UntodStam
Envtronmwital Protection
Agency
Odk» of
EPA/ROO/R07-88/018
Separator 1988
Superfund
Record of Decision:
Hastings Ground Water/Col. Ave, NE
-------
». tat
REPORT DOCUMENTATION
PMC
L. REPORT NO.
EPA/ROD/R07-88/018
4. TWa Mrf tuMttto
SJ1PERPUND RECORD OP DECISION
tings Ground Water (Colorado Ave.), NE
Remedial. Action
7. Authe^t)
I Performing Organisation Rapt. No.
'». Performing Organisation Nama and Addrata
10. Protect/Task/Work Unrt No.
11. ContracttC) or OrantCO) No.
perties are located immediately south and east of the site.' Prom 1967 to May 1982
, site was used by Dravo Corporation for manufacturing of heating and air conditioning
equipment. Metals were cleaned prior to finishing with a vapor-degreasing process, and
the- waste solvents were discharged directly into the sanitary sewer and the storm
sewer. The site has since been acquired by Marshalltown Instruments Company, who claims
to have no involvement with disposal of the chemical contaminants. Ground water
contamination was discovered when an out-of-service drinking water well was put back in
service, resulting in complaints about the water quality. Subsequently, the Nebraska
Department of Health and the Nebraska Department of Environmental Control began
investigating widespread ground water contamination in the Hastings area. Active
Hastings municipal water wells are located within one block, 3,000 feet, and 4,500 feet
of the site, all three accessing a sole source aquifer. The highest levels of
contamination of soil and soil-gas occur along the sanitary and storm sewers at the
(See Attached Sheet)
17. Document Analysis i
Record of Decision
Hastings Ground Water (Colorado Ave.), NE
Pirst Remedial Action
Contaminated Media: gw, soil
Key Contaminants: VOCs (TCE, PCE)
b. Identiners/Open-Endod Terms
COSAT1 Plaid/Group
IS. Availability Statamont
19. Sacurlty CUM (This Report)
None
20. Sacurlty Class (This Page)
None
21. No. of Pigaa
28
22. Price
(S«o ANSI-Z39.lt)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-3S)
-------
°pA/ROD/R07-88/0l8
stings Ground Water (Colorado Ave.), NE
~rst Remedial Action
16.
ABSTRACT (continued)
site, with localized areas which correspond to joints in the sewers. The volume of
w contaminated soil is estimated to be 42,700 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 VOCs including
TCE and PCE.
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: 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 $3,603,000, 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.
. .
-------
RECORD OF DECISION
DECLARATION
INITIAL SOURCE CONTROL OPERABLE UNIT
-- --
nIl NAME Alfi2 LOCATION
Hastings Ground Water Contamination
Colorado Avenue
Hastings, Nebraska
STATEMENT Q[ BASIS AliQ PURPOSE
This decision document represents the selected remedial
action for the Colorado Avenue, subsite of the Hastings Ground
Wa~r contamination site, 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 to the extent practicable, the
National oil and Hazardous Substances Pollution Contingency Plan.
This decision is based upon the contents of the administra-
t~ve .record for. the Colorado Avenue site.
-
The State of Nebraska concurs on the selected remedy.
DESCRIPTION OF THE REMEDY
This initial source control operable unit was developed to
protect public health and the environment by controlling th~
migration of contaminants present in the soils which overlie the
aquifer. Prior to implementation of a full scale remedy, a
pilot-scale test will be undertaken. The operable unit is
fully consistent with all planned future site activities. Future
site activities will be addressed in subsequent Records of
Decision and will include a decision on possible remediation of
contaminated ground water for this subsite.
The major components of the selected remedy are as follows:
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.
-------
DECLARATION
The selected remedy is protective of human. health and the
environment, attains Federal and state requirements that are
applicable or 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 COl'lCerns"
~
q'- 2- <0 - ?s't
Date
.rJ'l,., / 1:1/
/S'lqnaturr (RA/AA)
Attachments:
Index to Administrative Record
Decision Summary
Responsiveness Summary
. .'
-------
_. --
RECORD OF DECISION
DECISION SUMMARY
HASTINGS GROUND WATER CONTAMINATION
COLORADO AVENUE SUBSITE
HASTINGS, NEBRASKA
. . .
Prepared By:
u.S. Environmental Protection Agency
Region VII
Kansas City, Kansas
September 1988
-------
I'
'"
section
I.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
X.
XI.
XII.
XIII.
XIV.
xv.
XVI.
Record of Decision
-~ -.....
Decision Summary
Contents
si te Des,cription
Site History
Enforcement History
Community Relations
Site Characteristics
Risk Assessment
Scope ~f.Operable unit
" .
No Significant Changes
. Evaluation of Alternatives
Summary of Alternatives
Selected. Alternat1ve
Cleanup Levels
operation and Maintenance
Statutory Findings
Schedule
Future Action
paae
1
4
5
6
6
8
10
19
10
11
14
15
15
16
16
16
-------
DECISION SUMMARY
COLORADO AVENUE SUBSITE
HASTINGS GROUND WATER CONTAMINATION
SITE DESCRIPTION
The Colorado Avenue subsite of the Hastinqs Ground Water
Contamin~~i9n site is located in the City of Hastinqs,
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 Colorado Avenue subsite is a part of the Central Industrial
Area which contains commercial and industrial properties situated
alonq the Burlinqton-Northern railroad riqht-of-way. Residential
properties are located immediately south and east of the Colorado
Avenue site.
Three industrial properties are included within the site.
These properties, alonq with the city's right-of-way for public
access and public utilities, will be impacted by the source
control remedy.. The property known as 108 South Colorado
consists of a main brick building and several additions known to
be over 25 years old. The 108 South Colorado property was used
by Dravo Corporation from 1967 to May 1982. Dravo Corporation
manufactured heatinq and air conditioninq equipment at this plant
.site. and us~d a vapor-deqreasinq process to cle~n'metals.prior to
finishinq. Waste solvents' were' discharged into the sanitary
sewer and the storm sewer at the site. These sewers are shown on
Fiqure 2.
The Burlington-Northern railroad right-of-way adjoins the
108 South Colorado prop-erty to the north. The riqht-of-way is
200 feet wide and is a 'major east-west transportation route.
Across the street east from the 108 South Colorado property
is the Zuber Company, a metal recyclinq business. The Zuber
Company leases Burlinqton-Northern Railroad (B-N) property which
adjoins it on the north. The leased property is used for
storaqe of salvaqe metals and staqinq of metals for loading onto
rail cars for shippinq.
Information available to the Aqency indicates
Company has not used chemical solvents and has riot
hazardous wastes from the manufacturing operations
Colorado.
A storm sewer was constructed from the 108 South Colorado
property, eastward across B-N property. This sewer carries
surface water and roof drainage (rain water) from the main
buildinq at 108 S. Colorado. Accordinq to information provided
by Dravo Corporation, there are several breaks in the storm
sewer. This supports EPA's conclusion that the contamination
found in soils on the B-N Railroad property is a result of
industrial discharges to the storm sewer-previously described.
the Zuber
accepted any
at 108 South
-------
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Site
Location Map
NEBRASKA
HASTINGS,
Nebraska
F ig~re
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-------
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LEGEND
SI~LET___-
---
-
. MUNICIPAL WELL
~ MONITORING WELL
..:.W EPA WELL
STATE WELL
qw
~ONTOURS REPRESENT
Od' APPROXIMATE AREAS Of
,,' EQUAL TCE Cug/l) CO~~S
CENTRATION IN SOIL.
, SANITARY SEWER AND
~~ DIRECTION Of FLOW
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COLORADOHA8TINQ8 ATION 811E
WATER CON'U"N
GROUND t
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- ........... .'0'.8
8<:8'8
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TCE
-------
4
The Union Pacific right-of-way is located east of the Zuber
Company properties. This track is a major north-south
transportation route.
Hastings municipal well number 10 is located one block west
of Colorado Avenue at the intersection of Kansas Avenue and the
Burlington-Northern tracks. Decommissioned Hastings municipal
well numbe~~8 is located approximately 1/2 mile east of the
Colorado Avenue site. Hastings municipal well number 7 is
located approximately 4,500 feet north-east of the site.
Hastings municipal well number 20 is located approximately 3,000
feet south of the site.
SITE HISTORY
Hastings Municipal Well number 18 had not been used for
approximately 30 years when, in March 1983, the city attempted to
put the well into service. Following start-up, complaints of
foul taste and odor resulted in the well being permanently
removed from service. That same year, the Nebraska Department of
Health (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 18 indicated that the well was contaminated with several
compounds, prima~ily chlorinated solv~n~s,'including
-trichloroethene (TCE), 1,1,1-trichloroeth~ne. (TCA). and
tetrachloroethane ("PCE). Subsequent to. discovery of these
.contaminants in well 18, Marshalltown Instruments Company
purchased the former Dravo Corporation property at 108 s.
Colorado.
In 1984, the State of Nebraska installed five pairs of
monitoring wells in the City of Hastings. .
The EPA began sampling wells in 1985. Field investigations
were conducted during 1986 to identify and characterize suspected sourc
areas.
The Colorado Avenue site was identified by EPA in 1986 as
the source of high levels of TCE found in well '18. The Colorado
Avenue site includes sanitary and storm sewers which received
metal degreasing'(solvent) waste discharges during the 1960s and
1970s. In the 1950s and early 1960s, the 108 South Colorado
property was o~cupied by a predecessor firm, Hastings Industries.
Hastings Industries used TCE at the site during the early-
to-mid 1960s. In 1967 Cravo Corporation purchased Hastings
Industries.' The operations at 108 South Colorado subsequently
became a wholly owned subsidiary of Cravo Corporation. The
facility at 108 South Colorado continued to use TCE in'their
vapor degreasing process until 1971, when Cravo Corporation
switched to using 1,1,1-TCA. Information available to
EPA indicates that spent solvents were discharged to
-------
the sewers at the Colorado Avenue site during the 1960s and
1970s. This information is supported by results of field
investigations conducted during 1986-1988 at the site.
The EPA conducted soil sampling and soil-gas sampling in
1987 and 1988 to better define the extent of contamination at the
site and to refine preliminary design data for the source control
remedy. _. --
,
An Enaineerinq Evaluations ~ Cost Analvsis (EE/CA) was
released by EPA for public comment on February 3, 1988. The
EE/CA described several initial response actions for this
subsite, including soil vapor extraction. The public comment
period for this site was subsequently extended to April 30, 1988.
The EPA has prepared a responsiveness summary which addresses the
comments received. .
Solid and semi-solid wastes from the vapor degreasing
process were sent to municipal landfills in the Hastings area.
Therefore, no onsite burial of wastes is suspected.
There are no known direct contact health threats from
contaminated soils, and public access to the site is not
restricted at this time.
ENFORCEMENT HISTORY
" . In septemb~ri~85; general notic.e letters were' iss~ed.to
~ potentially responsible parties (PRPs) connected with the '
Hastings Ground Water contamination NPL site. The first PRP
meeting 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 Dravo Corporation
Marshalltown Instruments of their potential liability
Colorado Avenue site. In January 1987, a PRP meeting
review EPA's findings to date. Dravo Corporation and
Marshalltown Instruments were asked to undertake the next phase
of investigations. Neither party made an offer. During meetings
held with the PRPs in 1987, EPA requested that the needed removal
actions be done by the PRPs. The first offer made to EPA was by
Dravo Corporation following the issuance of a special notice
letter on August 25, 1987 and the 60 day moratorium
which followed. Cravo asked to be considered for a de minimis
settlement. The Agency informed Cravo that it could not
accept its offer as it did not meet the requisite statutory
criteria for such a settlement. Cravo did not counter-offer
after receiving the Agency's response. Cravo and Marshalltown
subsequently received draft administrative orders on consent in
1988 which included, inter alia, source control. In April 1988,
Marshalltown requested its status as a PRP be reviewed and it
submitted documents. to support its position that it had not
disposed of TCA at its facility. The Agency reviewed
Marsha!ltown's status pursuant to this request and determined
and
at the
was held to
-------
.J
that Marshalltown was not eligible for a section 107(b) (3)
defense because it had an indirect contractual relationship with
one who had disposed of TCA at the site and Marshalltown had
reason to know. of the disposal, as that term is defined under
~ERCLA, when it purchased the property.
On April 13, 1988, the Hastings PRPs met with EPA and
offered ~o~dertake a pilot study of SVE. The Agency requested
. the PRPs submit a proposal. On June 8, June 28 and July 22,
1988, EPA met with the PRPs to discuss pilot scale testing for
source control at the Colorado Avenue site. A draft order
concerning Colorado Avenue was discussed on July 22, and
negotiations continued in August 1988.
,
COMMUNITY RELATIONS
Community relations activities for the Hastings Ground Water
contamination were initiated by the EPA in 1984 with the
development of a Community Relations Plan. Since December 1984,
EPA has conducted periodic meetings with Hastings city officials
to update them regarding site work and findings.
A public meeting was held in November 1985 to present site
information and plans for the RI/FS. In February 1987, the
Report of Investigations was placed in the public information
repository and was mailed to all interested parties.
. .
The.EPA .Region ~II Pub~ic Affairs Office ha~ mailed Fa~t
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 Colorado Avenue subsite.
. -..
A public meeting
findings and the need
environmental impacts
cleanup were voiced.
was held on March 5, 1988, to discuss EPA's
for site cleanup. Concerns regarding the
of contamination and the costs of
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 Recort 2t Investiqation. Hastinqs Ground Water
contamination. Colorado Avenue Subsite, dated February 16, 1987.
Data pres~nted by this report show that the h~ghest levels of TCE
contamination in the soils and soil-gas occur along the
previously described sanitary and storm sewers at the Colorado
-------
7
Avenue site. Approximately 70 feet of sand and sand/qravel were
found above the water table.
..
Data presented in this report also show very hiqh levels of
TCE in qround water at the site. The EPA has published a maximum
contaminant level (MCL) of 5 ppb for TCE. The above-referenced
report also contains an assessment of potential risks to human
health fr:o~~e contaminated qround water.
As a part of the risk assessment, analytical data were
reviewed for surface water exposure, for noncarcinoqenic health
effects and for direct contact to soils. Because these risk
levels did not pose a .threat to human health, the calculations
were not presented in the referenced report.
The amount of TCE contamination present in the qround water
and in soils above the water table necessitates some response
action at the Colorado Avenue site to reduce the potential
carcinoqenic risks to human health.
."
The carcinoqenic 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 1x10- excess lifetime cancer
risk represen~s ~n exposure that could result in one extra cance~
case per million. .people exposed.: .. '. .. .' .' ..'
Hiqh levels of 1,~,1-trichloroethane are present in th& .
qround water at the site. This chemical is not classified as a
carcinoqen.
Noncarcinoqenic risks are determined by co~parinq potential
doses of contaminants by site .visitors to contaminant specific
reference doses. The reference dose is an estimate of an
exposure level that would not be expected to cause adverse
effects when exposure occurs.
The analytical results from the site investiqation and the
risk assessment can be found in the referenced report for the
Colorado Avenue site. A brief summary of the results is
presented below.
Ground Water contamination
Ground water at the site is found at a depth of
approximately 125 feet. The site is underlain by a sand and
qravel aquifer, havinq a saturated zone approximately 100 feet
deep. This aquifer is the sole source of drinkinq water and is
used extensively for industrial and irriqation purposes. The
lateral flow in the aquifer was found to be qenerally eastward
from the site. However, the potentiometric surface map of the
area indicates the direction of flow east of the site is
influenced by the reqional east-southeast qradient.
-------
8
Ground water samples were collected' from 14 downgradient
monitoring wells and from public supply wells located upgradient
and downgradient from the site. The highest detected contaminant
concentrations. were seen at well MW-2 as shown in Table 1-1.
Contamination with TCE, TCA and PCE is seen in the shallow
portion of the aquifer (125-140 ft.) near the site. Monitoring
wells located 1,000-2,000 feet downgradient from the site have
shown TCE contamination at depths of 170-180 feet. 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 Hastings municipal supply wells
are given in Tables 1-2 and 1-3.
Soil contamination
soil sampling and soil-gas sampling was performed in 1986.
This sampling shows high levels of contamination in the soil-gas
associated with the sanitary and storm sewers. AnalYtical data
from the soils show several localized areas of contamination -
which correspond to joints in the sewers where liquids can leach
into the soils. Fiqure 3 shows the proposed response area which
has shown the highest levels of TCE in soil-gas. Approximately
70 feet of sand and sand/gravel are present above the water
table. Soils found above this highly permeable zone are
characterized by increasing silt and clay content moving upward
to the ground surface. Soil-gas sampling was conducted in 1987-
88 in order to better defi~e zones with the ,hiqhest concentration
of volatiles ,in-the soils.' This remedy will ~itigate'future
releases to the ground water by removing the high levels of TCE
and other volatiles 'in the unsaturated zone.!! ~-
Surface Water and Sediment contamination
Surface water and sediments are present in an open ditch
which is an outfall of the storm sewer. A number of years have
elapsed since TCE and TCA were discharged to the sewer. Large
quantities of water have passed through the storm sewer and
levels of contamination present in the surface water and
sediments do not present a significant risk to public health or
the environment.
RISK ASSESSMENT
The primary potential human health impact at the Colorado
Avenue ~ite is the exposure of residents 'to contaminated ground
!! ' Subsequent to publication of the EE/CA, data became available to
EPA, which indicate~ high levels of volatile organic chemicals in
the sand materials underlying the silt.' This information was
discussed at the public meeting on March 5, 1988, and reviewed
with the PRPs at a meeting on April 13, 1988.
-------
~
8A
hble 1-1
.ange of
Concentrations of Volatile Organic Compounds in
Ground Water et Colorado Avenue Site
1985 - 1987
State and EPA Monitoring Wells
Concentretions (ug/l)
-. --
"
Parameters
OW-4e.) OW-4ed) OW - 5C .) OW-5ed) !.!L:.l !!Jt.:..l. ~
.
10-3,500 20-1,800 100-1,900 NO-51 up to 54-120 1,300-
55,000 12,000
NO-42 NO-24 NO-55 NO-2 NO-550 NO 25-77
NO NO NO-3.5 NO NO-290 NO 4-20
NO-H.O NO NO NO NO-9 NO-0.12 ND-81
NO-40 NO-25 NO-350 NO-6 NO'- 960 NO 92-420
.
Trichloroethylene
(TCE)
Tetrachloroethylene
(PCE)
1,1-0ichloroethene
Trans-1,2-
Dichloroethene
1,1,1-Trichloroethane
(TCA)
.
---.}_. -----_.:.._----------~----
-
Notes
Ground water .onitoring data (1985-1987) do not indicate a specific trend for vec
conta.rnation over ti.e. However, hi~h conta.inant concentrations ~ersisted i.n 1986
and 1981 (e.g., at MW-2, TCE was observed at '55,000 ugll in September 1986, 20,000
ug/l in Dece.ber 1986 and 45,000 ugll in April 1987). Data were obtained from
the REM II site investigation report for Colorado Avenue subsite (Woodward-Clyde,
1987a) and quarterly ground water .a.pling conducted in Oece.ber 1986 and April
1987.
(5) shallow well (120-140 feet)
(d) deep well (approxi.ately 170-180 feet)
NO
not detected
Oata for other .onitoring well. located ea.t of .ite not .hown by this table.
-------
88
Table 1-2
R~nge of Concentrations of Volatile Organic Co.pounds in
Ground Water, City of Hastings
1983 - 1984
_. --
Concentrations Cug/l)
Parameters
~ !!:.1.
4.8 -
lID 6.81
!L:..l.!L
!!..:...1..1.
!.:..1l.
!!..:..!J..
Trichloroethyle~e
(TCE)
lID -
46.5
liD -
0.42
4.2 -
249.2
lID -
>2000
Tetrachloroethylene
(PCE)
lID
IIID
lID -
19.6
liD
liD -
352
IIID -
60.4
1,1-Dichloroethene
IIID
NO
NO
NO
ND
ND -
24.6
Trans-1,Z-
Dichloroethene
ND
ND
NO
NO
ND
NO -
75.7
1,1,1-Trichloroethane
(T CA)
ND'
NO
NO
lID
NO -
10.4
NO -
13~
. .
----------------------------
Notes
-
Ground water data (1983-1984) presented here reflects data from four
wells (M-3, M-10, M-12 and M-18) which have since been taken out of
regular service and/or disconnected from the distribution system.
Higher contaminant concentrations were f~und ~n 1983 when the wells'
were in use.
Data were obtained from the REM II ground water
report for Hastings Ground Water Contamination,
quarterly ground water sa.pling conducted since
investigation
May 7,1987, and
December 1986.
Carbon tetrachloride ranging fro. 6.4 - 46.4
ug/l was detected in well M-3 during this period.
Cs) shallow well
Cd) deep well
NO not detected
no data available
1983 and 1984 analyses were reported by State of Nebraska
-------
BC
Teble 1-3
.a~ge of
Concentrations of Volatile Organic
Ground Water, City of Hastings
1985 - 1987
Co.pounds in
~
Concentrations (ug/l)
Parameters
~ !!.:.L !!.:.lJ. ~ !!..:..ll. !!..:..!i !..:.l.!.
0.5 - 1.]- 1.7 1.7 8ID - ND -
ND 1.7 21 0.4 190
Trichloroethylene
(TCE)
Tetrachloroethylene
(PCE)
ND
ND
lID
lID
ND
lID
ND
1,1-Dichloroethene
ND
ND
ND
ND
ND
ND
ND
Trans-1,2-
Dichloroethene
ND
ND
ND
ND
ND
ND
ND
1,1,1-Trichloroethane
(TCA)
ND
ND
ND -
0.3
ND
ND
0.4
ND
N'D
---~-------~---------~------
. .
"-
("
Not e.i,
.
Ground water data (1985-1987) presented here reflects discontinued
use of four wells (M-3, M-10, M-12 and M-18) which have since been
taken out of regutar service and/or disconnected from the
distribution system." As shown by Table 2-2, higher contaminant
concentrations were found in 1983 when the welts were in use.
Data were obtained from the REM II ground water investigation report
for Hastings Ground Water Contamination, May 7, 1987, and quarterly
ground water sampling conducted since December 1986.
Carbon tetrachloride ranging fro. 22-26 ug/l waS detected. in well
M-3 during this petiod.
ND
Not detected
Above analyses were reported by EPA Labs and EPA Contract Lab..
-------
SECOND
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.R.
COLORADO AVENUE
SUBSITE
HASTINGS, NEBRASKA
RESPONSE AREA MAP
Figure 3
-------
water. In order to evaluate this public health impact, a risk
assessment, 'which evaluates risks to users as a result of the
exposure, was conducted. The risk assessment addressed the
health effects-associated with ingestion of contaminated ground
water. This assessment provides a quantitative estimate of risk
levels under existing conditions -- that is, in the absence of
remedial action. This serves as a baseline against which the
need for-rem~dial 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
Persons potentially at risk of exposure to the contaminants
in ground water include users of private and industrial wells
down gradient from the site and customers who depend on the CMS, Inc.,
public water supply east of Hastings. Future users of the ground
water would include communities located east of Hastings.
Development 'of a list of indicator chemicals is the first
stage in the char~cteriz~tiQn of. risk. Factors considere~
. include: maximum concentrations of contaminants. at the site and
their comparison to. standards, p~sence of conta~inants in ground
water samples collected down gradient from the site, and
carcinogenicity of contaminants. Three compounds were ultimately
selected and are listed in Table 2. Trichloroethene is
considered the main contaminant of conc~rn based on the above
factors. TCE is classified. as a probable human carcinogen.
'Degradation of TCE produces vinyl chloride which is classified as
a human carcinogen.
Because the overall incremental lifetime cancer risk shown
in Table 2 exceeds current US EPA guidelines, response action
alternatives were developed so as to reduce the potential for
human exposure to contaminated ground water. This remedy will
minimize the volume of contaminated ground water which will
migrate from the Colorado Avenue site.
The potential human health impact of the selected remedy has
investigated. Calculations have been presented in EPA reports
which show the need for air monitoring during cleanup actions.
As explained in the EE/CA, air emissions controls will be used if
needed. The Agency will request an opinion from the Agency for
Toxic Substances and Disease Registry (ATSDR) regarding proposed
ambient air emission levels.
been
Because the incremental c~ncer risks assgciated with direct
contact to onsite soils are less than 1 x 10- , it was determined
<~. - --.-',-r-;J ,-~. 4 - .~
"-~; ~._, ~:.~ ..>-~~.
-------
9A
_. ----
CHRONIC
TABLE 2
DAILY INTAKE OF CARCINOGENIC CONTAMINANTS
IN GROUND WATER AND CALCULATION
OF
POTENTIAL INCREMENTAL LIFETIME CANCER RISK
COLORADO AVENUE SITE
PRESENT
Maximum Chronic Carcinoqenic
Concen- Daily Intake Potency Incremental
tration (CDI) Factor Lifetime
Chemical (ug/ l) (mg/kg/day) (mg/kg/day)-l Cancer Ri!'k
1,1-Dichloroethene 290 8. 3xio-3 0.S8 SX10-3[C]
Tetrachloroethene 1,300 3.7x10-2 S.lX10-2 2X10-3[B2]
Trichloroethene. .SS, 000 1.6 1..lX~0-2 . 2X10-2 [~2]
~
)
- ~
Overall 3X10-2
a EPA's carcinogen classification scheme:
[A] = human carcinogen
[B2] = Probable human carcinogen on the
[C] = possible human carcinogen
basis of animal data
Source:
Table 3-4, Report of Investigation, Hastings Ground Water
contamination Site, Colorado Avenue Subsite, REM II,
February 16, 1987.
'.' ,M~"'.' '-_.'-"""."""';'~ ~'~'._'"-- .~.~~' .., .'., "~r""7.-:-"="
-------
10
that the surficial soils do not pose an imminent health threat
to the workers at the site.
SCOPE Ql OPERA~LE UNIT
This response action is an initial source control operable
unit and is consistent to the extent practicable with Section
300.68(c}. ~the National oil and Hazardous Substances Pollution
contingency Plan (NCP). This initial source control operable
unit is being implemented to protect public health and the
environment by controlling the migration of contaminants from the
soils to the ground water. The operable unit addresses. known
areas of contamination in the sands and silts which overlie the
aquifer is one of the 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 initial action is fully consistent with all future site
work, including the ongoing ground water investigations. In
addition, it is believed that the remedy will reduce overall
costs of cleanup actions needed at this site.
{
, Because the incremental cancer risks a~sociated with direct
contact to onsite soils are less than 1x10- , it was determined
that the surfi~jal soils do not pose an imminent health t~reat to
the workers at the site~ . .
. The selected remedy will be cost-effective' "because "recovery
and treatment of the hazardous substances in the soil-gas
incorporates technologies that are proven and easily adapted to
the Colorado Avenue site. Costs associated with recovery and
treatment of the contaminated ground water are significantly
higher, therefore, delay of the source control implementation
would increase the total response action costs for this site.
NO SIGNIFICANT CHANGES
The EPA has selected an initial remedy consisting of soil
vapor extraction at the Colorado Avenue subsite. This remedy is
identical to the preferred alternative identified in the EE/CA
document released by EPA on February 3, 1988. There are no
significant changes to EPA's proposed cleanup plan.
EVALUATION 2E ALTERNATIVES
Remedial alternatives have been developed in order to meet
the objectives of the Comprehensive Environmental Response,
Compensation and Liability Act of 1980, as amended (CERCLA): and,
to the extent practicable, the NCP, 40 CFR section 300.68. The
process used to evaluate alternatives for this site is discussed
in the EE/CAand is addressed briefly here.
The first step in the evaluation of alternatives was to
investigate technologies and determine which technologies may be
-------
11
both feasible and suitable for the Colorado Avenue site. The
technologies were screened based on technical feasibility, site
conditions, protectiveness of human health and the environment and
regulatory re~irements. Table 3 lists the technologies that
were considered in the screening process and whether or not the
technologies were considered for further evaluation.
Based~ 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, requires tha~ remedial actions
comply with applicable or relevant and appropriate requirements
or standards (ARARs) under Federal and state environmental laws.
The EPA's findings with regard to protectiveness are shown in
Table 4. Also shown in this table is the ability of the five
source control alternatives to meet major regulatory
requirements.
SUMMARY Q[ ALTERNATIv~S
CERCLA, as amended, and the National Contingency Plan
require th~t each alternative. developed, including ,the n~-action
alternatiye., must pe evaluated with respect to two major criteria
overall protection of human health and.'the environment and' 4
compliance with applicable ~r 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
Short-term effectiveness
Implementability
Cost
State acceptance
community acceptance
or volume
Each alternative must be evaluated for the degree of on and
offsite protection required (and thus, to be provided) by the
actions involved, as part of the overall effectiveness.
The following summary will focus on significant evaluation
criteria as they relate to the alternatives developed for the
Colorado Avenue subsite.
No-Action Alternative
The Agency has evaluated the no-action alternative for
source control. Because hazardous substances are known to exist
in the soils above the aquifer, the concept of a no-action
-------
llA
-.. --
TABLE 3
SCREENING OF
POTENTIAL RESPONSE TECHNOLOGIES FOR
CONTAMINATED SOILS
COLORADO AVENUE SITE
Screening Result
Technology
Potentially
Applicab~e
Not
Developed
Excavation X
Incineration X
Flushipg ,(with' water) " .' X
. - . '
,. -
Biodegradation X
Composting X
In situ soil vapor extraction X
In situ air stripping X
In situ stream stripping X
Thermal processing X
Capping X
-------
11 B
Table!
Summaxy of Alternatives Evaluation for Source Control
'Response Actions
Alternative
Is Response
Protective
Ability to Meet Major
Statutory &, Regulatory
Requirements.
No Action
No
No
Soil Vapor
Extraction
Yes
Yes
Excavation with
Onsite Treatment
Yes
It
Yes.. (Partial)
Excavation with
Offsite Treatment
Yes
Yes.. (Partial)
Limited Excavation
Treatmen~ Plus
SQil ,Vapor
Extraction
with
, .'
Yes
. Yes
.
The following potential ARARs have been identified and
evaluated for remedial alternatives in thi$ Record of Decision.
Federal laws are shown with the corresponding State regulations.
o Federal Resource Conservation and Recovery Act
-' State Regulations, Title 128, Title 132
. Federal Safe Drinking Water Act
State Regulations, Title 118, Title 178
. Federal Clean Water Act
State Regulation, Title 117
. Federal Clean Air Act
State Regulation, Title 129
.. Sand materials below silt-soils would not be treated,
therefore, contaminants would rem~in below depth of excavation.
-------
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 downgradient water.quality data and the high
levels of contamination at the Colorado Avenue site, 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 highest likelihood
for 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 the 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
'att~nuation of co~ta~inat~on is the only.process that could
reduce :. such. costs, but. due to tbe toxicity and concentrations of
the wastes present, this alternative would not be protectiye.
In situ Soil Vapor Extraction
This alternative involves treating 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 Agency. ~his alternative is acceptable to the
state of Nebraska and the community.
In a vapor extraction system, VOCs are removed from soil by
applying a vacuum and using a conventional industrial blower and
standard valving~ piping and instrumentation. Vacuum extraction
has been used successfully in full-scale operations for removing
many types of VOCs in soils ranging from fine-grained silts to
coarse-grained sand and gravels. The extracted vapor may have to
be treated by a vapor phase activated carbon system if
significant air emissions result from implementation of this
response alternative. This alternative was retained for cost
evaluation.
."J.
Excavation ~ Onsite Incineration
This alternative employs soil remediation and air treatment
"~>-'--."._.r..,'-'" ~- ",-1-,-.-".---
-------
13.
technologies that have been fUlly demonstrated to be effective.
Incineration following soils excavation will permanently destroy
organic compounds present at the Colorado Avenue site. This
alternative would comply with requirements of 1986 amendments to
CERCLA to reduce mobility, toxicity or volume. This alternative
would require air quality monitoring and other precautions to
minimize migration of air-borne contaminants from the site.
This ~ernative 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 minimizing further migration of contaminants to the
ground water. This alternative was retained for cost evaluation
to provide cost comparisons to other response action alternatives.
Excavation And Offsite Incineration
In terms of long-term public health and environmental
protection and reliability, this alternative is similar to the
alternative described above (involving onsite incineration).
Under this alternative, the excavated soil will be transported
offsite for incineration treatment at a RCRA-permitted facility,
which will require contingency planning in the event of a highway
accident. Air quality monitoring and other precautions may also
be required during soil excavation to minimize migration of air-
borne contaminants from the subsite.
. Implemen~ation of. this ~lternative for treatment of all
con~aminate~ soils may ~ot be cost-effective, but it could be
used in oombination with another alternative (such as vapor.
extraction) by excavating localized areas of high contamination
and incinerating this soil offsite. This alternative is retained
for cost evaluation to provide cost comparisons to other response
action alternatives.
Combination of Excavation and Incineration with In situ soil
VaDor Extraction ~ Treatment
This alternative involves excavating localized areas where
high concentrations of volatiles are present in soils and
destruction by incineration (onsite or offsite). The remaining
soils will be treated by in situ vapor extraction, and the VOC
air emissions treated by vapor phase carbon adsorption. This
alternative was not selected due to the fact that the highest
levels of contamination found are in the sand materials at depths
below the silts. Deep excavations were not considered feasible
for implementation at the Colorado Avenue site. Unit costs
(i.e., estimated cost per yard of soil excavated) were determined to
provide cost comparisons to other response action alternatives.
Cost Effectiveness
Cost comparison data is shown by Table 5. These estimates
were prepared based upon engineering judgments regarding
implementability of the alternatives eval «ted for source control
at the Colorado Avenue site. Clearly, so,. vapor extra'ction is
-------
13A
COST
TABLE 5
COMPARISON OF RESPONSE ACTION ALTERNATIVES
FOR CONTAMINATED SOILS
COLORADO AVENUE SITE
($ X 1,000)
-. - -...
$1,605
First Year
QiH Cost 1Rl
$527
Unit Cost
C$/CUbic Yard)
Alternative
In situ vapor
extraction and
treatment
Total (a)
C~pital Cost
84
Excavation and
onsite incineration
Excavatidt and
offsite incineration
25,998(c)
610
28,055(c)
660
Excavation and.
. .- '. . .-
l.nc1.nerat1.on Of
hotspots in
combination with
in situ vapor
extraction and
treatment
. (d)
-.
1,300
(Excavation and
.onsite
incineration)
1,500
(Excavation and
offsite
incineration)
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) Estimates include all costs associated with site work
tor an estimated volume of 42,700 cubic yards of soil.
(d) Total cost for this alternative was not estimated. .
Based on site sampling data, no localized zones of high
contamination at the surface were identified.
(e}
A total present worth estimate for. source control
implementation has been prepared. The estimated cost is
$3,603,000 based on -- a five-year operating period,
a 10 percent discount rate and projection of the first
year O&M costs over the five-year operating period.
-------
: . 4 ~
the more cost-effective alterna'::.ve.
SELECTED ALTERNATIVE
Based on available data and analysis conducted to date, the
u.S. EPA selected soil Vapor Extraction as the most appropriate
solution for meeting the 'goals of the source control operable
unit at th&~olorado Avenue site. The characteristics of Soil
Vapor Extraction 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 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
,undertak~n at this site., If new information o~'additional
. en~ironmental 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.
Selection of the vapor extraction source control remedy is
made at this time; however, a pilot project is planned prior to
full-scale implementation of the proposed actions. This pilot
scale testing for an active gas extraction system will provide
the following data:
being
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
7. information to design the gas monitoring well
network.
Pending successful completion of the pilot, the most cost-
-------
effective design will be prepared for the "source control remedy.
CT~AN-UP LEVELS
The initial source-control operable unit is being
implemented for the purpose of controlling contaminant migration,
not restoration of the aquifer to drinking water standards.
Therefore,~ 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. This 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 no direct contact
health risks exist at the site, a cleanup level for soils 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
succes~of the selected remedy.. The anticipated result is that
the duration of any long-term ~ctions will De decrease~.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 Colorado Avenue subsite. section 121 of
CERCLA, as 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 ~ 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&H 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
design after the initial phase of operation and testing of the
system.
A ground water 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. Dravo Corporation has been requested to
-------
..I...)
assume responsibility for the O&M. Marshalltown Instruments also
has potential liability for O&M costs. The EPA will assist the
PRPs during transition.
STATUTORY FINDINGS
The u.s. EPA and the State of Nebraska believe that this
remedy will-satisfy 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, will utilize
permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable
and satisfies the statutory preference for treatment of hazardous
substances.
SCHEDULE
The following are the key milestones for implementation of
the remedial action in the event that negotiations with
potentially responsible parties are not successful.
Approve Remedial Action (execute ROD)
Initiate Remedial Design (Funding)
Initiate Remedial Action (operational
Testing)
September 1988
September 1988
December 1988
Complete Remedial ~esign
,September 198~
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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