC emission control is more .cost
effective. The EPA and the state of Nebraska prefer the more
cost ieffective alternative.

Cost comparison data is shown in Table 7. These estimates
were based upon engineering judgments regarding implementability.
Clearly, soil vapor extraction using GAC is the more cost-
effective of the action alternatives.

Soil vapor extraction using GAC is also more cost-
effective as compared to the no-action alternative. By removing
the potential source of ground water contamination, the costs
associated with recovery and treatment of the contaminated ground
water are significantly reduced. Delay of source control action
will magnify the ground water contamination problem and thereby
cause total response action costs for this site to increase.

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TABLE 7

COST COMPARISON OF RESPONSE ACTION ALTERNATIVES
FOR CONTAMINATED SOIL GAS

Alternative

WELL NUMBER 3 SITE
($ X 1,000)
Total

Capital Cost fa.d)

First Year
O&M Cost fb.c)

No Action

NA(e)

In-Situ Soil Vapor
Extraction and Treatment
by Vapor Phase Carbon
Adsorption

874

154

In-Situ Soil Vapor
Extraction and Treatment
by Incineration

954

213

Notes: (a) Estimate includes gas extraction system, air

treatment system, engineering design, construction
management and other contingency costs.

(b) Estimates include power costs, maintenance, labor,
monitoring of air and soils and contingency costs.

(d) Cost estimate based on the installation of a system
with 19 extraction wells. A system with fewer wells
would be expected to cost less.

(e) Cost estimates need to be developed for the long term
monitoring required, if this alternative is selected.

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SELECTED ALTERNATIVE

Based on available data and analysis conducted to date, the
EPA selected soil vapor extraction with GAC vapor treatment as
the most appropriate solution for meeting the goals of the source
control operable unit at the Well Number 3 subsite. The
characteristics of SVE that are considered most important are:

- The alternative provides protection to human health and
the environment from the potential threats associated with
no action;

- The alternative limits migration of contaminants to the
aquifer at the site;

- The alternative provides for compliance with applicable
laws and regulations; and

- The alternative is consistent with additional site actions
and will be compatible with the final site remedy.

The Regional Administrator retains the authority to make
changes in the scope and nature of source control actions to be
undertaken at this site. If new information or additional
environmental data warrants a change, then the impacts of the
suggested change will be reviewed to determine if any significant
departure from the selected alternative does in fact exist. Cost
impact of any proposed changes will be taken into account.

The design of the system will include a review of the data
produced by the Colorado Avenue Soil Vapor Extraction (SVE)
pilot. If needed, other data collection activities could be
incorporated into the design. Examples of necessary design data
could include the following:

1. Rate of gas withdrawal and air recharge;

2. Information to properly size the vacuum/air withdrawal
system components;

3. Radius of influence and other information to design the
final gas extraction well network;

4. Calculations of air emissions resulting from the soil
vapor extraction process;

5. Information to demonstrate the capability to control air
emissions and determine whether or not air monitoring
would be required during the cleanup phase;

6. Information to select and design the most cost effective
system for air emissions treatment; and

7. Information to design the gas monitoring well network.

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CLEAN-UP LEVELS

This interim action is being implemented for the purpose of
controlling contaminant migration, not restoration of the aquifer
to drinking water standards. Therefore, no cleanup levels are
being established at this time. The vapor extraction system will
initially operate under controlled conditions to provide for
collection and analysis of operational data. The data will be
used to refine final design information and to establish
effectiveness of the vapor extraction system. Cleanup
effectiveness will be evaluated based on volume of contaminants
recovered from the soils. Review and decision-making regarding
cleanup levels will be closely coordinated with the state of
Nebraska. Since the potential threat existing at the site is
related to inhalation and ingestion of contaminated drinking
water rather than from a direct contact threat, the clean up
levels for soil and ground water can be addressed later.

As previously stated, recovery of volatiles by SVE will be
less costly than treating large volumes of contaminated ground
water at a future date. Therefore, the volume of volatile
contaminants recovered will be one measure of success of the
selected remedy. Ground water monitoring is expected to show a
decreased concentration of contaminated ground water migrating
from the site. These monitoring data will be direct measures of
success of the selected remedy. The anticipated result is that
the duration of any long-term actions will be decreased by this
remedy.

OPERATION AND MAINTENANCE

The recommended alternative requires a certain degree of
annual operation and maintenance (O&M) activity to ensure proper
operation of the system and compliance with environmental laws
and regulations. The costs of O&M will depend on volume of
contaminants recovered and the size of the completed vapor
extraction system. An O&M plan will be developed during design
of the system after the initial phase of operation and testing.

A ground water monitoring plan will also need to be
developed and implemented to demonstrate reduced migration of
contaminants in the ground water.

FUTURE ACTION

Ground water monitoring wells downgradient from the site
will continue to be sampled and a technical approach for plume
management will be developed. Agency decision-making regarding
ground water treatment will be discussed with the state of
Nebraska prior to preparation of a Record of Decision for ground
water treatment.

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STATE ROLE

The state of Nebraska's Department of Environmental Control
has reviewed the various alternatives and has indicated its
concurrence with the selected action. The state has also
reviewed the EE/CA and concurs with the selected action for the
Well Number 3 Subsite of the Hastings Ground Water Contamination
Site.

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RESPONSIVENESS SUMMARY

v/ERA

REGION 7

HASTINGS SUPERFUND SITE

HASTINGS, NEBRASKA

SEPTEMBER 1989

: _ _ _ _

... J

WELL NUMBER 3 SUBSITE

L OVERVIEW

The Hastings Ground Water Contamination Site is made up of several subsites within and immediately east of
the city of Hastings, Nebraska. These subsites include Colorado Avenue, FAR-MAR-CO, Well Number 3, North
Landfill, South Landfill, Second Street, and the former Naval Ammunition Depot (NAD).

In 1983, a city water well was taken out of service after reports from the public of a foul smell and taste in the
water. As a result, the Nebraska Department of Health (NDOH), Nebraska Department of Environmental Control
(NDEC), and the U.S. Environmental Protection Agency (EPA) began investigating ground water contamination in the
area. Due to the nature of the contaminants found In the ground water during this investigation, the Hastinp site was
placed on the National Priorities List (NPL) in 1986. The contaminants found in the initial investigation include
trichloroethylene (TCE), 1,1,1-trichIoroethane (TCA), tetrachloroethylene (PCE), carbon tetrachloride (CCly), and 1,2-
dibromoethane, also known as ethylene dibromide (EDB).

Since the discovery of contamination in the Hastings ground water In 1983, the City of Hastings has taken two
municipal wells out of service and placed other contaminated wells on a standby basis. Operators of Community
Municipal Services, Inc. (CMS), a privately owned public water supply system, also took two of their three wells out of
service due to contamination. Recent EPA testing indicates that the drinking water supplied by the City of Hastings is
free of contamination and is safe to drink

In 1987, EPA published reports regarding the field investiptions conducted by EPA in the Hasting area from
April 1985 to December 1986. These investigations focused on four subsites - Colorado Avenue, FAR-MAR-CO, the
North Landfill, and the former NAD. The studies identified and quantified the contamination present in the soil,
evaluated and defined potential source areas, and identified potential pathways for contaminant migration. Also in 1987,
EPA published a Ground Water report which presented the results of the ground water well sampling and evaluated the
extent of contamination for the area wide Hastings site. In 1988, EPA released an Engineering Evaluation and Cost
Analysis (EE/CA) report for the Colorado Avenue and FAR-MAR-CO subsites. Following a public comment period on
those two subsites, EPA Issued a Record of Decision (ROD) for these subsites.

In July 1989, EPA published an EE/CA report for the Well Number 3 Subsite based on investigations conducted
by EPA in the Hastings area from 1986 to 1989 which identified and characterized suspected source areas for the
subsite. These investigations indicated that the major contaminants of concern are CC14 and chloroform in the ground
water and soil gases. Both of these contaminants are volatile organic compounds (VOCs). Following the release of
the report, EPA held a public meeting to discuss the findings and proposed remedial alternatives. A public comment
period on the EE/CA began on July 31, 1989 and ended on August 21,1989. Oral and written comments received from
the general public and city officials regarding the Well Number 3 Subsite and EPA's responses to those comments are
summarized in this responsiveness summary.

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Hastings Superfund Site
Well Number 3 Subsite
Responsiveness Summary
Page Two

As stated in the EE/CA for the Well Number 3 subsite, EPA's preferred alternative for remedying the
contaminated soils at that subsite entails extraction and treatment of volatile contaminants from the unsaturated zones,
monitoring contaminants in the soils above the aquifer, and monitoring the ground water at the site.

This responsiveness summary is divided into the following sections:

• Background of Community Involvement; and

• Summary of Comments Received during the Public Comment Period and Agency Responses.

In addition, Attachment A describes the community relations activities conducted to date at the Hastings
Ground Water Contamination Site.

D. BACKGROUND OF COMMUNITY INVOLVEMENT

Community interest in the Hastings Ground Water Contamination site dates back to 1943 when municipal well
18, located approximately one-half mile east of Colorado Avenue, was installed. Shortly after it was completed, the well
was taken out of service in response to complaints from residents about the odor and taste of the water. The well was
returned to service in 1953, but additional complaints were received and it was taken out of service again.

In 1981, the City determined that a new well was needed. After review of available data by NDOH, the city
placed municipal well 18 back in service in March 1983. After spending nearly S16.000 to revamp well 18, the City
placed it back in service in March 1983. Again, the well was taken out of service in response to complaints. Additional
test results received from the NDOH indicated that the well was contaminated with trichloroethylene (TCE) and other
volatile chemicals.

In 1983, the NDOH and the NDEC began investigating widespread ground water contamination in the Hastings
area. Public water supply wells operated by the city and wells operated by CMS, Inc. are located within the area of
investigation. Analyses of water samples collected in 1983 from city water supply wells indicated that the regional
ground-water aquifer was locally contaminated with several volatile organic compounds (VOCs), primarily chlorinated
solvents including TCE, TCA, and PCE. Sampling of the CMS system located east of Hastings showed CC14 and TCE
contamination. In addition to these VOCs, further investigations found the presence of EDB at CMS well number 24
and at the FAR-MAR-CO subsite. In 1986, EPA reported that explosives and elevated levels of heavy metals were
found in the soils at the Hastings East Industrial Park subsite.

In 1984, the State of Nebraska installed five pairs of monitoring wells in the City of Hastings. In 1985, EPA
began sampling wells and field investigations were initiated to identify and characterize suspected source areas.

Based on the data collected by NDOH and NDEC, the Hastings Ground Water Contamination site was added
to the NPL in May 1986. The NPL is EPA's list of the most serious uncontrolled or abandoned hazardous waste sites
nationwide that have been identified for possible long-term remedial response. Superfund monies are available for
cleanup of NPL sites. The list is based primarily on the score a site receives on EPA's Hazard Ranking System, which
evaluates potential risks to public health and the environment from releases or threatened releases of hazardous
substances.

Following the preliminary investigation conducted in 1985, EPA conducted testing from November 1986 to
March 1989 to locate the source of the ground water contamination in the area of decommissioned city well number 3.

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Hastings Superfund Site
Well Number 3 Subsite
Responsiveness Summary
Page Three

These investigations indicated that the contamination found in the abandoned municipal well may be due to an
accidental grain fumigant spill at a former grain storage facility located east of Maple Avenue and north of the
Burlington Northern Railroad tracks in the central section of the city.

Investigations indicated that the soil gas and ground water at the subsite are contaminated with volatile organic
compounds. The contaminants of concern are CCI4 and chloroform. These contaminants are present in the soil gas
and ground water.

The major concerns expressed by the community, city and state officials during the remedial planning are stated
in the Community Relations Plan developed in 1989 for the Hastings Ground Water Contamination site. These
concerns focused on the distribution of information about site activities, the cost of the investigations and future site
activities, water quality and quantity, the role of the EPA, State of Nebraska, and potentially responsible parties (PRPs)
in the activities at the site, the economic impact of the cleanup on present and future PRPs and on the city's economy,
and that the technologies proposed in the remedial alternatives may not clean up the contamination. These concerns
and EPA's responses are described below:

1. City officials expressed the need to be informed of all EPA proposals and activities so that they may
respond accurately to questions from the media.

EPA Response: To provide current information, EPA prepared and distributed fact sheets on findings
and activities at the site and maintained regular telephone contact with city officials and concerned
citizens.

2. Citizens expressed concern about who would pay for the site investigations and future site activities.

EPA Response: Under the Superfund law, costs may be recovered from past and present facility owners
and operators, as well as those who arrange for transportion of hazardous substances to and from the
site. EPA may recover federal response costs from any or all of the responsible parties involved in a
cleanup action. The dollars recovered go back into the Fund for use in future response actions. EPA
has identified several such 'potentially responsible parties" (PRPs) for the Hastings site and discussions
with the PRPs continued. No one has been identified as a PRP at this site. Superfund monies are
presently being spent for site activities.

3. Citizens and officials expressed concern regarding the economic impact of the cleanup on present and
future PRPs and on the city's economy.

EPA Response: While EPA's mission is to protect human health and the environment, the Agency
recognizes that in undertaking response actions where health, welfare or the environment are threatened,
economic conditions may be affected. EPA has made every attempt to determine the sources of the
contamination so that corrective actions could be initiated. For that reason, EPA Region VII personnel
worked with prospective buyers of real estate in Hastings to explain the potential liability that could be
incurred and discuss how it could be minimized.

4. Because the Hastings site is one of the first Superfund sites in Nebraska, citizens and local and state
officials had many questions regarding the National Priorities List, Superfund, and how the various levels
of government interact to determine and implement the appropriate actions at the site.

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Hastings Superfund Site
Well Number 3 Subsite
Responsiveness Summary
Page Four

EPA Response: EPA held frequent meetings with State and local officials to address these questions.
In addition, fact sheets were prepared and distributed to answer these questions and inform citizens
about activities at the site. Copies of these fact sheets are available at the information repositories or
by requesting them from EPA Region VII in Kansas City.

5. Citizens expressed a concern regarding the future and availability of clean water.

EPA Response: EPA understands this concern and although the water supply for the City of Hastings
is free of contamination, EPA believes that it is the responsibility of the agency and all citizens to
ensure that our water resources are kept clean and usable for future generations.

6. Citizens and officials expressed a concern regarding the effectiveness of the technologies proposed in the
remedial alternatives to clean up the contamination.

EPA Response: The remedial action proposed for the subsite would control the migration of
contaminants present in the soils which overlie the aquifer. During implementation of a full-scale
remedy for soil vapor contamination, a pilot-scale test will be undertaken. The selected remedial
alternative involves in situ ("in place") soil vapor extraction. The alternative is an innovative technology
that involves treating contaminated soils without excavation. In a vapor extraction system, volatile
organic compounds are removed from the soil through a vacuum. The extracted vapor is then treated
to meet quality air standards. The removal of these contaminants from the soils will prevent these
contaminants from migrating into the ground water.

m. SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC COMMENT PERIOD AND AGENCY
RESPONSES

EPA held a public comment period on the Well Number 3 Subsite of the Hastings Ground Water
Contamination site from July 31 to August 21, 1989. Oral and written comments received from citizens during the
public comment period on the draft Engineering Evaluation/Cost Analysis which incorporates the Proposed Plan are
summarized briefly below. The comments are organized by subject matter into three categories: (A) general comments;
(B) cost/funding; and (C) technical questions/concerns regarding remedial alternatives. All comments were received
during the August 10, 1989 public meeting.

A. GENERAL COMMENTS

1. A city official stated that the Hastings city government shares the goals of Superfund in striving for a
safe and clean environment and stated that these goals must be pursued with common sense and at a
reasonable cost The official added that the city is committed to providing safe, clean drinking water to
its citizens and stated that the city does not want any actions taken at this subsite to adversely affect the
municipal water supply.

EPA Response: EPA agrees with these comments. The remedial alternative selected for the subsite
will not adversely affect the municipal water supply.

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Hastings Superfund Site
Well Number 3 Subsite
Responsiveness Summary
Page Five

B. COST/FUNDING

1. A city official expressed a concern regarding who would be responsible for the costs of the remedial
alternative.

EPA Response: The Superfund law stipulates that, whenever possible, PRPs pay for remedial actions at
a Superfund site. If PRPs are unable to pay for the costs of the cleanup, cleanup costs will come from
the tax on the oil/chemical industry (which creates the Fund known as "Superfund"), not general
revenues. At this time, no PRPs have been identified for the Well Number 3 Subsite and it is possible
that the subsite will be a Superfund lead action and it is possible that the cleanup costs will be borne by
the Trust Fund.

2. A state official asked how much money has been spent to date on the study and cleanup of the subsite.

EPA Response: To date, approximately $500,000 has been spent on the remedial investigation and
feasibility study portions of the Well Number 3 Subsite project

C. TECHNICAL QUESTIONS/CONCERNS REGARDING REMEDIAL ALTERNATIVES

1. A citizen expressed a concern regarding the remedial design of the treatment methodology, specifically
where the vacuum wells would be located.

EPA Response: At this time, a remedial design has not been devised. A conceptional design has been
created which illustrates the number of wells needed to cleanup the site. The location of these wells
will be included in the final remedial design.

2. A citizen expressed a concern regarding the procedure EPA uses when abandoning the treatment wells
following the conclusion of the remedial alternative.

EPA Response: EPA will adhere to the State of Nebraska regulations that deal with abandonment of
wells at the conclusion of the remedial action.

3. A citizen expressed a concern regarding the temperature of the air that would be sent into the vacuum
wells in order to extract the contaminants. The citizen stated that the air should be diy because any
moisture in the air would condense in the ground and inhibit the ability of the vacuum to draw the
contaminants from the soil gases.

EPA Response: The soil vapor extraction process entails removing volatile organic compounds through
the use of a vacuum. To enhance contaminant removal, air can be injected into the soils. If air
injection is needed at the Well Number 3 subsite, then dry air would be required as the comment
suggests.

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Hastings Superfund Site
Well Number 3 Subsite
Responsiveness Summary
Page Six

4. A state official asked at what rate the contamination travels downward into the aquifer.

EPA Response: The rate at which contaminants travel downward toward the aquifer is dependent on
various factors, including the soil type, the amount and mobility of the contaminants in the soil. At this
time, EPA is unable to determine the exact rate at which the contaminants are traveling due to the
various £actors relating to this subsite.

5. A state official asked what the time schedule for cleaning up the subsite is and how much time is
required to complete the cleanup.

EPA Response: EPA expects to complete the remedial design by the end of 1990. Cleanup of the
subsite would begin following the completion of the remedial design. The length of time required for
the cleanup is dependent on the actual remedial design, but the cleanup may take up to five years.

6. A state official expressed a concern regarding the proximity of contamination to the ground water since
the estimated contaminant spill in 1959 and the possibility of additional contamination to the ground
water before the subsite is cleaned up.

EPA Response: The EPA study of this subsite indicates that a small percentage of the initial
contaminant spill could have reached the ground water within a year following the spill. At this time
(1989), there is still a contaminant vapor phase plume. Without any remedial activity, the contaminants
present in the soils will continue to migrate to the ground water. The remedial activity will recover a
large percentage of the contamination currently found in the soils at the subsite.

7. A city official expressed a concern that the remedial design for the subsite would be initiated without
considering the results from the pilot study of the same design at the Colorado Avenue Subsite.

EPA Response: EPA will include all results from the pilot study at the Colorado Avenue Subsite in
the remedial design at the Well Number 3 Subsite.

8. A citizen expressed a concern that the proposed alternative would create more environmental pollutants
and hazards in the area than have already been documented.

EPA Response: The preferred alternative will not create any additional environmental contamination
because the contaminants released would be treated through granular activated carbon adsorption. The
spent carbon wastes would be treated at an EPA approved facility.

9. A citizen asked the size of the initial spilL

EPA Response: At this time, EPA does not have sufficient data to indicate the exact size of the initial
spill. Current information indicates that approximately 400 pounds of carbon tetrachloride and
chloroform are currently in the soil gas at the site.

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Hastings Superfund Site
Well Number 3 Subsite
Responsiveness Summary
Page Eight

ATTACHMENT A

COMMUNITY RELATIONS ACTIVITIES
AT THE HASTINGS SUPERFUND SITE

Community relations activities conducted to date at the Hastings Ground Water Contamination site include:

• EPA meets with city and state officials to discuss the site (December 1984).

• EPA prepares a draft Community Relations Plan (November 1984).

• EPA conducts community interviews with local officials and interested residents (February 1985).

• EPA establishes an information repository in Hastings, Nebraska (February 1985).

• EPA meets with city officials to discuss the site (May 1985).

• EPA prepares and distributes a fact sheet on the background of the site, sampling procedures, and levels
of contamination found (November 1985).

• EPA holds a public meeting in Hastings to describe the field investigation activities and findings and to
respond to citizens' questions (November 22, 1985).

• EPA prepares and distributes a fact sheet on the objectives of the remedial investigation, and
background on Superfund legislation (March 1986).

• EPA prepares and distributes a fact sheet summarizing field investigation activities and findings (August
1986).

• EPA meets with City and State officials and PRPs to discuss EPA findings at the Colorado Avenue and
FAR-MAR-CO subsites (January 1987).

• EPA prepares and distributes a fact sheet explaining the reports of investigation for the Colorado
Avenue and FAR-MAR-CO subsites (April 1987).

• EPA meets with City officials regarding the remedial investigation of the NAD subsite (June 1987).

• EPA prepares and distributes a fact sheet explaining the EE/CAs being developed and current findings
at the subsite (January 1988).

• EPA revises the Community Relations Plan (January 1988).

• EPA releases EE/CAs for the Colorado Avenue and FAR-MAR-CO subsites (February 3, 1988).

• EPA establishes two additional information repositories in Hastings, Nebraska (February 1988).

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Hastings Superfund Site
\VeU Number 3 Subsite
Responsiveness Summary
Page Nine

• EPA holds a public meeting in Hastings to discuss the preferred alternatives for cleanup activities and
to respond to citizens questions (March 5, 1988).

• EPA allows an extension to the public comment period. The comment period lasts from February 3,
1988 to April 30, 1988.

• EPA prepares and distributes a fact sheet on recent PRP activities and on new sampling information
(April 1988).

• EPA prepares and distributes a fact sheet on recent activities regarding the proposed pilot project at the
Colorado Avenue subsite and other activities at the Hastings site (August 1988).

• EPA prepares and distributes a fact sheet on recent activities regarding the Hastings Ground Water
Contamination Site (April 1989).

• EPA releases an EE/CA for the Well Number 3 Subsite (July 1989).

• EPA prepares and distributes a fact sheet on the cleanup alternatives evaluated for the Well Number 3
Subsite (August 1989).

• EPA holds a public meeting in Hastings to discuss the preferred alternatives for cleanup activities at the
Well Number 3 Subsite and to respond to citizens questions (August 10, 1989).

• EPA revises the Community Relations Plan (September 1989).

• EPA prepares a Record of Decision and Responsiveness Summary on the Well Number 3 Subsite
(September 1989).

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