[Federal Register Volume 61, Number 168 (Wednesday, August 28, 1996)]
[Proposed Rules]
[Pages 44275-44278]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-21631]


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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 300

[FRL-5560-2]


National Oil and Hazardous Substances Pollution Contingency Plan; 
National Priorities List

AGENCY: Environmental Protection Agency.

ACTION: Notice of intent to delete the Sand Creek Industrial Site from 
the National Priorities List: Request for Comments.

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SUMMARY: The Environmental Protection Agency (EPA), Region VIII 
announces its intent to delete the Sand Creek Industrial Site (Site) 
from the National Priorities List (NPL) and requests public comment on 
this action. The NPL constitutes Appendix B to the National Oil and 
Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR part 300. 
EPA, in consultation with the Colorado Department of Health and 
Environment (State), has determined that all appropriate response 
actions have been implemented at the Site and that no further response 
action by responsible parties is appropriate. Moreover, EPA after 
consultation with the State, has determined that remedial activities 
conducted at the Site are protective of public health, welfare, and the 
environment.

DATES: Comments concerning the proposed deletion of the Sand Creek Site 
may be submitted to EPA on or before September 27, 1996.

ADDRESSES: Comments may be mailed to: Erna Acheson, 8EPR-SR, U.S. 
Environmental Protection Agency, Region VIII, 999 18th Street, Suite 
500, Denver, Colorado 80202-2466.
    Comprehensive information on this Site is available through the 
EPA, Region VIII public docket, which is located at EPA's Region VIII 
Administrative Records Center and is available for viewing from 8:00 
a.m. to 4:30 p.m., Monday through Friday, excluding holidays. Requests 
for documents should be directed to the EPA, Region VIII Records 
Center.
    The address for the Regional Records Center is: Administrative 
Records Center, U.S. Environmental Protection Agency, Region VIII, 999 
18th Street, 5th Floor, Denver, Colorado 80202-2466, (303) 312-6473.
    Background information from the Regional public docket is also 
available for viewing at the Sand Creek Industrial site information 
repositories located at the:

Colorado Department of Public Health and Environment, Hazardous 
Materials and Waste Management Division, 4300 Cherry Creek Drive South, 
Denver, Colorado 80222, (303) 692-3300, Hours: 8:00 a.m. to 5:00 p.m., 
Monday through Friday
Adams County Library, 7185 Monaco Street, Commerce City, CO 80022, 
(303) 287-0063

FOR FURTHER INFORMATION, CONTACT: Erna Acheson, 8EPR-SR, U.S. EPA, 
Region VIII, 999 18th Street, Suite 500, Denver, Colorado 80202-2466, 
(303) 312-6762.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction
II. NPL Deletion Criteria
III. Deletion Procedures
IV. Basis for Intended Site Deletion
V. Community Relations
VI. Summary

I. Introduction

    The Environmental Protection Agency (EPA), Region VIII announces 
its intent to delete the Sand Creek Industrial Site (Site) located in 
Commerce City, Colorado from the National Priorities List (NPL) and 
requests comments on this deletion. The NPL constitutes Appendix B of 
the National Oil and Hazardous Substances Pollution Contingency Plan 
(NCP), Title 40 of the Code of Federal Regulations (40 CFR), as 
amended. EPA identifies sites that appear to present a significant risk 
to public health, welfare, or the environment and maintains the NPL as 
a list of those sites. Sites on the NPL may be the subject of remedial 
actions financed by the Hazardous Substance Superfund Response Trust 
Fund (Fund). Pursuant to Sec. 300.425(e)(3) of the NCP, any site 
deleted from the NPL remains eligible for Fund-financed remedial 
actions in the unlikely event that future conditions at the site 
warrant such action.
    It is EPA's intent to delete the Sand Creek Industrial Site from 
the NPL. EPA will accept comments on this proposed deletion for thirty 
days following publication of this notice in the Federal Register.
    Section II of this notice explains the criteria for deleting sites 
from the NPL. Section III discusses procedures that EPA is using for 
this action. Section IV discusses how the Sand Creek Industrial site 
meets the deletion criteria.
    Deletion of sites from the NPL does not itself create, alter, or 
revoke any individual's rights or obligations with regard to an 
individual site. The NPL is designed primarily for informational 
purposes and to assist EPA management.

II. NPL Deletion Criteria

    The NCP establishes the criteria that EPA uses to delete sites from 
the NPL. In accordance with 40 CFR Sec. 300.425(e), sites may be 
deleted from the NPL where no further response is appropriate. In 
making this determination, EPA will consider whether any of the 
following criteria have been met:

    (i) EPA, in consultation with the State, has determined that 
responsible or other parties have implemented all appropriate 
response actions required; or
    (ii) All appropriate Fund-financed responses under CERCLA have 
been implemented and EPA, in consultation with the State, has 
determined that no further cleanup by responsible parties is 
appropriate; or
    (iii) Based on a remedial investigation, EPA, in consultation 
with the State, has determined that the release poses no significant 
threat to public health or the environment and, therefore, taking of 
remedial measures is not appropriate.

    For all Remedial Actions (RA) which result in hazardous substances, 
pollutants, or contaminants remaining at the site above levels that 
allow for unlimited use and unrestricted exposure, it is EPA's policy 
that a review of such action be conducted no less than every five years 
after initiation of the selected RA. As stated under ``Basis for 
Intended Deletion,'' the selected remedy for the Sand Creek Industrial 
Site required the removal of the contaminated soils, rubble, and 
investigation-derived waste from the Site. There were also ground water 
and landfill gas components to the remedy. Site contaminants had 
affected the ground water aquifer. As a result of implementing this 
remedy, hazardous substances, pollutants, and contaminants were removed 
from the Site and eliminated as potential sources of contamination. The 
site has been remediated to allow industrial use only. Institutional 
Controls, groundwater monitoring, landfill gas monitoring, and 
operation and maintenance of the LFGES at OUs 3 & 6 are required to 
ensure that the remedies remain protective. In accordance with 40 CFR 
Sec. 300.430(f)(4)(ii), five-year reviews are required for this Site. 
The first five-year review was completed on this site on September 20, 
1995.

III. Deletion Procedures

    EPA, Region VIII will accept and evaluate public comments before 
making a final decision to delete the Sand Creek Industrial Site. The 
following procedures were used for the intended deletion of this Site:


[[Page 44276]]


    1. EPA, Region VIII has recommended deletion of the Sand Creek 
Industrial Site and has prepared the relevant documents.
    2. The State of Colorado has concurred with EPA's recommendation 
for deletion.
    3. Concurrent with this National Notice of Intent to Delete, a 
local notice has been published in local newspapers and has been 
distributed to appropriate Federal, State and local officials, and 
other interested parties.
    4. The Region has made all relevant documents available in the 
Regional Office and local site information repositories.

    The comments received during the notice and comment period will be 
evaluated before making a final decision to delete. The Region will 
prepare a Responsiveness Summary, which will address the comments 
received during the public comment period.
    Subsequent to the public comment period, a deletion will occur 
after EPA publishes a Notice of Deletion in the Federal Register. The 
NPL will reflect any deletions in the next final update. Public notices 
and copies of the Responsiveness Summary will be made available to 
local residents by Region VIII.

IV. Basis for Intended Site Deletion

    The following summary provides EPA's rationale for recommending 
deletion of the Sand Creek Industrial Superfund Site.
    The Sand Creek Industrial site is located in Commerce City and 
Denver, Colorado. Most of the site and surrounding area is 
industrialized and contains trucking firms, petroleum and chemical 
supply and production companies, warehouses, small businesses and a few 
residences. Previous industrial activity and waste disposal practices 
at the Sand Creek site resulted in the contamination of ground water, 
and soil in the area. During the 1970's and early 1980's, a variety of 
environmental contamination was discovered and identified at the Site 
by the State of Colorado and EPA which included the following 
properties:

    1. The Oriental Refinery property was the site of a fire in 1955 
which resulted in the release of approximately 48,000 gallons of 
refined petroleum products. In 1980, the EPA discovered diesel fuel 
contamination in several groundwater monitoring wells.
    2. The Colorado Organic Chemical Company (COC) manufactured 
pesticides beginning in the 1960's and intermittently through 1984. 
There was a serious fire at this property in 1968.
    3. The L-C Corporation (LCC) property was used to store and 
neutralize spent acidic wastes from a herbicide chemical plant. In 
1974, livestock that strayed onto the property had severe chemical 
burns.
    4. At the 48th and Holly Landfill (Landfill) waste disposal 
operations were conducted between 1968 and 1975. Demolition and 
domestic refuse was accepted. In 1977, two explosions of combustible 
gas, which killed two men and injured five others, were traced to 
the migration of the methane gas from the Landfill.

    The Sand Creek site was added to the original National Priorities 
List (NPL) of 400 sites in December 1982. The primary concerns for 
potential harm to human health and the environment presented by these 
properties on the site were exposure to contaminated soils and 
sediments, landfill gas and debris, and potential ingestion of 
contaminated groundwater.
    The contaminants of concern for the Sand Creek site included 
volatile and semi-volatile organics, pesticides, herbicides and heavy 
metals.
    The objectives of the response actions at the Sand Creek Site were 
to protect human health and the environment and to restore the Site for 
industrial re-development. These objectives consisted of four primary 
goals as follows:
     To reduce the risk to industrial workers exposed to soil 
through ingestion or inhalation so that they would not suffer health 
problems;
     To ensure that a child walking or playing while 
trespassing onto the Site would not have health problems resulting from 
area soils;
     To ensure that gases generated from the Landfill would not 
migrate off-site and cause explosions or otherwise endanger health; and
     To reduce the contamination source area for groundwater 
absorption so that ``potential groundwater use'' would be possible.
    Where appropriate, selected remedies utilized permanent solutions 
and alternative treatment technologies to the maximum extent 
practicable and satisfied the statutory preference for treatment as a 
principal element.
    The Sand Creek site was divided into six Operable Units (OUs) or 
study areas to address the complexities associated with the site. These 
OUs and the response actions taken to address the specific problems 
associated with these areas are briefly described below:

Operable Unit # 1 (The Colorado Organic Chemicals Property)

    Other than an estimated 1,000 cubic yards of surface soils highly 
contaminated with Halogenated Organic Compounds (HOCs), OU 1 
remediation focused on treatment of subsurface soils contaminated with 
Volatile Organic Compounds (VOCs). The surface soils were treated 
through excavation and incineration and the subsurface soils were 
treated with Soil Vapor Extraction (SVE).
    During 1991 and 1992, EPA removed approximately 2000 cubic yards of 
debris, including four buildings, four rail cars, two concrete tanks, 
and 13 steel tanks. This debris was removed by a licensed hauler and 
disposed in permitted landfills. Between September 1993 and April 1994 
EPA utilized SVE to remove over 176,000 pounds of VOC contamination 
from the OU1 soils, of which approximately 3,250 pounds were specified 
contaminants of concern for OU 1.
    There were no aspects of the RA for OU 1 which failed to conform to 
the remedial objectives as specified in the ROD and ESD for OU 1.

Operable Unit # 2

    The acid pits on the LCC property were neutralized on three 
occasions in the late 1970s and early 1980s. Because of these cleanup 
activities, in addition to low levels of contaminants of concern at the 
site, it was determined that no significant risk to human health or the 
environment existed at OU 2. Therefore, a ``no further action'' 
alternative was adopted, and no RA took place at OU 2.

OU # 3/6 (The 48th and Holly Landfill)

    On August 15, 1990, EPA signed an Unilateral Administrative Order 
(UAO) for a removal action for OU 6 which became effective August 25, 
1990 (Docket No. CERCLA-VIII-90-20). The UAO addressed risks associated 
with gaseous emissions from the Landfill. On December 24, 1990, EPA 
issued an Action Memorandum for an Enforcement-Lead Removal Action. The 
Action Memorandum required the installation and operation of a Landfill 
Gas Extraction System (LFGES), and installation and maintenance of a 
security fence and a vegetative cover for the Landfill. The LFGES 
system began operating on May 31, 1991. An EPA approved Final Removal 
Action Report for OU 6 (October 31, 1991) documented that the removal 
action was completed in accordance with the requirements of the Action 
Memorandum.
    The selected RAs for OUs 3 and 6 were described in a single ROD 
since OUs 3 and 6 are both associated with the 48th and Holly Landfill. 
Remediation of the Landfill focused on methane gas removal, 
institutional controls, and monitoring.
    The first requirement of the ROD was to continue operation and 
maintenance of the LFGES installed by the PRPs in 1991 under the 
August, 1990 UAO. The LFGES collects methane gas through underground 
pipes and destroys it in an enclosed flare system. In addition to 
methane gas removal, the ROD required institutional controls and 
monitoring of Landfill gas and groundwater. Landfill gas monitoring 
(for methane) began in

[[Page 44277]]

1991, and groundwater monitoring began in September, 1994.
    An EPA approved Final Remedial Action Completion Report (RACR), 
dated November 22, 1994, documented that the remedial action for OUs 3/
6 was completed and the on-going operation and maintenance continues in 
accordance with the requirements of the June 30, 1993 ROD. The RACR and 
all remedial actions were completed by Potentially Responsible Parties 
(PRPs).
    There were no aspects of the RA for OUs 3/6 which failed to conform 
to the remedial objectives as specified in the ROD for OUs 3/6.

Operable Unit # 4

    Remediation of OU 4 focused on institutional controls and 
monitoring of site-wide groundwater. The RA also included removal of a 
Light Non-Aqueous Phase Liquid (LNAPL) contamination plume.
    Institutional controls for OU 4 are being implemented by the State 
of Colorado in conjunction with local governments. These controls will 
minimize exposure to contaminated groundwater in this area by 
preventing any use of highly contaminated groundwater and limiting 
general groundwater use to non-domestic purposes only.
    EPA conducted quarterly groundwater monitoring and semi-annual 
surface water monitoring during the period of September, 1994 to June, 
1995 for OU 4. Monitoring was specified as a primary objective in the 
April, 1994 ROD. At the time of the writing of this report, the 
sampling results indicate that groundwater contamination is isolated 
on-site and that (due to the low permeability of the subsurface soils) 
it is not migrating off-site. These results support the decisions 
documented in the ROD which identified the primary goals of OU 4 
response actions as institutional controls and monitoring.
    A secondary goal identified in the April, 1994 ROD was to recover a 
portion of an LNAPL plume located in the northwest portion of the Site. 
The removal was to be accomplished by utilizing Dual Vapor Extraction 
(DVE). The equipment used for DVE was fundamentally the same as that 
used for the SVE treatment of OU 1 soils. EPA operated the DVE system 
from October, 1994 to April, 1995. During this time, only 6000 gallons 
of LNAPL was recovered, far below the estimated total volume of the 
LNAPL. These data show that even with an active ``pump and treat'' 
system, the LNAPL contamination is very immobile. The design and 
results of this system can be utilized by EPA in the future if 
contaminants are determined to be migrating off-site and if an active 
pump and treat system is deemed to be necessary to contain the 
contaminant migration.
    An EPA approved RACR, dated September 20, 1995, documents that the 
remedial action for OU 4 was completed in accordance with the remedial 
action objectives specified in the April, 1994 ROD.

Operable Unit #5

    Remediation for OU 5 focused on excavation and Low Temperature 
Thermal Treatment (LTTT) of surface and shallow soils (soils from 
ground level to a depth of five feet) contaminated with pesticides, 
metals, and VOCs.
    A total volume of 8,254 cubic yards of soil was excavated. The 
excavated soil was remediated between June 28 and July 29, 1994 using 
LTTT. After backfilling with the treated soil, a cover crop was planted 
to restore the Site and to help prevent erosion.
    An EPA approved RACR, dated October 28, 1994 documents that the 
remedial action for OU 5 was completed in accordance with the 
requirements of the September 8, 1993 ROD Amendment, with one 
exception. The target cleanup level for arsenic (12.7 mg/kg) was not 
achieved in a majority of post-remediation confirmatory soil samples 
obtained from stockpiles of 100 cubic yards of treated soil. The 
average post-remediation concentration of arsenic in the treated soil 
was 24.9 mg/kg. Because the arsenic target level was not achieved, EPA 
performed a post-remediation risk assessment in order to determine if 
the Site conditions were protective of human health and the 
environment. Since all other contaminants of concern were reduced below 
their target action levels, the maximum overall carcinogenic risk at 
the Site, even with the higher concentrations of arsenic, was 
calculated to be 2 X 10-5. This level falls well within the EPA's 
acceptable risk range of 10-4 to 10-6. Therefore, the post-
remediation condition of OU 5 is considered to be protective of human 
health and the environment. Thus, EPA does not plan any further 
remedial activities at this area of the Site.
    During the pre-final inspection of the Site, which occurred on 
August 22, 1994, EPA investigators discovered additional wastes in the 
area of OU 5. These wastes consisted of soils contaminated with 
pesticides and oil, drums containing pesticides and laboratory 
chemicals, and contaminated building debris and asbestos. As these 
wastes posed a high risk, EPA initiated a time-critical removal action 
to respond to the situation.
    The removal response activity was carried out from October 1994 to 
September, 1995. This activity consisted of the removal and offsite 
disposal of: 188 drums containing various chemicals and pesticides, 7 
compressed gas cylinders containing toxic and non-toxic gases, 2400 
cubic yards of oily and pesticide contaminated soils, approximately 240 
cubic yards of asbestos and oil contaminated soils, 40 cubic yards of 
contaminated building debris, and 30 cubic yards of RCRA contaminated 
drums and debris. An additional 600 gallons of Number 36 waste fuel oil 
was also removed and sent offsite to a recycling facility. This area of 
the site was regraded and reseeded following the completion of all 
removal and disposal activities. The Final Pollution Report (U.S. EPA, 
September 20, 1995) documents all removal activities performed and 
disposition of the wastes sent off-site.

V. Community Relations

    Community interest in the Sand Creek Superfund Site has been 
limited. However, EPA's community relations effort was comprehensive. 
EPA distributed Fact Sheets to area businesses, residents, and local 
agencies. EPA also provided public meetings and site tours to explain 
the Superfund process and cleanup activities planned for the Site. In 
addition, EPA met with Tri-County Health Department staff, South Adams 
County Water and Sanitation District, the Rocky Mountain Arsenal 
Superfund team, Commerce City/Adams County officials, U.S. 
Representative Patricia Schroeder, and other interested individuals.

VI. Summary

    The remedies completed at the site were mandated by the Records of 
Decision and based on the Remedial Design and Remedial Investigation 
and Feasibility Study Reports. The LTTT, SVE, and DVE were 
comprehensive ``one-time'' restoration activities and do not include 
operation and/or maintenance requirements. However, there are ongoing 
institutional controls, groundwater monitoring activities, and O & M 
requirements for OU 3/6 remaining at the Site. The completed remedies 
do result in hazardous substances remaining on site at levels which do 
not allow for unlimited land use and unrestricted exposure; therefore, 
there is a requirement for five-year reviews of the Site to ensure that 
remedies remain protective. The first five-year review for the Sand 
Creek site was completed on September 20, 1995. All completion 
requirements for the

[[Page 44278]]

Sand Creek Site have been achieved as outlined in OSWER Directive 
9320.2-3A.
    EPA, with the concurrence of the State of Colorado, has determined 
that all appropriate Fund-financed responses required by CERCLA at the 
Sand Creek Site have been completed. Continued maintenance of the LFGES 
and landfill cap/cover/fencing is required as well as continuance of 
the groundwater and landfill gas monitoring programs.

    Dated: August 12, 1996.
Jack W. McGraw,
 Acting Regional Administrator, U.S. Environmental Protection Agency, 
Region VIII.
[FR Doc. 96-21631 Filed 8-27-96; 8:45 am]
BILLING CODE 6560-50-P