United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R05-93/243
September 1993
SEPA Superfund
Record of Decision:
Ott/Story/Cordova Chemical,
Ml
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R05-93/243
3. Recipient's Accession No.
Title and Subtitle
SUPERFUND RECORD OF ^DECISION
Ott/Story/Cordova Chemical, MI
Third Remedial Action - Final
5. Report Date
09/27/93
6.
7. Authors)
8. Performing Organization Rept. No.
9. Performing Organization Name and Address
10 Project Taskwork Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/800
14.
15. Supplementary Notes
PB94-964108
16. Abstract (Limit: 200 words)
The 20-acre Ott/Story/Cordova site is an inactive chemical production facility located
in North Muskegon, Michigan. Land use in the area is predominantly residential, with
woodlands surrounding the facility. In addition to three onsite residential areas,
houses and a mobile home park are located to the west and northwest of the site,
respectively. One half-mile east of the former production areas, Little Bear Creek and
an unnamed tributary of the creek flow south into Bear Creek, which empties into Bear
Lake. From 1957 to 1985, various sets of parent corporations, divisions, and
subsidiaries used the site to manufacture pharmaceutical intermediates, veterinary
medicines, agricultural chemicals, herbicides, dye stuffs, and other products. For a
significant portion of the site's operating history, waste by-products from the
chemical manufacturing processes were placed in unlined lagoons or stored in drums
onsite. By 1959, issues with onsite ground water contamination were noted due to
improper storage and handling procedures. An onsite water supply well became
contaminated by the spread of chemicals that had entered the aquifer after seepage from
the lagoons. In the mid-1960s, untreated ground water and process flows were directed
to the Little Bear Creek for discharge. In the late 1960s, an incinerator was
installed onsite to treat more concentrated waste; however during the considerable
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - Ott/Story/Cordova Chemical, MI
Third Remedial Action - Final
Contaminated Media: Soil, sediment
Key Contaminants: VOCs (PCE, TCE, toluene, xylenes),
b. Identifiers/Open-Ended Terms
c. COSATI Reid/Group
other organics (PCBs, pesticides)
18. Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
52
22. Prica
(See ANSI-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
y NTIS-35)
ent of Commerce
^r^ • i^m**iB i ^nim ebl
(Formerly NTIS-35)
Departmen
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EPA/ROD/RO5-93/243
Ott/Story/Cordova Chemical, MI
Third Remedial Action - Final
Abstract (Continued)
downtime for incinerator operations, the waste was stored in drums. As the drums
accumulated onsite, open lands were used for waste and drum disposal. Beginning in 1973
or 1974, the plant extended its effluent pipe line to the Muskegon County POTW. By the
mid-1970s contamination of offsite residential wells downgradient of the plant was noted.
In 1977, the State negotiated with a new site owner to remove several thousand drums and
thousands of cubic yards of lagoon sludge, and to destroy or neutralize phosgene gas left
onsite. By 1982, an alternate water supply was installed in the site vicinity as a
settlement of a citizens' suit against a number of former site owners. A 1989 ROD
addressed the interception and treatment of contaminated ground water before its entry
into the creek system, as OU1. A 1990 ROD addressed the capture and treatment of all
known contaminated ground water below and downgradient of the site, as OU2. This ROD
addresses the residual areas of contaminated soil and sediment at the site, as OU3. The
primary contaminants of concern affecting the soil and sediment are VOCs, including PCE,
TCE, toluene, and xylenes; and other organics, including PCBs and pesticides.
The selected remedial action for this site includes excavating and treating contaminated
soil and sediment onsite using low temperature thermal desorption; backfilling the
excavated areas with the treated soil that meets cleanup levels; disposing of treated soil
above cleanup levels offsite; and monitoring ground water. The estimated present worth
cost for this remedial action is $6,808,254, which includes an estimated annual O&M cost
of $154,000.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific soil cleanup goals are based on health-risk criteria, and include PCB
1,000 mg/kg; butyl benzyl phthalate 22,000 mg/kg; chlorobenzene 2,600 mg/kg; 1,2-DCA 8
mg/kg; 4,4-DDT 2 mg/kg; 1,2-dichlorobenzene 30 mg/kg; dieldrin 0.04 mg/kg; ethyl benzene
1,500 mg/kg; endosulfan sulfate 3.3 mg/kg; hexachlorobenzene 0.4 mg/kg; methylene chloride
92 mg/kg; methoxychlor 700 mg/kg; PCE 14 mg/kg; 1,1,1-TCA 4,000 mg/kg; 1,1,2-TCA 13 mg/kg;
1,1,2,2-TCA 14 mg/kg; TCE 44 mg/kg; 1,2,4-trichlorobenzene 2,200 mg/kg; toluene 16,000
mg/kg; and xylenes 5,600 mg/kg.
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Table of Contents
Record of Decision
Operable Unit Three
Ott/Story/Cordova Site
Page(s)
Site Location 1
Site History and Enforcement 1-5
Community Participation 6-7
Scope/Role of Operable Units 7-9
Site Characteristics 9-14
Site Risks 14-22
Alternatives Description 22-27
Evaluation criteria 27-28
Comparative Analysis 28-36
-ARARs Discussion 29-33
Significant Changes 36-39
Selected Remedy 39
Statutory Determinations 40-41
Figures: Following Page
-Vicinity Maps 1
-Sampling Locations 8
-Areas Proposed to Undergo 20
Remediation
-Cross-section of Act 641 22
Landfill
-Cross-section of Act 64 22
Landfill
-Depiction of Low Temperature 25
Thermal Desorption Treatment
Unit
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RECORD OF DECISION
ROD SUMMARY
OTT/STORY/CORDOVA SITE
NORTH MUSKEGON, MICHIGAN
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DECLARATION FOR THE RECORD OF DECISION
Site Name and Location
ott/Story/Cordova site
North Muskegon, Michigan
Statement of Basis and Purpose
This decision document presents the selected remedial action for
the ott /Story /Cordova site, in North Muskegon, Michigan, which was
chosen in accordance with the requirements of the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA) and, to the extent practicable,
the National Oil and Hazardous Substances Pollution Contingency
Plan (NCP). This decision is based on information and documents
contained in the administrative record for this site.
The State of Michigan concurs with the selected remedy.
Assessment of the Site
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response action selected
in this Record of Decision (ROD), may present an imminent and
substantial threat to public health, welfare, or the environment.
Description of the Selected Remedy
This remedy is the third of three operable units selected for the
Ott/Story/Cordova site and consists of a remedy for the
contaminated soils and sediments. The remedy is viewed as
consistent with the previous two remedies selected for this site.
The primary goals of this selected remedial action at the
Ott/Story/Cordova site are to reduce infiltration into contaminated
soils which may add to the burden of groundwater contamination to
be dealt with by Operable Units One and Two and to reduce the
health and environmental risks associated with exposure to such
contaminated materials.
The Ott/Story/Cordova Operable Unit Three field work, which was
conducted in 1992, supplements the Remedial Investigation of 1988-
1989. The major components of the selected remedy consist of
excavation of contaminated soils/sediments, treatment of such
materials utilizing the technique of low temperature thermal
desorption, on-site backfilling of those treated soils which
successfully attain pertinent soil cleanup criteria, and off-site
disposal of that portion of treated soils which do not attain
cleanup criteria. Emissions created from contaminants driven off
the soils by this treatment technique would be controlled as
necessary through utilization of such techniques as flaring of
vapors thus generated, routing such vapors through carbon
adsorbants, and/or collection and subsequent treatment of vapor
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condensate. Monitoring will be necessary to ensure that cleanup
criteria are attained.
Declaration of Statutory Determinations
The selected remedy is protective of human health and the
environment, and is cost effective. The selected alternative will
comply with all Applicable or Relevant and Appropriate Requirements
(ARARs). The remedy utilizes permanent solutions treatment
technologies to the maximum extent practicable. There may be some
contaminated sediments left on or near the Little Bear Creek
portion of the site; future monitoring will determine if such
sediments require remediation after the construction of extraction
wells and treatment facilities designed to serve the goals and
objectives of Operable Units One and Two.
As required by SARA, when hazardous substances are left on site, a
review will be conducted within five years after commencement of
remedial action to ensure that the remedies continue to provide
adequate protection of human health and the environment.
f27/?3
Valdas. V. Adamkus, Regional Administrator Date
U.S. Environmental Protection Agency, Region V
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DECISION SUMMARY FOR THE RECORD OF DECISION
1. SITE NAME. LOCATION. AND DESCRIPTION
The ott/Story/Cordova Superfund site consists in part of a former
chemical production site located at the end of Agard Road in Dalton
Township, Michigan, five miles north of the city of Muskegon. The
former production area is approximately 20 acres in size, and is
surrounded by wooded land. Houses are located to the west of the
site along Whitehall Road, and a mobile home park is located about
a quarter of a mile northwest of the facility. Residential areas
are also located in close proximity to the former production areas
along Central, River, and Russell Roads. These residential areas
are considered as part of the facility. About one-half mile east
of the former production areas, Little Bear Creek and an unnamed
tributary of the creek flow south, joining near River Road, to the
southeast. Little Bear Creek flows into Bear Creek, which empties
into Bear Lake. Bear Lake eventually flows into Muskegon Lake, and
then into Lake Michigan. See the diagram denoted as "Vicinity Map"
for an approximate depiction of site setting.
2. SITE HISTORY AND ENFORCEMENT ACTIVITIES
Since the 1950s, various sets of parent corporations, divisions,
and subsidiaries have owned and/or operated chemical plants on the
site. The names of the previous and present owners most likely
familiar to the public are ott Chemical Company, Story Chemical
Company, and Cordova Chemical Company. The chemical plants used
various raw materials to manufacture pharmaceutical intermediates,
veterinary medicines, agricultural chemicals, herbicides,
dyestuffs, and other products. For a significant portion of the
site's operating history, waste by-products from the chemical
manufacturing processes were placed in unlined lagoons or stored in
drums on the property.
As early as 1959, groundwater problems began to be noted at the
site. At that time, an on-site water supply well used by Ott
Chemical became fouled, due in part to the spread of contaminants
that had entered the aquifer after seepage from the lagoons. The
act of seeking new water supplies, and abandoning former supply
wells was repeated by site operators several times during the
site's history.
Later, in response to State of Michigan concerns, efforts were made
by the site owners to slow the spread of the groundwater
contaminant plume. By the mid 1960s, a program of purging certain
portions of the aquifer was begun, and by 1968 an effort was made
to segregate particularly high-strength organic waste from more
dilute process and cooling flows.
Lagoon utilization for lower strength process and cooling flows
continued for a time. Plant documentation indicates that due to
spills and other mishaps, the conceived plan of only less-
concentrated waters reaching the lagoons did not always occur. By
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the 1970s, lagoon usage on a day-to-day basis began to give way to
usage for cooling water only, as measures to help protect the
integrity of water supply wells needed for facility operation.
Neutralization and flow equalization basins were installed about
1968-69. The purpose of the latter devices appears to have been
for primary treatment of process wastewater flows routed thereto.
Certain plant wastewaters were highly acidic or basic; hence the
role of the neutralization basin.
In the mid-1960s, untreated groundwaters and process flows were
directed to Little Bear Creek for discharge. Correspondence by
representatives of the Michigan Water Resources Commission and
later the Michigan Department of Natural Resources (MDNR) expressed
concern as to the effectiveness of such efforts. Several instances
of exceedances of allowable discharge limitations to the receiving
stream as established by the State of Michigan occurred from time
to time. Citizen complaints and concerns of the State of Michigan
resulted in the construction of a pipeline in the later 1960s to
reroute wastewaters to the Muskegon River. At that time, analysis
of the wastewaters centered on conventional parameters such as
solids, pH, phenol content, and BOD/COD. In an effort to help
gauge possible biological effects, fish taint tests were also
conducted from the mid to late 1960s to the early 1970s. This
consisted of a panel of plant personnel comparing the flavor of
control trout to those exposed to the plant effluent. By about
1973 or 1974, the plant extended the pipe line to the Muskegon
county Publicly Operated Treatment Works (POTW). Production
wastewater discharges from the site to the POTW via the pipeline
continued until 1985. (It may be of interest to the reader to note
that in recent years, and reinforced by a 1992 vote of the County
Public Works Board, Muskegon County has adopted a strict policy of
refraining from accepting; a discharge which originated from
contaminated groundwater within the County.)
In an effort to reduce the volume of wastes accumulating on site,
an incinerator was installed on the site by the late 1960s to treat
more concentrated industrial wastes. Plant documentation indicates
that this unit experienced considerable downtime, plus there were
instances when this and other plant equipment actually exploded.
During such downtimes, wastes were stored in drums. While some
effort was made to reduce this backlog, the net effect was that
drums of waste accumulated on site in the 1970s. Testimony of past
plant operators indicated that some open land areas of the site
were used for waste and drum disposal.
By 1977, with the then present site owner (Story Chemical) in
bankruptcy, a removal action was undertaken by the Michigan
Department of Natural Resources (MDNR) and financed in part by a
new site owner. Several thousand drums and thousands of cubic
yards of lagoon sludges were removed and disposed of from the site.
It appears that even though lagoon usage as a day to day measure of
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handling plant: process flows declined over time, the sludges in the
lagoons were not removed until several years later.
During the site's history, various information and documents were
filed with federal and state governments. Briefly, and in
approximate chronological order, these are:
Information generated by Ott Chemical regarding Michigan
Orders of Determination concerning groundwater and lagoon
usage (approximately 1965-1966).
Information generated by Ott and Story Chemical concerning
effluent content to .waters of the State of Michigan
(approximately 1967-1973).
Information generated by Ott Chemical and submitted to the
Corps of Engineers regarding the River and Harbors Act, (a
forerunner of the National Pollutant Discharge Elimination
System) (approximately 1971).
Filing for generator status and treatment /storage permits by
Cordova Chemical of Michigan under the Resource Conservation
and Recovery Act (approximately 1980).
Filing by Cordova Chemical for various Michigan air permits
(early 1980s).
By at least the mid 1970s, contamination of off-site residential
wells downgradient of the plant was noted. For a time, the county
and state helped to assist local residents by providing a supply of
bottled water, and through increased monitoring efforts of
potentially affected wells.
In 1981, the MDNR referred the Ott/Story/Cordova site to U.S. EPA
for inclusion in the newly established Superfund program. In 1982,
the site was placed on the National Priorities List (NPL) . Also in
1982, an alternate water supply was installed in the vicinity of
the site as settlement of a citizens' suit against some former site
owners, and financed in part by a former site owner, and in part by
the State of Michigan.
Distinct sets of site owner /operators have been involved in the
site during its history. The Ott Chemical Company began operations
at the site in the 1950s as an independent company. In 1965, Corn
Products Company, now CPC International, Inc., purchased all stock
of Ott Chemical. In 1972, CPC sold assets that comprised the Ott
Chemical operations to Story Chemical. In late 1976-early 1977,
Story Chemical initiated bankruptcy proceedings. In late 1977-
early 1978, Cordova Chemical Company of Michigan purchased the site
after entering into an agreement with the State of Michigan. The
agreement called for Cordova to destroy or neutralize phosgene gas
left at the site, and to finance in part the State's action to
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remove drums of waste and lagoon sludges. U.S. EPA was not a party
to the agreement.
In 1985, U.S. EPA sent a notice letter to Cordova and CPC, which
advised them of their potential liability under CERCLA for cleanup
of the site. The letter offered them an opportunity to conduct a
site Remedial Investigation/Feasibility Study (RI/FS). Both CPC
and Cordova declined this offer, and U.S. EPA conducted an RI/FS.
In March 1989, U.S. EPA sent demand letters for cost recovery to
CPC and Cordova. In May 1989, U.S. EPA also informed Cordova
Chemical Company of California (Cordova CAL), parent company of
Cordova-Mi, Aerojet-General (parent company of Cordova of
California) and Swanton-Story Corporation (successor of Story
Chemical) of their potential liability with regards to this site
and sent demand letters to these firms.
In August 1989, pursuant to a Section 122(a) letter, Aerojet-
General, Cordova CAL, Cordova-MI, and CPC International were given
notice that U.S. EPA had determined that a period of negotiations
would not facilitate an agreement for remedial design and action
for Operable Unit One. The availability of the Proposed Plan/
Focused Feasibility Study, and notice of the start of a public
comment period were also stated in the letter.
Litigation among the various private parties, the State of
Michigan, and U.S. EPA began in the summer and fall of 1989 with
the-filing in federal district court of various suits concerning
claims for reimbursement and allegations of liability for actions
taken and environmental conditions at the site. Following the
discovery phase of the litigation, a trial concerning the issue of
liability of the PRPs and the State of Michigan commenced in the
U.S. District Court in Grand Rapids, Michigan. Although U.S. EPA
had not named the MDNR or the State of Michigan as a PRP, Aerojet-
General and CPC asked the Court to declare Michigan as liable on
the theory of having arranged for disposal of hazardous substances.
Prior to the commencement of trial, the U.S. EPA had reached a
tentative settlement agreement with Dr. Arnold Ott for past
response costs. A Consent Decree memorializing such settlement has
been entered by the Court, and the terms of this Decree have been
met. Trial was conducted from early May to the middle of June
1991. A verdict was reached concerning liability on August 27,
1991. The Court found Aerojet-General Corporation and Cordova-Mi
liable for response costs under CERCLA section 107(a)(1).
Additionally, the Court found these persons, plus CPC International
Inc., and Cordova CAL liable under CERCLA section 107(a) (2). MDNR
was found not liable under any part of CERCLA section 107.
CPC, Aerojet and the U.S. Government, after the findings of
liability, entered into a stipulated settlement over the amount of .
federal response costs owed through June 1990, subject to an appeal
of liability. On September 10, 1992 the Court entered judgement
for this amount and also entered a declaratory judgement that the
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Aerojet defendants and CPC are liable for future response costs
incurred by the government. Aerojet and CPC have appealed the
district Court's judgement to the Sixth circuit Court of Appeals.
Briefs have now been filed with the Court of Appeals.
U.S. EPA also notes that litigation is currently proceeding in the
state courts of Michigan between Aerojet and the State of Michigan.
A lower court has found that Michigan breached the afore-mentioned
contract. This decision is being appealed by the State of
Michigan.
U.S. EPA began field work for the Remedial Investigation (RI) in
January 1988. The report discussing this investigation was
completed in April 1989, supplemented in 1990, with further
information on site soils/sediments becoming available in 1992. In
August 1989, U.S. EPA initiated a public comment period concerning
the Proposed Plan for the first operable unit, which dealt with
preventing further groundwater contamination from entering Little
Bear Creek. Upon consideration of comments made, U.S. EPA
developed a Record of Decision for the first operable unit in
September 1989. U.S. EPA reopened the public comment period from
November to December 1989, and based upon review of comments
received affirmed its initial decision in March 1990. In May 1990,
U.S. EPA obligated federal dollars to initiate the Remedial Design
for the first operable unit.
The Feasibility Study (FS) for the site was completed in early
summer 1990. In July 1990, U.S. EPA began a public comment period
for a second operable unit for the site, which considered the
matter of aquifer restoration. In response to a request from one
party, U.S. EPA extended the comment period into September 1990.
After evaluation of public comment and response to significant
comment, U.S. EPA selected a remedy which, through extraction and
treatment of contaminated groundwater, would be designed to restore
the contaminated aquifer. In October 1990, PRPs were informed by
U.S. EPA that the Agency could not make a determination that a
period of negotiation would facilitate settlement between those
persons and the Agency, but that U.S. EPA would consider PRP
response which might allow the making of such determination. No
responses were received which caused U.S. EPA to make such
determination. In the first quarter of calendar year 1991, U.S.
EPA obligated funds for remedial design of the second operable
unit. In 1992, U.S. EPA and MDNR obligated remedial action funds,
and in March 1993 the U.S. Army Corps of Engineers solicited
construction bids. Bids were opened in July 1993, and a contract
awarded in September 1993.
During the RI, U.S. EPA found elevated levels of numerous organic
compounds in soils and groundwater at and downgradient of the site.
As noted previously, U.S. EPA has developed two Records of Decision
(ROD) for the site which deal with halting surface-water
contamination at the site, and with groundwater restoration
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efforts, respectively.
3. HIGHLIGHTS OF COMMUNITY PARTICIPATION
An RI/FS "kickoff" availability session was held near the site in
November 1987. Upon completion of the RI in April 1989, a copy of
the RI report was made available to the public at the information
repositories maintained at the Oalton Township Public Hall and the
Walker Memorial Library in North Muskegon. The RI was also made a
part of the administrative record file maintained in Region 5 and
at the local repository at the Walker Memorial Library. A Proposed
Plan and Focused Feasibility Study for operable Unit one, which
dealt with the contamination of Little Bear creek and its unnamed
tributary, were released to the public on August i, 1989 to
initiate a public comment period for the proposed action. A public
meeting was held in August 1989. U.S. EPA extended the comment
period into September 1989. Upon consideration of comments made,
U.S. EPA developed a ROD for the first operable unit in September
1989. U.S. EPA reopened the public comment period from November to
December 1989, and based upon review of comments received affirmed
its initial decision in March 1990.
The Feasibility Study (FS) and Proposed Plan for Operable Unit Two
were made available to the public in July 1990. A notice of
availability was published in the Muskeaon Chronicle on July 24,
1990 to initiate a public comment period on the alternatives from
July 2.5, 1990 to August 23, 1990. In addition, a public meeting
was held on August 16, 1990 in Muskegon County. In response to a
request for extension, U.S. EPA subsequently extended the public
comment period to September 24, 1990. After evaluation of public
comment and response to significant comment, U.S. EPA selected a
remedy which, through extraction and treatment of contaminated
groundwater, is designed to restore the contaminated aquifer.
In December 1991, U.S. EPA conducted an informal public meeting at
the Dalton Township Hall to discuss with interested citizens what
appeared at that time to be the leading treatment concepts for
contaminated groundwater in the remedial design, and the objectives
of sampling envisioned for the third operable unit. MDNR also
participated, and discussed design questions and explained the
goals and objectives of pump testing proposed by private parties.
On April 5, 1993, U.S. EPA released a supplement to the FS and a
Proposed Plan for Operable Unit Three to the public. A notice of
the availability of these documents was placed in the Muskeaon
Chronicle on March 31, 1993 to initiate a public comment period on
the alternatives from April 5, 1993 to May 4, 1993. In addition,
a public meeting was held on April 20, 1993 in Dalton Township,
Muskegon County. At this meeting, representatives from U.S. EPA
and the MDNR answered questions concerning site conditions and
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remedial alternatives under consideration. A court reporter was
present to record oral comments. Written comments were also
solicited at the hearing. The public was reminded that anyone
desiring additional information about the Superfund process or the
activities to be conducted by U.S. EPA at the ott/ Story /Cordova
site can review the documents that have been prepared for the site.
The location of such documents was noted. In response to a request
for extension, U.S. EPA subsequently extended the public comment
period to June 3, 1993. In response to a further request for
extension of the public comment period received by U.S. EPA on May
27, 1993, U.S. EPA subsequently extended the public comment period
to July 6, 1993.
A response to the comments received during this period is included
in the Responsiveness Summary, which is part of this ROD. This
decision document presents the selected remedial action for
Operable Unit Three for the Ott/Story/Cordova Site in North
Muskegon, Michigan, chosen in accordance with CERCLA, as amended by
SARA, and to the extent practicable, the National Contingency Plan
(NCP). The decision for this site is based on the administrative
record.
4. SCOPE AND ROLE OF OPERABLE UNIT
As with many Superfund sites, the problems at the Ott /Story /Cordova
site are complex. Consequently, U.S. EPA organized the remedial
work into three planned operable units at the site. This ROD
addresses the third operable unit planned for the site.
As noted within the NCP, total site remediation is the desired
objective. However, as the NCP states, often it is necessary and
appropriate, particularly when dealing with complex sites, to
divide the site into remedial categories for effective management.
The RI developed for the Ott /Story /Cordova site indicated the
presence of a wide variety of hazardous substances in groundwater,
surface water, soils, and sediments. Therefore, U.S. EPA divided
the site into three operable units (OU) as follows:
OU One: Considers surface water degradation of Little Bear
Creek due to the influx of a portion of the
contaminated groundwater caused by past disposal
practices at the site.
OU Two: Considers site groundwater and aquifer quality
restoration.
OU Three: Considers whether certain areas of site surface and
near surface soils and sediments should undergo
remediation.
U.S. EPA has already selected the cleanup remedy for OU One and
Two. Entry of contaminated groundwater into the Little Bear Creek
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8
system constituted a threat at the site because of the resultant
degradation of a portion of the creek system. Therefore, OU One
seeks to intercept contaminated groundwater before it enters the
creek system, and to provide treatment for waters thus collected.
The capture and treatment of all known contaminated groundwater
below and downgradient of the site, and the matter of attempting to
attain pertinent federal and state regulations concerning
groundwater were addressed by OU Two.
OU Three will address residual areas of contaminated soils and
sediments at the site. U.S. EPA believes, in keeping with the NCP,
that the selection and execution of a remedy for OU Three will be
neither inconsistent with nor preclude the implementation of other
remedies selected for the site.
In this third and final planned operable unit for the site, U.S.
EPA considers the matter of contaminated soil areas at the
Ott/Story/Cordova site. In 1992, U.S. EPA completed a Field
Investigation Memorandum concerning results of recent sampling
activity, updated risk calculations to account for the recent
sampling activity, and supplemented the FS for the
Ott/Story/Cordova site. This information helped U.S. EPA assess
the potential impacts on remedial alternatives of certain
requirements under the federal Resource Conservation and Recovery
Act (RCRA) and the Michigan Act No. 307 which were effective in the
spring, and summer of 1990, respectively. Under RCRA, new
regulations involving Toxicity Characteristic Leaching Procedure
(TCLP) became effective. Approximately 25 organic compounds were
added to a list of compounds that could classify a waste as
hazardous dependent on the leaching potential of such compounds
from that waste. The TCLP test now includes such compounds as
hexachlorobenzene, methoxychlor, and 1,4- dichlorobenzene which are
compounds previously found in certain site soil samples during U.S.
EPA's Remedial Investigation (RI) of the site. U.S. EPA has also
considered past acts of disposal conducted at the site, and whether
such acts may involve disposal of certain listed wastes as
discussed within Part 261 of RCRA. Under Act 307, rules were
enacted specifying how cleanup criteria may be applied to a site.
The volume of soils to be managed have been revised somewhat from
earlier FS estimates based on these new enactments, as well as
field findings from sampling conducted at the site in winter 1992.
During the trial on liability issues, several former employees
appeared as witnesses before the Court and discussed their
recollections of past disposal activity at the site. In planning
for Operable Unit Three sampling activity, U.S. EPA met some of
these persons at the site and exchanged correspondence with others
in an effort to better locate possible areas subject to disposal
activity. In January and February 1992, U.S. EPA performed the
field sampling for Operable Unit Three investigative purposes.
U.S. EPA excavated and made visual examinations in certain areas of
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the Site in order to check areas of unusual geophysical
characteristics and points brought to the Agency's attention by
past plant operators. The inspections revealed that some site
areas were formerly used as places of waste disposal. An area east
of the former production facilities and located in a field south of
the equalization basin, in particular, was found through these
visual inspections to contain hazardous substances and disposed
drum fragments.
U.S. EPA also collected a select number of soil samples near
locations where past waste incineration or other burning may have
been conducted. U.S. EPA learned during the course of recent site
investigations and through review of plant operator testimony at
trial that the former incinerator had been subject to certain
process upsets, and that combustion efficiency of past burning
operations may have been low.
U.S. EPA also arranged for the collection of soil samples near
areas of sparse vegetation at the site, and through its Corvallis,
Oregon Research Laboratory conducted biological screening of such
samples to see if, compared to background conditions, such soils
pose an environmental threat due to past releases of raw materials,
intermediates, or products utilized at the site.
Results of these sampling efforts were received by U.S. EPA in
1992, and subsequently placed in the administrative record file, as
well as pictures of the field investigation efforts.
Volumes of soils estimated to be dealt with have also been modified
somewhat based on the outcome of further exploration of surface and
shallow subsurface soil areas. The areas explored were those noted
by plant operator personnel in court testimony presented in May
1991 and areas of unusual geophysical characteristics found by U.S.
EPA.
5. SUMMARY OF SITE CHARACTERISTICS
An important site characteristic at Ott/ Story /Cordova is the sandy
nature of site soils which have a high permeability. Although
there is likely some seasonal variation, the groundwater is
encountered only about five feet below the ground surface of the
site. Past usage of unlined waste lagoons and subsequent plant
spills/releases through vessel overfill, container failure, pump
failure, improper valve function, product line blockage, etc., have
resulted in introduction of pollutants into the soil and
groundwater.
The site is at the headwaters of a very small surface water and
likely groundwater divide. Drainage is generally to the southeast.
It should be noted that at the extreme western end of the site,
toward Whitehall Road, surface drainage patterns likely shift to
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10
the Green Creek basin. U.S. EPA is not aware to date that site
releases have affected this stream as opposed to the Little Bear
Creek basin. Monitoring wells to be placed near the site as part
of Operable Unit One and Two remedial action will help provide
further information whether contaminated groundwaters have migrated
or could migrate beyond the Little Bear Creek basin.
Down to about the 65 foot depth, soils are predominantly sandy.
The aquifer in this zone is unconfined. From about 65'-85' below
the ground's surface, there are layers of silts and clays, which
tend to subdivide the upper sandy zone from the lower sandy zone
which predominates again below the 100 • depth until a thick clay
zone is encountered at about 150'. Information from a pump test
conducted by consultants for the responsible parties in the winter
of 1992 indicated that the silt/clay layers allowed leakage between
deeper and intermediate aquifer zones. Some borings performed
during this test, which was near the intersection of River and
Central Roads, indicated some signs of soil staining and chemical
odors at approximately the 90' depth.
In the context of Operable Unit Three, the term "subsurface soil"
includes only those areas that are at or above the groundwater
table. As discussed in the 1989 RI Report, a contaminant's
characteristics such as structure, solubility, and vapor pressure
influence its potential to migrate and its rate of migration in
soils and groundwater.
Background sample collection in the area of the facility in 1988
revealed negligible levels of organic contamination in soils,
sediments, and surface waters. These conditions held true in 1992
also.
Highlights of field results for Operable Unit Three sampling are
presented below. Results are presented in terms of micrograms per
liter for water samples, and in terms of micrograms per kilogram
for soil or sediment samples. Such units correspond roughly to
parts per billion. Figures 1 and 2 provide a depiction of some of
the key sampling points utilized in the 1992 supplement to the FS
field work. Tentatively identified compounds and their estimated
concentrations are indicated by "*."
1992 Supplemental Sampling Results
Sample Location/Type Contaminant Concentration
SW 3 (water) Benzene 6000
Toluene 4800
4-Chloroaniline 1000
* various alkyl 1100
benzeneamines
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11
SO 3(sediment soil)
SO 4(sediment soil)
SW 4(water)
TP 3A(test pit soil)
TP 3B(test pit soil)
TP 5A(.test pit soil)
TP 5B(test pit soil)
SS 2(surface soil)
SS 3(surface soil)
SS 5(surface soil)
Benzene 17000
Toluene 42000
4-Chloroaniline 1200
4-Methylphenol 1000
* congeners of dimethyl 22000
benzenamine
* congeners of ethyl 22000
benzenamine
Benzene 17000
Toluene 99000
* congeners of ethyl 12000
benzenamine
Benzene 4500
Toluene 6400
Chloroethane 1000
4-Chloroaniline 2300
* various alkyl 3600
benz eneamines
Arochlor-1254 3900
Hexachlorobenzene 1600
Lead 102000
Chloroform 1600
1,2 - Dichloroethane 3400
Carbon Tetrachloride 26000
1,1,2 - Trichloroethane 3100
Tetrachloroethene 2300
4-Chloroaniline 1200
Lead 91700
* benzamide 15000
* l-chloro-2-isocyano- 2600
benzene
* Trifluralin 6700
2,3,7,8- Tetra- 0.02
chloro- dibenzo-
1,4-dioxin (estimated
value)
Arochlor-1248 5800
Lead 16800
* 2,6-Dichlorobenzamide 19000
* 2,6-Dichlorobenzo- 33000
nitrile
* 2,6-Dichlorobenzo- 17000
nitrile
-------
SS 7(surface soil)
12
4-Chloroaniline
Hexachlorobenzene
Lead
Chromium
1700
1300
28300
21600
Highlights of 1988 Remedial Investigation Results for Soils
Sample Location/Type
SF-01SW(surface soil)
SF-01SE(surface soil)
SF-01NE(surface soil)
SF-02W(surface soil)
SF-02E(surface soil)
SF-05S(surface soil)
SF-05N(surface soil)
SF-06(surface soil)
SF-09(surface soil)
SF-10SW(surface soil)
SF-10NW(surface soil)
SF-11W(surface soil)
SF-llE(surface soil)
SF-12M(surface soil)
SB-07(near surface
soil in close proximity
to SF-12)
SF-16(surface soil)
SB-24(near surface
soil in close proximity
to SF-16)
Contaminant
4-Nitroaniline
4-Nitroaniline
4-Nitroaniline
4,4'-DDT
4,4'-DDT
4,4'-DDT
4,4'-DDT
Methoxychlor
4-Chloroani1ine
Aroclor-1248
Hexachlorobenzene
Methoxychlor
4,4'-DDT
4,4'-DDT
4,4'-DDT
Methoxychlor
1,1,1-Trichloroethane
Xylene(s)
Benzoic Acid
Hexachlorobenz ene
4,4'-DDT
1,4-Dichlorobenzene
1,2-Dichlorobenzene
Hexachlorobenz ene
Concentration
2300
2700
2400
25000
1900
4200
5900
5300
1200
15000
3400
1300
5500
5400
2700
8400
17000
79000
2900
1300
1200
7600
13000
7800
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13
*
SF-20(surface soil) 1,2-Dichlorobenzene 11000
Benzole Acid 75000
Methoxychlor 25000
A look at this information indicates that in general, aside from
the areas subject to waste disposal activity, soil contamination
tends to predominate in those areas of the plant where raw
materials/products were shipped in and out of the plant, or where
internal routing of wastewaters took place.
The TCLP testing conducted at the site by U.S. EPA indicated that
the contaminated soils/sediments were not characteristically
hazardous waste with regard to such compounds as methoxychlor,
hexachlorobenzene, and 1,4-dichlorobenzene. TCLP testing conducted
by certain private persons indicated that one soil sample may be
characteristically hazardous for the compound carbon tetrachloride.
U.S. EPA also performed limited biological testing on certain site
soil samples to explore possible environmental damage consequences.
Biological testing consisted of the standard vegetative root
elongation toxicity test and "Microtox" testing. Microtox is a
commercially produced bacterium used for toxicity testing which is
luminescent. If its metabolic processes are inhibited such as by
being exposed to toxic media, its luminescence decreases
proportionately with relative luminescence thereby providing a
measure of toxicity. These tests were conducted on four soil
samples collected from the site. One of these points was from
beyond the fenceline northwest of the former production area, and
was collected for background purposes. No indications of toxicity
were revealed for this sample. Of the other three samples, two
were collected in the vicinity of the former pilot plant area, and
one from an area south of Agard Road believed to have been used for
fire training purposes. Notably in the vicinity of the pilot
plant, there were indications of significant toxicity with regard
to both the root elongation and Microtox test.
Oioxin sampling in the vicinity of the former incinerator pad
indicated positively the presence of dioxins, although at a level
below quantifiable detection limits.
Soil/Sediment Cleanup Criteria
U.S. EPA indicated in its April 1993 Proposed Plan for this site
that, in this situation, it appears appropriate to conduct any
necessary site soils/sediment cleanup to attain Michigan Act 307
Type B soils criteria. These criteria are listed on the next page
for contaminants of concern at the Ott/ Story /Cordova site. It
should be noted that Type B criteria take into account the
potential for contaminants in soil to contaminate groundwater, and
health risk from direct contact with contaminated soils. The
potential to contaminate groundwater is based on a level of 20
times the corresponding groundwater criterion for a given
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14
contaminant. The selected Type B cleanup level is then based on
the more restrictive of these two values. However, in some cases
one of the values calculated may fall below analytical detection
limits for a given compound, in which case the analytical detection
limit becomes the cleanup criterion. In developing these criteria,
calculations by U.S. EPA contractors underwent review by MDNR
staff. It would be appropriate to invoke these criteria if an
examination of potential risk to human health or the environment at
the site revealed an unacceptable degree of risk posed by the site
soil/sediment conditions.
Soil Cleanup Criteria
Contaminant
Aldrin
Aroclor- 1248 (PCS)
Bis (2-ethyl hexyl) Phthalate
Butyl Benzyl Phthalate
Chlorobenzene
4,4-DDT
1,2-Dichloroethane
1,2-Dichlorobenzene
1,4-Dichlorobenzene
Dieldrin
Ethyl Benzene
Endosulfan Sulfate
Hexachlorobenzene
Methylene Chloride
Methoxychlor
1,1,2,2-Tetrachloroethane
Tetrachloroethene
1,1,l-Trichloroethane
1,1,2-Trichloroethane
Trichloroethene
1,2,4-Trichlorobenzene
Toluene
Xylene
Type B Cleanup Criterion
in parts per billion*
1.7
1000
60
22000
2600
2
8
12000
30
0.04
1500
3.3
0.4
92
700
3.6
14
4000
13
44
2200
16000
5600
(to detection limit)
6.
SUMMARY OF SITE RISKS
The purpose of risk assessment is to estimate the magnitude of
potential risk to public health and the environment which may be
due to exposure to contaminants identified at the site. Such
assessment involves identifying contaminants of potential concern,
routes by which such contaminants may migrate, and populations
which may come into contact with the contaminants. Furthermore,
the assessment is based on the premise that no action will be taken
at the site to remediate areas of contamination. The assessment
may also consider current site conditions, and possible future land
use changes.
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15
Factors in selecting contaminants of concern include whether a
given substance was found at levels above background, the degree of
occurrence for the substance, and the relative toxicity of a
compound. For estimates of human health risk, the general types of
toxicity may be subdivided into the two major categories of
carcinogenic and noncarcinogenic effects. As used within the
context of a site risk evaluation, the term noncarcinogenic refers
to deleterious health effects other than cancer which may be caused
by exposure to a given substance; carcinogenic refers to a
substance or agent which produces or incites cancer.
Contaminated soils, sediments, and water may create pathways for
exposure to such chemicals through dermal contact, ingestion, or
inhalation.
With regard to Operable Unit Three, the pathways of exposure of
primary concern involving soils/sediments are exposure to site
workers, and future exposure to soils and sediments should
residential usage of the site occur. Future workers may include
construction and/or maintenance workers performing most of their
activity outside, as well as general workers who may work both
inside and out of doors. The routes of exposure would include
dermal absorption for contaminated soil particles adhering to the
skin, ingestion of soil particles, and inhalation of materials
which may volatilize from soils/sediments into the air.
Different categories of site users or workers may have varying
degrees of exposure to site contaminants. Factors which may affect
degree of exposure include the amount of incidental ingestion of
soil and dust, the number of times a worker or visitor may come to
the site in a given length of time, the type of activity engaged in
by an individual, the weight of the individual, the degree to which
a substance may be absorbed through the skin, etc. U.S. EPA makes
note of certain standard default exposure factors listed in a March
25, 1991 directive from its Office of Solid Waste and Emergency
Response on these topics. Using the information in this directive,
as well as professional judgement, certain assumptions are made
concerning individuals who may utilize the site now and in the
future:
General Workers:
Incidental soil ingestion of 50 milligrams/day (directive)
250 days/year of exposure during a working career of 25
years (directive)
Body weight of 70 kilograms (directive)
Exposure to surface soils only with no access restriction
(judgement)
Construction Workers:
Incidental soil ingestion of 480 milligrams/day (directive)
250 days/year of exposure during a working career of
1 year for a given project (directive)
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16
Body weight of 70 kilograms (directive)
Exposure to both subsurface and surface soils
in former central plant areas (judgement)
Maintenance Workers:
Incidental soil ingestion of 480 milligrams/day
50% of working day; otherwise 50 milligrams/day
250 days/year of exposure during a working career of
25 years (judgement)
Body weight of 70 kilograms (directive)
Exposure to both subsurface and surface soils
in former central plant areas (judgement)
Future Site Residents:
Incidental soil ingestion of 100 milligrams/day
for all persons above the age of 6 (directive)
Incidental soil ingestion of 200 milligrams/day
for persons up to the age of 6 (directive)
350 visits/year (directive)
Body weight of 70 kilograms for adults (directive)
Body weight of 15 kilograms for children (directive)
Exposure to surface soils only (judgement)
Data sets were evaluated to consider those chemicals above
background levels, toxicity constants for noncarcinogens and
carcinogens were reviewed, and the degree of occurrence of a given
substance at the site was considered.
EXPOSURE ASSESSMENT
Historically, during production periods at the site, non-regulated
releases of contaminants occurred to the air, soil and water.
Contaminants in soils at the site have a pathway for potential
exposure to humans by either direct contact or use of groundwater.
Allowable rates of release to waterways were established through
state Orders; the history of the site indicates that several
instances of exceedance of such allowable discharge rates occurred.
Further releases and migration of the contaminants can occur by
movement of contaminants into groundwater with potential exposure
pathways by means of production wells, subsequent discharge to
surface water of at least a portion of the contaminated
groundwater, volatilization into the air or suspension of
contaminated dusts into the air, or runoff of surface water that
may carry contaminated soils. RODs developed for Operable Units
One and Two addressed risk and exposure from contaminants in the
surface water and groundwater, respectively.
The presence of contaminants in soils and sediments result in
several exposure pathways. Persons who may come in contact with
soils/sediments are considered a potentially exposed population.
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17
Operable Unit Three will address the primary exposure scenario
posed by contaminated surface and near surface soils and
sediments. This scenario focuses on ingestion and dermal contact
by potential site users. Volatilization of some substances from
soils into the air is also possible.
TOXICITY ASSESSMENT
The degree of toxicity which may be posed by a given chemical may
be described in part by its acceptable intake or its reference dose
and in the case of carcinogens by its carcinogenic potency factor
(CPF). Reference doses, or RfDs, are derived from information
available from studies on animals or human epidemiologic studies.
Adjustments from animal studies to predicted behavior with humans
is subject to multiplication by various uncertainty factors. These
values are normally reported in rag/kg body weight/day, and
generally represent the highest calculated exposure level below
which the given adverse effect will not occur. A carcinogenic
potency factor is expressed as lifetime cancer risk per mg/kg body
weight/day, and is estimated at the upper 95 percent confidence
limit of the carcinogenic potency of a given chemical.
CPFs have been developed by EPA's Carcinogenic Assessment Group for
estimating excess lifetime cancer risks associated with exposure to
potentially carcinogenic chemicals. CPFs, which are expressed in
units of (mg/kg-day)"1, are multiplied by the estimated intake of a
potential carcinogen, in mg/kg-day, to provide an upper-bound
estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound" reflects the
conservative estimate of the risks calculated from the CPF. Use of
this approach makes underestimation of the actual cancer risk
highly unlikely. CPFs are derived from the results of human
epidemiological studies or chronic animal bioassays to which
animal-to-human extrapolation and uncertainty factors have been
applied.
RfDs have been developed by U.S. EPA to indicate the potential for
adverse health effects from exposure to chemicals. The RfD is
based on the assumption that thresholds exist for certain toxic
effects such as cellular necrosis, but may not exist for other
toxic effects such as carcinogenicity. In general, the RfD is an
estimate with an uncertainty spanning perhaps an order of magnitude
of a daily exposure to the human population. This includes
sensitive subgroups that are likely to be without an appreciable
risk of deleterious effects during a lifetime. RfDs can be derived
for noncarcinogenic compounds, as well as for the noncarcinpgenic
health effects of compounds which are also carcinogens. Estimated
intakes of chemicals from environmental media (e.g., the amount of
a chemical ingested from contaminated drinking water) can be
compared to the RfD. Uncertainty factors help ensure that the RfDs
will not underestimate the potential for adverse noncarcinogenic
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18
effects to occur.
The following information notes ingestion RfDs and CPFs for
selected chemicals at the Ott/Story/Cordova site. (The term "E"
refers to exponential notation, and for example in the case of "E-
03" means to move the decimal point for the value given three
places to the left.) Also noted is the weight of evidence for the
various categories of potential carcinogens. The weight of
evidence for carcinogenic behavior is divided into the following
groups:
Group A chemicals, known human carcinogens, are agents for which
there is sufficient evidence to support the causal association
between exposure to the agents in humans and the on-set of cancer.
Group Bl and B2 chemicals, probable human carcinogens, are agents
for which there is limited (Bl) or inadequate (B2) evidence of
carcinogenicity from human studies, but for which there is
sufficient evidence of carcinogenicity from animal studies.
Group C chemicals, possible human carcinogens, are agents for which
there is limited evidence of carcinogenicity in animals.
Group 0 chemicals, not classified, are agents with inadequate human
and animal evidence of carcinogenicity or for which no data are
available.
Group E chemicals are agents for which there is no evidence of
carcinogenicity in adequately performed human or animal studies.
Hazardous Substance RfD
1,1,2-trichloroethane 4.3 E-03
1,2-dichloroethane
Benzene
Chloroform 1.OE-02
Tetrachloroethene 1.OE-02
Toluene 2.0E-01
1,2-dichlorobenzene 9.OE-02
1,4-dichlorobenzene
4-chloroaniline 4.0E-03
4-nitroaniline
Benzoic Acid 4.0E+00
Benzo(a)pyrene
Hexachlordbenzene 8.OE-04
4,4'-DDT 5.OE-04
Aldrin 3.OE-05
Aroclor 1248
Methoxychlor 5.0E-03
Dioxin
Lead
Slope Factor Weight of Evidence
9.1E-02
2.9E-02
6.1E-03
5.1E-02
2.4E-02
3.0E-07
7,
1,
.2E+00
,6E+00
3.4E-01
1.7E+01
7.7E+00
1.5E+05
B2
A
B2
B2
D
D
C
B2
B2
B2
B2
B2
B2
B2
B2
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19
RISK CHARACTERIZATION
Estimating the risk of a noncarcinogenic health effect is
accomplished by calculating the hazard quotient (HQ); this is done
by dividing the dose estimated to be received by someone exposed to
a substance by the established safe dosage estimate for that
chemical. If the resulting answer is greater than 1 then the
exposure has exceeded a safe level. Adding all the HQs for the
chemicals of concern in a given route of exposure pathway gives a
hazard index (HI) for that pathway. According to the NCP, when the
HI exceeds 1, there is a potential health risk.
Carcinogenic risk is estimated by multiplying the estimated dose of
the chemical by its published or calculated slope factor. As with
noncarcinogenic hazard quotients, carcinogenic risks are assumed to
be additive for all chemicals within an exposure pathway. The NCP
has established a carcinogenic risk of greater than 1 x 10 "4 as
being unacceptable for human health. (This represents the
contracting of cancer due to environmental exposure as one in ten
thousand.) The reduction of such risk to within the risk range of
1 x 10~4 to 1 x 10"6 is viewed by the NCP as acceptable; U.S. EPA
often uses the 1 x 10"6 figure as a desirable goal for adequate
protection.
It may then be calculated under Risk Assessment Guidance for
Superfund (1989 guidance to U.S. EPA) that risk for human
populations may be expressed as follows:
Category Noncarcinogenic Carcinogenic
(Hazard Index) (Excess Cancer Risk)
General Worker 0.3 1.18 x 10"4
Construction Worker 0.46 3.0 x 10"6
Maintenance Worker 0.4 9.0xlO~5
Future Site Visitor/ 2.4 3.Ox 10"4
Resident (HI of 1.9 age group 4-6;
HI of 0.5 age group 7-30)
Current Visitor 0.02 2.0 x 10"7
(assumes exposure only to presently unrestricted site areas;
surface soils only)
As can be seen from the scenarios reviewed above, risk associated
with soils/sediments at the Ott/Story/Cordova site are above the
threshold of acceptability for the general site worker, and
threefold above this threshold for the case involving future
residential usage. A special case is presented for soils in the
vicinity of the former incinerator pad. At this point, dioxin
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20
compounds were detected. Because of the high slope factor utilized
in calculations involving such compounds, exposure to surface soils
at this point results in the following risk characterization for
the site users noted on the previous page:
Carcinogenic
(Excess Cancer Risk)
General Worker 1.2 x 10"3
Construction Worker 9.1 x 10"5
Maintenance Worker 1.2 x 10"3
Future Site Visitor/Resident 7.3 x 10"2
Averaging of dioxin values across the site was not performed
because the dioxin detected occurred only at the single point noted
above.
Uncertainty associated with site risk concerns to what degree
exposure parameter assumptions and land-usage patterns may change.
For example, when remedial actions for operable Unit One come on
line fully, an improvement in stream water quality is the desired
outcome. This factor may tend to promote stream usage; exposure to
contaminated sediments may increase if sediment quality does not
change as rapidly as water quality. Future land-usage patterns
concerning former production areas and former administrative-type
office areas are not certain.
Current and future risks to site users have the potential for over
and underestimation. Should frequency or duration of exposure to
future site users prove less than assumed, actual risk may be less
than what is projected now. Current remedial action guidance
emphasizes an examination of maximum expected risk, and not
necessarily the worst possible case. Hence, the soils actually
sampled do not likely reflect the worst case potentially presented.
U.S. EPA has reason to believe, however, that more severe
contaminant concentrations may exist on the site. For example, the
contractor's log of test pit 5A as noted in the Field Investigation
Memorandum speaks of a finding of a "... white & creamy sludge in
a 2 ft. [by] 3ft. cavity in the bottom of pit w/lab bottles floating
in it...", as well as "...black and purple staining..." elsewhere
in the pit. Additionally, the tentatively identified compounds
associated with both surface and subsurface sampling points may
present some unknown risk to site users which are not now factored
into these discussions. To illustrate this matter, 1992 sampling
results indicate that there were 9300 ug/kg of tentatively
identified semivolatile compounds associated with the background
sampling location. This value may be contrasted with the finding
of 329,000 ug/kg of tentatively identified semivolatile compounds
-------
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21
associated with a sampling point northwest of the former pilot
plant location, and 44,000 ug/kg of tentatively identified
semivolatile compounds associated with a sampling point near the
former plant's southern railroad spur., One compound tentatively
identified at test pit sampling point SB was Trifluralin. Page
9599 of the eleventh edition of The Merck Index as published by
Merck & Co., Inc., in 1989 informs the reader that Trifluralin is
used as a pre-emergence herbicide. Tentative identification of
chlorinated benzonitrile compounds occurred at surface soil
sampling points SS03, SS04, and SS05. The reference source Sax's
Dangerous Properties of Industrial Materials,, by R. A. Lewis,
eighth edition as published in 1992 by Van Nostrand Reinhold of New
York provides safety profile information on these compounds. This
text describes nitriles in general as organic compounds having the
CN, or cyanide, grouping within the molecule. Chlorobenzonitrile
is further characterized as moderately toxic by ingestion, and is
considered an eye irritant. Upon contact with water, acid, or acid
fumes, Chlorobenzonitrile may release toxic fumes. This same
reference source also discusses isocyanate compounds, and notes
that organic isocyanates can cause irritation and allergic
reactions. Organic compounds tentatively identified as having the
isocyanate structure within the molecule were indicated at surface
soil sampling points SS03, SS05, and test pits TP3B, TP5A, and
TP5B. Azobenzene was tentatively identified at shallow soil boring
SB03. The Condensed Chemical Dictionary, tenth edition, as
published in 1981 by Van Rostrand Reinhold Company indicates that
azobenzene is used in the manufacture of fumigants and acaricides,
and that it is moderately toxic and may cause liver damage.
Furthermore, some substances such as lead which were definitively
identified and quantified do not have necessary toxicity
information in the literature to perform risk calculations; hence
risk may be underestimated for that reason.
Notably in the vicinity of the pilot plant there were indications
of toxicity with regard to both the root elongation and the
Microtox test. U.S. EPA interprets these test results as
indicating that some past disposal practices may be having an
adverse effect on the environment.
In summary, quantifiable risk to public health presented by
soils/sediments at the Ott/Story/Cordova site are above upper
limits as far as an acceptable degree of risk. Such calculations
assume zero risk from tentatively identified compounds, and zero
risk contribution from certain positively identified compounds for
which no values exist in the literature to further quantify risk.
U.S. EPA observes that it appears improbable that the true risk
contributions of such compounds is zero. Furthermore, there is
demonstration of environmental risk associated with such soils.
These results indicate that a potential ingestion or absorption of
soils/sediments from certain areas at the Ott/Story/Cordova site
pose significant health and environmental risks. The above
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22
discussions indicate that the risks from current and potential
exposure to contaminated soils/sediments are unacceptable. Actual
or threatened releases of hazardous substances from this site, if
not addressed by implementing the response action selected in this
ROD, may present an imminent and substantial endangerment to public
health, welfare, or the environment.
7. DESCRIPTION OF ALTERNATIVES
The alternatives analyzed for OU Three are presented below:
Alternative l - No Action
U.S. EPA is required to consider a no-action alternative. This
alternative serves as a baseline for comparison purposes. Under
this alternative, U.S. EPA would take no further action at the site
to monitor, control, collect, treat, or otherwise cleanup
contaminated soils/sediments. The cost of this alternative is
therefore zero.
Alternative 2 - Institutional Control
Capital Cost: $ 54,000
Annual O & M Costs: $ 10,000/year for up to 30 years
Net Present Worth: $ 207,000
Time to Implement: 6 months
Access to some portions of the Ott/Story/Cordova site are
restricted, notably by the fencing surrounding former production
areas. Other portions of the site are unrestricted, and such areas
include contaminated soil zones east and south of Agard Road. To
further restrict public access to such areas, fencing could be
extended/constructed and warning signs placed. Property deeds may
need to be amended, so as to place restrictions on land use by
current/future owners, precluding such persons from using certain
land segments. No excavation or treatment of contaminated soil
areas is envisioned.
Alternative 3a - Construction of an on-site landfill with
subsequent excavation and disposal of
contaminated soils/sediments therein, capping,
monitoring, attain RCRA subtitle D - Michigan
Act 641, restriction of further land usage,
security measures, maintenance of the landfill,
clean fill
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23
Capital Cost: $ 3,900,000
Annual O & M Costs: $ 50,000
Net Present Worth: $ 4,700,000
Tine to Implement: 23-28 months
This alternative would involve the construction of an on-site
landfill for the disposal of contaminated soils and sediments
excavated from the site. Excavation will be conducted such that
after disposal all other site areas will have either attained the
cleanup criteria or the groundwater table will have been reached.
The only exception to this excavation procedure would be in
instances where obvious signs of past waste disposal activity are
encountered at the groundwater table. Because of the relatively
shallow groundwater table at the site, the landfill would be
constructed above grade. It is estimated that approximately 7200
cubic yards of contaminated materials would undergo excavation.
The landfill will be constructed to meet the requirements of Act
641, Michigan's solid waste regulations. Providing adequate cover
over the contaminated soil and sediment would be at least two feet
of clay, a drainage layer over the clay, a suitable geotextile
membrane between the drainage layer and overlying soil of at least
1.5 feet in thickness, and finally topsoil and a vegetative cover
to help minimize erosion. The design life of the landfill is
estimated at 30 years.
Alternative 3b - Construction of an on-site landfill with
subsequent excavation and disposal of
contaminated soils/sediments therein, capping,
monitoring, attain RCRA Subtitle C - Michigan
Act 64, restriction of further land usage,
security measures, maintenance of the landfill,
clean fill
capital cost: $ 4,600,000 to 10,400,000
Annual 0 & M Costs: $ 50,000
Net Present Worth: $ 5,400,000 to 11,200,000
Time to Implement: 23-28 months
Alternative 3b differs from Alternative 3 a in that a more rigorous
manner of landfill structure design and capping is called for.
Alternative 3b would be designed to manage excavated
soils/sediments as though they were hazardous wastes. Alternative
3b presumes that the presence of numerous tentatively identified
compounds, the wide variety of chemicals handled at the site during
its history and the limited ability of routine analytical service
to detect all such compounds, and the evidence that there may be
more concentrated areas of contaminants on site than sampling
results have thus far quantified should result in more conservative
management of excavated soils than in Alternative 3a. Operation
and management costs for both Alternatives 3a and 3b reflect
Operable Unit Three monitoring obligations only. U.S. EPA notes
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24
that proper management of a waste disposal facility is to include
groundwater monitoring to check for releases from such facility.
U.S. EPA further notes that design for both Alternatives 3a and 3b
should likely consider whether monitoring wells associated with
Operable Units One and Two might be able to play a role in Operable
Unit Three. U.S. EPA also notes that the coming on line of
construction planned for Operable Units one and Two may bring about
a situation where sediment quality may improve, such that sediment
excavation may be of minimal volume. U.S. EPA will monitor this
situation, and observes that biological monitoring may be a useful
measure. Any excavation necessary in the vicinity of Little Bear
Creek is expected to involve only light remedial activity.
Alternative 4 - Excavation of contaminated soils/sediments,
monitoring, transport to an off-site landfill,
placement of clean fill at the Ott/Story/Cordova
site
Capital Cost: $ 4,500,000
Annual 0 & M Costs: $ 10,000
Net Present Worth: $ 4,600,000
Time to Implement: 8-10 months
As with alternatives 3a and 3b, contaminated soils and sediments
will be excavated but sent off site for disposal in an existing
landfill. The off-site landfill selected must be compatible with
receipt of such waste material. Any off-site shipment of
contaminated hazardous soils/sediments must consider rules which
discuss shipment to treatment, storage, or disposal facilities,
appropriate site security measures, inspection, etc. Some further
analysis required by the receiving facility may be appropriate
before materials are accepted for disposal.
Alternative 5 - Excavation of contaminated soils/sediments,
monitoring, transport to an off-site incineration
facility, treatment therein, disposal of residue
in an off-site facility, placement of clean fill
Capital Cost: $ 18,600,000
Annual 0 & M Costs: $ 10,000
Net Present Worth: $ 18,800,000
Time to Implement: 12-14 months
In this alternative, the contaminated soils/sediments would be
excavated and transported to an off-site incinerator where the
waste materials would undergo thermal treatment. conventional
incineration is typically performed in the temperature range of
1600-2200° F. There may be more than one combustion unit.
Residuals consist of ash, stack gases, scrubber/quench solutions.
There are three basic types of incinerators; a fluidized bed model,
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25
rotary kiln, or infrared type. A fluidized bed type may eliminate
some/all scrubber water compared to the rotary kiln or infrared
models, since the fluidized bed type typically uses limestone
internally to help control emissions. This model also operates at
a somewhat lower temperature than the other two types. A screening
step after excavation is important to eliminate large diameter
objects from entering the device. Some metals can lead to
troublesome emission control problems, that is, metals that can
volatilize at temperatures below 2000° F., such as arsenic,
mercury, and lead. This alternative may require test burns by the
proposed treatment facility. Once materials undergo treatment, the
residuals will require final disposal. The goal of conventional
incineration is to convert organic contaminants to harmless by-
products .
Alternative 6 - Excavation of contaminated soils/sediments,
treatment on site by means of low temperature
thermal desorption, monitoring, replacement of
clean fill and/or transport of residue to off-
site facility, land-usage restriction as
appropriate
Capital Cost: $ 6,800,000
Annual O & M Costs: $ 10,000
Net 0 & M: $ 6,900,000
Time to Implement: 13-19 months
This alternative would utilize the technique of low temperature
thermal desorption (LTTD) for on-site treatment of contaminated
soils/sediments. To differentiate this treatment technique from
conventional incineration, LTTD has as its objective the driving
off of contaminants from the waste mass, rather than the
destruction of such contaminants. There is no combustion in the
primary unit of the waste itself; instead some portion of the
organic contaminants are volatilized and then undergo further
treatment, such as through an afterburner, condenser, or sorption
unit. In LTTD application, materials are heated in three basic
ways: direct heat, indirect heat, or in-situ steam extraction.
Direct heat application is rather like an 800° F. rotary kiln; such
application is most often used for non-chlorinated organics
handling. Indirect heat may heat a fluid such as oil first, and
pass the heated fluid through some jacket to heat the waste
material. In-situ steam extraction involves working temperatures
of around 300-450° F. In LTTD, the temperature 600° F. is seen as
something of a "breakpoint". Below this temperature, it is assumed
that the main application is for volatiles; from 600-1150° F.,
semivolatiles and PCBs are being attacked, also. 1150° F. is about
the upper range for LTTD application. At these lower temperatures,
metals such as lead do not volatilize, making an easier emissions
control situation. After treatment, the residuals are soils, not
ash. Unfavorable site characteristics include excessive clay/silt
content in the soil, many large diameter rocks, excessive moisture
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26
content - since energy is wasted driving off water first. LTTD is
best applied when the organic contaminants do not make up more than
10% of the soil matrix. After treatment, dust generation may
become a problem, so water is added to dampen the treated material.
To prevent combustion, sometimes an inert gas such as nitrogen is
injected countercurrent to the flow of treated material. Following
treatment the residual soils may be suitable for replacement on
site. Prior to commencing operation, treatability study would be
necessary to define optimum operating conditions. '
Alternative 7 - Construction of an on-site landfill with
subsequent excavation of and disposal of a
substantial portion of contaminated
soils/sediments therein, excavation and off-site
treatment of more highly contaminated
soils/sediments, capping, monitoring,
restriction of further land usage, security
measures, maintenance, clean fill
Capital Cost: $ 4,113,000 (if 100 cubic yards treated)
Capital Cost: $ 6,480,000 (if 1200 cubic yards treated)
Annual 0 & M Costs: $ 50,000
Net Present Worth: $ $ 4,882,000 to $ 7,249,000
Time to Implement: 23-28 months
This alternative combines the usage of containment to deal with the
majority of contaminated soils/sediments with treatment of that
lesser volume containing more contaminated materials. From RI
sampling, and supplemental sampling to obtain TCLP, dioxin,
toxicity, and excavation analysis results, two site areas appear to
have been more highly contaminated. These are: l) The areas around
1992 sampling area test pits 4 and 5 because of their
concentrations of such mobile and toxic compounds as carbon
tetrachloride, 1,2-dichloroethane, chloroform, etc.; and 2) Surface
soils identified as dioxin-contaminated near the former incinerator
pad area. The volume of soils associated with these areas of
greater soil contamination is estimated at from 100 cubic yards for
the incinerator area to 1200 cubic yards for areas near test pits
# 4 & 5. For the purpose of cost estimation of this alternative,
it is assumed that the treatment of such higher contamination areas
will be performed off site by conventional incineration.
Common Elements: Except for the "No-Action" alternative, other
alternatives noted have certain elements in common. Alternatives
which would leave contaminated soils or fill on the
ott/ Story/ Cordova site all envision some form of land-usage
restriction. In alternatives 3a, 3b and 7, the key objective of
restricting land usage is so that the newly created on-site
landfill is not unduly disturbed. This is in addition to an
objective of alternative 2, where land usage restriction through
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27
enhanced security or deed restriction has as a goal the reduction
of exposure to otherwise contaminated soil areas. Monitoring is a
component of alternatives 3 through 7. In all cases, monitoring
implies sampling of soils/sediments areas undergoing remediation to
ensure that desired cleanup criteria have been attained. In
alternatives 3a, 3b and 7, monitoring also implies periodic
examination of the integrity of the landfill cover, while in
alternatives 5 and 6 monitoring further means checking
soil/sediment condition after treatment. Appropriate monitoring of
such units often involves placement and sampling of groundwater
monitoring wells as a means of checking for effectiveness. (In
this instance remedial design may show that placement of such wells
may not be required because the execution of Operable Units one and
Two requires the development of an appropriate groundwater
monitoring network which may prove to be sufficient for such
purpose.) Operation and maintenance might normally require
consideration of installation of facilities a means of treating
liquids/leachate that may be gathered from the fill area. However,
U.S. EPA makes the assumption at this time that any liquids so
gathered from an on-site landfill will be compatible with the
contaminated groundwater treatment works necessary for Operable
Units one and Two.
Excavation of affected areas is also a common component of
alternatives 3 through 7. With regard to excavation, it should be
noted that excavation of contaminated soils near former production
areas.may involve relatively heavy earth-moving equipment, whereas
any excavation of any contaminated sediments in the vicinity of the
creeks would involve small volumes and light manual equipment.
U.S. EPA observes that the principal identifiable hazardous
substances associated with deposits along the stream banks are
volatile organic materials such as benzene and toluene. U.S. EPA
will be guided by monitoring and observation to be conducted as a
part of Operable Units One and Two to changes in sediment
condition, and the necessity to actively perform light remediation
activity along the stream banks. Another common element of
alternatives 3 through 7 is the amount of soil /sediment to be
excavated. This volume is estimated at 7200 cubic yards, and is
derived from calculations performed to attain Michigan Act 307 Type
B criteria, which U.S. EPA believes is an appropriate Act 307
application in this instance.
8. Summary of Comparative Analysis of Alternatives
A. The Nine Evaluation Criteria
In selecting its preferred remedial alternative, U.S. EPA uses the
following criteria to evaluate each of the cleanup alternatives
developed in the FS and its supplement. The nine evaluation
criteria are summarized below:
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28
1) Overall protection of human health and the environment
addresses whether or not an alternative provides adequate
protection of human health and the environment and describes
how risks are eliminated, reduced or controlled through
treatment, engineering controls, or institutional controls.
2) Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs) addresses whether or not an alternative
will meet all of the ARARs pertaining to federal and state
environmental lavs and regulations and/or justifies the
invoking of a waiver of such ARARs.
3) Long-term Effectiveness and Permanence refers to the
expected residual risk and the ability of an alternative to
maintain reliable protection of human health and the
environment over time, once cleanup objectives have been
met.
4) Reduction of Toxicity, Mobility, or Volume through treatment
is the anticipated performance of the treatment technologies
an alternative may employ.
5) Short-term Effectiveness involves the period of time needed
to achieve protection and any adverse impacts on human
health and the environment that may be posed during the
construction and implementation period until cleanup
.. objectives are achieved.
6) Implementability is the technical and administrative
feasibility of an alternative, including the availability
of materials and services needed to implement the given
option.
7) Cost includes estimated capital costs, as well as operation
and maintenance costs. A present net worth cost is then
calculated from these costs.
8) State Acceptance indicates aspects of the preferred
alternative and other alternatives that the state support
agency (MDNR) favors or objects to, and comments regarding
state ARARs or the proposed use of waivers.
9) Community Acceptance indicates the public support of a given
alternative. This criterion is discussed in the
Responsiveness Summary.
B. Comparative Analysis
overall protection of human health and the environment - The "no-
action" alternative does not offer adequate protection of human
health and the environment. Taking no action would allow the
unabated presence of a level of risk beyond that deemed acceptable.
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29
Additionally, as biological testing performed on site soils has
indicated, harm to the environment may result if certain site areas
do not undergo remediation. Alternative 2, which relies solely on
institutional control as a means of remedy, is not protective of
human health and the environment. Even if measures limiting site
access and deed restrictions were rigorously observed, areas of the
site would still pose possible problems. While site manufacturing
activity has been curtailed, a "skeleton" staff still remains. The
site gets visitors from time to time from persons interested in
surplus chemical equipment. Furthermore, actions taken to restrict
access by persons would not provide sufficient environmental
protection to those site areas which appear to have some inhibitory
effect upon plant life and soil bacteria. Such restrictions also
would do nothing to mitigate further release of hazardous
substances into groundwater. Therefore, while some manner of
institutional control may have a role to play in site remediation,
such control in itself does not provide adequate protection.
Furthermore, the NCP at 40 CFR 300.430(a)(l) (iii) (g) indicates that
the use of institutional controls is generally only appropriate as
supplemental to active remediation, such as treatment or
containment, unless such active remedies are not practicable, which
they are in this case.
All other alternatives are viewed as protective of human health and
the environment because they will remove contaminated soils and
leave behind concentrations attaining soil cleanup criteria. Since
the "no action" alternative and the alternative relying solely on
institutional control (Alternatives 1 and 2) are not protective of
human health and the environment, they will not be considered
further in this document.
Compliance with ARARs - The primary ARARs for Operable Unit Three
include federal and state regulations dealing with soil cleanup
criteria, waste management and landfill cover and liner
construction, proper management of fugitive dusts created through
excavation, management of leachate generated and collected, soil
erosion protection measures, proper shipment and waste
characterization steps, control of air emissions generated, and
restriction of inappropriate materials from being disposed. TCLP
testing conducted by U.S. EPA indicated that the soils/sediments to
undergo disposal are not characteristically hazardous with regard
to such compounds as methoxychlor, hexachlorobenzene, and 1,4-
dichlorobenzene. The significance of such testing was that at the
time of release of the proposed plan to the public concerning
possible remedial action for Operable Unit Three that U.S. EPA did
not advocate a landfill design which would attain the even more
restrictive specifications which may be found in RCRA Subtitle c or
Michigan Act 64 which deal with management of hazardous wastes.
The Landfill Disposal Restrictions noted in 40 CFR Part 268 were
therefore not relevant and appropriate with regard to these
compounds. Another key ARAR for this and all other alternatives
discussed is to minimize the creation of fugitive dusts that may
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30
be created during the excavation and/or transportation phases of
the remedial action. Parts 3, 7, and 9 of Michigan Act 348 (Air
Pollution Act) discuss the limitation of particulates, fugitive
dusts, and volatile organics which may result from construction and
excavation activity performed to implement a given remedy. Any
collection and subsequent routing of leachate or other water
generated by undertaking action for Operable Unit Three would be
subject to provisions of the Clean Water Act of 1977, as amended,
dealing with the discharge of specific compounds into navigable
waters. At this time, U.S. EPA makes the presumption that any
leachate or other water generated and collected on-site would be
compatible with and would be routed to the treatment system to be
built to serve Operable Units One and Two. The substantive
requirements of Michigan Act 347, dealing with soil erosion and
sedimentation, may also apply to acts of remediation. It would be
appropriate in the undertaking of Alternatives 3a through 7 to take
representative samples of soils handled or shipped with frequency
sufficient to adequately develop information on how the soils
should be treated, stored, or disposed. Alternatives 3a through 7
should comply with all of the major ARARs 'noted above provided due
care is taken in the construction and maintenance phases of the
work to be done. Given the numerous instances of discarding
specific chemicals on the site, it would appear that for
Alternative 4 a compatible, landfill for disposal of untreated
contaminated soils must comply with RCRA Subtitle C design
standards. U.S. EPA notes that the greatest burden of compliance
with air emission regulations would appear to fall on Alternative
6, since that alternative contemplates on-site treatment.
It is noted for purposes of ARARs discussion that the State of
Michigan has promulgated rules pursuant to the Michigan
Environmental Response Act, Act 307. This state statute was
originally enacted in 1982, but underwent significant amendment in
1990. The State of Michigan issued rules reflecting such amendment
in July 1990. In general, U.S. EPA maintains that substantive
provisions of state regulations which are more stringent than
CERCLA requirements constitute ARARs. Act 307 consists of eight
parts, but of particular note are parts 6 and 7 which deal with
remedial action and cleanup criteria, respectively. U.S. EPA notes
that upon examination of these parts, certain administrative
provisions are very similar to the nine criteria which form the
basis for remedial decisions under the NCP. Such administrative
provisions are not ARARs. However, the substantive provisions of
these parts are considered ARARs for this response action.
Rule 705(2) and (3) require that all remedial actions shall attain
the degree of cleanup for a Type A, B or C remedy, or a combination
thereof. U.S. EPA believes such cleanup selection to constitute an
ARAR. A Type A cleanup generally achieves cleanup to background
levels. A Type B cleanup generally achieves specific standard
risk-based cleanup levels. A Type C cleanup is based on a site-
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31
specific risk assessment that considers specific criteria. Also,
Type A cleanup is to attain the standards noted in Rule 707. Type
B cleanup must reflect attainment of Rules 709-715 and Rule 723.
Rule 717 discusses Type C cleanup. U.S. EPA notes that it has
consulted with the MDNR concerning the soils cleanup criteria noted
elsewhere in this document.
Under the NCP, U.S. EPA is responsible for determining how Act 307
applies to the site. U.S. EPA has examined this matter and has
determined that the attainment of Type B soil criteria is an
appropriate application.
The following summary lists other ARARs of significance for this
operable unit, as may they pertain to a given alternative:
Clean Air Act and National Ambient Air Quality Standards (CAA
and NAAQS), 40 CFR Part 50: These regulations discuss site
emissions including par'ticulates during on-site excavation.
They provide methods and procedures for measuring specific air
pollutants; such methodology may apply to operation of soil
treatment systems. They are action-specific, regarding
alternatives 3a through 7.
Michigan Act 641 landfill regulations 299.4305(10), deal with
appropriate landfill topsoil application and drainage/sloping
requirements; 299.4308(1) deals with means of leachate
collection; 299.4307(2)(a) deals with synthetic liner usage;
299.4307(2)(a) deals with thickness of clay liners; 299.4310
deals with appropriate vertical isolation from the bottom of
the landfill to the top of the groundwater table.
40 C.F.R. Part 61; EPA Regulations on National Emission
Standards for Hazardous Air Pollutants: These rules denote
substances designated as hazardous air pollutants, prohibit
certain activities and describe procedures involving
construction and start of operations. These regulations may
provide substantive requirements concerning operations. They
are action-specific, regarding design of treatment for
alternatives 5 through 7.
Resource Conservation and Recovery Act (RCRA) of 1976, as
amended by the Hazardous Solid Waste Amendments (HSWA) of 1984,
42 U.S.C. 6901. Subtitle C regulates disposal of that portion
of solid waste designated as hazardous and the generation,
transport, storage, treatment and disposal of hazardous wastes.
RCRA ARARs are not strictly applicable to this situation but
are relevant and appropriate information, since RCRA wastes
were known to have been managed here and waste chemicals were
known to have been improperly land disposed on the site. RCRA
ARARs may pertain to remedial action regarding alternatives 3a
through 7, since residuals created require proper management.
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32
Michigan Air Pollution Act, Public Act 348 of 1965, as amended:
This act regulates air quality in the presence of new or
modified air sources. Parts 3, 7, and 9 of this regulation
discuss emissions and limitations for particulates, fugitive
dust, volatile organic compounds, and other contaminants which
may be injurious or adversely affect human health or welfare,
animal life, vegetation, property, or interfere with normal use
and enjoyment. Substantive portions of this regulation may
apply to excavation of contaminated soils, operation of any
soil treatment system, and related construction activity. This
act is action-specific, regarding monitoring or any needed
control of volatile organics in alternatives 3a through 7.
40 C.F.R. 262; Regulations for Hazardous Waste Generators and
Michigan Hazardous Waste Management Rules, Part 3, R299.9301 to
9309; "Generators of Hazardous Wastes."
Note: This, as well as the CERCLA off-site policy, is "to be
considered" information which may pertain to any necessary off-
site shipments of still-contaminated soils after treatment by
low temperature thermal description, such regulations are ARAR
if CERCLA site materials are shipped off site to RCRA
treatment, storage or disposal (TSD) facility and constitute a
hazardous waste. They are chemical-specific, as related to
soils/sediments and as pertaining to alternatives 4 through 7.
40 C.F.R. 264, Subpart C; Preparedness and Prevention.
40 C.F.R. 241, concerning construction of a RCRA Subtitle D land
fill for disposal of nonhazardous wastes. This is an action-
specific ARAR for alternatives 3a or 6.
40 C.F.R. 264.340-351, concerning incinerator performance
standards. A potential ARAR if on-site incineration is
selected.
40 C.F.R. 264 Subpart X. Describes substantive requirements for
miscellaneous RCRA treatment units, such as low temperature
thermal desorption. Pertinent to alternative 6.
Michigan Hazardous Waste Management Rules.
Note: As with RCRA, these State rules constitute relevant and
appropriate information, especially to the degree that they
exceed their counterpart federal regulations in substantive
requirements. They are potential ARARs for post-closure
detection monitoring after remediation if hazardous wastes
remain on-site. Action-specific, for alternatives 2 through 7.
(Design may indicate compliance is possible with portions of
these rules through monitoring necessary to undertake surface
water and groundwater restoration measures called for by Oper-
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33
ble Units One and Two, respectively.) Should an Act 64-
compliant landfill be selected, pertinent measures from Act 64
include regulations 299.9619(6) dealing with appropriate means
of synthetic cap installation, topspil placement, and drainage
measures; 299.9619(1) and (2) dealing with synthetic and clay
liners, respectively; 299.9619 (3) and (4) dealing with leak
detection and leachate collection, respectively; and 299.
9603(5) which discusses bottom layer thickness and permeability
characteristics of soils which are to intervene between the
landfill and the top of the groundwater table.
Part 7, R336.1702; New Sources of VOC Emissions.
Note: This is an ARAR for new sources of VOC emissions for new
remedial action. Any person responsible for any new source of
VOC emissions shall not cause or allow the emission of VOC
emissions from the new source to exceed the lowest maximum
allowable emission rates. A design consideration for
alternative .6 if treatment is performed on-site, since volatile
organics are a component of some soils/sediments and transfer
from soils to air without proper emission control is not
appropriate.
Michigan Environmental Response Act; Act No. 307
As discussed above.
Long- Term Effectiveness and Permanence - Through on-site or off-
site containment measures, Alternatives 3a, 3b, 4, and 7 would
provide effectiveness and permanence by reducing human exposure via
ingestion or direct contact to contaminated materials, and by
reducing the amount of water infiltration through such materials
thereby aiding in the reduction of amounts of contaminants that may
be introduced to the groundwater below the site. For on-site
alternatives, long-term maintenance would be required, and portions
of the cap may need repair in the future. Alternative 4 calls for
off-site landfill usage. U.S. EPA notes that under CERCLA, off-
site disposal without treatment is considered a least preferred
option for alternatives that otherwise offer adequate protection
and comply with ARARs. Alternatives 5, 6 and 7 may offer a
superior degree of attainment of this criterion in that they call
for the destruction or capture of the highest concentrations of the
contaminants. While employment of either a containment or
treatment remedy could result in attainment of appropriate criteria
concerning degree of risk remaining in soils to which site users
could be exposed, a treatment remedy offers less uncertainty and
greater permanence in the continuing attainment of cleanup criteria
than either institutional control or containment remedies. This,
in the case of the Alternatives 5, 6 and 7 is accomplished either
through the direct destruction of hazardous substances or the
driving off and subsequent destruction of such compounds. U.S. EPA
notes that site remedies previously selected call for the capture
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of the groundwater contamination. The excavation and subsequent
treatment/disposal of contaminated materials will reduce the
ability of such materials to act as a future source of groundwater
contamination. An alternative featuring such source reduction
capability is therefore compatible with remedies previously
selected.
Reduction of Toxicity, Mobility, or Volume of the contaminants
through Treatment - Alternative 5, conventional incineration,
offers the highest degree of attainment of this criterion in that
the entire mass of contaminated soil would be subjected to intense
thermal treatment. Alternatives 6 and 7 (LTTD and treatment of
certain more highly contaminated soil areas) also attain this
criterion, although to a lesser degree. Although in Alternative 6
the entire waste mass is to be treated, the intensity of treatment
is not as rigorous as in Alternative 5. Treatment addresses
principal threats posed at the site, in that employment of a
technique such as LTTD is expected to result in significant removal
and subsequent destruction of site soil contaminants such as
aniline compounds, 4,4'- DDT, PCBs, carbon tetrachloride, etc.
Benefits of LTTD employment as compared to conventional
incineration are less risk of generation of metallic compound
emissions, and less risk of generation of products of incomplete
combustion, since there is no direct combustion of the waste mass
itself. Selection of LTTD at other sites indicates that this
technology would appear to have practicable application.
Alternatives 3a and 3b, on-site landfilling and capping, and
Alternative 4, off-site landfilling, do not provide for reduction
of toxicity, mobility, or volume through treatment.
Short-Term Effectiveness - Alternatives 3a through 7 all have the
potential for exposure during excavation and construction,
transport, or treatment phases. Instituting proper health and
safety and emission control procedures will aid in minimizing such
risk, one possible advantage of Alternatives 3a, 3b, 6, and 7 when
compared to Alternatives 4 and 5 is that they call for on- site
handling of all or most contaminated soils and sediments.
Therefore, there is no risk of exposure during transportation. The
on-site treatment that Alternative 6 envisions may require a more
rigorous means of emissions control than Alternatives 3a or 3b,
such as employment of flaring, condensation, or carbon adsorption
techniques for contaminants driven off the soil mass.
Implementability - Alternatives 3a through 7 are all considered to
be implementable. Landfill capping techniques and construction or
usage are well established. U.S. EPA notes that Alternatives 4 and
5 rely to a large degree on presumed existing disposal and
treatment capacity, respectively. It is also presumed that vendor
developed mobile equipment would be utilized for Alternative 6.
Therefore, remedial design efforts in implementing Alternatives 4,
5 and 6 may be less rigorous than for other alternatives such as 3a
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or 3b. Techniques involving on- or off-site treatment should also
be implementable from a technical standpoint; however U.S. EPA
cannot predict with certainty as to what degree vendor services and
capacity at the time treatment is needed will be available.
Alternative 6 may require further information to be derived from
pre-design work prior to implementation. Such information may
focus on whether all soils thus treated should be heated to a
common temperature, or whether a portion thereof would be more
effectively treated at a higher temperature. Design for
Alternative 6 also considers what proportion of emissions thus
created from driving contaminants off the soils should be performed
by flaring, condensation, or usage of carbon adsorption. These
emission control techniques are considered reliable, and necessary
monitoring can be performed for each.
Cost - The present worths of Alternatives 3a, 3b, 4, 5, 6, and 7
were estimated as: (3a) $ 4,700,000; (3b) $ 5,400,000 to $
11,200,000; (4) $ 4,600,000; (5) $ 18,800,000; (6) $ 6,900,000; and
(7) $ 7,249,000, at the time of issue of the proposed plan to the
public. Based on review of commentary received, U.S. EPA now
believes that the upper-most cost range for Alternative 3b ($
11,200,000) is more truly indicative of the cost for on-site
containment without prior treatment, and that the present worth of
Alternative 6 is revised to an estimated $ 6,808,000 as discussed
in the Documentation of significant Chances section of this
decision record. Hence, the selected alternative, Alternative 6,
is far less costly than either conventional incineration or
Alternative 3bf which features containment only in an on-site
landfill taking into account the possibility of risk
underestimation in managing the contaminated soils. One possible
uncertainty in predicting cost of any alternative is with the
volume of soil to be managed. With regard to Alternative 6, it
should be noted that U.S. EPA has utilized a cost per cubic yard
basis at the high end of an expected spectrum of costs. As is
noted in U.S. EPA's Responsiveness Summary, U.S. EPA has utilized
an estimate of $ 340 per cubic yard for LTTD treatment. The
literature and vendor information suggest a range of from $ 45 to
$ 350 per cubic yard. Variance in these figures is attributed to
contract terms, soil moisture content, type of organic contaminant
to be dealt with, and degree of treatment efficiency sought.
State Acceptance - The MDNR has indicated a decided preference for
low temperature thermal desorption treatment of the contaminated
soils. The MDNR has also indicated that if containment of such,
soils without prior treatment were contemplated, an Act 64 type of
landfill with full vertical isolation measures incorporated would
be preferable to an on-site Act 641 landfill.
community Acceptance - Community acceptance of the preferred
alternative has been evaluated after the close of the public
comment period and is described in the Responsiveness Summary
portion of the ROD. The public responded negatively to the
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creation of landfills in the Muskegon area. The public's reaction
to the suggestion of the possibility of combined response action at
Muskegon area CERCLA sites was mixed; the public did not advocate
combined response action involving the Ott/Story/Cordova and Bofors
sites, but did advocate combined response action between the
Ott/Story/Cordova and Duell & Gardner sites especially in the area
of contaminated soils. It should be noted that the Ouell & Gardner
proposed plan called for dealing with portions of contaminated
soils at that site through usage of low temperature thermal
desorption treatment followed by management of residuals and site
closure through placement of an Act 641-compliant cover over that
site. The public sent 10 letters to U.S. EPA urging that some
manner of treatment technology be utilized, as opposed to landfill
utilization.
9. Documentation of Significant Changes
U.S. EPA has reviewed and responded to all significant comments
received from interested parties during the public comment period.
Comments were made on the alternative indicated as preferred in the
Proposed Plan as well as other alternatives. Based on review of
these comments, the U.S. EPA has determined that there should be a
significant change made in the alternative selected. At the time
of the release of U.S. EPA's Proposed Plan to the public, U.S. EPA
indicated that Alternative 3a was the preferred alternative. This
alternative includes construction of an on-site landfill with
subsequent excavation and disposal of contaminated soils/sediments
therein, capping, monitoring, restriction of further land usage,
security measures, maintenance, clean fill placement. After
evaluation of the comments received, and a review of the
alternatives using the nine evaluation criteria, U.S. EPA now has
a preference for Alternative 6, as set forth in the Proposed Plan,
with slight modifications thereto. Alternative 6 involves
excavation of contaminated soils/sediments, treatment on site by
means of low temperature thermal desorption, monitoring, usage of
treated soils which successfully attain soil cleanup criteria as
on-site backfill material, and transport of residue not attaining
soil cleanup criteria to an appropriate off-site facility, with
imposition of land-usage restrictions as appropriate.
Compared to either Alternative 3a or 3b, Alternative 6 provides a
shorter estimated implementation time, provides for superior
reduction of toxicity, mobility, or volume of hazardous substances,
provides for a superior degree of long-term effectiveness and
permanence, and appears to be far more cost-effective than
Alternative 3b. Alternative 6 provides superior short-term
effectiveness in that the amount of time necessary to complete the
remedial design is less than Alternative 3a or 3b. There is also
a higher degree of state and community acceptance of LTTD treatment
as opposed to construction of a landfill.
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U.S. EPA makes note of certain public comments received which
argued that untreated contaminated soils should be disposed of
within a landfill structure attaining the more rigorous Michigan
Act 64 criteria, due to the presence of tentatively identified
compounds within the soils. These tentatively identified compounds
appeared to include substances which are used as a herbicide,
pesticide, or which have a chemical structure featuring the cyanide
grouping. Some commentary suggest that certain site soils may be
characteristically hazardous. Discarded chemicals were known to
have been improperly land disposed on the property. Since relevant
and appropriate criteria associated with the construction of an Act
64 compliant landfill call for, among other measures, a 20 foot
thick layer of compacted clay beneath the landfill and above the
groundwater table, the cost of appropriate on-site landfill
construction is at the high end, i.e., $ 10-11 million, of U.S.
EPA's estimate for construction of such an on-site hazardous waste
landfill. While U.S. EPA may elect to waive a given ARAR, it may
not be appropriate to do so in this instance because of the
relatively high groundwater table at the Ott/Story/Cordova site.
As noted in the supplement to the FS and the proposed plan, it was
assumed that soils which did not achieve soil cleanup criteria
after initial treatment by low temperature thermal desorption
(LTTD) would undergo more rigorous treatment through incineration
in an effort to achieve cleanup criteria. Hence, capital costs for
the LTTD alternative in the proposed plan include costs for
treatment by incineration for the 25% of contaminated soil volume
which was estimated not to attain soil cleanup criteria after LTTD
treatment. The supplement to the FS estimates off-site
incineration costs as $ 2,952,000. Comment received by the State
of Michigan indicates that application of LTTD technology should
provide an acceptable degree of treatment such that soil residuals
not attaining soil cleanup criteria will have attained a sufficient
degree of treatment such that placement in an Act 641 compliant
landfill would be acceptable. This comment appears to be supported
by treatability information which appears in the Ott /Story /Cordova
record which was obtained from studies performed at the Anderson
and Duell & Gardner sites. In both those instances, LTTD
application resulted in 90-99% removal of organic compounds. The
99% removal rate was achieved at the Duell & Gardner site. Because
of the similarity of soil characteristics between the Duell &
Gardner and Ott /Story /Cordova sites (the sites are both located in
Dalton Township, only a few miles apart) , U.S. EPA has reason to
believe similar removal efficiencies could be realized through LTTD
application at the Ott/Story/Cordova site. In removing
contaminants with this degree of efficiency, U.S. EPA concurs with
the State's assertion that subsequent management after LTTD
application could be conducted in accordance with solid waste,
rather than hazardous waste, regulations.
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Deleting the incineration cost, and adding in a disposal fee of
approximately $ 25/cubic yard for usage of a commercially available
Act 641 compliant landfill results in revised cost estimates for
the LTTD alternative as shown:
Previous Estimate Revised Estimate
option subtotal $ 7,575,950 $ 4,683,950
-i-bid contingency (8%) 606,075 374,716
+scope contingency (15%) 1.136.390 702.592
construction cost 9,318,415 5,761,259
+permit/legal (5%) 465,920 288,063
+construction service (5%) 465.920 288.063
implementation costs 10,250,255 6,337,385
+design costs 512.515 316.869
total capital costs 10,762,770 6,654,254
+O & M COStS 154.000 154.000
present net worth 10,919,800 6,808,254
As noted in the proposed plan, were an on-site landfill to be built
so as to fully comply with all aspects of Michigan Act 64, capital
costs would be approximately $ 10,400,000. Allowing for operation
and maintenance costs present worth would total approximately
$ 11,200,000. Hence, assuming that more intensive treatment of
those soils which do not fully attain soil cleanup criteria is
unnecessary, LTTD treatment followed by usage of a less rigorous
landfilling option would appear to be a distinctly more cost-
effective form of remediation as opposed to disposal in a more
rigorously designed on-site landfill. Upon review of comments
received, and in light of the existence of TICs and the
observations made during test pit excavation, U.S. EPA concludes
that untreated contaminated soils, if landfilled on site, should be
put in a hazardous waste landfill. After considering LTTD results
at the Anderson and Duell & Gardner sites, U.S. EPA has reason to
believe that a significant amount of contaminated soils will attain
soil cleanup criteria after LTTD treatment at the Ott/ Story /Cordova
site such that designing an on-site landfill for this lesser volume
would be impractical and not cost effective. Because of the high
level of removal efficiency realized in LTTD testing at the Duell
& Gardner site, and the proximity of that site as well as its
similar soil and contaminant characteristics to the
Ott/Story/Cordova site, U.S. EPA presumes that, after LTTD
treatment, soils not fully attaining soil cleanup criteria can be
managed off-site in an Act 641 (nonhazardous) landfill.
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In the event that additional data or information during the design
of the remedy reveals the need for modification, U.S. EPA will
notify the public of any changes to the remedy presented in this
ROD in accordance with applicable law and Agency guidance.
10. Selected Remedy
The selected alternative for the third Operable Unit is Alternative
6. Alternative 6 involves excavation of contaminated
soils/sediments, treatment on site by means of low temperature
thermal desorption, monitoring, usage of treated soils which
successfully attain soil cleanup criteria as on-site fill material,
and transport of residue not attaining soil cleanup criteria to an
appropriate off-site facility, with imposition of land-usage
restrictions as appropriate.
Alternative 6 provides a high degree of long-term effectiveness and
permanence and is compatible with remedies previously selected.
Based on the current information, this alternative would appear to
provide the best balance or trade off among the alternatives with
respect to the nine criteria that U.S. EPA uses to evaluate
aIternatives.
The selected alternative would be protective of human health and
the environment, and would comply with all ARARs. The goal of
Operable Unit Three is to bring about the disposal and treatment of
those soils and sediments which pose unacceptable risks to human
health and the environment. The selected remedy utilizes permanent
solutions and alternative treatment technologies, not solely
because of the need to provide treatment of a principal threat
involving risk to human health or the environment, but rather
because usage of treatment techniques in this instance appears to
result in selection of a more cost-effective remedy rather than
usage of containment measures only. Due to certain characteristics
of this site, specifically the high groundwater table and the
possibility for underestimation of risk, selection of a treatment
technique to manage most of the contaminated soils/sediments
appears warranted.
Some changes to this alternative may result due to normal remedial
design and construction processes. For example, items which are
physically incompatible with the LTTD process, such as the
introduction of excessively large drum fragments, discarded lab.
bottles, or potential highly concentrated waste forms - as opposed
to contaminated soils - should likely be placed in overpack
containers and subsequently managed in accordance with pertinent
waste regulations.
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11. Statutory Determinations
Protection of Human Health and the Environment
The soils and sediments associated with the OTT/STORY/CORDOVA site
have been degraded through the introduction of contaminants
associated with former material or product usage activity at the
site. At least a portion of the soils and sediments pose an
unacceptable risk to potential site users, with excess cancer risks
greater than 1 x 10"4 for future site workers. The toxicity
results of vegetative root elongation and Microtox testing
performed on soil samples collected in areas of sparse vegetation
when compared to background sample conditions also indicate that
the site as it exists may pose an environmental risk.
The selected remedy protects human health and the environment with
regard to contaminated soils. The excavation of these contaminated
areas and the subsequent treatment/containment of such contaminated
soil/sediments utilizing techniques of appropriate design will aid
in reducing contaminant levels and assist in preventing exposure
above acceptable levels. Monitoring and institutional controls
will also promote the evaluation of effectiveness of remediation
measures.
Implementation of the remedy will not pose unacceptable short-term
risks or cross-media impacts. With regard to risk to human health,
the selected remedy will reduce levels of risk to potential users
of the soils/sediments such that levels of protection as called for
through achievement of Michigan Act 307 Type B cleanup criteria are
attained. With regard to protection of the environment, the
selected remedy will eliminate undue toxicity to life forms now
posed by soil conditions.
Chemical and biological monitoring so as to assure the attainment
of soil/sediment cleanup criteria and toxicity reduction goals in
the surface and near surface site soils will be a necessary part of
ensuring the achievement of these goals.
Compliance with Applicable or Relevant and Appropriate Requirements
rARARsl
The selected remedy is required to fully comply with all federal
and more stringent state ARARs unless a waiver is invoked. The
selected remedy complies with all ARARs. With regard to soils and
sediments, the selected remedy has as its goal the attainment of
all soil cleanup criteria as determined by Michigan Act No. 307,
and the attainment of all federal/state ARARs concerning the
management and handling of waste materials. The selected remedy
therefore will be in conformance with CERCLA Section 121.
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Cost Effectiveness
The selected remedy affords overall effectiveness proportionate to
its cost. The remedy promotes the attainment of soil cleanup
criteria. Alternative 6 is far less costly than either
conventional incineration or Alternative 3b, which features
containment only in an on-site landfill.
Utilization of Permanent Solutions and Alternative Treatment
technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
The remedy selected provides the best balance of tradeoffs among
the alternatives considered with respect to the nine evaluation
criteria. The selected remedy utilizes permanent solutions and
alternative treatment technologies. The site poses unacceptable
risks with regard to soils/sediments, and U.S. EPA perceives that
the presence of numerous tentatively identified compounds as well
as compounds for which no pertinent slope factors exist may have
resulted in an underestimation of risk to human health. There
appears to have been some demonstration of environmental risk as
well. Given the number of tentatively identified compounds
detected in site soils, the high groundwater table at the site, the
likelihood that certain treatment techniques may be brought to bear
on site soils at less cost than certain "contain-only" options, it
appears prudent to select a remedy featuring such treatment
techniques for most contaminated site soils/sediments.
The MDNR has been consulted during development of the site FS,
proposed plan, and participated in the public comment period.
Community views were solicited during the public comment period.
U.S. EPA attempted to keep the community informed of site
developments via the local information repositories and by the
local establishment of certain documents in the administrative
record for this site prior to the commencement of the public
comment period.
Preference for Treatment as a Principal Element
The alternative selected, Alternative 6, features treatment of
contaminated soils as a principal element of the remedy utilizing
the technique of low temperature thermal desorption.
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