United States
Environmental Protection
Agency
Off ice of
Emergency and
Remedial Response
EPA/ROD/R08-93/074
September 1993
S-EPA Superfund
Record of Decision:
Sand Creek Industrial
(Operable Unit 5)
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S0272-101
REPORT DOCUMENTAl1ON 11. REPORT NO.
PAGE EPA/ROD/R08-93/074
~
3. Recipient'. Ace.... No.
4.
Tille .nd Sublllle
SUPERFUND RECORD OF DECISION
Sand Creek Industrial (Operable
Fifth Remedial Action - Final
A~hor(.)
5
A8port 0818
09/08/93
Unit 5)
(Amendment), CO
6.
7.
8.
Pwtonnlng Organlutlon Repr. No.
i.
Performing Organization N8me .nd Add-
10
Project TuklWortc Unit No.
11. Contr8Ct(C) or Gnlnt(Q) No.
(C)
(0)
12. Sponeor\ng OrganIzation N8me .nd Add,...
U.S. Environmental Protection
401 M Street, S.W.
Washington, D.C. 20460
Agency
13. Type of R8pOrt . PerIod eov...
800/800
14.
15. Supplementary Not.
PB94-964412
16. Ab8tr8Ct (Umlt: 200 wont.)
The Sand Creek Industrial (Operable Unit S) site, a former pesticide manufacturing
~acility, is part of the SSO-acre Sand Creek Industrial site located within the Sand
Creek floodplain in Commerce City, Colorado. The site surface is composed principally
of alluvial materials and imported fill, which covers the area so that natural features
are difficult to discern. Surficial fill materials at the site consist of clay, silt,
sand, gravel, and debris including concrete, brick, wood, metal, plastic, glass, and
trash. Land use in the area is predominantly industrial and residential, with some
agricultural. The estimated 25 people who reside within a one-mile radius of the site
use production wells to the north and downgradient of the site, ground water, and
surface water from alluvial and bedrock wells to obtain their drinking water supply.
The Sand Creek Industrial site lies in the vicinity of three other Superfund sites:
Woodbury Chemical, Chemical Sales, and Rocky Mountain Arsenal. Four suspected
contaminant source areas were identified at the Sand Creek Industrial site: the
Oriental Refinery, the Colorado Organic Chemical Company (COC) facility, the 48th and
Holly Landfill, and the L.C. Corporation property; the COC facility is the focus of
this action. Beginning in the 1960s, the COC manufactured pesticides onsite. Disposal
and onsite storage areas include a landfill and acid pits. Onsite fires in 1968 and
(See Attached Page)
17. Document Analpla a. D88c:rlptora
Record of Decision - Sand Creek Industrial (Operable Unit 5) (Amendment), CO
Fifth Remedial Action - Final
Contaminated Medium: soil
Key Contaminants: organics (pesticides), metals (arsenic, chromium)
b.
1d8nt11l8~nd8d Term.
c.
COSATI.Fl8lcUGroup
18. Availability Statement
19. Security CIau (Thla Report)
None
211. Security Ctaa. (This Page)
None
21. No. of Pagn
26
22. PrIce
(S88 AHSI-Z38.18)
s..IMttUCtlona - Rav-
OPTIONAL FORM 272 (4-77)
~ NTIS-35)
rtment of ComIll8rC8
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EPA/ROD/R08-93/074
Sand Creek Industrial (Operable Unit 5)
Fifth Remedial Action - Final
(Amendment), CO
Abstract (Continued)
1977, as well as improper pesticide storage practices, resulted in pesticide-contaminated
soil, ground water, and surface water. In 1978, COC removed some contaminated soil, and
in 1984, COC removed drummed wastes, excess product, additional contaminated soil, and
implemented site access restrictions, including fencing. The Sand Creek Industrial site
was divided into,six OUs to facilitate remediation. A 1989 ROD addressed OU1, which
included remediating the most highly contaminated soil and some of the subsurface soil
within the COC area. A 1990 ROD addressed source control of the remaining surface soil in
the COC area through excavation of 14,000 yd3 of contaminated soil, soil washing,
incineration, backfilling, and grading and revegetation of the site~ as OU5; however, the
remedial action was not implemented because new technical data and cost information
obtained during the Remedial Design phase determined that soil washing would not reduce
the contamination to the cleanup levels, and the cost of this treatment would be three to
four times greater than originally estimated in the ROD. In 1991, the U.S. Army Corps of
Engineers (USACE) conducted a bench-scale treatability study to evaluate the effectiveness
of soil washing for the removal of pesticides. Results of these tests were inconclusive
since the soil samples used in the study did not contain contaminant concentrations above
action levels. In 1992, EPA and State studies indicated that soil washing could reduce
pesticide concentrations in the soil, but could not achieve the action levels established
in the 1990 ROD. This ROD amendment provides a final source remedy for the contaminated
soil present onsite at the COC area, as OU5. Other 1993 RODs address contaminated soil,
ground water, surface water, and air contamination, as OUs 2, 3, and 6. The primary
contaminants of concern affecting the soil are organics, including pesticides; and metals,
including arsenic and chromium.
The amended remedial action for this site includes excavating and treating 8,000 yd3 of
contaminated soil onsite to a depth of 5 feet, using low-temperature thermal treatment
(LTTT) to volatilize the pesticides and arsenic; collecting volatilized contaminants on
GAC; transporting spent activated carbon offsite for regeneration; backfilling and
revegetating the excavated area with the treated soil: and conducting treatability
studies. The estimated present worth cost for this remedial action is $5,422,782.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific soil cleanup goals are based upon health risk-based action levels, and
include aldrin 1.45 mg/kg: arsenic 12.7 mg/kg; alpha-BHC 3.91 mg/kg: beta-BHC 13.7 mg/kg;
gamma-BHC 18.9 mg/kg; chlordane 18.9 mg/kg: chromium 56.2 mg/kg; DDD 104 mg/kg; DDE 73.2
mg/kg; DDT 72.4 mg/kg: dieldrin 1.54 mg/kg; heptachlor 5.47 mg/kg; heptachlor E 2.71
mg/kg: and toxaphene 22.4 mg/kg. This list includes new action levels for arsenic,
dieldrin, heptachlor, and other pesticides. These levels are more comprehensive than
those established in the 1990 ROD; however, the levels for heptachlor and dieldrin are
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DECLARATIONSTATEME~~
AMENDMENT TO ~~EPTEMBER 28, 1990 t rF" ~~.
RECORD OF DECISION ,-. ..
SAND CREEK I~~USTRIAL SUPERFUND SITE, COMMERCE CITY, COLORADO
OPERABLE UNIT 5
SITE NAMf: AND LOCATION
Operable Unit S (OUS) - Colorado Organic Chemical Company Shallow Soils, Sand Creek
Industrial Superfund Site, Commerce City, Colorado.
ST A TEME1\"T OF BASIS AND PURPOSE
This decision document is an amendment to the Record of Decision (ROD) signed
September 28, 1990 and presents the new selected remedial action for cleanup of
contaminated shallow soils at OUS at the Sand Creek Industrial Superfund Site. OUS is
located " immediately north of S2nd and Dahli~ Street in Commerce City, Colorado. This
ROD Amendment is undertaken pursuant to the requirements delineated in Section 300.435
(c)(2)(ii) of the National Contingency Plan (NCP) and SeCtion 117 of the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended
by the Superfund Amendments and Reauthorization Act of 1986 (SARA).
This decision document explains the basis for selecting a different rem.edy for the cleanup
of contaminated shallow soils at OUS than th~t selected in the September 1990 ROD. The
information that forms the basis for this remedial action decision is contained in the
Administrative Record for OUS and is summarized in the attached Decision Summary. The
State of Colorado concurs with tbe new selected remedy for cleanup of contaminated soils
at OUS.
ACtUal or threatened releaseS" of hazardous substances from this site, if not addressed by
implementing the response action. selected in this ROD. Amendmen~ may present an
;mm;nent and substanti~ endangerment to public health, welfare, or the environment.
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"
NT AMINATED S ILS
The new selected remedy for OUS addresses shallow soils contaminated with pesticides and
metals in the Colorado Organic Chemical Company area at the Sand Creek Industrial Site.
The major components of the September 1990 ROD were excavation and soil washing
treatment of contaminated shallow soils, incineration of soil wash residuals, backfilling of
the treated soils, and grading and revegetation of the site. Based on new technical data and
cost information obtained subsequent to the September 1990 ROD, EP A has reconsidered
its decision to employ soil washing and incineration of the generated residuals as a source
control measure for OUS. New data evaluated by' EP A included technical data on
contaminant removal efficiency via soil washing and cost information for incineration
received during the remedial design for OUS. Other components of the September 1990
ROD are not affected by this new information.
The new'remedial action selected by EP A for OUS involves treatment of the contaminated
soils and includes the following principal components:
.
Excavation of contaminated soils and treatment in an on-site low-temperature
thermal treatment (L TIT) facility,
.
Off-site treatment (regeneration) of spent activated carbon, and
.
Backfilling of excavated areas with treated soil and revegetation of the site to
minimize erosion and dust emissions.
RY DETERMINATI N
The new selected remedy in this ROD Amendment is protective of human health and the
. environment, complies with federal and state requirements that are legally applicable or
relevant and appropriate to the remedial action, and is cost effective. This remedy utilizes
permanent solutions and alternative treatment or resource recovery technologies, to the
maximum extent practicable, and satisfies the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a principal element.'
-.
D'1qff3
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TABLE OF CONTENTS
SECTION
PAGE
I.
INTRODUCTION
......................... ..... .........1
ill.
COMMUNITY PARTICIPATION SINCE THE
SEP1EMBER 1990 ROD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1
, SITE ACTIVrnES SINCE TIIE SEPTEMBER 1990 ROD. . . . . . .'. 2
II.
IV.
SUMMARY OF SITE RISKS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. S
"
v.
DESCRIPTION OF THE ALTERNATIVES. . . . . . . . . . . . . . . . . .. 10
VI.
SUMMARY OF COMPARATIVE ANALYSIS OF
ALTERNATIVES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
Vil.
Vill.
NEW SELECTED REMEDY. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1S
STATUTORY DETERMINATIONS. . . . . . . . . . . . . .. . . . . . . . .. 16
LIST OF TABLES
TABLE 1. UST OF TABLES PESTICIDE PRODUCTION/STORAGE
AREA AT OUS (SURFACE TO ONE FOOT DEPTH) ........... 7
TABLE 2. PESTICIDE PRODUCTION/STORAGE AREA AT OUS
(ONE TO THREE FOOT DEPTH) .......................... 7
TABLE 3.. PESTICIDE PRODUCTION/STORAGE AREA AT OUS
(THREE TO FIVE FOOT DEPTH) . .. .. . .. . . . . . . . . . . . . . . .. .. 8
TABLE 4.
RAIL ROAD AREA AT OUS '
(SURFACE TO ONE FOOT DEPTH) ........................ 8
TABLE S.' HEALTa RISK-BASED ACTION LEVELS FOR OUS :,""""" 9
TABLE 6. ESTIMATED COSTS FOR SELECTED REMEDY............. 17
APPENDIX A
RECORD OF DECISION OPERABLE UNIT S, SAND CREEK
INDUSTRICAL SUPERFUND SITE, COMMERCE CITY,
COLORADO, ,SEPTEMBER 28, 1990
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DECISION SUMMARY -
FOR
AMENDMENT TO THE SEPTEMBER 28, 1990
RECORD OF DECISION
SAND CREEK INDUSTRIAL SUPERFUND SITE, COMMERCE CI'IY, COLORADO
OPERABLE UNIT 5
I.
INTRODUCTION
This document summarizes the infonnation that forms the basis for EP A's selection of a
new remedial action for treatment of contaminated shallow soils at Operable Unit S (OUS)
at the Sand Creek Industrial Superfund Site in Commerce City, Colorado. This ROD
Amendment will become part of the Administrative Record pursuant to Section
300.825(a)(2) of the NCP.
In September 1990, EPA.issued a ROD for OUS which selected soil washing with off-site
incineration and disposal of contaminated residuals as the preferred alternative for
remediation of contaminated shallow soils at OUS. However, during the Remedial Design
(RD) phase the objectives of the ROD were found to be unachievable because: (1) soil
washing would not reduce the contamination to the cleanup levels specified in the 1990
OUS ROD, and (2) the cost of soil washing is 3 to 4 times greater than originally estimated
in the ROD.
In response to this bUormation, EP A and CDH performed additional sampling of OUS soils,
updated the evaluation of -the health risks associated with exposure to the contaminated
soils, and studied additional remedial technologies as an alternative for cleaning up the OUS
soils. The original ROD, which was signed on September 28, 1990, is attached to this
document as Appendix A, and should be referred to for funher infonnation regarding the
site description, history of operations, enforcement activities, and community relations prior
to September 1990.- This OUS ROD Amendment documents modifications to the original
1990 ROD. -
II.
COMMUNITY PARTICIPATION SINCE THE SEPTEMBER 1990 ROD
- -
Community interest at OUS generally has been low, with involvement primarily from a few
residents and businesses located in the vicinity of the site. The public participation
requirements as specified in CERCLA Section 113(k)(2)(B)(i-v) have been met as described
below. .
.~
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.
In June 1993, EP A sent a fact sheet to 988 persons on the mailing list that included
residents, business owners, and public officials~ This fact sheet described the Proposed Plan
to amend the September 1990 ROD for treatment of contaminated shallow soils at OUS.'
The fact sheet also described opportunities for public involvement, including the public
meeting on June 29, 1993 and the public comment period for the Proposed Plan from June
17 through July 19, 1993. In addition, on June 15, 1993 EPA placed public notices in the
Denver Post and Commerce City Express announcing the public meeting and comment period,
and informed the public of the availability of peninent information at the information
repositories. .
The public meeting, to discuss the new Proposed Plan was held on June 29, 1993 at the
Commerce City Recreation Center at 5:30 pm. A transcript of the meeting was prepared
for placement in the Administrative Record files at the information repositories. Two
individuals attended the meeting and no significant comments were presented. EP A
received no written comments during the comment period for the OUS Proposed Plan.
III.
SITE ACTMTIES SINCE THE SEPTEMBER 1990 ROD
During the Remedial Design (RD) phase, several activities were conducted at OUS, as
discussed below:
A
Soil Sampling.
Soil sampling (Phase 1) was conducted by EPA and CDH in July 1992 to accurately
determine the variability of pesticide contamination on the OUS propeny and to establish
more precise soil volumes requiring remediation than could be estimated from the RI data.
To better define the location and magnitude of contami~ation, the sampling was performed
. on six Environmental Units (BUs). Each EU covered an area of 50 by 50 feet and was
funher subdivided into 25 subunits each measuring 10 by 10 feet. The EUs were located
in areas with elevated dieldrin. and heptachlor contamination, based on data from the
Remedial Investigation (RI). Within each EU, ~ of the 2S subunits were randomly selected
for sampling for a statistically representative evaluation: Soil samples from the surface to
one foot depth were collected from each sampling location, and an aliquot from each of the
six grab samples was combined to form a composited sample for each EU.
A Phase 2 sampling effon was planned to determine the accuracy of field immunoassay test
kits for pesticides in soil samples. Field and laboratory results were to. have been compared
to assess the accuracy of the test kits. However, Phase 2 sampling was canceled because no
adequate immunoassay test kits were available.
In October 1992, a more extensive sampling effort (Phase 3) was performed by EP A on 138
EU subunit locations. The EU subunits are areas identified in the ROD as contaminated
from depth increments ofG-l, 1-3, and/or 3-5 ft. Soil samples were collected from the three
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depth increments at each sampling location. In addition, at each. EU subunit where the
September 1990 ROD indicated contamination existed to a depth of 5 feet, a sample was
collected from the 5-7 ft. depth interval. The analytical results from this sampling were used
. as confirmation for the depth of the contamination. The primary objectives of this sampling
effort were: .
.
To further define the extent of soil contamination prior to excavation. This
information was also used to re-calculate the volume of soil requiring
remediation.
.
To determine the quantity of fine-grained materials. The fine fraction
segregated by the washing process is highly contaminated and must be
incinerated and disposed of off-site.
.
Provide analytical data for development of a pilot test evaluation.
In the Phase 3 sampling effort, a total of 259 pesticide samples, 97 samples of total metals,
and 176 volatile organic compound (VOC) samples were analyzed. In addition, a total of
nine soil samples were collecte9 for geotechnical testing. Geotechnical samples were tested
for moisture content, dry unit weight, specific gravity, grain size analysis, and Atterberg
limits.
Tbe results of the Phase 3 sampling indicated that concentrations of dieldrin were less than
those estimated in the 1990 ROD and were highest in the shallow sample depth increments.
Concentrations of heptachlor were greater than the original OU5 ROD estimates and
increased with depth. Arsenic concentrations were typically less than' values presented in
the RI. The extent of contamination based on the Phase 3 sample results generally
coincided with estimates presented in the 1990 OU5 ROD. However, there appeared to be
little relationship betWeen metals and pesticide occurrence.
B.
Treatability Studies
In October 1991, the U.S. Army Corp of Engineers conducted a bench-scale treatability
study to evaluate the effectiveness of the soil washing process for removal of organochlorine
pesticides. Results of these tests were not conclusive since the soil samples used in the study
did not contain contaminant concentrations elevated above action levels. Consequently, a
pilot study was needed to effectively evaluate the performance of the soil washing process
on contaminated soils. .
'-.
In the fall of 1992, the EPA Volume Reduction Unit (VRU), a type of mobile small-scale
soil washing unit, was brought to OU5 to perform on-site soil washing tests. This pilot-scale
test was designed to provide a more comprehensive evaluation of the remediation costs and
effectiveness of soil washing for the removal of contamination in the OU5 soils. Due to the
heterogeneity of soils at OU5, soils from tWo separate contaminated areas were sampled at
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"
three depth intervals. Samples from the three intervals were composited and chemically
analyzed for use in the pilot-scale treatability study. Using thes'e samples, with a wide range
of soil contamination, the pilot study was better able to model the varying concentrations
of contaminants to be encountered in a full-scale soil washing operation.
A total of 23 experimental runs were 'conducted during the pilot treatability study. The
following variables were evaluated to assess the effectiveness of the soil washing under
different operating conditions: '
.
Soils from three different depth increments (0-1, 1-3, and 0-5 ft.) were
collected to evaluate effects of soil type at depth.
.
Several types of surfactants were tested to evaluate their contaminant removal
efficiency at OU5. Sodium Dodecyl Sulfate (SDS), a combination of Adsee
799 and Witconol NP-100 (50/50 ratio), and TergitoI15-S-9 were selected due
to their documented ability to remove dieldrin, heptachlor and other
organochlorine pesticides from soils.
.
Four surfactant concentrations at 0, 0.4, 1.0, and 1.5% (percentage of
surfactant to water) were used to evaluate the effects of different surfactant
concentrations.
.
Two liquid to soil (L/S) ratios (6: 1 and 9: 1, by volume) to evaluate the effects
of the L/S ratio.
.
Two temperatures (ambient and 1300 F) were used to evaluate the effects of
temperature.
.
Two pH levels (7.0 and 10.0) were used to evaluate the effects of pH on
contaminant removal efficiency.
.
Both single and double washes were used to evaluate the effects of re-washing
contaminated soil. '
Results from the tests indicated that soil washing could reduce dieldrin and heptachlQr
concentrations in OU5 soils, but could not achieve action levels established in the
September 1990 ROD. In addition, it was determined that remediation costs with this
technology would be 3 to 4 times greater than originally estimated in_~e ROD.
'-.
. Due to the unsatisfactory performance of soil washing on OU5 soils and the much higher
than anticipated costs associated with this alternative, additional remediation processes were
evaluated in a technology assessment during the winter of 1993. The technology assessment
evaluated the capabilities, availability, and applicability of the following processes: low-
temperature thermal treatment (LTIT)~ ex-situ vitrification, off-site incineration, and on-site
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and off-site disposal. These processes have the greatest potential for remediation of OUS
soils and were evaluated either alone or in conjunction with soil washing. The alternatives
assembled were then compared based on the following factors: short-term protection of
human health and the environment; long-term protection of human health and the
environment; and reduction of mobility, toxicity, or volume of waste. Based on the limited
bench-scale data for L1TT performance at approximately 700°F, residual concentrations of
dieldrin and heptachlor well below the September 1990 ROD action levels appeared to be
achievable. The L 1TT process was also reported to be very effective in removing other
pesticides of concern and was extremely cost effective in comparison with soil washing.
IV.
SUMMARY OF SITE RISKS
A Risk Assessment (RA) prepared specifically for OUS in 1990 established that a potential
human health threat existed at OUS. Industrial workers in the area who were exposed to
contaminants through the inadvertent ingestion of soil were considered to be the population
at greatest risk. The OUS RA identified: pesticides (dieldrin, heptachlor, chlordane and
DDT); a herbicide (2,4-D); and metals (arsenic and chromium) as chemicals' of concern
(CoCs). The pesticides dieldrin and heptachlor were chosen as driver compounds for
remediation of OUS due to their carcinogenicity and concentrationS. Data used in the OUS
RA indicated that by focusing on treating dieldrin and heptachlor to action levels of 0.1SS
and 0.5S3 mg/kg~ respectively, an acceptable overall excess carcinogenic risk (for the
occupational soil-ingestion pathway) of 2.7 in 100,000 (2.7£-OS) would be achieved for OUS.
The NCP specifies that action levels must be within the target risk range of 1 in 10,000 to
1 in 1 million (1.0E-04 to 1.0E-06). The extent of contamination from other identified CoCs
was found from additional sampling to coincide with dieldrin and heptachlor contamination.
An analysis of the data collected in the faU of 1992 revealed that in addition to heptachlor
and dieldrin, other contaminants, including chlordane, DDT, aldrin, toxaphene, and metals
also contributed significantly to the carcinogenic risk at OUS. Consequently, a risk analysis
which incorporated the new data was performed for OUS -in May 1993. The same exposure
assumptions used in developing the 1990 OUS RA were incorporated in the 1993 risk
analysis. .
Based on historical information regarding past activities at the Site, tWo distinct regions were
established: (1) the railroad right-of-way in the northern area of OUS and (2) the pesticide
production and storage area (Le., COC facility) in the southern portion of the site. To
calculate health hazards associated with the new data, the soil ingestion scenario for workers
was evaluated in both areas. In addition, risks posed to a child' walking or playing
(trespassing) in the railroad track area were assessed. In accordance with recent .EPA
guidance (Supplemental Guidance to RAGS: Calculating the Concentration Term, May
1992), average concentrations and Reasonable Maximum Exposure (RME) concentrations
were calculated for all cheniicals detected in the tWo areas. Risks associated with the
pesticide production/storage area were calculated individually for the three soil intervals
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sampled (i.e., 0-1, 1-3, .and 3-S feet deep). However, only the 0-1 fpot soil interval was
analyzed during the Phase 3 sampling investigation in the railroad right-of-way area.
In the pestiCide production/storage area (Tables 1,2, and 3), the overall carcinogenic risk
for workers exposed to contaminated soil was found to be an unacceptable hazard.
Therefore, a comprehensive list of action levels was established for cleanup of the OUS soils
from health-based concentrations. (HBCs) corresponding to a 1 in 100,000 (1.0E-OS)
carcinogenic target risk. This list is presented in Table S and includes action levels for
chlordane, DDT, aldrin, and toxaphene as well as new action levels for arsenic, dieldrin,
heptachlor, and other pesticides. Chromium is not considered by EPA to be carcinogenic
via the ingestion route, but chromium does' have a non-carcinogenic oral reference dose
(RID) that corresponds with a non-carcinogenic HBC (hazard index less than 1) of
approximately S,319 mg/kg. This value is well above the maximum chromium concentration
(118 mg/kg) detected at OUS. The newly developed action levels are more comprehensive
than those established in the 1990 OUS ROD; however, the action levels for heptachlor and
dieldrin are approximately S mg/kg and 1 mg/kg, respectively, less stringent than the
original action levels. The higher action levels for heptachlor and dieldrin resulted from
using a target risk of 1 in 100,000 (1.0E-OS) for this ROD Amendment instead of the target
risk of 1 in 1 million (1.0E-06) used in the 1990 OUS ROD. The change in target risk used
to establish action levels was made in response to recent EP A guidance.
In the railroad right-of-way area (Table 4), the total RME carcinogenic risk for workers due
to exposure to pesticides, metals, and other org~c compounds is approximately S in
100,000 (S.OE-OS). The total RME carcinogenic risk for children walking or playing in the
railroad right-of-way area is approximately S in 1 million (S.OE-06). The total non-
carcinogenic hazards to workers and children in the region are both approximately 0.3 and,
therefore, are below EP A's hazard index of concern (greater than or equal to 1.0). While
a ttespassing child represents the most likely current receptor and is exposed to no
unacceptable risk, potential future risk to an industrial worker must also be considered in
remediating the railroad right-of-way region at OUS. Consequently, it will be necessary to
remediate 8 cells with CoC concentrations that exceed action levels out of the 73 SOxSo-foot
cells established in this region. One cell located in this area exceeds the chromium action
level via the inhalation pathway. The other 7 cells requiring remediation exceed either
toxaphene or pesticide action levels. Soil contamination above action levels in the 8 cells
is limited to a depth of 1 foot below ground. This cleanup action will ensure that no
unacceptable carcinogenic risks are posed to workers and that the site will be unrestricted.
for industrial use in the future. Remediation of the railroad right-of-way area is complicated
by the presence of railroad .tracks, buried pipelines, and other utilities that will make
cleanup of the area relatively expensive. Based on the depth of contaniination, economic
considerations, and the most probable future exposure scenarios for workers, only the top
foot of soil in those areas that exceed action levels in the railroad right-of-way will warrant
clean up.
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TABLE 3.
PESTICIDE PRODUCTION/STORAGE AREA AT OUS
(1HREE TO FIVE FOOT DEPTH)
me AVE CONC RME COSC MAX CONC
~ MGIKG MGlKG MGIKG
Hepcacb10r 15/36 11.28 28.3S 364.15
DieldriD '1JJ/36 2.19 3.72 24.51
O1IorcIaDe '1JJ/36 1.74 17.52 213.07
DDT 27/36 2.99 4.40 21.70
Alpha-BHC 4/36 1.06 2.01 17.93
Beta-BHC 7/36 . 0.39 0.52 32.26
Oamma-BHC 7/36 2.26 4.80 50.91
Delta-BHC 6/36 0.98 1.95 '1JJ.79
Heptachlor E 5/36 0.33 0.40 1.66
Endosulfan 9/36 0.52 0.85 6E7
DDE 25/36 1.40 2.00 11.45
DDD 22/36 1.25 2.56 28.84
Endrin 9/36 0.34 0.40 32.26
Endrin a 13/36 0.27 0.29 0.46
Endrin K 10/36 0.94 2.03 23.46
Aldrin 8/36 0.47 0.72 4.28
Methoxychlor 3/36 3.32 8.44 1!JC.?.24
Toxaphene 6/38 2.55 4.99 26.16
. ..
AJsenic: 22/22 3.10 4.60 '1JJ.4O
Chromium 22/22 12.10 15.40 48.90
TABLE 4.
RAIL ROAD AREA AT OUS
(SURFACE TO ONE FOOT DEPTH)
me AVE CONC RME CONC MAX CONC
CBEM1CAL ~ MGlKG MGIKG MG/KG
Hep~hlor 16/72 0.38 0.65 9.75
Dieldrin 36/72 1.42 2.55 38.36
Chlordane TI/72 1.74 4.59 l2.3S
DDT 41fT2 3.59 6.08 '1JJ.14
Alpha-BHC 4fT2 0.26 0.17 0.48
Beta-BHC 6/72 0.27 0.30 1.10
Gamma-BHC 8fT2 0.28 0.31 1.43
Delta-BHC 5fT2 0.27 0.29 0.82
Heptachlor E SfT2 0.37 0.51 2.40
Endosulfan 23/72 0.45 0.61 2.11
DDE 44/72 1.53 2.23 9.81
DDD 29fT2 1.12 2.27 2.61
EndriD 4/72 0.46 0.69 4.58
EndriD a 1/72 0.27 0.27 0.27
EndriD K 6fT2 0.57 0.61 1.37
Aldrin " 3/72 0.28 0.29 0.87
Methoxychlor SfT2 0.28 0.30 0.86
Toxaphene '2B/72 13.69 24..38 144.18
. . . "
Arsenic: 48/48 8.60 14.30 83.70
OIromium 48/48 14..80 . 22..80 118.00
em - Frequency of detection which is the number of samples analyzed for a particular chemical over the total
number of samples taken for this specific location.
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TABLE 1.
PESTICIDE PRODUcnON/STORAGE AREA AT OUS
(SURFACE TO ONE FOOT DEPTH)
me AVE CONC RME CONC MAX CONC
CHEMICAL 'It MG/KG MGIKG MGIKG
I..., .. ...:...,:.>,.:.:..: .:::::) :.. ......:.,.,... ~:.
..
:.,".;.;,";:;":".. .., ...'..'.:;'.' ...,. .:,. .. :.::.:.:,..,.. ...
Heptachlor 29/S3 3.81 6.78 84.81
Dieldrin 45/S3 4.29 7.87 109.81
O1lcndane 44/S3 4.sS 10.68 SS.OI
DDT 4S/S3 10.36 15.56 65.70
AIpba-BHC 6/53 0.25 0.26 0.27
Beta-BHC 14/S3 0.26 0.28 0.37
Gamma-BHC 14/S3 0.26 0.28 0.43
De1ta-BHC 13/53 0.26 0.28 0.50
HeptaCblorE 22/S3 0.50 0.72 4.21
Endosulfan 32/S3 0.83 1.24 2.66
DDE 45/S3 2.84 3.85 6.90
DDD 42/53 1.s5 2.21 5.76
Endrin 21/53 0.87 1.44 2.2S
Endrin a 6/53 0.26 0.28 0.84
Endrin K 22/53 0.66 0.96 4.78
Aldrin 11/53 0.40 0.61 6.64
Methoxychlor 9/S3 0.28 0.31 0.71
Toxaphene 26/53 17.82 36.96 418.79
]i:.. . ........ .... .. '
. .'::':\(:'..:':".. ..: ",,:,.,..:,., "..,..:-'::::(
Arsenic 2A/24 16.30 22.70 131.00
O1romium 2A/'2A 12.80 17.10 37.50
TABLE 2.
PESTICIDE PRODUcnON/STORAGE AREA AT OUS
(ONE TO THREE FOOT DEPTH)
me AVE CONC RME CONC MAX CONC
CHEMICAL 'It MG/KG MGIKG MGlKG
... ' ....
HeptaChlor 32/S9 8.75 16.85 2A9.42
Dieldrin 4OIS9 2.39 3.92 46.73
O1lordane 35/59 4.63 11.25 139.02
DDT 44/S9 9.35 15.72 183.78
Alpha-BHC 11/S9 1.66 3.37 58.03
Bcta-BHC 15/S9 0.s5 0.90 11.93
Gamma-BHC 13/59 3.28 6.71 116.70
Dclta-BHC 13/59 1.56 3.15 53.03
Hepw:blor E 9/59 0.76 1.21 13.41
EDdosulfan 16/59 0.65 1.01 7.50
DDE 42/S9 1.34 1.71 6.84
DDD 32/59 0.92 1.39 "-. 5.46
Endrin 19/59 1.25 2.39 40.13
EDdrin a 4/59 0.28 0.30 0.31
EndrinK .' 16/59 0.86 1.60 25.86
Aldrin 121S9 1.87 3.97 73.72
Metboxychlor 10/59 1.63 3.24 53.91
Toxaphene 26159 11.00 98.09 134.12
Arsenic 22/22 5.50 9.90 58.10
Quomium 22/22 10.70 . 11.90 20.90
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TABLE 5. HEALTH RISK-BASED AcrION LEVELS FOR OU5
CHEMICAL OF CONCERN
PESTICIDES
CONCENTRATION (mgjkg)
Heptachlor
Dieldrin
Chlordane
DDT
a-BHC
~-BHC
g-BHC
Heptachlor E .
DDE
DDD
Aldrin
Toxaphene
METALS
5.47
1.54
18.9
72.4
3.91
13.70
18.9
2.71
73.2
104.0
1.45
22.4
Arsenic
Chromium.
12.7
56.2
Action levels were developed based on 1.0E-05 target risk (excess lifetime carcinogenic risk)
for all of the above chemicals of concern.
-.
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v.
DESCRIPTION OF THE ALTERNATIVES
The principal goal in remediating OUS is that same as stated in the September 1990 ROD;
to return the site to industrial land use. Commerce Cityts Comprehensive Plan (1985-2010)
indicates that present and future land use of this area will be primarily industrial' with a
recreationaljopenspace designation for the Sand Creek floodplain. The specific remedial
action objectives at OUs are: (1) source control of contaminated soils, and (2) mitigating
risks or pathways for ingestion and direct contact with contaminated soils. Based on the risk
analysis performed on data collected since the September 1990 ROD, the estimated volume
of soils requiring remediation'at OUs has been decreased from 14,000 ydJ to approximately
8,000 ydJ. This volume may be adjusted based on confirmation sampling of both treated
soils and soils located at the perimeter of currently known contamination.
In addition to remedial" alternatives, the NCP requires that a no-action alternative be
considered at every site. This alternative serves primarily as a point of comparison for other
alternatives. As in the 1990 OUS ROD, the no-action alternative is unacceptable because
it is not protective of human health or' the environment and because a remedy can be
implemented at the site. EP Ats re-evaluation of the remedial alternatives identified tWo
alternatives that are compatible with the remedial action objectives and current site
conditions. The tWo alternatives are discussed and evaluated below:
1. Alternative t: On-Site SoH Wasping Treatment of Contaminated~
Incineration and-Pis,posaLm Soil Was~s (Originally Selected in the
September 1990 ROD)
This alternative for treatment is unchanged from the September 1990 ROD except that the
previous range of costs have increased due to market conditions. Soil contamination above
action levels would be excavated and treated on-site using a soil washing process. Once the
soil has been cleaned to required health risk-based levels; excavated areas would be
backfilled with treated soil and revegetated in order to minimize erosion and wind-blown
dust. However, based on treatability study data, it is uncertain whether soil washing can
achieve all contaminant action levels established for ODS. The contaminated liquids and
solids generated during 'soil washing would be removed from the site, incineratedt and
. disposed off-site in a RCRA Subtitle C landfill in accordance with Land Disposal
Restrictions (LDRs). ,
2. .Alternative 2: On-Site ~emperature 1]1ermalJreatment ~ Contaminated
~-Site Treatment of Spent Activated Carbon
'-
Soil contamination above action levels would be excavated and treated on-site using a L TIT
process. LTIT is commercially available and has been shown to be effective in removing
volatile organic compounds, including PCBs and pesticidest and metals, including ,arsenic
from soil. Contaminated soils would be fed to a LTIT system that heats the soils to
betWeen 300-8000 F and volatilizes the pesticides and arsenic. Contaminants released from
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the soil would be transported in an enclosed gas stream that is sprayed with water to
minimize dust generation, and the contaminants would be collected on a sulfur-impregnated
activated carbon bed. Once the soil has been cleaned to required health risk-based levels,
excavated areas would be backfilled with treated soil and revegetated in order to minimize
erosion and wind-blown dust. In the event that the treated soils still contain elevated levels
of metals, the soils would be re-treated in the L TIT unit. The spent activated carbon would
. be transported off-site and regenerated.
VI.
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
In this section, alternatives developed for OUS of the Sand Creek Industrial.Superfund Site
are evaluated and compared to each other using the nine evaluation criteria required by the
NCP to identify the alternative that provides the best balance among the criteria. The
. relative performance of the alternatives is summarized by highlighting the key differences
among the alternatives according to the following criteria:
1. Overall Protection of Human Health and the Environment .
2. Compliance with Applicable, or Relevant and Appropriate Requirements (ARARs)
3. Long-Term Effectiveness and Performance
4. Reduction of Toxicity, Mobility, or Volume Through Treatment'
5. Short-Term Effectiveness
6. Implementability
7. Cost .
8. State Acceptance
9. Community Acceptance
The first tWo criteria are categorized as threshold criteria, in that alternatives must pass
these criteria in order to remain in the evaluation. Criteria 3 through 7 are designated as
balancing criteria. These criteria are used to measure the positive and negative aspects of
performance, implementability, and cost for each alternative. The last tWo criteria are
classified as modifying ~teria.
A
Criterion 1: OveralLProtection of Human Health and the Environment
This criterion' assesses the protection afforded by each alternative, considering the
. magnitude of the residual risk remaining at the site after the response objectives have been
met. Protectiveness is determined by evaluating how site risks from eac)1 exposure route are
eHminated, reduced, or controlled by the specific alternative. The evaluation also takes into
account short..term or cross-media impacts that result from implementation of the alternative
remedial activity.
Overall protection of human health and the environment would be provided by Alternatives
1 and 2 since both ensure that the soil is cleaned up for unrestricted industrial use. If some
-------
soil requires additional treatment under Alternative 2 due to elevated concentrations of
metals, the soil would be re-treated. Both alternatives would reduce the potential health
'risks posed by direct contact with contaminants and would allow industrial use of the OU5
area. No institutional controls would be necessary once remediation is completed under
either alternative.
B.
Criterion 2: Compliance with ARARs
Section 121(d) of the Superfund Amendments and Reauthorization Act (SARA) mandates
that for all remedial actions conducted under CERCLA, cleanup activities must be
conducted in a manner that complies with ARARs, or if ARARs cannot be attained, a
justifiable ARARs waiver must be obtained. .
Both alternatives 1 and 2 would comply with ARARs (presented in Appendix A of the 1990
ROD). The ARARs associated with Alternatives 1 and 2 pertain to excavation, stockpiling,
demolition, soil washing, LTIT, and backfilling activities for on-site operations, and
, hazardous waste transpo'rt, incineration,emissions, and LDRs for off-site activities. During
on-site operations, dust generation, excavation and treatmen~ noise, and vapor emissions
would be of concern. Workers would be required to follow OSHA health and safety
regulations during all phases of the remedial action. Federal Clean Air Act National, Air
Quality Standards and State of Colorado Air Quality Regulations would require the control
of vapor and particulate emissions.
In the 1990 ROD, the application of LDRs (40 CFR 268, Subpart D) was evaluated for soil
washing (Alternative 1). LDRs generally require excavated soils to be treated to the "best
demonstrated available technology" (BDA T) prior to being placed on the land or disposed
of outside the area of contamination.. However, it was determined that BDAT would be
inappropriate and/or unachievable due to the cOInplexity of the soil and debris mixture and
that BDAT treatment may yield little benefit over other treatment methods. Consequently,
a treatability variance was established to allow use of a treatment method other than BDA T
for soils to be placed on-site~ The highly contaminated (>.1000mg/L) waste water and
residual materials generated during soil washing would be taken off-site for incineration and
disposal, as required by BDA T for California List fluids. For this ROD Amendment, health
risk-based action levels have been established to determine both the soils requiring
remediation and when soils are clean enough to be placed back on-site following treatment.
A treatability variance is no longer necessary.
C.
.Qjterion 3: Long-Term Effectiveness and Permanence
~-
The focus of this evaluation is to determine the effectiveness of each alternative with respect
to the risk posed by treatment of residuals and/or untreated wastes after the cleanup criteria
have been achieved.
-------
Both Alternatives 1 and 2 provide long-term effectiveness and permane~ce by removal and
treatment of contaminated soils. Contaminants present in the residuals and wash-water in
Alternative 1 would be destroyed by incineration. Similarly, the spent activated carbon
resulting in Alternative 2 would be regenerated, thus destroying the contaminants.
D.
Criterion ~uction oIToxicity. Mobility. or Volume Through Treatment
This criterion evaluates the ability of the alternatives to significantly achieve reduction of
the toxicity, mobility, or volume of the contaminants or wastes at the site, through treatment.
The criterion is a principal statutory requirement of CERClA. This analysis evaluates the
quantity of contaminants treated and destroyed; the degree of expected reduction in toxicity,
mobility, or volume; the degree to which the treatment will be irreversible; the type and
quantity of residuals produced; and the manner in which the principal threat will be
addressed through treatment. .
Both alternatives. 1 and 2 employ removal and. subsequent destruction of contamination as
a principal element, thereby reducing the toxicity, mobility, or volume of contamination.
The treatment process is irreversible. On-site treatability studies and data from other
Superfund sites indicates that Alternative 2 is superior to Alternative 1 with respect to the
efficiency of contaminant removal from OUS soils.
E.
Criterion 5: Short-Term Effectiveness
The short-term effectiveness of each alternative was assessed based on the risk associated
with the implementation of the remedial action to the community, workers, and environment
and the time required to achieve the response objectives. Measures to mitigate releases and
provide protection are central to this determination.
The evaluation of the alternatives indicate that both. create some short-term risk in
excavating and treating the soils, and transporting the contaminated materials off-site. A
greater volume of contaminated material would be transported off-site in Alternative 1,
compared with Alternative 2. Both alternatives involve risks associated with air emissions
when the contaminated residual materials are incinerated. However, both alternatives
would be required to meet local and state air emission standards.
F.
Criterion 6: Implementability
This criterion analyzes technical and administrative feasibility, and the availability of services
and materials. Technical feasibility assesses the difficulty of construction or operation of a
particular alternative and unknowns associated with process technologies. The reliability
of the technologies based on the likelihood of technical problems that would lead to project
delays is critical in this determination. Necessary equipment, specialists, and additional
. resources are evaluated in determining the ease by which these needs could be fulfilled.
The ability to monitor the effectiveness of the alternative is also considered.
-------
Both Alternatives 1 and 2 are highly implementable, although Alternative 2 is easier since
it does not require off-site incineration and disposal of contaminated materials. Off-site
incineration involves transportation of contaminated materials and has the potential for air
emissions due to fugitive dust. Additionally, off-site incineration has the potential for long-
. term off-site liabilities. Alternative 2 would require transport of relatively small volumes
of spent activated carbon, has a much lower potential for air emissions due to fugitive dust
releases, and a much lower potential for long-term off-site liabilities than Alternative 1. A
much greater volume of water would be required during the treatment process for
Alternative 1.
Both soil washing and L 1Tf are offered by various vendors, have been used successfully at
several sites, and have available people skilled in the operation of these treatment systems.
The typical commercial capacity available for soil washing and L1Tf are 10 and 50 tons per
hour, respectively. Therefore, the duration of soil remediation may be significantly less
under Alt~rnative 2 due to the larger capacity of the L 1Tf equipment. It is estimated that
it would take 9 to 12 months to implement Alternative 1 and approximately 6 to 9 months
for implementation of Alternative 2. Both' alternatives are administratively feasible.
G.
Criterion 7: Cost
Alternatives are evaluated for cost in terms of both capital costs and long-term operation
and maintenance (O&M) costs necessary to ensure continued effectiveness of the
alternatives. Capital costs include the sum of the direct capital costs (materials, equipment,
labor, land purchases) and indirect capital costs (engineering, licenses, or permits). Long-
. term O&M costs include laboT, materials, energy, equipment replacement, disposal, and
sampling necessary to implement the alternative.
In comparison with Alternative 1, costs associated with Alternative 2 are much lower. The
estimated capital (and total present worth) costs for Alternatives 1 and 2 are $13.9 million
and $5.4 million, respectively. Under Alternative 1, the washing solution and treatment and
disposal of contaminated wash-water and residuals at an off-site incineration facility are the
primary components of the costs, in addition to the cost of equipment operators and electric
consumption. For remediation of OU5 by soil washing, approximately 21-25% of fine-
grained materials are estimated to require off-site transport for incineration, treatment (i.e.,
stabilization of waste c01itaminated with arsenic and chromium) and disposal. Although the
fines would be dewatered prior to off-site transport, current technology available for
dewatering results in the fine-grained fraction being 50% water. This significantly increases
incineration costs. Permitting requirements and LDRs necessary to traI!sport and dispose
of the hazardous wastes may also substantially impact the cost for Alternative 1. There are
no O&M costs associated with either alternative since the soil will be clean once. the
processes are completed. .. .
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H.
Criterion 8: State Acceptance
This criterion evaluates technical and administrative issues that may be raised by the State.
EPA has involved CDH throughout the RI/FS, RD, and remedy selection processes. The
State of Colorado concurs with EP A's selected alternative, as presented in Section Vll.
I.
Criterion 9: Community Acceptance
This criterion evaluates questions and comments on the Proposed Plan received from
members of the community. It appears that the community supports EP A's selected remedy,
as presented in Section yn. No comments on the Proposed Plan were received by EP A
during the public comment period. Therefore, preparation of a Responsiveness Summary
for this ROD Amendment was not necessary.
VII.
NEW SELECTED REMEDY
Based on the information available following the September 1990 ROD and EP A's
consideration of the treatment alternatives for the contaminated shallow soils, EP A, with
the concurrence of the State of Colorado, has selected Alternative 2 (On-Site Low-
Temperature Thermal Treatment (LTIT) of Contaminated Soils/Off-Site Treatment of
Spent Activated Carbon) as the preferred remedy for OUS. The selection of this remedy'
is based on the comparative analysis of alternatives presented above, and provides the best
balance of tradeoffs with respect to the nine evaluation criteria. It is estimated that
approximately 8,000 cubic yards of soil will require remediation at OUS. Cost estimates for
the selected alternative are provided in Table 6. .
The LTIT process heats the soil enough to volatilize pesticides and arsenic, but does not
result in combustion or incineration. The degree of contaminant removal can be controlled
by adjusting the ,feed rate and te~perature. Contaminants released from the soil will be
transported in an enclosed gas stream that is quenched with water to minimize dust
generation, and the pesticides Will be collected on a sulfur-impregnated activated carbon
bed. Arsenic vapors will react with the' sulfur to form a stable arsenic sulfide. Typical
emissions to the atmosphere from a LTIT unit consist of water vapor.
The principal components of the new selected remedy include:
.
All soils within the site boundaries (to a maximum estimated depth of S feet)
contaminated above action levels in Table S will be excavated' and treated with
LlTI'. The soils will be treated such that contaminant levels are at, or below, the
action levels. Confirmation sampling will be performed to ensure that treated soils
do not exceed action levels.
.
The treated soils will be backfilled on the site.
-------
.
The site will be revegetated in order to minimize erosion and dispersion of soil from
OUS.
.
The spent activated carbon from the L TIT unit will be transported off-site and
regenerated.
The advantages of the. selected remedy include: (1) reduces contaminant mobility and
toxicity; (2) results in long-term protection from contaminants; (3) does not restrict future
industrial land use; (4) reduces the time required for remediation; (S) is cost effective
compared with other alternatives; (6) is a proven method for cleaning up pesticide
contaminated soils to very low levels.
VIII. STATUTORY DETERMINATIONS
EP A's primary responsibility at CERCLA sites is to undertake remedial actions that achieve
adequate protection of human health and the environment. In addition, Section 121 of
CERClA also requires that the selected remedial action for a site must comply with
applicable or relevant and appropriate environmental requirements established under
federal and state environmental laws, unless a statUtory waiver is granted. The selected
remedy must also be cost effective and utilize permanent treatment technologies or resource
recovery technologies to the maximum extent practicable. In addition, the statUte contains
a preference for remedies that include treatment as a principal element. The following
discussion addresses how the riew selected. remedy for Sand Creek OUS meets these
statutory requirements. "
A
)?rotectUm...QLHuman Health and the Environment
The remedy selected for OUS addresses the exposure or potential exposure to contaminated
soil. The LTIT alternative is protective of human health by ensuring that the soil is cleaned
up for industrial land use. If some soils require additional treatment due to elevated
concentrations of metals, a contingency plan is in place to re-treat these soils. During
"LTIT, contaminants will be adsorbed onto activated carbon beds which will be transported
off-site. Regeneration of the spent carbon will permanently destroy the contaminants.
"-.
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TABLE 6. ESTIMATED COSTS FOR SELECTED REMEDY
DESCRIPTION
1. Excavation (assume 9,200 cubic yds-115% of est. volume)
2. Mobilization
3. Low Temperature Thermal Treatment (LTIT)
4. Spent Carbon Regeneration
5. Treatability Studies
6. Backfilling/Compaction
7. Stabilizations/Solidifications
8. Top Soil- for Seeding
9. . Seeding
10. Analytical (3% of Items 1-9)
11. Engineering (10% of Items 1-10)
12. Construction (10% of Items 1-.10)
13. Contingency (15% of Items 1-12)
TOTAL
17
$
$
$
$
$
$
$
$
$
$
$
$
$
$
COST
138,000
600,000
2,622,700
6,400
40,000
20,000
350,000
32,000
6,000
114,453
392,955
392,955
707,319
5,422,782
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B.
The selected remedy of L TIT of contaminated soils and off-site treatment of spent activated
carbon will comply with all chemical-, location-, and action-specific ARARs. The primary
ARARs pertinent to the selected remedy are summarized below:
Chemical-Specific ARARs:
.
Land Disposal Restriction (LDR) Treatment Standards (40 CFR 268 Subpart
D)
Location-Specific ARARs:
.
None
Action-Specific ARARs:
Federal.
.
A Public Health Evaluation (PHE) must be performed at least every 5 years
(CERCLA 121 [c])
.
Occupational Safety and Health Act (OSHA)
.
Hazardous Materials Transportation Regulations
.
The requirements of 29 USC Sections 651-658, and 29 CFR 1910.120, which
regulate worker health and safety.
State of Colorado
CRS Section 25-123-101, et. seq. must be followed to maintain compliance
wi~ the State of Colorado noise abatement requirements. .
.
.
6 CCR 1007.:3 Part 99 must be followed. This regulation requires notification
of hazardous waste activities when hazardous waste is generated.
.
The manifest requirements of '6 CCR 1007-3 Part 262.~ubpart B must be
followed for off-site transportation of hazardous waste. -.
.
Tbe pre-transpon regulations of 6 CCR 1007-3 Part 262.30, .31, and.33 must
be adhered to for off-site transportation of hazardous waste. .
-------
.
An EP A identification number must be obtained for transponing hazardous
waste per the requirements of 6 CCR 1007-3 Part 263.11(A).
.
.
CCR 1001-3 Section VI.B regulates air emissions and must be followed.
Appendix A of the September 1990 ROD presents ARARs and To Be Considered (TBC)
items penment to OUS.
C.
Cost Effectiveness
The selected remedy is cost effective in mitigating the risk of exposure to contaminated soil.
Cost effectiveness is determined by evaluating long-term effectiveness and permanence;
reduction of toxicity, mobility, or volume; and short-term effectiveness to determine overall
effectiveness. The selected remedy meets these criteria and produces the best overall
effectiveness in proportion to its cost. The estimated cost for the selected remedy is $S.4
million, which is 2 to 3 times less than the remedy selected in the 1990 OUS ROD.
D.
.ll1llization ot.Permanent S01utions and Alternative Treatment Technologies or
Resource Recovery Technologies to the Maximum Extent Practicable
The selected remedy represents the maximum extent to which permanent solutions and
treatment technologies can be utilized in a cost effective manner at OUS. Of the
alternatives that are protective of human health and the environment and comply with
ARARs, the selected remedy provides the best balance of trade-offs in terms of long-term
effectiveness and permanence; reduction in toxicity, mobility, or volume achieved through
treatment; short-term effectiveness; implementability; and cost, and also considering the
statutory preference for treatment as a principal element and considering State and
community acceptance. Long-term effectiveness and permanence, and cost were the most
decisive factors in choosing the selected remedy.
E. .
fuference for Treatment as a Principal Element
The selected remedy satisfies the statutory preference for treatment as a principal element
and is fully consistent with the NCP. By treating the pesticide and metal contaminated soils
at ODS with "a LTIT system, the selected remedy addresses the principal threat "of potential
ingestion and direct contact posed by the site through the use of treatment technologies.
The modified remedy satisfies the requirements of CERCLA Section 121.
"-.
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APPENDIX A
Record of Decision
Operable Unit 5, Sand Creek Industrial Superfund Site
Commerce City, Colorado
September 28, 1990
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