United States Office of OSWER Directive 9355.3-17
Environmental Protection Emergency and EPA 540-R-93-059
Agency Remedial Response PB93-963328
Washington, D.C. 20406 April 1993
Superfund
vvEPA Compendium of
ROD Language
for FY 1993 Focus Areas
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Publication 9355.3-17
April 1993
COMPENDIUM OF ROD LANGUAGE
FOR FY 1993 FOCUS AREAS
Office of Emergency and Remedial Response
U.S. Environmental Protection Agency
Washington, DC 20460
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NOTICE
The polices and procedures set forth here are intended as guidance to Agency and other
government employees. They do not constitute rulemaking by the Agency, and may not
be relied on to create a substantive or procedural right enforceable by any other person.
The Government may take action that is at variance with the policies and procedures in
this manual.
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CONTENTS
SECTION PAGE
I. RATIONALE FOR THE SELECTED REMEDY 1
II. CLEAN-UP LEVELS 5
III. ECO-RISK ASSESSMENT 11
IV. ARARs IN DESCRIPTION OF ALTERNATIVES 27
V. ARARs IN STATUTORY DETERMINATIONS 37
VI. ENFORCEMENT HISTORY 43
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COMPENDIUM OF ROD LANGUAGE
FOR FY 1993 FOCUS AREAS
Introduction
This compendium has been prepared to help improve national consistency and required
documentation in Superfund Records of Decision (RODs).
Sections 113, 117 and 121 of CERCLA, as amended, require the issuance of a
decision document for remedial action, known as a Record of Decision (ROD). A ROD must
include the rationale and purpose for the selected remedy, based on site-specific information
and supporting analysis. It is important that RODs be consistent both within and across
Regions with respect to organization and content to determine that all statutory and regulatory
requirements have been met.
Background
During the past four years, from FY 1988 through FY 1991, ROD analyses were
conducted by the Office of Emergency and Remedial Response (OERR) and the Office of
Waste Programs Enforcement (OWPE) to gather data on remedies selected, to determine how
well RODs were being written to comply with guidance and CERCLA requirements, and to
examine overall quality and consistency. These studies have resulted in many improvements
in ROD documentation over the last several years. However, because the focus and scope of
the annual ROD analysis have changed considerably since 1988, the following projects are
being conducted in lieu of holding a traditional three day Headquarters/Regional ROD
questionnaire analysis.
The OWPE has conducted a mini-analysis of the FY 1992 source control RODs to
address the distribution of treatment and containment remedies at Fund versus Enforcement-
lead sites. OWPE and OERR are coordinating the development of a new data base which
will be capable of analyzing current and future ROD documentation requirements and
technical data. OWPE and OERR have also worked together to gather sample ROD language
that pertains to ROD documentation areas which continue to be critically important from a
national perspective. The resulting collection of ROD sample language, this Compendium of
ROD Language for FY 1993 Focus Areas, is being sent to every Region for use in preparing
FY 1993 and future RODs.
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Implementation
There are five major areas of focus for ROD language which may help improve FY
1993 RODs. These were identified based on the results of the FY 1991 ROD Analysis,
(conducted in January 1992 and presented to the Regions in a memorandum titled, Transmittal
of the Results of the FY 1991 Records of Decision Analysis. September 4, 1992), and on
issues which have continued to be of importance from a national perspective. These include:
• Rationale for the Selected Remedy. A ROD should specify which of the five
balancing criteria (long-term effectiveness and permanence; reduction of
toxicity, mobility, or volume through treatment; short-term effectiveness;
implementability; cost) that were most important in selecting the remedy. It
should include a clear and concise explanation of why one alternative was
chosen over the other alternatives.
Clean-up Levels. While the land use assumptions in the baseline risk
assessments are being well documented, often the land use on which the
selected remedy's clean-up levels are based, is not always being documented.
We need to ensure that the land use associated with the clean-up levels is
clearly identified in RODs.
• Eco-Risk Assessment. A ROD should provide a good description of any
ecological risk assessments conducted, or an explanation of why ecological risk
was not evaluated.
• ARARs. Improved ARAR documentation is needed
in the Description of Alternatives section of ROD;
in the Statutory Determinations section of ROD.
• Enforcement Activities. A ROD should provide thorough documentation of the
history of enforcement activities at a site, including;
Notice letters for RI/FS
Negotiation period for RI/FS
Administrative Order on Consent (AOC) date; or
Consent Decree (CD) date; or
Unilateral Administrative Order (UAO) date of issuance and the date of
the compliance letter
Compliance History under AOC, CD or UAO.
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Examples of good documentation of each of the five ROD areas of focus are presented
in this compendium. The primary criteria used to compile these examples were:
• Whether the sections followed the format and contained the appropriate
contents recommended by ROD guidance.
• Whether the sections were clearly written and effectively presented.
• Whether the sections appropriately reflect current Superfund program policy.
This compendium reflects the fact that there is often more than one way to present
similar information, and that the level of detail may vary from ROD to ROD. However, the
essential information should always be included in the ROD.
Language in the following ROD excerpts are identified in bold type, and highlight the
examples of good documentation.
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SECTION I
RATIONALE FOR THE SELECTED REMEDY
A ROD should specify which of the five balancing criteria (long-term
effectiveness and permanence; reduction of toxicity, mobility, or volume through
treatment; short-term effectiveness; implementability; cost) were most important in
selecting the remedy. It should include a clear and concise explanation of why one
alternative was chosen over the other alternatives.
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RATIONALE FOR THE SELECTED REMEDY
Example 1
D. Utilization of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable
The selected remedy for OU3 utilizes permanent solutions and treatment technologies
to the maximum extent practicable while providing the best balance among the other
evaluation criteria. It achieves the best balance of tradeoffs with respect to the
primary balancing criteria of long-term effectiveness and permanence; reduction in
toxicity, mobility, and volume through treatment; short-term effectiveness;
implementability; and cost; while also considering the statutory preference for
treatment as a principal element and State and community acceptance.
The selected remedy provides a high degree of long-term effectiveness and
permanence as the removal of the fluff pile through the recycling process would
be permanent and irreversible. Recycling the fluff would encapsulate the
contaminants in a plastic matrix (the recycled product) which will prevent exposure
and reduce mobility. Any residuals would be treated which would permanently
remove any hazardous characteristics, and then removed and securely contained
offsite. Capping the fluff would achieve only a moderate level of long-term
effectiveness and permanence as the fluff would remain onsite permanently and its
long-term effectiveness would require ensured long-term maintenance. Onsite
incineration could achieve a moderate to high level of long-term effectiveness and
permanence because destruction of the fluff would be permanent and irreversible;
however, large quantities of ash and residuals would need to be treated and disposed
and the implementation time period could be excessive.
The selected remedy provides significant reductions in toxicity, mobility, and
volume by immobilizing contaminants in the recycled product and achieving
significant volume reductions. Capping provides no reduction in toxicity or
volume. Incineration would destroy organic contaminants and require treatment
to stabilize the inorganic contaminants for ultimate disposal. The selected
remedy is less effective than capping in the short-term, but significantly more
effective than incineration which could take anywhere from nine to eighty-seven
years to achieve protectiveness. The selected remedy may be slightly less
implementable than capping due to the uncertainties with regard to recycling
markets, but is probably more easily implementable than incineration. With
regard to cost, the selected remedy may be less expensive than capping and
would be less expensive than incineration.
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RATIONALE FOR THE SELECTED REMEDY
Example 2
Community Acceptance
Verbal comments received at the Proposed Plan public meeting, held on June 13,
1991, in Wallingford, Kentucky, and on comments submitted to EPA during the
public comment period on the Proposed Plan, indicate that the community favors
Alternative 5, Natural Stabilization, over the other alternatives considered. However,
the community urged inclusion of a number of features in the Record of Decision and
RD/RA Consent Decree. The community's comments and suggestions, as well as
EPA responses, can be found in the Responsiveness section of this Record of
Decision.
The community opposes the dynamic compaction alternative (Alternatives 4, 10 and
17) for the MFDS, primarily because of concerns over accelerated release of
contaminants to the environment during the compaction process. The community
does not favor the grouting alternative due to concern over potential contaminant
release from intact containers during the grout injection process and uncertainties
over the ability of grout to adequately fill void spaces within the trenches.
9.8 Conclusions of the Comparative Analysis Summary
Of the nine criteria described above, the differences among the six remedial
alternatives evaluated are not great, except with respect to the following four
criteria: 1) Implementability; 2) Reduction of Toxicity, Mobility, or Volume; 3)
State Acceptance; and 4) Community Acceptance. All remedial alternatives
provide for roughly the same degree of long-term and short-term effectiveness. All
remedial alternatives provide for overall protection of human health and the
environment and all achieve ARARs. Although cost estimates differ among the
remedial alternatives, none differ by more than an order of magnitude.
Therefore, Implementability, Reduction of Toxicity, Mobility or Volume, State
Acceptance, and Community Acceptance weighed heavily in favor of selection of
Alternative 5. Alternative 5 is the least difficult remedy to implement, utilizing
proven and reliable technologies to achieve final remediation, while not requiring
time-consuming research and development prior to implementation. It is less
likely to result in container rupture and, therefore, benefits from the added
protection of containers within the trenches. Both the State and Community
favor the Natural Stabilization technology.
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SECTION II
CLEAN-UP LEVELS
While the land use assumptions in the baseline risk assessments are being well
documented, often the land use on which the selected remedy's clean-up levels are
based, is not always being documented. We need to ensure that the land use
associated with the clean-up levels is clearly identified in RODs.
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CLEAN-UP LEVELS
Example 1
....twelve (12) inches of clean site soils. The estimated costs for the selected remedy
are: Capital costs: $1,498,000; Annual O&M costs: $5,000; Present worth costs:
$1,557,000.
Cleanup Levels
To meet the target range of 95% of the population with blood lead levels less
than 10 ug/dl, a residential lead cleanup level of 640 mg/kg was determined for
the site. Cleanup levels to achieve a 1 x 10" excess cancer risk or a
hazard index value of not greater than one (1) for non-carcinogenic risk for
other contaminants under a residential setting at the site are: antimony,
110 ppm; arsenic, 0.37 ppm (106) and 270 ppm (HI=1); cadmium, 140 ppm;
mercury, 82 ppm; and for PAHs, 3 ppm benzo(a)pyrene equivalents.
X. Statutory Determinations
Under CERCLA section 121 42 U.S.C. §9621, EPA must select remedies that are
protective of human health and the environment, comply with applicable or relevant
and appropriate requirements, are cost-effective, and utilize permanent solutions and
alternative treatment technologies or resource recovery technologies to the maximum
extent practicable. In addition, CERCLA includes a preference for remedies that
employ treatment that permanently and significantly reduce the volume, toxicity, or
mobility of hazardous wastes as their principal element. The following sections
discuss how the selected remedy meets these statutory requirements.
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CLEAN-UP LEVELS
Example 2
....in Exhibit C for determining when excavation of soils is necessary. A CLI of less
than one for a particular location indicates that the total cancer risk associated with
all chemicals in the location is below the target risk level. If the CLI is one or greater
in a particular location, then excavation will be required. The decision on the specific
method to be used will be made when the sampling and analysis program is
developed during remedial design.
Fisher Ditch sediments with concentrations of carbazole greater than the 23.2 mg/kg
will be excavated and treated. This action level is based on ecological risk factors.
Treatment Levels for Excavated Soils. Table 12 lists the treatment levels to be
achieved in the LTU for the soils from the impoundment, process and surrounding
areas. Benzo(a)pyrene and dibenzo(a,h)anthracene together represent 96% of the
risk front the carcinogenic PAHs. Reducing the concentrations of these two PAH
compounds to their treatment levels should reduce the total risk from the PAHs
to, or below, the 10"s risk level for an industrial use scenario. Therefore, these
two compounds are used as indicators for total PAH reduction. The 2,3,7,8-
TCDD equivalent concentration incorporates all dioxins/furans found in the soils.
Ex-Situ Bioremediation of the organics-contaminated soils will comply with the
LDRs through a treatability variance. The treatability variance treatment level ranges
or percent reduction ranges (considered ARARs) that Ex-situ Bioremediation will
attain for the K001 constituents are listed in Table 12. These treatment levels fall
within the 10"6 to 10"7 risk range for an industrial use scenario.
LDR standards will apply to the metals-contaminated soils. To meet the LDR
standards, it will have to be shown that the stabilized soil is below Toxicity
Characteristic levels. These treatment levels are also listed in Table 12.
The treatment levels for the sediments will be the same as for the organics-
contaminated soils.
The health risks of dioxins are presently being reassessed by the Office of Research
and Development (ORD). If EPA's policy on dioxins changes due to this
reassessment before or during the implementation of this remedy, the equivalency
concentrations for dibenzo-p-dioxins and dibenzofurans combined will be changed
accordingly.
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CLEAN-UP LEVELS
Example 2 (Continued)
Remediation Goals and Treatment Levels for the Surficial Ground Water
Ground water cleanup criteria to meet the remediation goals have been determined by
examination and consideration of pre-established ARARs such as the Safe Drinking
Water Act Maximum Contaminant Levels (MCLs) and the Colorado Basic Standards
for Ground Water and the use of a human health risk assessment to determine
contaminant concentrations which are protective of human health.
Table 13 lists the treatment levels for the surficial aquifer. EPA has determined that
ground water treatment levels for carcinogenic compounds will be the following for
the surficial aquifer: 1) total 2,3,7,8-TCDD equivalency concentrations for
dioxins/furans will be reduced to no greater than 0.5 (pg/L) picograms per liter; 2)
trichloroethylene will be reduced to concentrations no greater than 5 micrograms per
liter (ug/L); 3) tetrachloroethylene will be reduced to concentrations no greater than
1.6 ug/L; 4) carbazole will be reduced to concentrations no greater than 4.1 ug/L; and
5) other organics, if detected, which may be present in the ground water will be
reduced to the most stringent Federal or state standard identified as an ARAR or
TBC. The total TCDD equivalent is a proposed MCL. The treatment level for
trichloroethylene is a Colorado Basic Groundwater Standard. Although a Colorado
Basic Standard applies, the more stringent risk-based level was selected for
tetrachloroethylene. The treatment level for carbazole was determined by risk analysis
and corresponds to a 106 risk level.
EPA has also determined that groundwater treatment levels for non-carcinogenic
compounds will be as listed in Table 13. All of these treatment levels, except for
PCP, were determined by risk analysis and correspond to Hazard Quotients less than
1. The treatment level for PCP is a Proposed MCL identified as a TBC.
One of the goals of the ground water component of this remedial action is to
restore the surficial ground water to a quality consistent with its beneficial use
which is for domestic use. Based on information obtained during the remedial
investigation, and the analysis of all....
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CLEAN-UP LEVELS
Example 3
Final Remediation Goals
Final remediation goals were selected based on the PRGs previously described and
the results of the alternatives analysis. Table 14 shows the final remediation goals for
the . All surface soils shall be excavated to depth until arsenic
concentrations meet the 10"4 remediation goal of 36 mg/kg for industrial use.
Soils beneath the treatment building shall be shall to excavated to meet the 10"4
remediation goal of 336 mg/kg, for industrial use. EPA has selected the more
stringent cleanup level for surface soil because this is where the greatest
potential for human contact exists and it will also allow residential use. Because
the 10"5 industrial remediation goal for surface soils is approximately equal to
the 10"4 residential cleanup level, this strategy will allow residential use of all
portions of the site except the treatment building area. Based on the results from
the removal action, cleanup of soil to the selected arsenic cleanup levels will also
achieve chromium and copper cleanup levels of 1,351 mg/kg and 10,000 mg/kg,
respectively, associated with hazard index of 1. The selected remedy should meet the
final remediation goals.
The State of Oregon cleanup standard i~ to clean up to background levels if possible,
or if not, to a level that is protective of human health and the environment.
Background arsenic levels near the were measured in the range of 4 to
11 mg/kg. EPA's cleanup goal of 36 mg/kg for surface soil will be close to, but
slightly higher than, measured background levels. It is EPA's judgment that the
marginal increase in protection provided by cleaning up to background levels does
not justify the additional remediation effort and costs.
Groundwater monitoring results will be used to verify that arsenic and chromium
levels remain below the MCL.
X. Statutory Determination
The procedures and standards for responding to release of hazardous substances,
pollutants, and contaminants at the Site shall be in accordance with CERCLA, as
amended by SARA, and to the maximum extent practicable, the NCP, 40 C.F.R. Part
300 (1990), promulgated in the Federal Register on March 8, 1990.
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SECTION III
ECO-RISK ASSESSMENT
A ROD should provide a good description of any ecological risk assessments
conducted, or an explanation of why ecological risk was not evaluated.
The unique ecological characteristics of each site and the nature of the
chemical contamination will dictate the direction and scope of the Ecological Risk
Assessment to be conducted. Reference to specific test procedures and methods in
the "ROD language" does not imply universal applicability at all Superfund sites, but
that for the site in question, the tests and procedures selected were appropriate and
the description clearly and succinctly addressed the important aspects of the risk
assessment.
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EGO-RISK ASSESSMENT
Example 1
....samples at the indicate soil lead concentrations less than 640 mg/kg would
reduce lead risk below the target level.
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.
Ecological Risk
The ecological risk assessment conducted at the consisted of:
1) an ecological site description,
2) identification of the ecological contaminant of concern (hazard
identification) and inclusion of a toxicological profile,
3) a description of the objectives, endpoints, and methods used for the
ecological field study,
4) characterization of the ecological receptors being assessed,
5) identification of toxicological benchmarks from literature references for
each receptor being assessed,
6) an exposure assessment for each of the receptors being assessed,
7) a characterization of risk for each of the receptors being assessed using the
hazard quotient method and including a qualitative description of
uncertainty, and
8) conclusions, tables, a map, and references.
The ecosystem of concern is a terrestrial desert (Chihuahuan) ecosystem,
consisting of grass and shrub habitat. There were no perennial surface water
bodies for assessment, just dry arroyos. The terrain has a very slight slope and
some rolling topography near the arroyos, but, in general, is fairly flat. The
desert plants observed were mainly mesquite, creosote bush, cacti, and grasses.
Desert animals observed were lizards, snakes, jack rabbits, kangaroo rats and
other rodents, road runners, and other birds. Cattle graze in the study area as
well as on Bureau of Land Management (BLM) land to the west of the site.
Grasses are more predominant on the south side where fencing prevents access
to cattle. No threatened and endangered species were observed or expected to be
affected by the site activities.
The ecological hazardous substance of concern attributable to site activities was
determined to be lead. The determination of whether there are any other
ecological contaminants of concern besides lead was based on full scan chemical
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ECO-RISK ASSESSMENT
Example 1 (Continued)
analyses conducted on some of the soil and tissue samples. Also, the soil was
analyzed for total organic carbon, pH, and grain size to characterize its binding
ability and the mobility and bioavailability of contaminants. There were no
detections above quantification limits for any site-related chemicals besides lead.
There was a BNA (di-n-butylphthalate) detected which was attributed to blank
contamination.
The overall objective is to determine ecological risk attributable to Other
objectives or endpoints evaluated included:
1) targeting areas for ecological field sampling (vegetation transects and small
mammal trapping) with an X-Ray Fluorescence (XRF) spectrometry field
technique which was used to screen soils for lead contamination gradients;
2) determining the biological integrity or viability of vegetation by surveying
vegetative populations on the site as well as in the reference areas to
determine ecological differences in structure and function attributable to
3) analyzing vegetation and small mammal tissue residues in site and
reference samples to determine uptake or bioaccumulation of
contaminant(s) attributable to ;
4) estimating bioaccumulation of contaminant(s) attributable to in other
animals higher in the food chain which feed on the vegetation and small
mammals directly sampled;
5) measuring indicators of sublethal toxicological effects of lead (such as delta
aminolevulinic acid dehydratase which is a blood lead biomarker, and
histopathological indicators) in site and reference small mammal samples;
6) identifying toxic benchmarks for lead from literature references for each
plant or animal sampled or indirectly assessed;
7) analyzing contaminant(s) attributable to by atomic absorption
spectrometry on random composite site and reference soil samples taken
concurrently and collected with the tissue samples for correlation with
tissue residue data; and
8) using the XRF technique to determine whether highway traffic lead
emissions are a confounding source of soil lead not attributable to
The study was designed to assess ecological risk posed by the site only in areas
where soil lead concentrations were below those concentrations (500-1,000
mg/kg) that would be remediated for the protection of human health. Since
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ECO-RISK ASSESSMENT
Example 1 (Continued)
earlier studies indicated that the fenced portion (12.5 acres) of the site contained
high lead concentration and would be remediated, the ecological sampling was
done outside the 12.5 acre fenced area. The study areas sampled were the areas
to the north and to the south of the 12.5 acre fenced site area; the reference area
sampled was the Bureau of Land Management (BLM) land located west of the
site.
In addition to the plant population survey, samples of soils, vegetation (bush
muhly grass and mesquite) tissues, and small mammal (kangaroo rat) tissues
were taken. Kangaroo rats were selected for assessment because they were the
only small mammals trapped in sufficient numbers in both the site and reference
areas. The vegetation population survey and tissue residue analyses were to
provide information on the availability of habitat and the effects of habitat
alteration, the uptake of contaminant(s) in vegetation from soil, and the impacts
of contaminant(s) on vegetation and impacts potentially on grazing animals
(herbivores). The small mammal samples were to provide information on uptake
of contaminant(s) and impact to the small mammals themselves as well as
information on site specific exposure for predators (tissue residue potentially
ingested by predators).
The objective in the live-trapping of small mammals was to obtain those species
likely to be exposed to contamination and with a home range size limited to the
size of the site to facilitate determining ecological risk attributable only to
In order to indirectly assess ecological risk attributable only to for other
species having a home range size larger than the site and occupying a niche
higher up the food chain, an area use factor was calculated. An area use factor
is calculated using literature values for home range size, and it is a
determination of what proportion the site size is of the home range size. The
species selected for indirect assessment of ecological risk were the pronghorn
antelope, coyote, and red-tailed hawk. They were selected on the basis of the
various ecological niches they occupy and on information from previous local
studies estimating their occurrence and available habitat.
In the Receptor Characterization section, life history information from the
literature is described for each of the ecological receptors (kangaroo rat,
pronghorn antelope, coyote, and red-tailed hawk) being assessed. The life history
information described includes body weight, diet (percentage of foods ingested
and ingestion rate by weight per day), and home range size.
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ECO-RISK ASSESSMENT
Example 1 (Continued)
In the Toxicological-Response Assessment section, toxicity benchmarks from
literature references for each of the ecological receptors being assessed are listed.
Due to various sampling and analytical difficulties encountered with field toxicity
studies, literature toxicity values were used in the risk characterization. For the
animals assessed, the toxicity benchmarks were based on an oral chronic toxic
dose. For vegetation, the toxicity benchmark was based on a toxic absorbed
tissue value.
There was clear evidence of a soil lead contamination gradient from the site. Soil
lead decreased in concentration with distance from the site in both the areas to
the north and south of the 12.5 acre fenced site area. There were localized
elevations of soil lead in the north and south areas attributable to arroyo
drainage and in the north area attributable to a breach which occurred from the
site waste pond. Also, soil lead was much greater in the site-related areas
compared to the reference area. The reference area lead value measured was
representative of background lead measured in other previous local studies
unrelated to There was no indication of a contaminated soil lead gradient
attributable to highway traffic lead emissions that would confound the
evaluation of lead impacts from
In the Exposure Assessment section, exposure or dose estimates are calculated
for each of the ecological receptors. The only exposure pathway evaluated for
animals was ingestion of food. The method used has been used in other EPA
regional ecological risk assessments. Exposure or dose in food is converted to
dose in the receptor (herbivores and carnivores). The formula used multiplies
the measured tissue residue value of lead in the food item in wet weight times
the percentage that the food item represents in the diet of the ecological receptor
times the ingestion rate in weight per day for the ecological receptor times the
area use factor discussed above divided by the body weight of the ecological
receptor. All terms except the first term in the formula were obtained from
literature references. The values for the first term were analyses of the mesquite,
bush muhly grass, and kangaroo rat tissue sampled in the field study. Exposure
estimates were calculated separately for the site and reference areas.
For vegetation, exposure was evaluated more qualitatively. Since vegetation
tissues were not washed, distinction between internal (uptake) and external
(aerial deposition) exposure pathways could not be made. Total lead diethylene
triamine pentaacetic acid (DTPA)-extractable lead (an estimate of the availability
for plant uptake), and aqueous-extractable lead were measured in collocated soil
samples for correlation with plant tissue residues. Vegetation tissue lead values
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ECO-RISK ASSESSMENT
Example 1 (Continued)
were positively correlated with soil lead values, although there was much less
lead in the vegetative tissues compared to that in the soil. Availability of soil lead
may be low due to the high soil pH (7.2-8.1) which was measured. Despite
vegetation tissue lead values correlation with soil lead values, there were no
apparent vegetation population trends detected in the survey correlated with soil
lead that could be attributable to Rather, some of the trends in the
ecological measures of the vegetation populations could be attributable to
differences in habitat, drainage, elevation, moisture, nutrient availability,
elevated pH, and cattle grazing.
In the Risk Characterization section, toxicological and exposure information was
integrated to estimate ecological risk, and uncertainty was qualitatively
described.
This was achieved using EPA's hazard quotient method. The hazard quotient is
a ratio of the exposure estimate divided by the toxicological benchmark value for
each ecological receptor. When the result is less than one, one concludes that
there is no indication of significant risk.
For the animals assessed, none of the site-related hazard quotients exceeded one.
Therefore, there is no indication of site-related significant risk for the areas
evaluated. A probable factor is the small size of the site compared to the larger
home range sizes of some of the ecological receptors. The highest hazard
quotient was 0.1 found in the kangaroo rat. Proportioning the hazard quotient
from 0.1 to one (1) would result in a soil lead concentration higher than the
upper end cleanup level of 1,000 ppm used for protection of human health and
would be protective of the ecology considering site-related risks only.
Reference area hazard quotients exceeded one for the coyote and red-tailed
hawk which indicates significant reference area risk (not attributable to ).
This was probably attributable to the larger size of the reference area used
which encompassed the large home sizes of the ecological receptors and
increased the area use factors.
For vegetation, ecological risk was more qualitatively characterized. Although
vegetation tissue lead values were significantly different between site and
reference study areas, none of the vegetation tissue residue values exceeded the
tissue-based toxicity benchmark value used from the literature. Thus, the hazard
quotient was inferred to be less than one which does not indicate significant risk
to vegetation attributable to This was supported by the results of the
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ECO-RISK ASSESSMENT
Example 1 (Continued)
population survey where no population differences could be attributed to
impacts.
Based on the field investigation conducted at the and data from the
results of the laboratory analyses, the following conclusions are drawn:
1) All site-related hazard quotients were less than one which did not indicate
significant ecological risk attributable to in the areas and at the lead
levels evaluated.
2) The small size of the site compared to larger home range sizes of ecological
receptors higher up in the food chain indicates that it would be an unlikely
occurrence for lead (from the areas studied) to bioaccumulate up the food chain.
3) There was clear evidence of a soil lead contamination gradient related to
4) Mean body burden of lead was higher in kangaroo rats collected in the north
area, but lead was also present in reference animals.
5) Plant species are distributed consistent with regional vegetation patterns.
There was no clear indication that exposure of vegetation to site-related soil lead
resulted in adverse effects as reflected in population measurements.
6) Lead availability to plants from the lead contaminated soils is low due to the
high pH level in the soil.
7) Lead in plants is significantly higher in contaminated areas than in the
reference area. However, none of the plant tissue lead values exceeded the tissue-
based toxicity benchmark value from the literature.
8) Lead in and on plants is available to grazing animals.
9) Remediation of soils for the protection of human health within the range of
500-1,000 mg/kg should be adequate regarding ecological risks attributable to
contaminants.
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EGO-RISK ASSESSMENT
Example 2
7.2 Ecological Assessment
The ecological assessment focused on biological effects in subtidal areas.
During the RI, sediment chemical and physical data were collected, laboratory
bioassays were conducted on subtidal sediments, and evaluation of the existing
benthic communities were completed. Available information from previous
studies and research was incorporated as appropriate. Although clam tissue and
sediment chemical data were developed for evaluating intertidal areas, the
emphasis in intertidal areas was on evaluating potential human health risks.
The assessment of ecological risks relied on the "triad approach", which links
contamination to specific adverse ecological effects using a preponderance of
field and laboratory evidence. The three elements of sediment chemical analyses,
laboratory toxicity tests (bioassays), and evaluation of the abundance of benthic
organisms from specific locations are used in combination as the three elements
of the triad approach. The approach was used to develop the AETs, and
these chemical concentrations, in conjunction with site-specific biological data,
formed the basis of the ecological assessment in
As described in Section 6, an AET, or "Apparent Effects Threshold," is the
concentration of a chemical in sediment above which a particular adverse
biological response has always been observed. Generally, for any one chemical,
different biological indicators are associated with different levels of chemical
contamination, leading to a range of AETs (e.g., for benthic effects, amphipod
toxicity, oyster larvae effects, and microtox responses) for each compound (See
Table 2, Section 6).
7.2.1 Chemicals of Concern
RI sampling of sediments included a broad range of metals and organic
compounds of potential concern for environmental risk. Contaminants of
concern were identified for the ecological assessment based on information about
their effects in the marine environment. For this reason, not all were the same
as the contaminants of concern identified for human health.
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ECO-RISK ASSESSMENT
Example 2 (Continued)
Sediments in exceeded 2.1 mg/kg, the high AET (HAET) for mercury, at
several stations sampled during the RI, and exceeded two AETs (for oyster
larvae and microtox) in most remaining contaminated areas. Above the HAET,
AETs for four biological measures are exceeded. Individual PAHs exceeded
their respective benthic AETs in much of the harbor, and at several locations all
16 PAH compounds exceeded their benthic AETs.
Based on the comparison of the concentrations in samples with the 1988
benthic AETs for , EPA selected mercury and all sixteen PAHs as
contaminants of concern. These contaminants are used as indicators of the
extents of contamination. Toxicity information for PAH and mercury was
summarized in the ecological risk assessment.
Contaminants that exceeded AETs at only one or two locations were not carried
forward as contaminants of concern for the ecological risk assessment. These
locations are included within areas of concern for mercury of PAHs, and cleanup
for PAHs and mercury would also address these contaminants.
7.2.2 Biological Effects
Laboratory bioassay results from samples were grouped by sediment
grain size and statistically compared with control samples and background
samples. Bioassays for acute toxicity indicated that sediments from the majority
of sampled locations in the East Harbor, and from several locations in the West
Harbor, were toxic to amphipods, oyster larvae, or both. In general, the
bioassay responses were most severe in areas of high PAH contamination.
The test species used in amphipod toxicity tests (Rhepoxynius abronius) resides
in and is a member of a crustacean group that forms an important part
of the diet of many esturine fish. Amphipods are sensitive to many chemical
contaminants, and species such as R. abronium have a high pollutant exposure
potential because the burrow into the sediment and feed on sediment material.
The oyster larvae used as a test species (Crassastrea gigas) resides in and
supports commercial and recreational fisheries. The life stages tested (embryo
and larva) are very sensitive stages of the organism's life cycle. The primary
endpoint is a sublethal change in devlopment that has a high potential for
affecting larval recruitment.
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ECO-RISK ASSESSMENT
Example 2 (Continued)
Benthic infauna are valuable indicators because they live in direct contact with
the sediments, they are relatively stationary, and they are important components
of esturine ecosystems. If sediment-associated impacts are not present in the
infauna, then it is unlikely that such impacts are present in other biotic groups
such as fish or plankton unless contaminants are bioaccumulating at levels
significant for higher food-chain organisms.
During the RI, replicate benthic infauna measures were not conducted at each
station in Consequently, statistical comparisons of benthic abundance
data between individual stations was not possible. Overall, there was a greater
abundance of polychaetes in than in the background areas, which could
indicate a predominance of pollution tolerant organisms. However, no
statistically significant difference relative to background areas was observed for
molluscs, amphipods, and other crustaceans.
Other benthic studies of tend to support the indication in the RI that,
while sediment contamination is present above the AETs, adverse effects on
benthic communities may not be occurring in the level of major taxa
(polychaeta, molluscs, amphipods, other Crustacea) in most subtidal areas of the
West Harbor.
Additional evidence of biological effects in includes the prevalence of liver
lesions and tumors in English sole, as documented by NOAA (Malins, 1985).
The high incidence of such effects in relative to other embayments
was confirmed in the Ambient Monitoring Program 1991 sampling. This
and laboratory research citing the effects of PAH and other sediments
contaminants on marine organisms add to the preponderance of evidence
already indicating potential damage to marine life. In addition, PAH and
metals in the tissues of fish and shellfish indicate uptake of sediment
contamination. Mercury tends to bioaccumulate in fish, while PAHs can
bioaccumulate in some invertebrates.
Uncertainty in the ecological assessment is associated with data variability,
spatial variability of contamination and benthic communities, potential biological
effects of organic enrichment, grain size, and physical disturbances, and the
availability of appropriate background locations for comparison.
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ECO-RISK ASSESSMENT
Example 2 (Continued)
In summary, biological risks due to contamination in the West Harbor are
evidenced by documented acute toxicity of sediments near the former shipyard
and at some locations in the central channel, by predicted adverse effects of
other sediments above AETs, and by the widespread presence of mercury and
PAHs, which can accumulate in the tissues of food chain organisms.
7.3 Summary of Risk Assessment
Actual or potential releases of hazardous substances from the West Harbor OU,
if not addressed by implementing the remedial action selected in this ROD, may
present an imminent and substantial endangerment to public health or welfare,
or the environment.
Based on the RI, the risk assessments, and available information, cleanup of the
West Harbor OU is warranted. Consumption of shellfish from certain intertidal
locations of the West Harbor pose a human health risk above the acceptable risk
range. Sediment cleanup is expected to result in reductions of contaminant levels
in fish and shellfish, and over the long term, sediment cleanup and natural
recovery may eventually reduce risks to levels comparable to background.
However, the correlation between fish or clam tissue contamination and
sediment chemical concentrations is not sufficient to develop sediment cleanup
levels corresponding to specific reductions in human health risks.
Adverse biological effects have been documented in portions of the West Harbor
and are predicted by the contaminant concentrations present. Most of the
biological effects observed are associated with areas of heavy sediment
contamination. Potential redistribution of contaminants through sediment
redistribution from heavily contaminated areas is also of concern, as is the
potential for uptake by marine organisms. Where chemical information predicts
significant adverse effects on benthic organisms but redistribution and biological
uptake are not of concern, cleanup is warranted unless the absence of adverse
biological effects at levels of concern is documented.
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ECO-RISK ASSESSMENT
Example 3
VI.3 Environmental Risks
The principal risks posed by the runoff of metals-bearing AMD from are
the associated impacts on aquatic life in the Spring Creek drainage, Keswick
Reservoir, and the Sacramento River downstream of Keswick Dam. Among these
natural resources, the most important are the fishery resources in the
Sacramento River downstream of Keswick Dam. Migratory populations of
Chinook salmon, steelhead trout, resident trout, and numerous other aquatic and
terrestrial species can be or are affected by AMD from (EPA, 1992b).
The salmon and steelhead trout populations have high commercial and/or
recreational value to the region (USFWS and USBR, 1984; USFWS and CDFG,
1987). The susceptibility of these populations to contaminants originating from
has been documented (Wilson, 1982). One of the chinook salmon runs, the
winter run, is a species listed by the Federal Government as threatened with
extinction and listed by the State of California as a species endangered with
extinction.
Pollution from is considered to be a major factor causing the decline in
Sacramento River fishery resources, and an impediment in achieving fishery
resource restoration goals. Other major factors contributing to the decline
include loss of spawning habitat, predation, habitat degradation, mortality at
dams and diversions, overfishing, and natural disasters (such as drought) (Vogel,
1989). Fish migrating into the uppermost river reach of the Sacramento River
risk being killed by AMD from ; offspring of adult fish spawning in that
reach have reduced chances of survival due to the AMD (Finlayson and
Wilson, 1979). There is an indication that AMD from has reduced the
suitability of available spawning grounds for salmon in the uppermost reaches of
the Sacramento River and that fish population reductions have occurred
following uncontrolled spillage of AMD (Finlayson, 1979). The greatest
decline in salmon-spawning populations has occurred within the uppermost river
reach from Balls Ferry upstream to Redding, a distance of approximately 26
river miles (NOAA, 1989).
Since the late 1960s, when fish counts were initiated at Red Bluff Diversion Dam
(RBDD), each of the anadromous salmonid runs has suffered major declines. A
more extensive data base is available specifically for fall-run chinook. This data
base demonstrates that recent levels of spawning escapement to the upper
23
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ECO-RISK ASSESSMENT
Example 3 (Continued)
Sacramento River are only about 50 percent of levels observed during the late
1950s. The greatest decline among the salmon runs has occurred for the winter
run, which has been reduced to less than 5 percent of run sizes during the late
1960s. This serious decline prompted the 1989 listing of this fish as a threatened
species by the Federal Government (NMFS, 1989) and an endangered species by
the State of California (CDFG, 1989).
The primary potential exposed fisheries populations are the salmonids and
steelhead trout present in the Sacramento River; Boulder Creek and Spring
Creek are devoid of fisheries and aquatic invertebrates below the mine drainage
area. The upper Sacramento River chinook salmon runs, steelhead trout run,
and resident populations of rainbow trout have life history characteristics that
make them vulnerable to potential adverse effects from AMD originating from
The probability and magnitude of potential exposure depends on the
releases of contaminated water from Spring Creek Debris Dam (SCDD), the
releases of water from Shasta Dam, and the life stages present within the zone of
impact.
For spring- and fall-run chinook salmon, in a worst-case scenario, approximately
half of an entire year's fall spawning production could be at risk from
contaminants released from The impact of the release depends in large
part on the pattern of releases from Shasta Dam relative to when releases occur
from AMD. For example, if flood control releases from Shasta Dam could cause
most of the year's production to migrate downstream of the affected water
quality zone, thereby reducing the AMD's impact.
Winter-run chinook salmon could be at higher risk compared to other runs.
They are most likely to seek cooler water areas closest to Keswick Dam due to
potentially lethal water temperatures in lower reaches of the Sacramento River.
Under drought-type conditions, these fish are the most important to future runs
because eggs laid farther downstream are more likely to be adversely affected by
lethal warm water temperatures. However, these same drought conditions are
more likely to create conditions (uncontrolled AMD release and low dilution in
the Sacramento River) where AMD from could pose a high risk to
juvenile rearing in the uppermost reach of the river.
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ECO-RISK ASSESSMENT
Example 3 (Continued)
The steelhead trout and resident rainbow trout populations that are potentially
at risk are not well defined or understood. However, both the adult and yearling
life phases are potentially at risk because both are present in the river when fish
kills have historically occurred.
At present, a memorandum of understanding commits the U.S. Bureau of
Reclamation (USBR) to operate SCDD in a manner that (when considering
releases of dilution water from Shasta Dam) will protect aquatic life in the
Sacramento River downstream of Keswick Dam. The USBR must also operate
Shasta Dam to provide electric power, irrigation water, and flood control. The
USBR estimated that during an average year it may lose between $16 million
and $168 million, depending on the level of protection required in the
Sacramento River, by supplying water to dilute Spring Creek flows. There is the
potential that USBR's ability to supply adequate dilution water will be further
reduced due to conflicting priorities for water use, thereby increasing the
potential risk to the aquatic community.
It is extremely difficult to quantify fish mortality in the Sacramento River as a
result of contamination from This is due to a variety of factors, including
the general size of the Sacramento River downstream of Keswick Reservoir and
difficulty of visually observing dying or dead fish during periods when the water
is turbid. However, there have been 39 documented fish kills near Redding since
1940, and there have been observations of adult steelhead mortalities near
Redding attributable to metal contamination from since installation of the
SCDD.
Boulder and Spring Creeks, downstream from discharges, do not support
aquatic populations, and the creeks may remain sterile following remediation at
Aquatic populations, water column and benthic, in Keswick Reservoir
downstream of Spring Creek are at risk because of sediment contamination, as
well as water column contamination. Below Keswick Dam, contaminant
concentrations occasionally exceed toxic concentrations for sensitive life stages
and frequently exceed both EPA and State of California criteria to protect
aquatic life, indicating that these populations are also at risk.
Any terrestrial wildlife onsite has the potential for direct exposure to AMD, such
as deer drinking from contaminated creeks or licking metals-laden salts along
the flume system, or consuming contaminated plants, fish or other organisms.
More than 300 species of amphibians, reptiles, birds, and mammals can be
expected to occur in the Boulder Creek basin and downstream areas that may be
directly exposed to AMD.
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ECO-RISK ASSESSMENT
Example 4
6.5 Soil Cleanup Goals for Groundwater Protection
U.S. EPA's Center for Environmental Assessment Modeling (CEAM) provided their
Exposure Assessment Multimedia Model (MultiMed) for application at the .
The model was used in conjunction with traditional contaminant mass partitioning
formulae to determine the soil cleanup goals necessary for protection of Memphis
Sands aquifer quality. Based on Site-specific soil and hydrogeologic conditions, a soil
cleanup goal of 533 ug/kg TCE was determined to be protective of the Memphis
Sand aquifer. The goal is applicable to the contaminant source areas ("hot spots")
previously discussed. Remedial efforts need only focus on a limited portion of the
Site as soil contaminants are restricted to approximately 20% of the total Site area.
All discussions regarding MultiMed input variable selection, model outputs and soil
cleanup goal calculations are provided in Appendix R of the RI.
6.6 Ecological Considerations
No U.S. Dept. of Interior or State of TDEC lands or federally listed endangered
species of wildlife were identified at the Site. The nature of the Site is such that
avian or terrestrial wildlife would not be drawn to the Site. A surface water
quality assessment and a biological impact assessment were conducted. The
assessments included a quantitative study of benthic species diversity in
Nonconnah Creek, and a qualitative review of sensitive and endangered species
typical of southeastern Shelby County. Data to date indicate no significant
adverse ecological impacts from the present soil or groundwater contamination.
This preliminary survey does not rule out ecological impacts to aquatic and
terrestrial species through contaminated food chain mechanisms. However, TCE
is not biocumulative and as a result, it is not expected to cause deleterious food
chain effects based on currently available data.
26
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SECTION IV
ARARs IN DESCRIPTION OF ALTERNATIVES
Improved ARAR documentation is needed in the Description of Alternatives
section of ROD.
27
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ARARs IN DESCRIPTION OF ALTERNATIVES
Example 1
C. Summary
Multi-layer capping is a reliable technology for isolating wastes from the above-
ground environment and significantly mitigates the effects of contaminants on human
health and the environment. Soil and synthetic materials for capping are readily
available and equipment used for implementation is primarily standard road
construction equipment. Although capping significantly reduces contaminant
mobility, it does not reduce the toxicity or volume of the waste and requires long-
term maintenance and monitoring for continued effectiveness.
D. ARARs and TBCs
Major ARARs under this alternative include:
1. Chemical-Specific ARARs
(a) 25 PA Code Chapter 261 and 40 C.F.R. § 261.24 for identification
of characteristic ha/ardous wastes;
(b) the National Ambient Air Quality Standards (NAAQS) set forth at 40
C.F.R. Part 50;
(c) the Pennsylvania Air Pollution Control Act, 25 PA Code Chapters 123
and 127;
2. Action-Specific ARARs
(d) 25 PA Code Chapter 102, which pertains to erosion control
requirements related to excavation activities;
(e) 25 PA Code § 264.310 relating to closure and post-closure care;
(f) OSHA standards for worker's protection, 29 C.F.R Parts 1904,
1910, and 1926;
3. Location-Specific ARARs
(g) The Clean Water Act, 33 U.S.C. §§ 1251 et seq.; 40 C.F.R. Part
403 relating to the discharge of wastewaters to a publicly owned
treatment works;
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ARARs IN STATUTORY DETERMINATIONS
Example 1 (Continued)
4. To Be Considered
(h) Executive Order 11988, 40 C.F.R. §6, Appendix A, concerning
federal wetlands policies;
(i) PA Proposed Residual Waste Regulations to be codified at 25 PA
Code Parts 287-299 (requirements will be considered during
remedial design);
(j) Draft Interim Guidance on Establishing Soil Lead Cleanup
Levels at Superfund Sites (OSWER Directive No. 9355.4-02
(June 13, 1989)).
D. Summary
Incineration would eliminate the toxicity and mobility of organic contaminants
and reduce the total volume of contaminated media. Stabilization of the
incinerator residuals, if necessary, would reduce the toxicity and mobility of
inorganic contaminants by chemically and/or physically binding them in the
stabilized matrix. Volume would increase somewhat after stabilization. Disposal
of the residuals offsite would prevent human and environmental contact. The
fluff feed rate into the incinerator would be very low in order to achieve optimal
performance of the pollution control equipment in capturing lead and other
inorganic contaminants. Therefore, incineration of the fluff would take from
nine to eight-seven years.
E. ARARs and TBCs
Major ARARs under this alternative include:
1. Chemical-Specific ARARs
(a) 25 PA Code Chapter 261 and 40 C.F.R. § 261.24 for identification
of characteristic hazardous wastes;
(b) the National Ambient Air Quality Standards (NAAQS) set forth at
40 C.F.R. Part 50;
(c) the Pennsylvania Air Pollution Control Act, 25 PA Code
Chapters 123 and 127;
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ARARs IN STATUTORY DETERMINATIONS
Example 1 (Continued)
2. Action-Specific ARARs
(d) 25 PA Code Chapter 102, which pertains to erosion control
requirements related to excavation activities;
(e) 25 PA Code Chapter 264, subchapter 0 - Pennsylvania
regulations for hazardous waste incineration;
(f) the EPA TSCA regulations for incineration of PCB materials, 40
C.F.R. § 761.70;
(g) RCRA incineration standards set forth at 40 C.F.R. Part 264,
subpart 0;
(h) 25 PA Code Chapter 264 and 40 C.F.R. Part 268 regarding
storage, disposal, and treatment of hazardous wastes;
(i) RCRA and Department of Transportation regulations governing
the transportation of hazardous wastes, 25 PA Code Chapters 262
and 263 and 49 C.F.F. Parts 107 and 171-179, respectively;
(j) OSHA standards for worker's protection, 29 C.F.R. Parts 1904,
1910, and 1926;
3. Location-Specific ARARs
(k) The Clean Water Act, 33 U.S.C. §§ 1251 et seq.; 40 C.F.R. Part
403 relating to the discharge of wastewaters to a publicly owned
treatment works;
4. To Be Considered
(1) the EPA Guidance on Metals and Hydrogen Chloride Controls for
Hazardous Waste Incinerators (EPA Office of Solid Waste, August
1989);
(m) Executive Order 11988, 40 C.F.R. § 6, Appendix A, concerning
federal wetlands policies;
(n) PA Proposed Residual Waste Regulations to be codified at 25 PA
Code Parts 287-299 (requirements will be considered during
remedial design);
(o) Draft Interim Guidance on Establishing Soil Lead Cleanup
Levels at Superfund Sites (OSWER Directive No. 9355.4-02
(June 13, 1989)).
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ARARs IN DESCRIPTION OF ALTERNATIVES
Example 2
....higher cost). This alternative entails total removal of grease skimmings
(though not any contaminated soil) which would then be disposed of offsite at
a permitted hazardous waste landfill. As this is an offsite activity, such
disposal must comply with all applicable hazardous and solid waste disposal
requirements. These include RCRA and the state Dangerous Waste and solid
waste regulations.
d) Excavation and Onsite Treatment. Treatment onsite is either through land
treatment or incineration. Land treatment is described as biological treatment
of the waste done onsite but not in-situ. This meets EPA's preference for
onsite treatment.
The chief advantages of this alternative are its permanent elimination of one
potential contaminant source. Its elimination of the health hazard for this area
of the site, and the fact that it restores the area for possible future use. No
administrative restrictions would be necessary after excavation and treatment
were completed.
Disadvantages of this alternative include health and safety impacts associated
with excavation, environmental concerns (e.g., worker exposure to
contaminants during excavations and treatment), demonstrated effectiveness,
and costs.
ARARs
Several action-specific ARARs are identified for excavation and treatment
alternatives evaluated for the Skimmings Unit area within the landfill.
The skimmings originated soils not excavated can be treated as a non-
disturbed solid waste unit (not hazardous) and capped according to
applicable regulations.
Excavation of the skimmings could also be expected to result in the
release of some quantity of volatile organics. There are currently no
standards for PERC emission, so any requirements would be determined
by risk assessments which are not ARARs, but are "to be considered" in
design of the remedial action.
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ARARs IN DESCRIPTION OF ALTERNATIVES
Example 2 (Continued)
Excavation and onsite treatment of the skimmings includes two treatment
options. Both options include the excavation of the grease skimmings
followed by treatment and placement back onsite. Land treatment of the
skimmings has no applicable regulations. However, the disposal of any
hazardous wastes generated as a result of the treatment process would be
required to meet the RCRA disposal requirements, which would be
applicable to this new waste's disposal.
The incineration of the skimmings has relevant and appropriate RCRA
requirements for the operation and disposal of the waste streams.
Although the incoming waste is not RCRA regulated. The RCRA ash and
air emissions requirements for incineration would be relevant and
appropriate because of the PERC concentrations in the waste.
There were no chemical-specific or location-specific ARARs identified for
the excavation alternatives.
For the excavation with offsite disposal alternative, the RCRA hazardous
waste regulations are not applicable because the skimmings are not a
RCRA waste. However, offsite activities, such as disposal, will be
regulated by applicable laws and regulations, and are not subject to
ARAR analysis. For example, the transportation and packaging of the
skimmings as hazardous solid waste because of the PERC content is
regulated by the U.S. Department of Transportation.
d) Administrative Restrictions This would involve restricting land use with
respect to future onsite excavation and construction.
The chief advantages of this alternative are its low cost and ease of
implementation. Public health would be protected by reducing exposure to the
contaminants at the site.
The primary disadvantage is that administrative restrictions would not be
effective in eliminating or reducing health concerns offsite. Infiltration would
not be reduced nor surface water or groundwater flow controlled; thus the
leachate would continue to be produced. The MFS, which is an ARAR and
requires landfill capping, would not be met.
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ARARs IN DESCRIPTION OF ALTERNATIVES
Example 2 (Continued)
e) No Action. The landfill would be left in its current condition without any
remedial action being taken. There would be no cost, but public health would
not be protected. ARARs would not be met. The extracted contaminated
groundwater would then be treated or discharged into the city's wastewater
treatment plant for treatment and then discharged into the Spokane River.
Three levels of treatment have been identified in the FS, which are no
treatment, treatment to drinking water levels and Ambient Water Quality
Criteria (AWQC) levels, or treatment to background levels.
All of the pump and treat alternatives would also require groundwater
monitoring, administrative restrictions, and an alternative drinking water
supply. There would be minimal environmental impact during well
construction and few anticipated health or safety concerns for the surrounding
community.
ARARs
The ARARs are essentially the same for the two extraction alternatives.
The major regulations that contribute to the list of potential chemical-
specific ARARs are the Clean Water Act (CWA), the Safe Drinking
Water Act (SDWA), and the Water Quality Standards for the State of
Washington (WAC-173-201) (90.48 RCW). The acts are under the
jurisdiction of and are enforced by the Washington State Department of
Health Services, the Washington State Department of Ecology (Ecology),
and EPA.
The SDWA Maximum Contaminant Level (MCL) standards are
enforceable standards that are applicable to surface water or
groundwater that can be classified as a source or potential source of
drinking water. The MCLs are applicable to any action that affects the
concentration of contaminants in groundwater which is a source of
drinking water, such as the SVRPA.
The discharge of extracted water to the Spokane River is considered to be
offsite and is therefore not subject to ARARs analysis. Compliance with
the applicable laws regulation and permit requirements is necessary.
Some discussion of the discharge requirements is included since
treatment may be done onsite.
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ARARs IN DESCRIPTION OF ALTERNATIVES
Example 2 (Continued)
The CWA Ambient Water Quality Criteria (AWQC) are designed to
protect aquatic life and human health. The state of Washington adopts
the AWQC by reference into their water quality standards, so the AWQC
are requirements for surface water discharges. Table 5 presents
chemical-specific potential ARARs for water. The table is arranged by
chemical compound.
35
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SECTION V
ARARs IN STATUTORY DETERMINATIONS
Improved ARAR documentation is needed in the Statutory Determinations
section of ROD.
37
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ARARs IN STATUTORY DETERMINATIONS
Example 1
1. Chemical Specific
The bedrock aquifer at and beyond the compliance boundary of the Landfill
is a possible drinking water source. Maximum Contaminant Levels (MCLs)
promulgated under the Safe Drinking Water Act which regulate public
drinking water supplies, are applicable to drinking water at the tap and are
not applicable to ground water. However, because the ground water may be
used a potential drinking water source, MCLs are relevant and appropriate.
The Vermont Groundwater Protection Act establishes primary ground water
quality standards and contains enforcement standards. Under the Act, two
enforcement standards have been established which are more stringent than
MCLs. The standards are for tetrachloroethene and xylenes. EPA has
incorporated the enforcement standard for xylenes as the cleanup level for
this contaminant of concern. Pursuant to CERCLA section 121(d)(4)(C) and
section 300.430(f)(l)(ii)(C)(3) of the NCP, EPA is invoking a waiver of the
enforcement standard for tetrachloroethene.
2. Action Specific
RCRA hazardous waste closure requirements, 40 CFR Part 264, Subpart G,
and hazardous waste landfill closure requirements, 40 CFR 264.310, Subpart
N, are ARARs for a substantial part of the remedial action. Under Part 264,
Subpart G, closure of a hazardous waste disposal facility must be done so as
to control, minimize, or eliminate "post-closure escape of hazardous waste,
hazardous constituents, leachate, contaminated run-off, or hazardous waste
decomposition products to the ground or surface waters or to the
atmosphere." Section 264.111(b). Section 264.310, Subpart N, provides
specific closure requirements for a hazardous waste landfill.
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ARARs IN STATUTORY DETERMINATIONS
Example 2
....to reduce this risk to 1.4E-4 and is expected to lower the noncarcinogenic risks
to acceptable levels. Institutional controls to restrict the use of ground water until
cleanup levels are attained will eliminate the short-term potential risk from this
route of exposure. The remedy also provides protection from direct contact with
contaminated soils by the installation of security fencing.
The potential for continuing contamination of the ground water will be
significantly reduced by in-situ vapor stripping of the landfill materials and
surrounding soils in conjunction with the existing landfill cap and ground water
cut-off wall. By reducing the contamination in the surrounding soils in-situ vapor
stripping will also greatly reduce the risk of direct contact.
There are no short-term risks associated with the Selected Remedy that
cannot be readily controlled. In addition, no adverse cross media impacts are
expected to result from implementation of the Selected Remedy.
Compliance with Applicable or Relevant and Appropriate Requirements
The Selected Remedy of ground water extraction and treatment and
in-situ vacuum extraction will comply with all applicable or relevant and
appropriate chemical-, location-, and action-specific ARARs. Those ARARs
are as follows:
1. Chemical-Specific ARARs
a. Relevant and appropriate Maximum Contaminant Levels (MCLs)
promulgated Under the Safe Drinking Water Act, 43 U.S.C. §300f
to 300J-26 and set forth at 40 C.F.R. §§141.11(b) and 141.61(a) and
proposed MCLs set for in 54 Fed. Reg. 22062 (May 22, 1989) are:
Substance MCL [Proposed MCL]
Benzene 5 ppb
Chlorobenzene [100 ppb]
Tetrachloroethene [5 ppb]
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ARARs IN STATUTORY DETERMINATIONS
Example 2 (Continued)
Toluene [2000 ppb]
Trans-1,2 dichloroethylene [100 ppb]
Trichloroethene 5 ppb
Vinyl Chloride 2 ppb
Arsenic 50 ppb
Barium 1000 ppb
Cadmium 10 ppb
Chromium 50 ppb
Lead 50 ppb
41
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SECTION VI
ENFORCEMENT HISTORY
A ROD should provide thorough documentation of the history of
enforcement activities at a site, including:
Notice letters for RI/FS
• Negotiation period for RI/FS
Administrative Order on Consent (AOC) date; or
Consent Decree (CD) date; or
Unilateral Administrative Order (UAO) date of issuance and the
date of the compliance letter
• Compliance History under AOC, CD, or UAO.
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ENFORCEMENT HISTORY
Example 1
....the lagoon, backfill and grading of the lagoon and illegal diversion ditch,
and repair of the Site's perimeter fence. A mobile onsite treatment system
was installed to provide treatment and filtration of heavy metal-contaminated
surface water that continues to flow across the Site after rain events. In
addition, Site security was provided through contracting with a local guard
service.
C. Inclusion on the National Priorities List
The was scored using the Hazard Ranking System (HRS) in 1987 by
EPA. The Site was given an HRS score of 46.58, based on pathway scores
for groundwater, surface water, and air. The Site was proposed for inclusion
on the National Priorities List (NPL) in June of 1988, and was promulgated
on the NPL on October 4, 1989.
D. History of CERCLA Enforcement Activities
Between 1987 and 1988, EPA identified and notified several hundred
potentially responsible parties ("PRPs") for the Site conditions. Based
upon review of documentation of the pounds of scrap batteries
generated and transported to the Site for processing and/or disposal, and
responses to requests for information from several companies who sent
scrap batteries to the Site, EPA developed a list of 391 PRPs. Following
the proposal of the Site on the NPL, EPA issued General Notice letters
to the PRPs in August 1988, requesting them to conduct or fund a
Removal Action and/or Remedial activities. On September 19, 1989, 46
PRPs entered into an Administrative Consent Order with EPA for the
conduct of a Remedial Investigation and Feasibility Study ("RI/FS").
On December 17, 1991, EPA issued a Unilateral Administrative Order
for Removal Action pursuant to Section 106(a) of CERCLA, 42 U.S.C.
Section 9606(a), to the 46 PRPs who performed the RI/FS for the Site.
This Order required the PRPs to operate and maintain an automated
onsite water treatment plant to address the contaminated surface water
that continues to flow across the Site during precipitation events.
EPA continued to develop information on the PRPs associated with the
Site, and the documents collected from offices during the
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ENFORCEMENT HISTORY
Example 1 (Continued)
course of the RI/FS. Upon identifying additional parties who generated,
transported and/or arranged for the treatment or disposal of scrap
batteries, EPA continued to issue General Notice letters and encourage
PRP participation in the response actions. As a result of this work, a
total of 528 PRPs were identified for the
Using the documents collected from the offices, EPA developed a
Waste-In List or Volumetric Ranking Summary which specified the
volume of waste contributed to the by individual PRPs. EPA
developed this list as a settlement tool to identify those PRPs who would
qualify as de minimis parties under CERCLA Section 22(g). Between
January and August of 1992, EPA completed activities associated with
an early de minimis waste contributor settlement, as authorized under
Section 122(g) of CERCLA. In July 1992, a de minimis settlement was
reached between EPA Region III and 170 PRPs. This settlement
is embodied in an Administrative Consent Order, pursuant to which the
settling PRPs agreed to pay approximately $3,491,233 toward EPA's
past response costs incurred at the Site, and the future costs associated
with the required remedial action.
E. Highlights of Community Participation
The public participation requirements of Sections 113(k)(2)(B) (i-v) and 117
of CERCLA have been met in this remedy selection process. A newspaper
advertisement was published in the Times News, Lehighton, Pennsylvania,
on Saturday, July 18, 1992. It specified the availability of the Proposed
Remedial Action Plan (PRAP), the duration of the public comment period,
and the location of the Administrative Record file.
The public comment period began on July 18, 1992, and was scheduled to
end on August 18, 1992. EPA received a timely request for an extension of
the comment period, and thus granted the minimum 30-day extension, in
accordance with the provisions of the NCP. A newspaper advertisement was
published in the Times News, Lehighton, Pennsylvania, on August 17, 1992,
notifying the public of the extension of the comment period to September
18, 1992.
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ENFORCEMENT HISTORY
Example 2
....bedrock formations of shale, limestone, and coal are mined locally as
economic resources. Within a two mile radius of the Site, there are several
sand and gravel pits in the valley, with clay and coal strip mines in the
valley sides.
The unconsolidated alluvial valley deposits form extensive aquifers which
are the principal water supplies for municipalities in the valley. Ground
water flow in the valley is generally southwestward. The Gnadenhutten
municipal well field is located approximately 4,000 feet northeast
(upgradient) of the . Several wells, including municipal, residential,
and plant wells are located within a 1.5 mile radius of the Site (see Figure
3).
Contamination at the Site was found in the form of sludge in the source
areas, in the soils beneath the sludges, in ground water, and in sediments.
The soil and sludges are being addressed under the first operable unit. The
contaminants found in the ground water include antimony, beryllium, total
chromium, cyanide, fluoride, lead, and bis (2-ethylhexyl) phthalate at levels
above the maximum contaminant levels (MCLs) established under the Safe
Drinking Water Act (SOWA). However, no one is currently drinking this
water. The sediments of the Tuscarawas River in the vicinity of the Site
contain elevated levels of chromium. Polychlorinated biphenyls (PCBs) were
found in 2 of 41 sediment samples.
II. Site History and Enforcement Activity
The plant was established by Harry (Red) Sugar in 1940. The
facility has manufactured aluminum products since 1945 when it was
incorporated as In 1969 merged with . The plant
was then acquired by the in August 1971. The was
acquired by the , a division of the , in January 1977.
In December of 1986, sold the plant to ; however,
retained ownership of a 4.8 acre portion of the property, most of used
for sludge disposal. This 4.8-acre area constitutes the NPL Site.
Prior to 1965, neutralized process wastewater was discharged directly to
the Tuscarawas River. A settling basin was completed in 1965 at the
request of the State of Ohio Department of Health.
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ENFORCEMENT HISTORY
Example 2 (Continued)
During the period from 1965 to 1978, the unlined settling basin and
sludge pit were used for disposal of wastewater and wastewater
treatment sludge. This sludge is a process waste which is included in the
Resource Conservation and Recovery Act (RCRA) list of hazardous
wastes. The sludge is listed under the waste code "F019" because
wastewater treatment sludges from the chemical conversion coating of
aluminum contain chromium and cyanide. As a result of effluent
overflow from the settling basin and plant wastewater discharge, sludge
is also located in the wooded area (formerly known as the "swamp"
area) adjacent to the settling basin. The total volume of sludge and soil
at the Site was originally estimated in the 1989 Record of Decision
(ROD) for the source material operable unit (SMOU) to be
approximately 8,850 tons. The current estimate is that 33,000 tons of
material, including debris, will require removal. Since 1978, no solid
wastes have been placed in the settlement basin or sludge pit;
wastewater treatment sludges have been mechanically dewatered at the
plant and shipped to an off-site facility for disposal. However, the
treated wastewater discharge route included the impoundments until
October 1980, when the effluent discharge was rerouted around the
impoundments to the wooded area, which drained to the river. In
October 1986, the outflow from the wastewater treatment plant was
rerouted away from the wooded area directly to a permitted outfall at
the river. No standing water was present in the wooded area within one
month of the diversion of the outfall. The treated process wastewater has
been discharged to the Tuscarawas River through a National Pollutant
Discharge Elimination System (NPDES) permitted outfall since 1976.
Based on reports filed by , the United States Environmental
Protection Agency (U.S. EPA) conducted a preliminary assessment of the
Site in 1983. Because of a concern that water resources might become
contaminated from sludge leachate, the Site was proposed for inclusion
on the NPL in October 1984. The Site was formally placed on the NPL
in June 1986.
In November of 1984, retained International Technologies
Corporation (IT) to perform a Remedial Investigation/ Feasibility Study
(RI/FS). In March 1985, RI activities began at the Site. An
Administrative Order by Consent was issued in January 1987 among
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ENFORCEMENT HISTORY
Example 2 (Continued)
U.S. EPA, the Ohio Environmental Protection Agency (OEPA), and
for conducting the RI/FS.
The RI was conducted at the Site from March 1985 through January
1989. During the study, samples of sludge, underlying soil, ground water,
and Tuscarawas River sediments were collected at and near the Site. An
investigation was also conducted to determine if drums containing waste
were buried at the Site. Sections of the draft RI pertaining to ground
water and sediments were not approved by U.S. EPA and OEPA.
Consequently, U.S. EPA split the Site into the SMOU and the ground
water operable unit (GWOU), and requested that a separate focused FS
be completed for the SMOU, as enough information was available to
study cleanup alternatives for the contaminated sludge and soil at the
Site. A Focused FS (FFS) developed for the SMOU, presenting an array
of alternatives to address the contaminated sludge and soil, was
completed in June 1989. The ROD for the SMOU was signed on
September 9,1989.
In a letter dated June 14,1989, U.S. EPA requested that submit a
supplemental RI work plan for the additional investigations to complete
the RI/FS for the GWOU. The primary goals of the supplemental RI
were to evaluate the nature and extent of affected ground water, to
prepare a Baseline Risk Assessment for the GWOU, and to evaluate
potential remedial alternatives. The work plan and related planning
documents were finalized on January 31,1991. The supplemental RI was
conducted by consultant, ERM-Southwest, between April and
July of 1991. The supplemental RI report was completed in January
1992. The Baseline Risk Assessment was approved in June 1992. The
FFS and the Proposed Plan for the GWOU were completed and made
available to the public on August 19, 1992. The supplemental RI work
was performed by under the existing Administrative Order on
Consent.
Pursuant to its authority under Section 122(e) of the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA),
U.S. EPA sent a special notice letter to on June 26, 1989,
notifying the company of its potential liability for CERCLA response
costs and responsibility for conducting the design and implementation of
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ENFORCEMENT HISTORY
Example 2 (Continued)
the U.S. EPA's preferred alternative for the . As a result of this
notice letter, informed U.S. EPA that Industries might also
be a potentially responsible party (PRP) as a former owner and
operator. Pursuant to its authority under Section 122(e)(2)(C) of
CERCLA, U.S. EPA notified Industries of its potential liability as
an additional PRP and invited to enter into negotiations with U.S.
EPA and
Negotiations with both companies were unsuccessful, and on December
28,1989, U.S. EPA issued Unilateral Administrative Orders to both
and Industries for the design and implementation of the
remedy for the SMOU. has written the required Site documents,
and is conducting the remedial action. has filed a complaint
against to compel binding arbitration to determine allocation of
financial responsibility. has not conducted any Site remedial work
to date. On April 11,1991, a petition for involuntary bankruptcy
reorganization of under Chapter 11 was filed in U.S. Bankruptcy
Court. On May 2,1991, filed a petition for voluntary
reorganization.
The U.S. EPA is the lead agency responsible for managing the investigation
of the being conducted by . OEPA is the support agency for the
Site cleanup.
50 * U.S. G.P.O.-.1993-341-835:81059
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