United SIMM
Environmental Protection
Agency
Office*
Emergency end
EPA/ROO/R07-88/017
September 1088
&EPA Superfund
Record of Decision:
Hasting Ground Water/Far-Mar, NE
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...!ft....
REPORT =MENTAtION .1 a. ItVOIIf "P A/ROD/R07 -8 8/0 17
t~~CORD OF DECISION ,
Hastings Ground Water (PAR-MAR-CO), NE
First Remedial Action
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10. .-.o)8CtIT.III!WO" Unit No.
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IL Contr8ct(C) or GI8I1t(Q) No.
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(0)
12. SponSOrinC Orpnlutlon N,me .nd Add,..,
U.S. Env~ronmenta~ Protection
401 M Street, S.W.
Washington, D.C. 20460
Agency
II. T1118 of "eOOft .. ...rIod CowNd
800/000
I"
II. Supplement8ry Not..
I" Ab8tr8ct fLJmlt: 200 words).. . . . .
The FAR-MAR-CO subslte of the Hastlngs Ground Water Contam1nat10n slte 1S located
east of the City of Hastings, Adams County, Nebraska. The subsite is a part of an
industrial enterprise zone which contains industrial properties situated along the
Burlington-Northern railroad' right-of-way. Residential properties. are located
immediately northwest of the site and agricultural lands are located east of the site.
Historical and current use of the area has been for grain storage and railcar loading.
The site is currently owned by Farmland Industries, Inc., who acquired the property
~ough a merger with FAR-MAR-CO, Inc. in 1967. The current and previous owners used
rious chemicals onsite for fumigation of stored grain. Contamination was discovered
when complaints about water quality were received by the Nebraska Department of Health
(NDOH). Subsequently, the NDOH and the Nebraska Department of Environmental Control
began investigating widespread ground water contamination in the Hastings area. Wells
that are part of CMS, Inc. public supply system are located east and downgradient of the
sUbsite. Contaminated soil a.t the subsite are believed to be the result of accidental
spills and may be the direct result of a 1959 grain dust explosion which damaged a
fumigation tank system, releasing 997 gallons of fumigant. The highest levels. of
contamination of soil and soil-gas occur within close proximity to the original grain
(See Attached Sheet)
17. Document AftaIy8l8 .0 Desertptora
Record of Decision
Hastings Ground Water (FAR-MAR-CO), NE
First Remedial Action
Contaminated Media: gw, soil
Key Contaminants: carbon tetrachloride,
b. ld8nt1f1era/Oll8ftoEnd8d TetmI
. .
ethylene dibromide
Co COSATI Fleld/Group
,-- Anll.bUIly St.tement
It. Security Clan (This Report)
None
21. No. of Pale'
29
I
--
20. Security Class (ThIs Pale)
None
Z2. Price
CS.. ANSI-Z39.Uh
$ee In.tn/ctlon. 0/1 R.".,..
OPTIONAL FOR" 272 14-171
(Formerly NTI5-35)
o.partment of Commerce
-------
EPA/ROD/R07-88/017
~tings Ground Water (FAR-MAR-CO), NE
st Remedial Action
16.
ABSTRACT (continued)
elevator in relatively small zones. The volume of contaminated soil is estimated to be
33,800 yd3 yards and is the focus of this ROD. High levels of the contaminants are
also found in the ground water beneath the site. The primary contaminants of concern
affecting soil and ground water are carbon tetrachloride and ethylene dibromide (EDB).
The selected remedial action for this site includes: in situ soil vapor extraction,
utilizing vacuum extraction technologies; treatment of extracted vapor with an activated
carbon system, if necessary; access restrictions; and implementation of an O&M program
which includes soil, air and ground water monitoring. Results of the ground water
monitoring will be used to develop a technical approach for plume management and
evaluate the need for ground water treatment in a subsequent ROD. The estimated present
worth cost for this remedial action is $2,526,000, which includes a projection of annual
O&M costs for the five year operating period. Long-term O&M costs will depend on the
success of the vapor extraction during the operating period.
r
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\
.
RECORD OF DECISION DECLARATION
INITIAL SOURCE CONTROL OPERABLE UNIT
SITE NAME AIm LOCATION
FAR-MAR-CO--
Hastings "Ground Water Contamination
Hastings, Nebraska
STATEMENT Ql BASIS MiD PURPOSE
This decision document presents the selected remedial action
for the FAR-MAR-CO subsite developed in accordance with the
Comprehensive Environmental Response, Compensation and Liability
Act of 1980, as amended by the Superfund Amendments and
Reauthorization Act of 1986 and consistent with the National oil
and Hazardous Substances Pollution Contingency Plan to the extent
practicable.
This decision is based upon the contents of the
administrative record for the FAR-MAR-CO subsite.
The State of Nebraska concurs on the selected remedy.
DESCRIPTION Ql rHI REMEDY
This initial source control operable unit was developed to
protect public health and the environment by controlling the
migration of contaminants present in the soils which overlie the
aquifer. Prior to implementation of a full-scale remedy for soil
vapor contamination, a pilot-scale test will be undertaken.
This pilot-scale test may be done at another subsite. 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.
The major components of the selected remedy are as follows:
Measures to prevent direct contact to soils contaminated
with ethylene dibromide:
Extraction of volatile contaminants from the silt and sand
unsaturated zones:
Monitoring contaminants in the soils above the aquifer: and
Monitoring ground water contamination at the site.
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2
DECLARATION
This selected remedy is protective of human health and the
environment, attains Federal and state requirements that are
applicable-Gr relevant and appropriate to the remedial action and
is cost-effective. This remedy satisfies the statutory
preference for remedies 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 remedy will mitiqate future
releases to the qround water: however, this action will not
address other contaminant source areas. Due to its limited scope
of miqration control, this remedy does not address remediation of
the qround water. Subsequent actions are planned for the site
that will address all remaininq concerns.
C(-30"'~'
Dat'e
/'I''l% /<~
~I/ .~,
S-iqnature/(RA/AA)
Attachments:
Index to Administrative Record
Decision Summary
Responsiveness Summary
.
- -- - -- ----~--- ----~-~ -
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-. -.-..
RECORD OF DECISION
DECISION SUMMARY
HASTINGS GROUND WATER CONTAMINATION
FAR-MAR-CO SUBSITE
HASTINGS, NEBRASKA
Prepared By:
U.S. Environmental Protection Agency
Region VII
Kansas City, Kansas
September 1988
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~
I.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
x.
XI.
XII.
XIII.
XIV.
xv.
Record of Decision
Decision Summary
_. ----
Contents
Paae
Site Description
site History
1
1
Enforcement History
Community Relations
5
5
Site Characteristics
6
Risk Assessment
13
Scope of Operable Unit
Evaluation of Alternatives
1.5
16
Summary of Alternatives
Selected Alternative
16
22
Cleanup Levels
Operation and Maintenance
24
24
Statutory Findings
Schedule
25
25
Future Action
25
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DECISION SUMMARY
FAR-MAR-CO SUBSITE
.HASTINGS GROUND WATER CONTAMINATION
SITE DESCRIPTION
The-:FAR-MAR-CO subsite is located east of the City of Hastings,
Adams County, Nebraska. Adams County has an estimated population
of 30,000 and is in south central Nebraska. The locations of
Adams County and Hastinqs are shown by Fiqure 1.
The subsite is a part of an industrial enterprise zone which
contains industrial properties situated alonq the Burlinqton-
Northern railroad riqht-of-way. These properties formerly
owned by the Morrison-Quirk Grain Corporation, were used for
qrain storaqe. However, one major qroup of buildings was converted
to manufacturing use in 1968. These buildinqs adjoin the current
grain elevator properties on the south and are occupied by
Hastings Irrigation Pipe Company. Residential properties are
located immediately northwest of the FAR-MAR-CO subsite.
Aqricultural lands are located east of the site.
Other industrial properties are adjacent to the subsitei
however, no significant levels of contamination have been found
on the other properties. Therefore, this remedial action will'
occur onsite.
The Burlinqton-Northern railroad right-of-way divides the
former Morrison-Quirk Grain Corporation properties into two
parcels. The right-of-way is a major east-west transportation
route. Railroad spur tracks used for loading grain into railcars
are also present at the subsite.
The contamination found in soils at the FAR-MAR-CO subsite
is believed to be a result of accidental spills and may be the
direct result of a 1959 qrain dust explosion. This explosion
damaged the tank and fumiqation system resultinq in loss of 997
qallons of fumigant. Volatile chemicals have miqrated downward,
entered the ground water and traveled in the ground water some
distance downgradient from the subsite. Wells that are part of
CMS, Inc., public supply system are located east and downgradient
of the subsite.
SITE HISTORY
In 1983, the Nebraska Department of Health sampled the CMS,
Inc. public water supply system east of Hastings in response to
citizen complaints of taste and color in the drinking water.
That same year, the Nebraska Department of Health (NDOH) and the
Nebraska Department of Environmental Control (NDEC) began
investigatinq wide-spread ground water contamination in the
Hastinqs area.
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Site
HASTINGS,
Location Map
NEBRASKA
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Hss tings
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116::> I
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Nebraska
Figure
1
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J
.
curing this investigation, samples collected from the CMS
Well 24 indicated that the well was contaminated with several
compounds, primarily chlorinated solvents, including carbon
tetrachloride (CC14 and low levels of trichloroethene (TCE).
eMS Well 24 is. located approximately one mile east of the FAR-MAR-CO
subsite. According to field investigations conducted by EPA, CMS
Well 24 is hydrologically downgradient from the subsite.
-. -.-..
In 1984, the state of Nebraska collected additional samples
from CMS, Inc. supply wells and from private wells in the area.
In late 1984, EPA laboratories confirmed findings by the State of
Nebraska Laboratory that ethylene dibromide (EDB) was also present
in samples taken from CMS Well 24.
In an effort to define the extent of contamination in
Hastings, Nebraska, EPA began sampling wells in 1985. Field
investigations, which included soil-gas sampling, soil sampling
and the installation of one monitoring well were conducted in
1986 to identify and characterize suspected sources of
contamination in the Hastings area.
As a result of the analysis of data collected in 1985 and
1986, EPA identified this subsite as the area from which CC14
and EDB found in CMS Well 24 emanated.
Results of soil-gas sampling are shown in Figure 2.. High
levels of CC14 were found in the soil-gas north of the original
grain elevator structure within approximately 10 feet of a large
liquid fumigant bulk storage tank. This same area also has
significant levels of EDB contamination in. the soils. The EDB
contaminated zone is small, indicating that its presence was
probably caused by an accidental spill.
Morrison-Quirk Grain corporation used CC14 at the site
during the 1950's and 1960's. The liquid fumigant bulk storage
tank was placed at the present location after a grain dust
explosion occurred in 1959. Morrison-Quirk Grain Corporation
sold the major part of the properties to FAR-MAR-CO Inc. in 1975.
Farmland Industries; Inc., the current owner of the FAR-MAR-
CO subsite, acquired the property through a merger with FAR-MAR-
CO, Inc. in 1976. The present owners have used CC14 (80-20
mixture) to fumigate grain at the site.
EDB has been found in the ground water, soil-gas and soil
onsite. Prior to its being banned by EPA in 1983, EDB was
commonly used to fumigate stored grain.
EPA's investigations at the FAR-MAR-CO subsite were
documented in a report prepared by REM II in 1987. Sampling of
an irrigation well (I-46) located at the Central Community
College has shown CC14 and EDB contamination. This well is
located approximately 1 1/2 miles southeast and downgradient of
the FAR-MAR-CO subsite.
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LEGEND
I
\ (f) ~ EPA MONITORING WELL
[ (f)
« fI)~ CONTOURS REPRESENT APPROXIMATE
0- L AREAS OF EQUAL CCI4 <"'9/1)
>-
\ m CONCENTRA 110N IN SOIL' 'GAS.
[ 1 r I
<0 t
>-= N
3: 0 100 200 300FEET
I C--=:J
~
BUAUNGTON NORtHERN R.R.
~
MW-8
HASTINGS
GROUND WATER CONTAMINATION SITE
HASTINGS, NEBRASKA
D
FAR-MAR-CO AREA SUBSITE
CCI4 CONCENTRATIONS IN SOIL GAS
Figure 2
o
HWY. U. S. 6
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5
EPA conducted soil samplinq and soil-qas samplinq in
1987 and 1988 to better define the extent of contamination at the
subsite and to refine preliminary desiqn data for the source control
remedy.
An Enaineerina Evaluations ADS Cost ~ (EE/CA) was
released by EPA for public comment on February 3, 1988. The
oriqinal-pUb~ic comment period for this subsite was extended until
April 30, 1988. EPA has prepared a responsiveness
summary which addresses the comments received.
EPA has no information indicatinq qeneration of hazardous
substances resultinq from qrain storaqe operations 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 durinq maintenance activities which
could disturb the contaminated soils.
ENFORCEMENT HISTORY
In September 1985, qeneral notice letters were issued to
potentially responsible parties (PRPs) connected with the Hastings
Ground Water contamination NPL site. The first PRP meetinq was held
in October 1985 at which time the PRPs were asked to perform the
needed RI/FS studies. No proposals to undertake the RI/FS were
made by the PRPs.
In December 1986, EPA notified Farmland Industries, Inc. and
Morrison-Quirk Grain Corporation of their potential liability at
the FAR-MAR-CO subsite. In January 1987, a PRP meeting was held
to review EPA's findings to date. Farmland Industries and
Morrison-Quirk Grain Corporation were asked to undertake the next
phase of investiqations. Neither party made an offer. Durinq
meetinqs held with the PRPs in 1987, EPA requested that the
needed removal actions be done by the PRPs. EPA issued special
notice letters on November 5, 1987 to Farmland Industries and
Morrison-Quirk Grain Corporation. The PRPs subsequently received
draft administrative orders on consent in March 1988 which
included source control and ground water remediation. The PRPs
responded to EPA on April 13, 1988, with an offer to participate
in a pilot study. of soil vapor extraction.
On June 8, June 28 and July 22, 1988, EPA met with PRPs to
discuss pilot scale testing for source control.
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.
-------
b
A public meeting was held in November 1985 to present site
information and plans for the RI/FS. In February 1987, the
Report ot Investiqation for the FAR-MAR-CO subsite was placed in
the public information repository and was mailed to all
interested parties.
EPA-:Req!on V1:I Public Affairs Office has mailed Fact
Sheets periodically to parties who have expressed an interest in
the Hastings Ground Water contamination site. This office also
responds to inquiries regarding this site made by news media and
members of the public.
An Engineering Evaluation/Cost Analysis was released for
public comment in February 1988. This document set forth EPA's
proposed cleanup plans for the FAR-MAR-CO subsite.
A public meetinq
findings and the need
environmental impacts
were voiced.
was held on March 5, 1988, to discuss EPA's
for site cleanup. Concerns regarding the
of contamination and the cost of cleanup
Several issues were raised by residents during the course of
the remedial investigation, as well as at the most recent public
meeting. A responsiveness summary, which addresses the comments
and questions raised, is attached to this ROD.
SITE CHARACTERISTICS
Investigations conducted by EPA during 1985 and 1986 are
documented by Report g! Investiaations. Hastinas Ground Water
contamination. FAR-MAR-CO Subsite, dated February 24, 1987. Data
presented by this report show that the highest levels of CC14
contamination in the soils and soil-gas occur in the area defined
by the soil-gas contours illustrated in Figure 2.
Data presented in this report also show high levels of CC14
in ground water at the subsite. EPA has published a maximum
contaminant level (MCL) of 5 ppb for CC14. Significant levels of
EDB contamination are a1so present in monitorinq well MW-8 at the
subsite and in downgradient water supply wells. The above-referen~ud
report a180 contains an assessment of potential risks to human
health from. the contaminated ground water.
The amount of CC14 and EDB contamination present in the
ground water and in 801ls above the water table necessitate some
response action at the FAR-MAR-CO subsite to reduce the potential
carcinogenic risks to human health.
The analytical
risk assessment can
FAR-MAR-OO subsite.
below.
results from the subsite investigation and th~
be found in the referenced report for the
A brief summary of the results is presented
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7
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
deep. ~~s_Aquifer is the sole source of drinking water and is
used extensively tor industrial and irrigation purposes. The
lateral flow in the aquifer was 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.
Ground water samples were collected from the monitoring well
located at the subsite and from monitoring wells located ,
upqradient from the subsite. The highest detected contaminant
concentrations were seen at well MW-8 as shown in Table 1-1.
contamination with CC14 and EDB is seen in the shallow portion of
the aquifer (120-140ft.) at the subsite. Private irrigation
wells located 2,000 - 6,000 feet downgradient from the subsite
have shown CC14 and EDB contamination. One domestic well (D-8)
is also contam1nated with EDB. 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. Historical water
quality data for municipal water supply well CMS 24 and private
wells are given in Tables 1-2 and 1-3.
Soil contamination
soil sampling and soil-gas sampling were performed in 1986.
This sampling shows high levels of contamination in the soil-gas.
Analytical data from the soils show localized areas of
contamination. Figure 3 shows the proposed response area where
the highest levels of CC14 in soil-gas have been detected. Soil-
gas sampling was conducted in 1987-88 in order to better define
zones with the highest concentration of volatiles in the soils.
The remedy selected in this document will mitigate future
releases to the ground water by removing the high levels of CC14
and EDB from the unsaturated zone above the ground water.~
As shown in Table 2, there is a significant threat to public
health for the EDB-contaminated zone. This increased risk could
occur as a' result of direct contact with the EDB-contaminated4
soils. The Total Incremental Lifetime Cancer Risk of 9 x 10-
corresponds to nine cancers in a population of 10,000. The CC14
and PCE found in soils at the subsite do not contribute to this
risk estimate for direct contact.
~ Subsequent to publication of the EE/CA, data became
available to EPA, which indicated high levels of CC14 and
EDB in the sand materials underlying the silt. This
information was discussed at the public meeting on March 5,
and reviewed with the PRPs at a meeting on April 13, 19~8.
1988,
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Table 1-1
Range of Concentrations of Volatile Organic Compounds in
Ground Water East of Hastings, Nebraska,
1985 - 1987.
Concentrations (ug/l)
-. --
Paramaters OW-2s OW-2d MW-8
Trichloroethylene NO - 13 NO - 92 NO - 21
Tetrachloroethylene NO NO NO
1,1 Oichloroethene NO NO NO
Trans-1,2- NO NO NO
Oichloroethene
1,1,1 Trichloroethane NO NO ND
Carbon Tetrachloride ND ND 570 - 1300
Ethylene Dibromide ND ND ND - 8
--------------------------------
Notes
Data were obtained from the REM II Ground Water Investigation
Report for Hastings Ground Water Contamination, May 7, 1987,
the REM II Report of Investigation for Colorado Avenue
Sub site , February 24, 1987, and quarterly ground water
sampling data for April 1987.
OW-2s and OW-2d are located upgradient of the FAR-MAR-CO
subsite.
MW-8 is located at the FAR-MAR-CO subsite.
Key:
ND - not detected
s - shallow well (120-140 feet)
d - deep well (approximately 170-180 feet)
8
~ .- -----.--.-- ""'----
----
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.
Table 1-2
Range of Concentrations of Volatile Organic Compounds in
Ground Water East of Hastings, Nebraska,
1983 - 1984
_. --
Concentrations (ug/l)
Paramaters 1-49 J2:i CMS-24 I-46
Trichloroethylene NS 607 - 764 2.3 - 2.4 NS
(TCE)
Tetrachloroethylene HS HD - 3.8 HD NS
(PCE)
1,1 Dichloroethene NS ND ND NS
Trans-1,2- NS 4 - 15 ND NS
Dichloroethene
1,1,1 Trichloroethane NS NO NO NS
(TCA)
Carbon Tetrachloride NS NO 20 - 22.6 NS
Ethylene Dibromide NS NS . NS
----------------------------
Notes
1983 and 1984 analyses were reported by state of Nebraska
Data were obtained from the state of Nebraska, Department
of Health for 1983.
No 1984 data found for 0-8 and CMS-24 wells.
Key:
NS - well not sampled by state
ND - not detected
* - Sampling of the CMS, Inc., distribution system
by NDOH in 1984 revealed EDB contamination in
the range of 0.62 - 1.7 ug/l. CMS well 24 was
the only supply well in use at that time.
9
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Table 1-3
Ranqe of Concentrations of Volatile Orqanic Compounds in
Ground Water East of Hastinqs, Nebraska,
1985 - 1987.
-. ----
Concentrations (uq/l)
Paramaters
1-49
45.0 - 69
Q:i
CMS-24
ND - 7
1-46
42 - 180J
Trichloroethylene
(TCE)
182 - 1200
Tetrachloroethylene
(PCE)
ND
- 1.8
ND - 6.3
ND
ND - 2J
1,1 Dichloroethene
1.0 - 5(J)
ND
ND - 1.5
ND - . 1
ND
Trans-1, 2-
Dichloroethene
ND
ND
ND
1,1,1 Trichloroethane
(TCA)
ND - 7(J)
ND - 8
ND - .5
ND
Carbon Tetrachloride
Ethylene Dibromide
25 - 45
ND - 4.4
1 - 22
ND - 4 - -
3.2 - 6.8
ND - .5
ND - .32
ND - 0 04~),
----------------------------
Notes
Ground water data presented here are for purposes of problem
definition. Well owners have been advised that water is not
suitable for drinkinq.
Data were obtained from the REM II Ground Water Investiqation
Report, Hastinqs Ground Water Contamination, May 7, 1987,
and quarterly qround water samplinq conducted in July 1987.
Above analyses were reported by EPA Labs and EPA Contract Labs
Key:
NO - not detected
J - Compound was qualitatively
meet all quality assurance
only an estimated value.
identified; but failed to
criteria and therefore is
10
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F AR-MAR-CO
SUB SITE .
EAST ,OF HASTINGS, NE.
D
D
D
RESPONSE AREA MAP
Figure 3
o
HWY. u.s. 6
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-. ---
TABLE 2
EXPOSURE TO CARCINOGENIC RISKS ASSOCIATED WITH
DIRECT CONTACT OF WORKERS WITH SOILS
FAR-MAR-CO SUBSITE
Maximum Lifetime Carcinogenic
Concen- Averaqe Potency Incremental
tration Daily Exposure Factor Lifetime
Chemical (uq/kq), (mq/kq/day) (mq/kq/day)-1 Cancer Riska
Carbon ~etrachloride 390 3.6X10-7 1.3X10-1 SX10-S(B]
Ethylene dibromideb 12,400 2.3x10-S 4.1X10-1 9X10-4(B]
Tetrachloroethene 1,200 1.1X10-6 S.1x10-2 6X10-S(B]
Overall 9xlO-4
a.
[B2) refers to EPA's carcinoqen classification scheme ranking
these compounds as probable human carcinoqens on the basis of
animal data.
b.
Analyses of surface soils (0-2 feet) at the same location
detected EDB at a concentration of 9,420 uq/kq.4 This corresponds
to an Incremental Lifetime Cancer Risk of 7X10-. Subsequent
samplinq has shown levels hiqher than 12,400 uq/kq at a depth
of 1-3 feet.
Source:
Table 3-4, Report of Investiqation, Hastinqs Ground Water
contamination Site, FAR-MAR-CO Subsite, REM II,
February 24, 1987.
- - .----
I ~.
--- --
-------
.J
The carcinogenic risks are theoretical quantifications and
are reported as excess lifetime cancer risks. Excess lifetime
cancer risk is defined as the incremental increase in the
probability of qettinq cancer compared tg the probability if no
exposure occurred. For example, a lxlO- excess lifetime cancer
risk represents an exposure that could result in one extra cancer
case per ~illion people exposed.
RISK ASSESSMENT
The primary potential human health impacts at the FAR-MAR-CO
subsite are the exposure of re.idents to contaminated ground
water and exposure of worker. to contaminated 80ils. In order to
evaluate this public health impact, a risk assessment, which
evaluates risks as a result of the exposure, was conducted. The
risk assessment addressed the health effects associated with
ingestion of contaminated ground water and incidental direct
contact to the contaminated soils. This assessment provides a
quantitative estimate of risk levels under existing conditions,
that is, an estimate of risk levels in the absence of remedial
action. This serves as a baseline against which the need for
remedial action is evaluated. The risk assessment included
calculations of the human dosage for contaminants in ground
water.
Potential exposure pathways to humans from the use of
contaminated ground water include:
Ingestion of ground water
Inhalation of volatile chemicals released
during water use
Direct dermal contact with contaminated water
l
Persons potentially at risk of exposure to the contaminants
in ground water include users of private and industrial wells
downgradient from the subsite and customers who depend on the CMS,
Inc. public water supply east of Hastings. This includes a11
employees at the Hastings East Industrial Park, all residents of
the u.S. Air Force housing located at the Hastings East
Industrial Park and all employees and students at the Hastings
Central Community College Campus. Future users of the
ground water would include communities located east of Hastings.
To characterize risk at a site, indicator chemicals are
first identified. Factors considered in identifyinq these
chemicals include: maximum concentrations of contaminants at the
subsite and their comparison to standards, presence of
contaminants in qround water samples collected downgradient from
the subsite, and carcinogenicity of contaminants. These
chemicals were ultimately selected and are listed in Table 2 and
Table 3. EDB and CCl4 are considered the main contaminants of
concern based on the above factors. Both are highly persistent
in the environment and are no longer used for grain fumigation.
EDB and CC14 are c~assified as probable human carcinogens.
--~--
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~it
_. -.-...
TABLE 3
CHRONIC DAILY INTAKE OF CARCINOGENIC
CONTAMINANTS PRESENT IN GROUND WATER AND
CALCULATION OF INCREMENTAL LIFETIME CANCER RISK
FAR-MAR-CO SUBSITE
Maximum Lifetime Carcinoqenic
Concen- Average Potency Incremental
tration Daily Exposure Factor Lifetime
Chemical (ug/kg) (mg/kg/day) (mg/kg/day)-1 Cancer Riskc
Carbon tetrachloride 1200 3.4X10-2 1.3x10-1 4X10-3[B]
Ethylene dibromide 6.8 1.9x10-4 41 8X10-3[B]
Overall
L
1XIO-2
a.
[B2] refers to EPA's carcinogen classification scheme ranking
these compounds as probable human carcinogens on the basis of
animal data.
NOTE:
Calculations were made utilizing the highest contaminant
concentrations observed (well MW-8) based on available data
in 1986. More recent ground water sampling of well MW-8
at the sUbsite has shown higher levels present for both
contaminants.
Source:
Table 3-8, Report of Investigation, Hastings Ground Water
Contamination Site, FAR-MAR-CO SUbsite, REM II,
February 24, 1987.
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.
The potential human health impact of the remedy has been
investiqated. Calculations based on air dispersion modelinq and
estimates of emissions have been presented in the EE/CA. The
results of these calculations show the need for air monitorinq
durinq cleanup. actions. As explained in the EE/CA, air emissions
controls will be used if needed. The Aqency will request an
opinion from the Aqency for Toxic Substances and Disease Reqistry
(ATSDR) ~~~~dinq proposed ambient air emission levels.
Because the incremental cancer risk associated with direct
contact to EDB-contaminated soils approximates one in one
thousand, it was determined that the surficial soils do pose an
imminent health threat to the workers at the subsite.
. I
SCOPE Ql OPERABLE UNIT
This response action is an initial source control operable
unit and is consistent with section 300.68(c) of the National Oil
and Hazardous Substances Pollution Continqency Plan (NCP). This
initial source control operable unit is beinq implemented to'
protect public health and the environment by qontro11inq the
miqration of contaminants from the soils to the qround water.
The operable unit addresses known areas of contamination in the
sands and silts which overlie the aquifer. . The miqration of
contaminants from the soils into the aquifer is one of the major
concerns posed by the site. This operable unit was initiated to
deal with these concerns and is further described in the EE/CA
document which was released for public comment.
The operable unit is fully consistent with all future site
work, inc1udinq the onqoinq qround water investiqations. In
addition, it is believed that the remedy will reduce overall
costs of cleanup actions needed at this site.
The pilot study will provide information to more accurately
determine the cost of an SVE system for the recovery and treatment
of volatile chemicals and further information reqardinq the
feasibility of removal of EDB from the upper 30 feet of soils at
the FAR-MAR-CO subsite.
l,l,l-trichloroethane (TCA) was found in surface soils at
the southern boundary of the Farmland Industries property. This
chemical is not classified as a carcinogen. As. a part of the
risk assessment, . analytical data were reviewed for noncarcinogenic
health etfects.
Noncarcinogenic risks are determined by comparinq potential
doses of contaminants received by site visitors to contaminant
specific.reterence doses. The reference dose is an estimate of
an exposure level that would not be expected to cause adverse
effects when exposure occurs.
This analysis shows an insiqnificant health risk from direct
contact to the TCA-contaminated soils; however, cleanup action
may be warranted to protect qround water. The TCA spill area is
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_...'
small and is located about 200 feet from the EDB-spill. The TCA
contamination is not being addressed in this Record of Decision
since the most cost-effective cleanup action has not been
determined.
EVALUATION Q[ ALTERNATIVES
Remedial alternatives for the FAR-MAR-CO subsite have been
developed. ~order to aeet the objectives of the Comprehensive
Environmental Response, Compensation and Liability Act of 1980,
as amended (CERCLA): and the NCP, 40 CFR Section 300.68. The
process used to evaluate alternatives for this subsite is
discussed 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
both feasible and suitable for the FAR-MAR-CO subsite. The
technologies were screened, based on technical feasibility, subsite
conditions, environmental/public health protectiveness and
regulatory requirements. Table 4 lists the technologies that
were considered in the screening process and whether or not the
technologies were considered for further evaluation.
Based on this initial screening, response action
alternatives were identified for development and evaluation of
their ability to meet environmental laws and standards. The
viable alternatives were then developed to permit relative cost
comparisons of the technically feasible alternatives. The
results of this evaluation were that four response alternatives
were identified in addition to the NO ACTION alternative. ,
section 121(d) of CERCLA, as amended by the Superfund
Amendments and Reauthorization Act of 1986 (SARA), requires that
remedial actions comply with applicable or relevant and
appropriate requirements or standards (ARARs) under Fe~eral and
State environmental laws. EPA's findings with regard to
protectiveness are shown in Table 5. Also shown in this table is
the ability of the five source control alternatives to meet major
regulatory requirements.
I .
Delay of the source control implementat~on would increase
the total response action costs for this subsite because costs
associated with recovery and treatment of the contaminated ground
water are significantly higher. The selected remedy will be
cost-effective because further contamination of the ground water
will be averted. Recovery and treatment of the hazardous
substances in the soils and soil-gas incorporates technologies
that are proven and easily adapted to the FAR-MAR-Co subsite.
SUMMARY Q[ ALTERNATIVES
CERCLA, as amended, and the National Contingency Plan
require that each alternative developed, including the no-action
<.---~-c
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."
TABLE 4
SCREENING OF
POTENTIAL RESPONSE TECHNOLOGIES FOR
CONTAMINATED SOILS
FAR-MAR-CO SUBSITE
-- ----
Screening Result
Technoloqy
Potentially
Applicable
Not
Developed
Excavation X
Incineration X
Flushing (with water) X
Biodegradation X
Composting 1. X -- -- -
.-.-- ---..
In situ soil vapor extraction X
In situ air stripping X
In situ stream stripping. X
Thermal processing X
Capping X
-.
- ~ --
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18
TABLE 5
Al ternative--
Summary of Alternatives Evaluation for
Source Control Response Actions
Ability to Meet Major
Statutory & Requlatory
Requirements.
Is Response
Protective
No Action
Soil Vapor
Extraction
No
No
Yes
Yes
Excavation with
Onsite Treatment
Yes
Yes.. (Partial)
Excavation with
Offsite Treatment
Yes
Yes.. (Partial)
Limited Excavation
Treatment Plus
Soil Vapor
Extraction
with
Yes
Yes
1..
---.. .---.--
. The following potential ARARs have been identified and
evaluated for remedial alternatives in this Record of
Decision. Federal laws are shown with the corresponding
state requlations.
. Federal Resource Conservation and Recovery Act
state Requlations, Title 128, Title 132
. Federal Safe Drinking Water Act
State Requlations, Title 118, Title 178
. Federal Clean Water Act .
state Requlation, Title 117
. Federal Clean Air Act
State Regulation, Title 129
.. Sand material below silt-soils would not be treated,
therefore, contaminants would remain below depth of
excavation.
.
---~
.._--_.~ .
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19
alternative, must be evaluated with respect to two major criteria
-- protection ~f human health and the environment and compliance
with applicable laws and regulations. Seven additional criteria
are considered as a means to compare the alternatives. These
include:
-- ----
Long-term effectiveness
Reduction of toxicity, mobility
Short-term effectiveness
Impl.mentability
Cost
State acceptance
Community acceptance
Each alternative must be evaluated for the degree of onsite
and ottsite protection required (and thus to be provided) by the
actions involved, as part of the overall effectiveness.
-
or volume
The follQwing summary will focus on significant evaluation
criteria as they relate to the alternatives developed for the
FAR-MAR-CO subsite.
No-Action Alternative
The Agency has evaluated the no-action alternative for
source control. Because hazard~us substances are known to exist
in the soils above the aquifer, the concept of a no-action
alternative is not protective. Moreover, this alternative does
not comply with cleanup objectives including protection of the
. drinking water aquifer for future use.
Monitoring of downgradient water quality would help identify
wells to be closed, but would 'not prevent continued migration and
would not assure availability of alternate water supplies to
users. Based on downqradient water quality and the hiqh levels
of contamination at the FAR-MAR-CO subsite, 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 in the soils. Regarding other long-term aspects of
the no-action alternative, long-term reliability of monitoring
would decrease with the passage of time and with distance from
the site. There would be no reduction of mobility, toxicity or
volume; therefore, no action would create the hiqhest likelihood
of future exposure to hazardous substances being released to the
environment. '
Under the 1986 amendments to CERCLA, should a remedial
action result in hazardous substances, pollutants or contaminants
remaining at a site, the remedial action taken must be reviewed
within five years to evaluate if the actions taken are protective
of public health and the environment. Potential remedial action
costs would thus be maximized, since all the contaminants present
might have to be remediated as a result of this review. Natural
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tJ.~
attenuation of contamination is the only process that could
reduce such costs, but due to the toxicity and concentrations of
the wastes present, this alternative would not be protective.
In situ soil Vapor Extraction
This alternative involves treatinq contaminated soils in-
place without excavation. This alternative will provide
permanent removal and destruction of contaminants and, thereby,
achieve a reduction in mobility, toxicity and volume.
The need for direct action was stressed in public comments
submitted to the Aqency. This alternative is acceptable to the
state of Nebraska and the co..unity.
In a vapor extraction system, VOCs are removed from soil by
applyinq a vacuum and usinq a conventional industrial blower and
standard valvinq, pipinq and instrumentation. Vacuum extraction
has been used successfully in full-scale operations for removinq
many types of VOCs in soils ranqinq from fine-qrained silts to
coarse~qrained sand and qravels. The extracted vapor may have to
be treated by a vapor phase activated carbon system if
siqnificant air emissions result from implementation of this
response alternative. This alternative was retained for cost
evaluation.
Excavation ADd Onsite Incineration
This alternative' employs soil remediation and air treatment
technoloqies that have been fully demonstrated to be effective.
Incineration followinq .soils excavation will permanently destroy
orqanic compounds present at the FAR-MAR-CO subsite. This
alternative would comply with requirements of 1986 amendments to
CERCLA to reduce mObil,ity, toxicity or volume. This alternative
would require air quality monitorinq and other precautions to
minimize miqration of air-borne contaminants from the subsite.
The air that will be emitted from the incinerator stack may
be subject to regulations under the Resource Conservation and
Recovery ~ct.
This alternative would address contaminated soils only to
the feasible limit of excavation depth. Therefore, additional
soil remediation measures would likely be needed to achieve
objectives of ainimizinq further miqration of contaminants to the
qround water. This alternative was retained for cost evaluation
to provide cost comparisons to other response action
alternatives.
Excavation ADd Offsite Incineration
In terms of lonq-term public health and environmental
protection and reliability, this alternative is similar to the
alternative described above (involvinq onsite incineration).
Under this alternative, the excavated 80il will be transported
offsite for incineration treatment at a RCRA-permitted facility,
-~- ~._. --
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21
.
which will require continqency planninq in the event of a hiqhway
accident. Air quality monitorinq and other precautions may also
be required durinq soil excavation to minimize miqration of air
borne contaminants from the subsite.
Implementation of this alternative for treatment of all
contaminated soils may not be cost-effective, but it could be
used in combination with another alternative (such as vapor
extraction) by excavatinq localized areas of hiqh contamination
and incineratinq this soil offsite. This alternative was retained
for cost evaluation to provide cost comparisons to other response
action alternatives.
~ 2f Excavation And Incineration with In situ Soil
VaDor Extraction ADd Treatment
This alternative involves excavatinq localized areas where
hiqh concentrations of volatiles are present in soils and
subsequently incineratinq these soils onsite. The remaininq
soils would be treated by in' situ vapor extraction (SVE), and the
VOC air emissions treated by vapor phase carbon adsorption if
emissions exceed state air emission requlations or result in
siqnificant increased risk to human health. The air that would be
.emitted from the incinerator stack may be subject to requlations
under the Resource Conservation and Recovery Act, and the EPA
would review the emissions control equipment to assure that air
emissions do not have an adverse effect on public health.
-
This alterpati ve may be' 'appropriate due to the fact that the
hiqhest levels of contamination are found in the upper 30 feet of
the soils. within the upper 30 feet of soil, the most contam-
inated section is the upper 5 feet.
Limited excavation is considered feasible for implementation
at the FAR-MAR-CO subsite. Under this alternative, the depth
of excavation would be determined by analysis of site specific
factors and would likely be between 5 and 25 feet.
Unit costs (i.e., estimated cost per yard of soil) were
determined to provide cost comparisons to other response action
alternatives. An estimate for total capital costs of this
alternative has been prepared. The EDB-contamination zone
extendinq to a depth of 5 feet consists of approximately 150
cubic yards of 80il. The volume of EDB contaminated soil
correspondinq to a depth of 30 feet is 400 yards. The estimated
costs associated with excavation and onsite thermal treatment of
400 cubic yards of soil is $520,000. Therefore, the maximum
total capital costs for this alternative could be as much as
$520,000 plus $1,044,000 - $1,564,000.
Cost comparison data are shown by Table 6. These estimates
were prepared based upon enqineerinq judqments reqardinq
implementability of the alternatives evaluated for abatement of
direct contact threats and source control at the FAR-MAR-CO
subsite.
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....
SELECTED ALTERNATIVE
Based on available data and analysis conducted to date, the
U.S. BPA .elected soil vapor extraction as the .ost appropriate
solution for .eeting the goals of the source control operable
uni t at the PAR-MAR-CO subsi te. The characteristics of the
selected remedy that are considered most important are:
_.- _~e alternative provides protection to human health
and the environment from the potential threats
associated with no action.
The alternative li.its .igration of contaminants to
the aquifer at the site.
The alternative provides for compliance with
applicable laws and requlations.
-
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 propos~d changes will be taken into account. New
information about the- subsite-- could alter the cost estimates
shown in Table 6.
Selection of the in situ vapor extraction technology is
being made at this time; however, a pilot project is planned
prior to full-scale implementation of soil vapor extraction.
The pilot scale testing for an active gas extraction system will
provide the following data:
1.
2.
rate of gas withdrawal and air recharge.
radius of influence and other information to design the
final gas extraction well network.
information to design the gas monitoring well network.
3.
Pending successful completion of the pilot, the most cost-
effective design will be prepared for the source control remedYe
As a part of the initial action, the PRPs have agreed to
construct a fence to restrict access to the EDB spill zone. This
temporary aeasure will minimize potential health risk to
employees and other site visitors.
--.-.. - ---
--~-~- ---
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TABLE 6
COST COMPARISON OF RESPONSE ACTION ALTERNATIVES
FOR CONTAMINATED SOILS
FAR-MAR-CO SUBSITE
($ x 1,000)
. Total (a) First Year unit Cost
-. --
Alternative ~ Cost 2iK Cost 1IU tS/CUbi.& Yard)
In situ vapor $1,044 $391 75
. extraction and
treatment (c)
Excavation and 20,354(d) 610
onsite incineration
Excavation---and 22,116(d) 660
offsite incineration
Excavation and
incineration of
hotspots in
combination with
in situ vapor
--extraction and
treatment
520(e)
1,300
(Excavation and
onsite
incineration)
600(e)
1,500
(Excavation and
offsite
incineration)
+ costs for in situ SVE
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.
(c) A total present worth estimate for this alternative
has been prepared. The estimated cost is
$2,526,000 based on a five-year operatinq
period, a 10 percent discount rate and projection of
the first year O'M costs over the five-year operating
period.
(d) Estimates include all costs associated with site work
for an estimated volume of 33,800 cubic yards of soil.
(e) Estimates include all costs associated with site work
for excavation and treatment of an estimated volume
of 400 cubic yards of 80il.
23
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24
temporary measure will minimize potential health risk to
employees and other site visitors.
.
CT.R1N-up LEVEIS
The initial source control operable unit is being
implement:_cl-40r the purpose of controlling contaminant
aigration, not restoration of the aquifer to drinking water
standards. Therefore, no cleanup levels for the SVE process 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. This data will be
used to refine final design information and to establish
ettectiveness of the vapor extraction system. Cleanup
effectiveness will be evaluated based on volume of contaminants
recovered trom the soils. In addition to 80il-gas monitoring,
soil sampling will be required to demonstrate effectiveness of
the cleanup. Review and decision-making regarding
cleanup levels will be closely coordinated with the state of
Nebraska.
Air emissions will be monitored to assure concentrations of
volatile chemicals which present a public health risk do not
occur.
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.
The Agency believes that the maximum contaminant levels
established under authority of the Safe Drinking Water,Act are
relevant and appropriate for ground water remedies. However,
this initial operable unit does not provide for treatment of
ground water at the FAR-MAR-CO subsite. section 121 of
CERCLA, a. amended,. does provide for waiver of the requirement to
attain MCLs where an interim remedy is to be selected. Air
emissions will be monitored to assure no significant air
emissions will be created by this remedy.
OPERATION aim 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 remedial
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1/..;)
\;
..
design after the initial phase of operation and testing of the
system.
A ground yater monitoring plan will also need to be developed
and implemented to demonstrate reduced migration of contaminants
in the ground water. This plan will be incorporated into the O&M
plan. Farmland Industries and Morrison-Quirk Grain Corporation,
the res~n.i:IIle parties, have been requested to assume
responsibility for the O~. The EPA will assist the PRPs during
transition.
,
STATUTORY PINDINGS
The U.S. EPA and the State of Nebraska believe that this
remedy will 8atisfy the statutory requirements for providing
protection of human health and the environment, attaining
applicable or relevant and appropriate requirements of other
environmental statutes, will be cost-effective and will utilize
permanent solutions for this operable unit and alternative
treatment technoloqies or resource recovery technoloqies to the
maximum extent practicable.
SCHEDULE
The following are the key milestones for implementatiort of the
remedial action in the event that RD/RA negotiations are not successfu:
Approve Remedial Action (execute ROD)
Initiate Remedial Design
Initiate Remedial Action
Complete Remedial Design
September 1988
September 1989
December 1989
April 1990
FUTURE ACTION
Ground water monitoring wells located at 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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