United States Office of Policy EPA-230-03-89-045
Environmental Protection Planning and Evaluation June 1989
Agency (PM-220)
r/EPA Ecological Risk
Management
In The Superfund
And RCRA Programs
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EPA-230-03-89-045
ECOLOGICAL RISK MANAGEMENT IN THE SUPERFUND
AND RCRA PROGRAMS
Office of Policy Analysis
Office of Policy, Planning, and Evaluation
U.S. Environmental Protection Agency
Washington, 0.C.
June 1989
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ACKNOWLEDGEMENTS
This document was developed by EPA's Office of Policy Analysis (OPA)
within the Office of Policy, Planning, and Evaluation. Dr. Craig Zamuda was
the EPA project director, with support provided by Dr. Dexter Hinckley, Mr.
Mike Cox, and Mr. Ron Benioff.
IGF Incorporated assisted OPA in development of this document. The ICF
project team was directed by Joanne Colt and Bill Ward, and included Charles
Chappell, Simon Heart, Michael Troyer, Steve Wyngarden, Randy Freed, and
Baxter Jones.
The authors of this document wish to acknowledge, with appreciation, the
inputs, cooperation, and review provided by the many other people who
contributed to the project. This includes numerous individuals within the
Department of the Interior (Fish and Wildlife Service and Office of
Environmental Proj ect Review), the National Oceanic and Atmospheric
Administration, all ten EPA Regions, EPA Laboratories, EPA Headquarters, and
several State organizations.
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TABLE OF CONTENTS
Page
1. INTRODUCTION 1
2. INFORMATION SOURCES 2
3. ECOLOGICAL RISK MANAGEMENT IN THE RCRA PROGRAM 3
3.1 Regulatory Development and Program Review 3
3.2 Hazardous Waste Definition and Determinations 8
3.3 Subtitle C Permitting 9
3.4 Subpart F Corrective Action 12
3.5 Subpart S Corrective Action 15
4. ECOLOGICAL RISK MANAGEMENT IN THE CERCIA PROGRAM 21
4.1 Selection of Sites for the NPL 21
4.2 Development and Selection of Site Remedies 22
5. SUMMARY/PROGRAM IMPLICATIONS 35
5.1 RCRA Programs 35
5.2 CERCLA Program 36
5.3 Cross-Program Ecological Risk Management Issues 37
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ECOLOGICAL RISK MANAGEMENT IN THE SUPERFUND AND RCRA PROGRAMS
1. INTRODUCTION
This report discusses the extent to which ecological concerns have been
used as a basis for decisionmaking in the CERCLA and RCRA programs. For each
program, the report first identifies areas in which ecological impacts could
be considered, and then examines the manner and extent to which ecological
concerns have, in fact, been taken into account in program activities.
Explanations are provided for program areas in which ecological risk
management appears to be limited, and approaches for improving the collection,
evaluation, and management of ecological information are outlined. The report
concludes with discussion of the major ecological risk management issues that
should be addressed by the Agency if ecological concerns are to be fully
considered in RCRA/CERCLA decisionmaking.
This document is organized into four sections. Section 2 discusses the
information sources upon which the analysis is based. Sections 3 and 4
discuss the role of ecological risk management in the RCRA and CERCLA
programs, respectively. Specific sites are used in Sections 3 and 4 to
illustrate how ecological risk management has been conducted in the RCRA and
CERCLA programs; the reader is referred to EPA's draft report "The Nature and
Extent of Ecological Risks at Superfund Sites and RCRA Facilities," EPA-230-
03-89-043 (June 1989) for additional information on most of these sites.
Section 5 summarizes the findings, discusses program implications, and
identifies ecological risk management issues.
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2. INFORMATION SOURCES
A variety of information sources were used to assess past and current
ecological risk management in the RCRA and CERCLA programs, including
telephone interviews with personnel in EPA and other agencies, meetings with
personnel in two EPA Regional offices, and document reviews.
Telephone interviews were conducted with RCRA and CERCLA staff at EPA
Headquarters, EPA Regional offices, and the States. These persons were
queried on the extent to which decisionmakers seek or are provided with
ecological threat information, whether any such information is actually used
in decisions, and the major issues involved in ecological risk management.
Visits were also made to RCRA offices in EPA Regions 3 and 4, and Georgia's
Department of Natural Resources. During these office visits, site-specific
file information was collected, and meetings were held with Regional and State
personnel to discuss how ecological threat information was being used in the
RCRA and CERCLA programs and to identify the main barriers to effective
ecological risk management.
For the RCRA program, two types of documentation were reviewed. Several
recent Regulatory Impact Analyses (RIAs) and Reports to Congress (RTCs) were
reviewed to evaluate the extent to which ecological considerations influence
regulatory development. Also included in the review were site-specific
documents such as ACL demonstrations, permit applications, RCRA facility
assessments, and RCRA facility investigations.
Site-specific Records of Decision (RODs) were reviewed for the CERCLA
program, as these provide the rationale for the selection of remedial actions
at CERCLA sites. Current and draft RI/FS and ROD guidance documents were also
reviewed, as was documentation on the Hazard Ranking System (HRS), a device
used to screen sites and establish priorities for action. Both the current
HRS and the proposed revisions to the HRS were reviewed. Interviews were also
held with Agency personnel in some EPA Regions, and representatives of two
Federal agencies that serve as trustees for natural resources under CERCLA
(the Department of the Interior, and the National Oceanic and Atmospheric
Administration, or NOAA, within the Department of Commerce).
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3. ECOLOGICAL RISK MANAGEMENT IN THE RCRA PROGRAM
This section discusses the extent to which ecological considerations
have influenced decisionmaking in the RCRA program. The role of ecological
risk management in regulatory development and program review is discussed
first, followed by a discussion of ecological risk management in four RCRA
program areas: hazardous waste definition, permitting, Subpart F corrective
action, and Subpart S corrective action.
3.1 Regulatory Development and Program Review
This section focuses on the use of ecological risk information in
Regulatory Impact Analyses (RIAs) developed to support RCRA rulemakings, and
Reports to Congress (RTC). RIAs serve as an important focal point for
evaluating information concerning human health and environmental impacts
addressed by RCRA rules. The manner in which RIAs address ecological impacts
should, therefore, indicate the general level of emphasis placed on these
concerns in the regulatory decisionmaking process. Reports to Congress
generally serve as broad policy and program review documentation. Hence,
these Reports illustrate the manner in which .the Agency measures program
impacts, including ecological risk. Although ecological concerns are also
considered in other types of documentation supporting regulatory development,
such as issue and option papers, background documents, and decision memos, an
extensive review of these documents was beyond the scope of this effort.
3.1.1 Background
Executive Order 12291 requires executive agencies to prepare an RIA for
all new major regulations. RIAs are used to evaluate the benefits, costs, and
economic impacts of proposed rulemakings; RIAs must also assess the potential
impacts of regulatory alternatives. EPA develops regulatory analyses under
Office of Management and Budget guidelines and has prepared RIAs for many RCRA
programs. Reports to Congress are mandated by statute. For example, Section
8002 of RCRA stipulates that EPA is to prepare reports assessing special
wastes under RCRA (e.g., mining wastes).
3.1.2 Ecological Risk Considerations in Regulatory Impact Analyses and
Reports to Congress
This section briefly summarizes the extent to which ecological risk is
considered in RIAs and Reports to Congress, and then discusses ecological risk
management in RCRA rulemaking in general.
Regulatory Impact Analyses (RIAs):
Subtitle D Criteria Revisions RIA - The RIA for the Subtitle D
Criteria revisions analyzes the costs and benefits of regulatory
options for municipal solid waste landfills. The Subtitle D Risk
Model is used to analyze potential releases to ground water and
the associated human health risks and ground-water resource
damages. The benefits of the regulatory options are evaluated only
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in terms of reduction in human health risk from consumption of
contaminated ground water, and reductions in water supply
replacement costs. Releases to air and surface water are not
considered, nor are ecological effects of any kind.
Corrective Action RIA - The Corrective Action RIA quantifies the
societal costs of alternative regulatory approaches, the economic
impacts on hazardous waste facilities, and the benefits of
increased protection for human health and the environment derived
from alternative approaches to corrective action. The RIA also
addresses alternatives and strategies associated with facilities
experiencing multi-media contamination. The RIA evaluates
potential contaminant sources, transport mechanisms, and human
health risks, but it does not address ecosystem-based risks as a
factor in assessing corrective action alternatives. The benefits
analysis focuses entirely on ground-water resource and human
health damages associated with alternative approaches for
addressing hazardous waste releases. Ecological impacts at RCRA
facilities are addressed only through limited case studies and no
quantitative information concerning the extent of ecological
damage is presented.
Land Disposal Restrictions for Solvent Wastes RIA - The Solvent
Wastes RIA evaluates the impacts of several regulatory approaches
for establishing land disposal restrictions for spent halogenated
and non-halogenated solvent wastes (EPA waste codes F001-F005).
The methods used describe typical release scenarios in relation to
human health risk. The RIA does not discuss ecosystem benefits
associated with the improved containment of solvents, nor does it
attempt to quantify ecological risks posed by releases of these
solvents to the environment.
RIA for Small Quantity Generators - This RIA analyzes the costs,
benefits, and economic impacts of rules promulgated for
owner/operators generating between 100 and 1,000 kg of hazardous
waste per month. The document mentions the threat of hazardous
waste releases to the environment and the health risks resulting
from different disposal practices, but does not address the
ecological risks associated with hazardous waste management by
small quantity generators.
Location Standards RIAs - For the location standards rule, several
RIAs were prepared to analyze the costs and benefits of the
location standards for several sensitive environments. The
benefits measured include reductions in human health risks, water
supply replacement costs, corrective action costs, and protection
of ecological resources. Ecological effects are, in fact, the
primary rationale for regulating hazardous waste management in
wetlands and floodplains. The RIA for wetlands measures benefits
in terms of reductions in the area of wetlands destroyed, wetland
restoration costs, and areal extent of contamination. The
floodplains RIA assesses benefits primarily in terms of protection
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of aquatic life. Both RIAs rely on case studies to demonstrate
the types of effects that can occur in these environments. The
baseline ecological damages and regulatory benefits are, in most
cases, assessed in qualitative terms only.
Reports to Congress (RTCs):
Smelting and Refining RTC - This RTC assesses damages from solid
wastes associated with the extraction, beneficiation, and
processing of primary ores and minerals. Case studies are used to
demonstrate instances of soil and water contamination and
devegetation. Aquatic toxicity is assessed by comparing waste
leachate concentrations to EPA acute ambient water quality
criteria for the protection of freshwater aquatic species.
Mining Wastes RTC - This RTC presents a screening assessment of
the risks of mining wastes to human health and the environment.
The risk assessment consists of four components: (1) evaluation of
waste quantity and composition, (2) fate and transport modeling
for air, ground water, and runoff, (3) calculation of human health
risk, and (4) comparison of simulated pollutant levels in surface
water to ambient water quality criteria. The RTC also assesses
the proximity of active mining sites to sensitive environments.
Oil and Gas RTC - This RTC estimates the range of human health and
environmental impacts associated with management of wastes
generated during the exploration, development, or production of
oil, natural gas, and geothermal energy. Case studies are
presented to demonstrate instances of contaminated surface water
and soil, vegetation kills, death of birds and small mammals,
damage to aquatic life, and bioaccumulation in oyster beds. A
quantitative risk assessment evaluates the potential for damages
to human and aquatic receptors. The RTC also assesses the
proximity of oil and gas sites to sensitive environments.
Coal Utilities RTC - This RTC assesses the economic impacts and
potential dangers to human health and the environment associated
with the management of wastes generated from the combustion of
coal by electric utility power plants. The document presents case
studies to qualitatively demonstrate potential human health risks
and ecosystem damage. It also examines the proximity of coal
utilities waste sites to sensitive environments containing
Federally-designated rare or endangered species. No quantitative
assessments of ecosystem effects are included in the analysis.
The review of RIAs and Reports to Congress indicates that reductions in
human health risk, rather than protection of the environment, provide the
justification for most RCRA rulemakings. This conclusion is supported by a
review, performed as part of this project, of all major RCRA Federal Register
notices from 1979 to the present; this review indicated that the threat of
ecological damage is rarely used as the primary basis of support for
regulations affecting RCRA facilities. Although rulemakings are implicitly
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intended to protect human health and the environment, their justification is
usually based upon human health risk assessments for quantitative measures of
benefit. Discussions of ecological benefits are addressed qualitatively.
Exhibit 3-1 summarizes the ecological considerations that are discussed
in recent RIAs and Reports to Congress. This exhibit also identifies the
primary factors considered in the benefits analyses (i.e., protection of human
health or the environment) presented in each of these RIAs and reports.
Although the exhibit indicates that ecological risks have been considered in
several of the documents, these discussions are generally limited to
qualitative assessments or limited quantitative analyses.
3.1.3 Discussion
Several factors contribute to the absence or inconsistent use of
ecological concerns in RIAs and Reports to Congress. First, policy and
guidance for the consideration of ecological or environmental parameters in
RIAs is insufficient. Current Agency guidance for preparing RIAs (see EPA
Document # EPA-230-01-84-003) describes direct methods for assessing damages
to environmental resources of known economic value, and other methods, which
rely on proxy measures of economic value, for estimating the costs for
replacing environmental resources of unknown value. These methods include:
Direct cost - measurements of damages to fisheries, forests, and
agriculture,
Travel cost - estimates of the value of improved recreational
effects of reduced pollution,
Property value - relates differences in property values between
areas with different environmental characteristics to infer the
value placed on environmental improvements, and
Contingent valuation - only available method for evaluating
impacts to nonmarket goods -- requests information from
individuals concerning their willingness to pay to enjoy
alternative levels of environmental quality.
These methods rely on estimating benefits in terms of preventing damage to
recreational areas or ecological resources with known value. The guidance
does not address impacts to ecological systems without a known value, or
systems that people may not be willing to pay to protect. As a result, the
guidance implicitly requires that such ecological systems need not be
considered. Nonetheless, ecosystems that do not have readily
quantifiable economic values may suffer severe impacts from RCRA activities.
Probably the most important reason for the lack of rigorous ecological
risk assessment and management is the absence of appropriate methods for
quantifying ecological damages on the national level. EPA has used case
studies and limited quantitative analysis to assess ecological risks at the
national level. Although the information generated by these methods is useful
in determining the need for a regulation, it cannot be readily assimilated and
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EXHIBIT 3-1
EDCHjOGICAL CONSIDERATIONS Di SUPPORT OF BORA RULEMAKING5
Regulatory Development Document
Ecological Considerations
Ecorisk Key Factors Considered
Considered in Benefits Analysis
Environmental Media Considered
Subtitle D Revised Criteria RIA None
Corrective Action RIA
Land Disposal Restrictions for
Solvent Wastes RIA
Limited case study analysis
Qualitative discussion of
environmental damage
None
No
Ho
No
Human health risks
Ground water resource damage
Human health risks
Ground water resource damage
Human health risks
Ground water
Ground water
Ground water
Air
Small Quantity Generator RIA
Hone
Ho
Human health risks
Ground water
Surface water
Air
Location Standards RIAs
Smelting and Refining RTC
Mining Wastes RTC
Oil and Gas RTC
Wetlands RIA considers the area of Yes
wetlands destroyed, wetland
restoration costs, and areal extent
of contamination to wetlands
> Floodplains RIA considers protection
of aquatic life
Case studies demonstrate damages
qxiali tat ively
Aquatic toxicity examined Yes
Case studies demonstrate soil and
water contaiiination and devegetation
Quantitative and qualitative ecorisk Yes
assessment to aquatic receptors
Assesses proximity of sites to
sensitive environments
Assesses damage to aquatic receptors Yes
Case studies demonstrate ecological
damage
Assesses proximity of sites to
sensitive enviionments
Human drinking water supplies
Aquatic wildlife and wetland
ecosystems
Surface water
Human health and ecological
risks
Human health and ecological
risks
Human health and ecological
risks
Ground water
Surface water
Ground water
Air
Surface water
Ground water
Surface water
Soil
Coal Utilities RTC
Case studies demonstrate ecological
damage
Assesses proximity of sites to
sensitive environments
Yes
Human health and ecological
risks
Ground water
Surface water
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weighed in certain types of decisionmaking (e.g., quanitifying the benefits of
a regulation, selecting among regulatory options). Developing such methods
may require long-term research. In the short term, the Agency needs to
establish a protocol for considering qualitative measures of ecological impact
in regulatory decisionmaking. Such methods may rely on subjective measures of
ecological damage provided by expert judgment or other subjective decision
analysis techniques.
The following sections describe other activities under RCRA that provide
opportunities for consideration of ecological impacts.
3.2 Hazardous ffaste Definition and Determinations
3.2.1 Background
The listing program identifies wastes and waste constituents that are to
be regulated as hazardous under Subtitle C of RCRA. Wastes and waste
constituents are listed as hazardous because they typically and frequently
exhibit one or more of the characteristics of hazardous wastes identified in
Subpart C Part 261 (ignitability, corrosivity, reactivity, EP toxicity) or
meet the criteria for toxicity contained in 40 CFR 261.11(a)(2). These
criteria include lethality to humans at low doses, or in the absence of data
on human toxicity, a measure of toxicity to laboratory animals. On June 13,
1986, EPA proposed the Toxicity Characteristic (TC) rule. This rule modifies
the EP toxicity characteristic procedure by, among other things, adding 38 new
chemicals to the list of toxic contaminants of concern and modifying the test
leaching procedure for wastes.
40 CFR 260.20 and 260.22 allow persons to demonstrate that a waste from
a specific generating facility should be "delisted", i.e., should not be
regulated as a hazardous waste. When evaluating a delisting petition, the
Agency considers the toxicity of the constituents, their concentration in the
waste, their tendency to bioaccumulate, their mobility and persistence,
plausible and specific types of management of the waste, the waste quantity
generated, and other factors. The decision to delist a waste is based in part
on applications of the VHS model, which focuses exclusively on pollutant
transport in ground water.
3.2.2 Ecological Risk Management in Hazardous Waste Definition and
Determinations
There is little consideration of ecological risk in either the listing
or delisting of hazardous wastes. Although ecological impacts are often noted
in listing and delisting documentation, there appear to have been no listing
or delisting decisions that have been based solely on the potential ecological
impacts posed by a waste stream. A limited amount of ecological information
is collected and evaluated in the listing and delisting processes. For
example, among the criteria for listing a hazardous waste, the Agency may
consider the degree to which a constituent in the waste may bioaccumulate, or
the "toxic, carcinogenic, mutagenic, or teratogenic effects on humans or other
life forms" caused by the constituents (see 40 CFR 261.11). Nonetheless,
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potential ecological threat carries very little weight in listing decisions
and is secondary in importance to human health considerations.
The proposed TC rule will not increase the extent to which ecological
impacts influence the identification of hazardous wastes; the TC regulatory
levels are set based on human consumption of contaminated ground water. In
general, the delisting program also considers only human exposure via ground-
water contamination.
3.2.3 Discussion
Ecological concerns, by regulation, must be considered in the
identification or definition of hazardous wastes. Under the RCRA regulations,
a waste can be listed for ecological concerns. For example, if a waste
contains any of the constituents in Appendix VIII, some of which are included
because they are toxic to environmental receptors, the waste can be listed.
In practice, though, listing rationales for individual hazardous wastes are
virtually always based on human health endpoints.
The use of ecological risk management in the listing, delisting, and
characteristic programs could be improved by: 1) developing policy and
guidance to direct the consideration of ecological concerns in listing and
delisting decisions; 2) developing guidance for Headquarters personnel or
petitioners on how to evaluate the ecological effects associated with waste
streams, or how to consider ecological damages in listing or delisting
decisions; 3) considering environmental effects thresholds as well as human
health risk thresholds as the basis for TC regulatory levels; 4) providing
guidance to delisting petitioners describing the type of ecological impact
data to be reported in petitions; and 5) expanding the delisting modeling
approach to consider exposures other than consumption of contaminated drinking
water, and to compare predicted pollutant concentrations in the environment to
ecological criteria as well as human health criteria.
3.3 Subtitle C Permitting
3.3.1 Background
Under Subtitle C of RCRA, all facilities that treat, store, or dispose
of hazardous wastes must obtain a RCRA operating permit. All land disposal
facilities were supposed to have been permitted by November 1988, incinerators
by November 1989, and other storage and treatment facilities by November 1992.
These permits establish the administrative and technical performance standards
required at treatment, storage, or disposal facilities (TSDFs). Permitting is
the mechanism through which technical standards established under Subtitle C
are applied to RCRA facilities.
The permitting process is divided into several steps: submittal of a
permit application; administrative review of the application; preparation of
the draft permit; incorporation of public comments; and modification,
maintenance, and termination of a permit. As part of this project, a limited
number of permitting actions were reviewed. The review indicates that if the
permit writer does not consider the ecological impacts at a facility, such
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considerations generally are raised only by outside parties during the public
comment period. At the public comment stage, comments may be received from
other government agencies such as the Fish and Wildlife Service and the
National Oceanic and Atmospheric Administration (NOAA). EPA or an authorized
State agency can grant or terminate an operating permit based on a facility's
ability to operate in a manner that is protective of human health and the
environment.
3.3.2 Ecological Risk Management in Permitting
The extent to which ecological concerns are addressed in permitting
decisions depends largely on the status of the facility seeking a permit.
Under current permitting practices, ecological information is not requested
from the owner or operator of most new facilities (see 40 CFR Part 270 for a
description of RCRA Part B permit application contents). Such information is
generally deemed unnecessary because the permitting process is designed to
ensure that facilities do not release hazardous wastes to the environment, and
the surrounding ecosystems therefore should not be affected. For example,
design and operating requirements for various disposal and treatment practices
refer to engineered containment to "prevent the migration" of wastes and
constituents into the environment (40 CFR Part 264). Nonetheless, certain
types of facilities do experience permitted releases to the environment, such
as air emissions from thermal treatment facilities or incinerators. In
addition, the RCRA Corrective Action RIA estimates that of all active RCRA
facilities, 62 percent have experienced a release to the environment that will
require a RCRA Facility Investigation. Therefore, some consideration of
ecological impacts at permitted facilities appears warranted.
Permits and permit modifications for existing facilities commonly
address ecological concerns only when past releases or impacts are observed at
a facility. This conclusion is based on discussions with EPA Regional
personnel and reviews of permit files. Ecological evaluations performed at
existing sites seeking permits are generally for the purpose of evaluating the
minimum level of cleanup required to address a past release, rather than the
controls needed to prevent future damage. For example:
A permit modification was requested for Defense General Supply
Center, a 640-acre storage facility. The facility encompasses two
creeks, a wetland area, a pond, and possible habitat for four
endangered species in the vicinity of the waste management areas.
An analysis has been performed comparing surface water contaminant
levels with chronic freshwater quality criteria. Coincident with
the permit modification, the facility operator has proposed to
extend facility investigations to include toxicity testing, a
wetlands assessment, and an aquatic survey. The proposed
ecological assessment at this facility is not designed to
determine the controls needed to prevent future ecological damage,
but may be used to evaluate the level of cleanup needed to address
past releases. The specific information that would provide the
basis for such decisionmaking, or the criteria upon which the
decisions would be based, are not specified in the proposed
workplan or in EPA's preliminary review of the workplan.
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Another case illustrates the use of an ecological assessment to identify
the permitting conditions needed to prevent future ecological damage; this
application of ecological assessment is less common in RCRA permitting:
This case involves an IRECO Chemicals facility that is currently
bound by a compliance order until EPA can set operational
standards regulating the explosion of hazardous materials. In the
meantime, operation of the facility is subject to general
requirements of Subtitle C, plus any conditions prescribed by the
Fish and Wildlife Service to protect or mitigate interference with
the nesting attempts of several raptors in the proposed RCRA site
area. Although this case does represent a more proactive use of
ecological information to support permitting decisions, the permit
conditions addressing ecological impacts resulted from the Fish
and Wildlife Service's involvement in the case. Following
informal notification of the proposed permitting action, Fish and
Wildlife raised objections with EPA. As a result, EPA requested
Fish and Wildlife's assistance in setting the permit conditions.
3.3.3 Discussion
Several approaches to permitting could be adopted to better ensure that
ecological impacts are considered at a facility before they become apparent.
Developing guidelines to require the addition of environmental assess-
ments and exposure information as an integral part of the Subtitle C
permit decision process.
There is a need for predictive ecological insight in the Subtitle C
permitting process, especially for. those facilities thought to pose a moderate
to high risk potential by the RCRA program (i.e., land disposal and land
treatment facilities; PCB and mixed waste management facilities; and thermal
treatment facilities). Since the enactment of HSWA, part B permit
applications submitted by owners or operators of landfills and surface
impoundments have been accompanied by exposure information and health
assessments for the purpose of identifying potential human health problems.
However, this exposure information does not include an analysis of potential
impacts to environmental receptors and is not actively used in the permitting
process. The addition of ecological information in the permit decision
process could provide needed foresight to aid in limiting the number of future
corrective actions.
Notifying and allowing other pertinent agencies and experts to take part
in the permitting process as early as possible.
There is a need for the early inclusion of expertise from other
environmental agencies in the permitting process. This is especially true for
agencies such as the Fish and Wildlife Service, NOAA, and others which
administer Federal laws that have the potential to impact the RCRA permitting
process (i.e., Wild and Scenic Rivers Act, Endangered Species Act, Coastal
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Zone Management Act, Fish and Wildlife Coordination Act, and the National
Historic Preservation Act of 1966. See 40 CFR Section 270.3).
3.4 Subpart F Corrective Action
3.4.1 Background
Under current Subtitle C regulations, corrective action is required at
hazardous waste TSDFs when hazardous constituents are measured in ground water
at the unit boundary at levels that either exceed background concentrations or
maximum contaminant levels (MCLs) (40 CFR Part 264, Subpart F). Under 40 CFR
264.94, owners or operators of TSDFs may petition to modify their permit
conditions to set allowable concentrations of hazardous constituents in ground
water to alternative concentration limits (ACLs). ACLs must be based on the
hydrogeologic characteristics of the site and the expected threat to human
health and the environment resulting from exposure to the constituents. EPA
is required to review ACL petitions and make a determination as to whether the
suggested values are appropriate and whether the facility permit conditions
should be modified accordingly.
3.4.2 Ecological Risk Management in Subpart F Corrective Action
As discussed above, corrective action under Subpart F Ls triggered when
constituent concentrations in ground water exceed background concentrations or
MCLs. There is little opportunity for any type of ecological (or human
health) risk assessment or management in this process. Ecological receptors
are implicitly protected by requiring cleanup when background levels are
exceeded. The exception is for constituents with MCLs or MCLGs.
Approximately 50 percent of the assigned MCLs or MCLGs are higher than
ecological reference concentrations and are thus not protective of aquatic
life (i.e., 13 of the 27 MCLs or MCLGs). For example, methoxychlor,
toxaphene, mercury, copper, and chlordane all have MCLs or MCLGs that are
above ecological reference concentrations. For these pollutants, cleaning up
to MCLs or MCLGs will not be protective of the environment. Although the
Subpart F program calls for cleanup to MCL levels, rather than MCLGs, the
program is nonetheless geared toward protection of humans as opposed to
ecological receptors.
Nonetheless, the ACL process provides an important regulatory tool
within the RCRA program to implement ecological risk management. Operators of
25 facilities have petitioned EPA or State agencies for ACLs (ACL Fact Sheet.
EPA. June 24, 1988). The guidance (see EPA/530-SW-87-017) and regulations
for the ACL process clearly require that ecological impacts, as well as human
health impacts, should be considered when setting ACLs. In fact, petitioners
often base their requested ACLs on ecological toxicity data for the
constituents in question, because environmental exposures are more likely than
human exposures in many facility settings. Five examples of ecological risk
management conducted in accordance with the ACL process are presented below:
A Union Carbide facility in Woodbine, Georgia, petitioned
unsuccessfully for an ACL at the facility's compliance point. An
ecological assessment of an adjacent wetlands/estuary indicated
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that observed ecological stress might be associated with
contaminants originating at the Union Carbide facility.
Observations of 100 percent oyster mortality in the estuary in the
vicinity of the facility and information on potential exposure to
a number of aquatic species in the estuary provided the primary
impetus for the denial of the ACL petition. Georgia's
Environmental Protection Division (EPD) stated that "as a basis
for making this determination [denial of the ACL petition], the
Division points to the proposed continuation of discharges of
contaminants into an ecosystem currently experiencing stress from
other environmental factors, as well as the adequacy of the ACL
petition itself." In particular, EPD decided that adequate
demonstration had not been made that proposed ACLs would be
protective of larval and juvenile crustaceans and fin fish or non-
motile organisms such as oysters and clams.
International Paper Company (IPC) proposed acceptable exposure
limits (AELs) for 27 compounds found in contaminated ground water
at their treated wood products plant in Joplin, Missouri. The AEL
for each compound was equivalent to EPA's drinking water standard,
criteria, or other recommended limit. The AELs were used in
conjunction with dilution and attenuation factors derived from
site-specific hydrogeologic data to determine the ACL for each
compound. Although environmental effects were evaluated, they did
not factor into the development of the ACLs. A subsequent review
by the Missouri Department of Natural Resources (MDNR) and EPA
found the proposed ACL demonstration to be deficient. In
particular, EPA/MDNR disagreed with IPC's assumption that human
health protection will always result in the most conservative ACL
value. In response to the petition, EPA/MDNR presented a plan to
establish ACLs for pentachlorophenol (PCP) and tetrachlorophenol
based on levels protective of freshwater algae as reported in
EPA's AWQC for PCP. EPA/MDNR also recommended setting lower ACL
values for toluene and naphthalene based on chronic health effects
levels for aquatic life calculated from EPA AWQC acute and chronic
toxicity data and a site-specific dilution factor (according to a
method established by Missouri's Ground-Water Quality program).
The Southern Dye Company (SODYECO) submitted a petition for ACLs
for a variety of Appendix VIII constituents. The petition argued
that all contaminated ground water discharged directly to the
Catawba River, with no potential human exposures through drinking
water wells, at concentrations below acceptable ambient levels
based on protection of human health and fish and wildlife. This
petition was denied on the basis of an incorrect characterization
of site hydrogeology. Although the management decision in this
case turned on considerations other than ecological impact, the
case does illustrate the manner in which ACLs may be used for
ecological risk management.
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National Industrial Environmental Services (NIES) petitioned for
ACLs in accordance with a consent order under RCRA and CERCLA.
Seventeen of 35 proposed ACLs were based on protection of aquatic
life through incorporation of EPA's chronic AWQC or maximum
chronic exposure levels derived from acute toxicity data. These
ACLs were approved by Region 7.
A Wyman-Gordon facility operating a treatment lagoon submitted a
petition for ACLs for three constituents in its Part B permit
application. This petition was subsequently withdrawn prior to
its review by the State of Massachusetts or EPA. However, the
petition did indicate the operator's intent to provide ecological
risk management through the ACL process. This petition requested
rather unique ACLs based on ecological studies of a stream and
wetland downgradient of the lagoon; the operator proposed ACLs
equivalent to the maximum concentrations previously observed at
the compliance point and supported this proposal with the
demonstration of no biological damage to the stream. This
approach to establishing ACLs differs from that used in the
previous cases in that the petitioner developed the ACLs based on
site observations of ecological and biological conditions, rather
than on peer-reviewed toxicological data.
3.4.3 Discussion
In the above cases, ecological impacts were considered through the
proposal and review of ACLs. Federal and State officials review tKe ACL
petitions and guide applicants concerning the need for additional information.
To support the management of this process, supporting materials are needed
both for permit writers and the public:
Limited policy and guidance stipulating the manner in which
ecological impacts should be considered have been developed (see
Chapter 10 of the ACL Guidance Document (June 1987), but
additional guidance is needed;
Direction to guide applicants in the presentation of ecological
data, identification of sensitive species, and comparison of acute
versus chronic exposures;
Ecological risk policy, guidance, and methodology developed and
applied consistently to all corrective action/ACL demonstration
cases; and
Direction available at the initial stages of the process as to
when ecological effects should be considered, what ecological
effects should be given attention, and what level of ecological
impact will warrant Agency action.
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3.5 Subpart S Corrective Action
3.5.1 Background
EPA is planning to issue a proposed rule under HSWA authority to create
new corrective action requirements at Subpart S of 40 CFR Part 264. The new
Subpart S outlines standards and procedures to address releases to air,
surface water, ground water, or soil from solid waste management units. The
rule stipulates requirements for performing remedial investigations, assessing
potential remedies, and selecting and implementing remedies at RCRA
facilities.
Under HSWA, all RCRA Subtitle C interim status or permitted facilities
must be assessed to determine whether past releases of hazardous waste have
occurred at the facility. This is the first step of the Subpart S process and
is known as the RCRA Facility Assessment (RFA). If a facility is found to
have experienced a release, a more detailed investigation is then carried out
to determine the extent of contamination. This second part of the Subpart S
process is known as the RCRA Facility Investigation (RFI). Corrective action
is triggered at those facilities that are found through the RFI to have
released hazardous constituents in concentrations that pose a threat to human
health or the environment. In such instances, the owner or operator of the
facility is required to conduct a Corrective Measures Study (CMS) to identify
alternative remedies. When EPA selects a remedy, the Agency will either issue
a follow up order in the case of a facility under interim status, or modify
the facility's permit to incorporate the remedy as a condition of the permit.
EPA will then oversee the implementation of the remedy by the owner or
operator.
3.5.2 Ecological Risk Management in Subpart S Corrective Action
The RFA process is not intended to provide an opportunity for ecological
risk management. The RFA focuses solely on identifying releases and potential
migration pathways, stopping short of considering ecological or human health
impacts. The following case illustrates the general approach of an RFA in
accordance with EPA's guidance:
A Pratt and Whitney facility submitted a workplan for an RFA
following the procedures outlined in EPA1s RFA guidance of June
19, 1986. The proposed steps of the assessment include a
preliminary site review and visual site inspection, to be followed
by more detailed investigations (including sampling) if deemed
necessary by the initial investigations. The outline of the
proposed RFA report indicates that the majority of the discussion
will address pollutant migration pathways and evidence of releases
to various environmental media with only a "brief description of
the potential impacts of any release."
Based on the RFA, a determination is made as to whether a RCRA Facility
Investigation (RFI) should be conducted. Given the limited resources
available and the large number of sites with past releases that will require
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some type of RFI, the Regions must set priorities. To date, EPA Headquarters
has provided no guidance to the Regions on setting priorities for RFIs. As a
result, the Regions are developing their own priority-setting schemes.
In addition to setting priorities for conducting RFIs, ecological risk
may also be considered when completing the RFI. Most of the detailed
information used in determining whether a corrective action is needed should
be collected during the RFI. However, only a handful of RFIs have been
completed at RCRA facilities; therefore it is difficult to assess the extent
to which ecological concerns are addressed under the current process. The
discussion below provides four examples of facilities at which RFAs and plans
for RFIs have been completed and decisions have been made concerning the need
for further studies. These examples provide some indication of the manner in
which ecological damage information may (or may not) be collected and managed.
Saco Defense, Inc., is a party to a consent order with EPA Region
1 to conduct a RFI to evaluate "significant environmental
contamination." Releases at this site involve seepage of waste
solvents and other contaminants from landfills and lagoons to
surface water and ground water and volatilization of VOCs to air.
The site's RFA identified no ecological impacts. However, the
consent order proposes an evaluation of environmental threats to
include an identification of nearby wildlife and sensitive areas,
and an evaluation of indicator chemicals to be used in assessing
environmental risks. Nonetheless, the consent order does not
stipulate any specific sampling to be conducted nor does it
outline the manner in which the ecological threat information is
to be used to evaluate the site.
Koppers Company, Inc., is a 112-acre wood treatment facility that
disposed of its wastewaters through spray irrigation and currently
maintains an uncovered product storage area. An RFA has been
completed for this facility and an RFI has been recommended. The
only ecological impact noted in the RFA was "very sparse
vegetation" in several areas. The RFA does recommend, however,
that certain solid waste management units (SWMUs) be more closely
inspected during the RFI.
An RFA has been conducted for ARCO's Prudhoe Bay Eastern Operating
Area facility. This RFA investigated records of releases at a
number of SWMUs and recommended RFIs for a limited number of these
units. The decision to perform the more detailed RFIs on a subset
of the facility's surface impoundments is based solely on evidence
of releases from these units, and not on potential or actual
ecological threats. EPA currently has the authority to address
only observed releases, rather than potential releases.
Ecological impacts are suspected at this facility, however.
Monroe Auto Equipment Company is not a permitted TSD facility, but
it is subject to oversight by the State of Georgia RCRA program as
it undertakes remediation efforts comparable to those required
under RCRA Subpart S corrective action. In the independent
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studies completed to date, the owner has measured the
concentration of contaminants in environmental media and compared
those concentrations to levels of concern. One comparison
relevant to ecological considerations indicates that surface water
concentrations of trichloroethene are far below levels of effect
for bluegill and fathead minnow. Another toxicity threshold
comparison demonstrated that the observed concentrations do not
exceed levels of concern for aquatic plants. This study concluded
that no further actions are required because the environmental
concentrations are below levels of concern for aquatic life and
human health.
The Agency could also weigh ecological risk at RCRA facilities when
evaluating the results of the RFI to determine whether a corrective measures
study is needed at a site. Under the pending draft Subpart S rules, a
corrective measures study is triggered if, during the RFI, pollutant
concentrations in air, water, or soil are found to exceed action levels for
specific constituents. The action levels for all media except surface water
are based on human health risk. Under the current EPA guidelines, action
levels for surface waters that are designated for uses other than drinking
water should be set to protect the designated use (e.g., supporting aquatic
life) of the water body. The following case demonstrates the potential use of
aquatic toxicity as a basis for determining action levels for a HSWA permit:
The Southern Wood Piedmont (SWP) Company owns a closed facility in
Baldwin, Florida with a draft permit that contains human health-
based ACLs. Because the site poses no direct threat to human
health, EPA Region IV personnel have decided that the corrective
action should be designed to protect environmental receptors.
Consequently, EPA personnel have continued investigating the
facility to facilitate the development of a site workplan prior to
the issuance of a HSWA permit. A toxicity test was performed on
ground-water samples taken at the plant boundary. A second round
of ground-water sampling and analysis is currently being
conducted. Region IV personnel have stated that they hope to use
the results of the toxicity testing to aid in developing action
levels for releases from SWMUs under the HSWA permit.
There is also opportunity to consider ecological concerns in the
corrective measures study itself. At present, very few facilities have
reached this point in the corrective action process. As a result, it is
difficult to assess the extent to which ecological risk management will occur
in the selection of corrective measures.
Two examples of facilities at which ecological risk management issues
have arisen during the implementation of corrective action to rectify past
releases from a solid waste management unit are provided below. These cases
illustrate the need to consider ecological impacts when choosing and designing
remedial measures.
The Kennedy Space Center is voluntarily engaging in corrective
action procedures to address releases from a solid waste
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management unit. Although the corrective action procedures
apparently comply with HSWA requirements, the site has not.
followed the formal RFA/RFI/CMS process. In consultation with EPA
Region IV, Kennedy began work on an air stripper unit to treat
contaminated ground water withdrawn from near the facility
boundary. However, Kennedy had installed the unit in a Wildlife
Refuge adjacent to the Space Center Facility. The Department of
the Interior (DOI) raised concerns over the impacts to the refuge
wildlife resulting from exposure to the air stripped solvents.
Such concerns had apparently not been raised during the earlier
stages of the corrective action remedial design. As a result, all
activities a£ the site have been halted pending negotiations among
EPA, DOI, and the Kennedy Space Center.
Allied Chemical Baltimore Chrome Ore Works is currently undergoing
negotiations with EPA Region III to address the selection and
design of corrective measures. This inactive site has been
investigated independently by the owner in a manner comparable to
a CERCLA remedial investigation. The results of these previous
investigations, which indicate chromium concentrations above
levels of concern in ground water and a nearby estuary, are the
basis for the corrective measures (e.g., RCRA-type cap and deep
ground-water barrier) being negotiated. The ecological impacts at
the site include increased body burden of chromium in benthic
invertebrates near the site.
A final area of ecological risk management associated with Subtitle C
corrective action concerns remediation efforts at facilities that have been
moved from CERCLA authority to RCRA Subtitle C corrective action authority.
Such transfers of authority may become more common under EPA policy as the
Agency endeavors to require privately funded cleanups when RCRA authority can
be applied to a site (see 51 FJg 21054, June 10, 1986). The following case
involves such a transfer of authority at a facility.
The Rohm and Haas Delaware Valley operation in Bristol,
Pennsylvania had been investigated under CERCLA before authority
for remediation at the facility was transferred to the RCRA
program. The investigative work that has been completed under the
CERCLA authority includes a remedial investigation with a survey
of plants and wildlife in the vicinity of the facility. This work
has focused on a landfill at the facility as the first operable
unit for remedial attention. The organization of RCRA corrective
action may preclude the use of the information generated in the
previously conducted remedial investigations until all SWMUs are
identified, their release histories assessed, and their priority
for continued study is determined. Only after this RCRA
investigation is complete will the opportunity arise for
application of the CERCLA investigation results to the RCRA
remedial design.
The eventual cleanup action taken at this facility should not differ under the
RCRA or CERCLA program. However, there may be a slight delay in remediating
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the ecological impacts at the unit as the site may need to comply with the
RCRA corrective action requirements.
3.5.3 Discussion
The proposed Subpart S rule gives the remedial investigator discretion
in determining if and when an environmental assessment is needed. The
ecological scope of the proposed rule is best characterized by the following
pertinent sections that implicitly or explicitly pertain to ecological risk
management.
Section 264.511 Scope of remedial investigations
(a)(3) Investigations may include, but are not limited to descriptions
of humans and environmental systems which have, or under site-specific
circumstances are potentially exposed to release(s).
(a)(5) Investigations may include extrapolations of future movement,
degradation and fate of contaminants.
Section 264.525(b) Remedy selection factors
(l)(iii) Any potential remedy(s) may be assessed for long-term
reliability and effectiveness, and factors that shall be considered in
such an evaluation include the potential for exposure of human and
environmental receptors to remaining wastes, especially with regard to
excavation, transportation, redisposal or containment.
(2)(iv) A potential remedy(s) may be assessed for the level of
treatment used to reduce toxicity, mobility or volume of hazardous
wastes and constituents. Factors that shall be considered in such an
assessment include the propensity of residual hazardous wastes and
hazardous constituents to bioaccumulate.
Section 264.525(d) Media cleanup standards
(l)(iii)(B) In establishing remedial cleanup standards the Regional
Administrator may consider exposure threats to sensitive environmental
receptors.
Section 264.551(b) Management of hazardous wastes
(4)(iv) The Regional Administrator may determine alternate design,
operating or closure requirements for some temporary units which store
or treat hazardous wastes. If the purpose is to establish standards,
the Regional Administrator shall consider, among other factors, the
potential for exposure of humans and environmental receptors if releases
occur from the unit(s).
Under these pending revisions to the Subtitle C corrective action
program, the Agency is moving to a more human health and environmental risk-
based approach for determining when corrective action is required and what
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cleanup target levels should be set. If the Subpart S program is to
aggressively address ecological impacts at RCRA facilities, strong emphasis
must be placed on assessing ecological impacts in the RFA/RFI process. At
this early stage of the Subpart S program, the critical management need is for
sufficient information to assess the extent of ecological impacts at Subtitle
C facilities. Hence, the Agency should set policy and develop methods to
adequately evaluate ecological damage during the RFA/RFI to ensure that
ecological risks are addressed properly during the corrective action.
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4. ECOLOGICAL RISK MANAGEMENT IN THE CERCLA PROGRAM
Ecological risk management can occur principally at two points in the
CERCLA remedial response process. The first is the decision on whether to
place a site on the CERCLA National Priorities List (NPL), and the second is
in the development and selection of remedies for individual sites during the
remedial investigation/feasibility study (Rl/FS).
4.1 Selection of Sites for National Priorities List (NPL)
4.1.1 Background
Once a CERCLA hazardous waste site has been identified, a preliminary
assessment and site inspection (PA/SI) are performed. These are relatively
brief, initial information gathering activities. A PA is usually limited to a
"desk audit" of previously documented information about the release and the
characteristics of the site. The SI typically includes a visual examination
of site conditions and the collection of samples.
The data gathered and observations made during the PA/SI phase are then
evaluated using a site scoring algorithm called the Hazard Ranking System
(HRS). The HRS is part of the National Contingency Plan (NCP), the
comprehensive set of regulations that implement the CERCLA statute. The HRS
is a uniform method for judging the degree of potential hazard presented by a
site relative to that presented by other sites. HRS scores are not estimates
of absolute risk, but are relative rankings.
If a site receives an HRS score of 28.5 or more, it is placed on the
National Priorities List (NPL), which means that further action on the site
will occur, and that Superfund monies may be considered as a means of paying
for such action. Site hazards will be investigated in greater detail, options
for remedying hazards (including a "no action" option) will be developed and
evaluated, and one option will be selected and executed. If the HRS score is
less than 28.5, the site will not be placed on the NPL unless (1) a State
government designates the site as that State's highest priority, or (2) EPA
does so based on conditions specified in Section 300.66(b) of the National
Contingency Plan.
4.1.2 Ecological Risk Management in Site Selection for the NPL
In most cases, the decision to place a site on the NPL is based on its
HRS score. The inclusion of ecological factors in the current HRS is
extremely limited; the principal factors score ecological hazard simply in
terms of the distance from a site to the nearest "sensitive environment" (the
HRS includes a short list of the types of environments that can be considered
"sensitive"). This score is built into two more summary scores: the hazard
from the site due to the migration of contaminants via surface water, and the
hazard due to air migration. These scores are then combined with other
summary scores to yield an overall HRS score for the site.
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4.1.3 Discussion
Given the current scoring algorithm, ecological risk considerations
alone cannot result in a site score of 28.5 or more. Thus, NPL listing is
currently not possible for sites where ecological risk is the sole concern.
Obviously, sites that score just below 28.5 based on human health risk can be
pushed past the threshold based on ecological concerns. Because remedial
action is very unlikely to occur if a site is not listed on the NPL, this is a
crucial decision point in the CERCLA program, and one in which ecological risk
is of secondary importance to human health concerns.
The proposed revisions to the HRS (53 Fed. Reg. 51962, December 23,
1988) will expand the consideration of ecological risk. These HRS revisions
expand the list of environments that can be considered sensitive, and
incorporate scores that reflect contaminant levels in wastes and surface water
relative to ambient water quality criteria and other toxicity values for
aquatic species. The larger, more summary components of the HRS have been
reorganized to include an "environmental threat" sub-pathway to the surface
water migration pathway, and a new "on-site exposure" pathway that includes
consideration of sensitive environments. The new threshold score for
determining whether or not a site will be placed on the NPL has not been
identified. Until the new threshold is established, it is unclear as to
whether ecological considerations will be sufficient to qualify a site for
listing on the NPL.
4.2 Development and Selection of Site Remedies
4.2.1 Background
After the site is listed on the NPL, a Remedial Investigation (RI) of
the site is performed. The RI typically examines the characteristics of the
site (e.g., the nature and the extent of the contamination; the principal
contaminants involved; land use, human population distribution, and
environmental receptors in the area of the site; site geology, hydrology, and
wind patterns) in detail. Ideally, the beginning of the RI stage (RI
planning) is the point at which CERCLA natural resource trustee agencies are
consulted. These agencies are the Department of the Interior (principally the
U.S. Fish and Wildlife Service), and the National Oceanic and Atmospheric
Administration (NOAA) in the Department of Commerce. These trustee agencies
use their ecological expertise to advise EPA on effects a site may have on
natural resources (e.g., wetlands), and to determine any liability that
parties responsible for site hazards may have for damage to natural
resources.1 The RI is followed by a Feasibility Study (FS), in which possible
alternatives for remedial action at the site are formulated and evaluated.
The selection of the actual remedial action to be taken is described and
documented in a Record of Decision (ROD) for the site. The ROD first provides
Although natural resource damage assessments are supposed to be
integrated into the RI/FS and remedial selection process, this report does not
focus on the natural resource damage assessment process.
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background for the decision by summarizing the data in the RI and FS reports,
and then describes the selected remedy and evaluates it according to the
criteria by which each of the remedial alternatives were judged.
4.2.2 Ecological Risk Management in Remedy Selection
The selection of the remedial action for a site is the most important
ecological risk management event for sites that have passed the HRS/NPL
screening process. It is at this point that decisions are made in terms of
the remedial actions necessary to protect human health and the environment. A
decision concerning remedial action may involve the establishment of specific
cleanup levels necessary to reduce ecological risk.
To estimate the frequency with which ecological considerations have
historically played a role in remedy selection, RODs were reviewed for 20
sites at which there is some indication of potential ecological problems. The
RODs indicate that ecological concerns did not affect remedy selection at
almost half of them. In these cases, the RODs typically contain only a
general statement of the need to "protect natural resources" or a brief
mention of an unspecified potential ecological effect. Sometimes the
evaluation of remedial alternatives and the selected remedy is limited to the
repeated use of the phrase, "protective of public health and the environment."
Little or no description of ecological threats, or of any other non-human
health threats that might fall under the term "environment" (e.g., diminished
recreational opportunities, materials damage, crop damage) is provided. Some
of the RODs clearly stated that sites were near wetlands or other sensitive
environments, but did not consider ecological threats on a level of detail
approaching what appears warranted.
Nevertheless, there are several CERCLA sites at which ecological effects
have been considered in the development or selection of remedial actions.
Some examples of how ecological concerns-have been or are being incorporated
into decisionmaking at CERCLA sites are given below. These examples were
identified based on review of the RODs and conversations with Superfund
program officials.
At several sites, toxicity testing of ecological receptors has been used
in conjunction with chemical testing (e.g., sampling and analysis of
sediments) as a basis for determining the need for remedial action, or for
identifying the portion(s) of the site that require cleanup. For example:
Harris Properties in West -Virginia is a removal site. Based on
chemical analysis of soil samples, there was concern that heavy
metals in soils could pose an ecological hazard. To determine
whether there was a basis for concern, leachate from soil samples
was used in acute and chronic toxicity tests on Selanastrum and
Ceriodaphnia. Based on the lack of evidence of lethality or
reproductive effects, these tests were used as a basis for
justifying no further action at the site.
Vineland Chemical in New Jersey is in the RI/FS stage. Arsenic-
containing pesticides have been discharged into a nearby river
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through ground water. A benthic survey was used to determine
which areas of the stream show evidence of ecological impacts and
therefore require remediation (such as dredging). In this survey,
macroinvertebrates were collected from areas upstream and
downstream of the site. Areas recommended for remedial action
based on ecological effects were those that displayed a
statistically significant change in one or more of several
different indices (e.g., species diversity, richness, number of
taxa present, functional feeding group assessments). Toxicity
testing on solid phase (sediment) samples was used to correlate
effects in the benthic population with laboratory-controlled
studies on benthic invertebrates. These same techniques (benthic
surveys combined with toxicity testing) are being used as a basis
for delineating the portion of the site requiring remediation at
Clear Creek, Colorado, which is in the RI stage.
Oconomowoc Electroplating in Wisconsin is a remedial and removal
site. The focus of ecological concern is elevated levels of heavy
metals and cyanide in a nearby wetland. Sediment samples are
being tested for toxicity to fathead minnows and Selenastrum; the
endpoints of concern are death and decreased growth. The results
of these tests will be used to delineate the boundaries of site
contamination and determine the need for remedial action.
Myers Property, a chemical femulator in New Jersey, is in the
RI/FS stage. Chemical monitoring has shown highly elevated DDT
levels in the soils of a nearby forested wetland that receives
surface runoff from the site. Removal of the DDT is being
considered based on potential effects on small mammals that could
bioaccumulate DDT. Because DDT removal will destroy a valuable
habitat, the Agency is trapping small mammals to determine whether
DDT accumulation has in fact occurred, and whether DDT removal is
justified.
At the Marion/Bragg inactive landfill in Indiana, the focus of
ecological concern is the high levels of ammonia and arsenic on-
site, which could cause ecological effects in a river that
receives ground-water discharge from the site. Ammonia levels in
some river water samples exceeded Indiana WQC for the protection
of aquatic life, but no adverse effects on aquatic life were
detected. Risk managers considered constructing a slurry wall and
pumping and treating ground water to prevent discharge of
contaminants to the river, but its high cost could not be
justified in light of the lack of actual damage to aquatic life in
the river (as well as technical inadequacies). An "interim
remedy" was selected which includes restricting access; regrading
and construction of a clay cap; construction of a levee to control
flooding; quarterly monitoring of both the river and the ground
water entering the river; and a series of studies on the aquatic
life of the river. These studies will include fish toxicity tests
using indicator chemicals for volatile organic compounds, PAHs,
and inorganics. They will also include "general toxicity tests"
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to determine if ammonia or other constituents in the ground water
cause a toxic effect on the 'aquatic environment; these general
tests may be modeled after toxicity tests that NFDES dischargers
are subject to. Based on the quarterly monitoring, the toxicity
tests, and observations on the performance of the interim measure,
the need for a more complete remedy will be assessed.
At several sites, performance or cleanup levels for the remedial actions
are being set at concentrations intended to be protective of ecological
receptors. Also, at sites for which ground-water extraction and treatment is
among the remedial alternatives, ecological considerations are frequently
taken into account in setting effluent limitations for the treated ground
water. For example:
The Marathon Battery site in New York discharges into Foundry
Cove, a shallow bay and cattail marsh on the Hudson River.
Elevated levels of cadmium, nickel, and lead were found in surface
water, sediments, and biota at the site, including fish and
mammals. The main remedial objectives were to prevent biota from
contacting contaminated sediments that would threaten them, and to
prevent resuspension and redistribution of contaminated sediments
that would threaten flora and fauna. To evaluate remedial
alternatives, it was necessary to establish an acceptable level of
cadmium in sediments. The effects of elevated metals levels were
examined in terms of both ecological and human health endpoints.
A cadmium level of 900 mg/kg in sediments was deemed acceptable to
protect public health. To identify an cadmium level in sediments
that would be acceptable from an ecological standpoint, a
partitioning approach was used to determine the sediment level
that would limit cadmium concentrations in the water column below
the AWQC. A site-specific remediation level of 100 mg/kg was
ultimately selected to protect against the threat to the
environment. The remedial action selected for the Foundry Cove
marsh was sediment dredging, chemical fixation, and off-site
disposal; restoration by addition of clean fill and clay with a
high affinity for cadmium and revegetation; and long-term
monitoring of sediments and biota.
At the Geiger site in South Carolina, contamination by lead,
chromium, and organics was detected in soils, ground water, and
nearby swamp and wetland areas; these wetland areas are critical
habitat for endangered species (bald eagle, wood stork, red-
cockaded woodpecker), threatened species (American alligator), and
other species being considered for future listing. The ground
water underlying the site has been identified by EPA as Class I
because it discharges to wetlands. The selected remedial action
was ground-water extraction, treatment, and discharge; and on-site
soil excavation, thermal treatment, stabilization/solidification,
and backfilling at the site. The ground-water cleanup levels were
driven by ecological considerations; the cleanup levels for
toluene and 1,1-dichlorobenzene were based on aquatic chronic
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toxicity values. Effluent limits for the ground-water treatment
system are to be based in part on toxicity tests.
At Re-Solve, Inc., in Massachusetts, PCBs and other contaminants
(methylene chloride, phthalates, cadmium, mercury) have been
detected in both surface water and sediments of a nearby wetland,
in a river designated by the State of Massachusetts for the
protection and propagation of aquatic life and wildlife, and in a
pond used for sport fishing; ground-water contamination has also
occurred. Site remedies include excavation and PCB removal from
on-site soils and wetland sediments, followed by recirculation
(pump, treat, recharge) of contaminated ground water, and
revegetation. The PCB cleanup levels for the soil and ground
water were based on human health; the PCB cleanup level of 1 ppm
for the wetland sediments was based on ecological criteria.
According to the ROD, the 1 ppm PCB cleanup level in sediments is
protective of "some but not all adverse effects" on freshwater
benthic organisms, and will result in a water column level below
the AUQC; fish tissue levels, however, "may exceed the FDA
tolerance limit." A less stringent cleanup level of 2.5 ppm was
rejected as being not sufficiently protective of aquatic life.
At the Mowbray site in Alabama, the areas of ecological concern
are a swamp with stressed vegetation, and a stream that receives
contaminated runoff and ground-water discharge from the swamp.
The principal contaminants are waste oils and PCBs. Site remedies
included cleanup of waste oils, excavation and incineration of
contaminated soils, drainage rerouting, and restoration of the
swamp area (backfilling, grading, revegetation, fertilization).
The cleanup level for PCBs in soils in the swamp was set at 25
ppm, after an analysis indicated that cleanup of soils to this
level would ensure compliance with AWQC in the nearby stream.
The Outboard Marine site in Illinois has resulted in PCB
contamination in Waukegan Harbor. PCB levels in the harbor exceed
AWQC, and elevated PCB levels have been detected in fish,
shellfish, and waterfowl. A decreased species diversity of
benthic macroinvertebrates has been noted, and there is a
"relative scarcity" of fish in the area. Endangered or threatened
species believed to be in the area include the bald eagle, lake
whitefish, and several species of birds and plants. The remedial
action involves the excavation of sediments containing more than
50 ppm of PCBs. This level was selected to ensure that water
column concentrations of PCBs would not exceed the chronic AQWC,
and that fish tissue levels would not exceed the FDA action level.
A hydrodynamic model of water and sediment transport was used to
determine the relationship between sediment and water column
concentrations; a safety factor of 2 was then applied to the model
results.
At the Takoma Landfill Site at Commencement Bay, Washington,
ground water contains heavy metals and organics at levels above
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AWQC. Although surface water contamination is not currently a
problem, there is concern that discharge of contaminated ground
water to creeks could result in surface water concentrations above
AWQC; these creeks support anadromous salmonid runs which could be
at risk if toxic compounds are present during critical phases in
their growth cycles. There is also concern that discharge from
the creeks to Puget Sound could adversely affect vulnerable larval
fishes and commercially important shellfish. The remedy selected
is capping of the landfill, extraction of methane gas, and ground-
water extraction and treatment; these controls will prevent
further contaminant migration and thereby protect both human
health and the environment. Ten constituents of concern were
identified, 8 based on human health and 2 (toluene, xylenes) based
on potential ecological risk. Although the ground-water cleanup
levels will be based on human health-based criteria, potential
impacts to the creek must be considered in a decision to shut off
the pump and treat operation. Also, levels of the 10 constituents
of concern in effluent from the ground-water treatment system
cannot exceed MCLs or AWQC if the effluent is to be discharged to
surface water. Toxicity tests will also be used as a basis for
developing standards for treatment system effluents.
In several cases, ecological considerations have led to the elimination
of certain remedial alternatives judged to have unacceptable ecological
impacts. Some examples, given below, illustrate the trade-offs that are often
made between the environmental benefits and damages that can result from a
remedial action.
As discussed above for the Re-Solve site in Massachusetts, a
cleanup level of 1 ppm for PCBs in sediments was selected based on
ecological concerns. This sediment criterion will result in water
levels below the AWQC. However, the ROD recognizes that this PCB
level is not protective of all adverse effects on freshwater
benthic organisms, and can result in fish tissue levels above the
FDA tolerance limit. A more protective level cleanup level of 100
ppb was rejected at this site because it would double the wetland
area disturbed, resulting in increased loss of flora and fauna.
At the Geiger site described above, excavation of contaminated
sediments in the swamp was rejected (in favor of extraction and
treatment of ground water and on-site soils) because it would
require clearing the vegetative cover, which would disrupt the
habitat and feeding groups of a wide variety of wildlife. The ROD
stated that "benefits to be obtained by swamp remediation would be
exceeded by the adverse environmental impacts which would be
realized."
At Mobray Engineering, discussed above, the remedial action
included excavation and incineration of contaminated soils,
followed by restoration and revegetation of the swamp. On-site
encapsulation of contaminated soils was rejected because it would
limit the ability of the site to be revegetated. Similarly,
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stabilization/solidification of the contaminated soils was
rejected because it would result in "permanent loss of wetland
resources in areas where soils are solidified."
At some sites, the selected remedial action is known to be unable to
comply with ecologically-based ARARs. This has been justified in some cases
based on the fund balancing provision of the NCP (40 CFR 300.68(i) (1) . This
provision allows EPA to choose a remedy 'hat does not meet ARARs when the need
for complying with ARARs is outweighed by the need for action at other sites,
given the total amount of money available in Superfund. Thus illustrates
another trade-off issue, i.e., the need for remedial action at one site versus
the availability of funds for remedial actions at other sites.
At the Iron Mountain Mine site in California, releases via runoff
and ground water from the inactive mine have contaminated surface
waters and sediments. Cadmium, copper, and zinc have been
detected in fish and aquatic invertebrates, and there have been
documented fish kills. The selected remedy is capping the mine to
reduce infiltration of clean water, diverting runon, and assessing
the feasibility of using concrete to reduce acid drainage from the
mine. This remedy will not reduce metals in surface water to
levels below the AWQC, nor will it protect the winter run of an
endangered species of salmon. A more expensive remedial
alternative (removal of waste rock, tailings piles, and sediments)
that could have met the ARARs was rejected as too costly ($1.4
billion) under the fund balancing provision of the NCP.
At the Outboard Marine site in Illinois, discussed above, the
selected remedial action was to remove sediments with PCB levels
above 50 ppm. This was selected in place of excavating all PCB-
contaminated sediments, which, according to the ROD, is the only
alternative that would have been in compliance with the Toxic
Substances Control Act (i.e., would meet all ARARs). This remedy,
however, would have cost over $75 million, about three times more
than the selected remedy, and was rejected based on the fund
balancing provision.
Other examples of how ecological concerns have been addressed at CERCLA
sites are provided below:
PCB contamination is of concern in the Hudson River in New York.
PCB levels in fish tissue have exceeded the FDA action level. PCB
concentrations in sediments are over 50 ppm in some "hot spots,"
exceed 20 ppm in "cold areas," and are over 10 ppm in areas
further downstream. An "interim" no action alternative was
selected for this site. Dredging of contaminated sediments was
rejected because it would result in releases of PCBs into the
water column, and because its expense could not be justified based
on the level of risk at the site and the need for actions at other
sites. Also, natural sedimentation processes appear to be
covering up the PCB contamination, making the chemical less
accessible to biota; in fact, there has been a downward trend in
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PCB levels in fish tissue. However, site personnel are not
convinced that remedial action should not be taken at the site.
Further investigations are being conducted to characterize the
contamination more completely, and new technologies for PCB
remediation are being investigated.
The Palmerton Zinc site consists of areas contaminated by a zinc
smelter in a deep valley of the Appalachian Mountains in
Pennsylvania. Releases from the Blue Mountain Operable Unit has
led to defoliation on one side of Blue Mountain, and contamination
of a creek that receives runoff from the mountain. The
contaminants of concern are cadmium, zinc, and lead, which are 400
to 2,600 times background levels in soil, 22 to 64 times the 4-day
AWQC in runoff, and are elevated in fish tissue. The selected
remedy calls for revegetation of the defoliated areas using a
mixture of sewage sludge and fly ash, and seeding (grass and
trees). The remedy is aimed at protecting existing ecological
resources and fostering new growth and ecological diversity on the
mountain. Its effectiveness in terms of improving the water
quality of the stream is not assessed quantitatively in the ROD,
nor are the AWQC for metals established as ARARs; these steps will
be reserved for consideration with respect to two other units at
the site. .The sole ARARs for the creek are the "best management
requirements" of the Clean Water Act concerning minimization of
erosion and runoff; an erosion and sedimentation control plan will
be developed. ARARs for the revegetation operation will be the
State's 1977 "Interim Guidelines for Sewage Use for Land
Reclamation," which set limits on metals levels in the sewage and
establish soil pH goals. The only alternative remedies considered
were the "no action" alternative and placement of restrictions in
property deeds prohibiting residential, agricultural, or other
uses of the property.
At the West Virginia Ordnance Works, the main area of ecological
concern is the McClinton Wildlife Station, which was developed for
the propagation of fish and waterfowl and covers about a third of
the site. The selected remedy consists mainly of burning
nitroaromatics found on surface soils and around subsurface sewer
lines; the burned areas will be covered with soil and revegetated.
The cleanup decisions appear to be driven by the desire to protect
the recreational use of the site for hunting, although the
selected remedial action will also protect aquatic.life in pond
waters. The soil cleanup level is based on protection of hunters;
revegetation will remediate wildlife habitat. A "wetlands
assessment" will be performed before construction activities
begin, in which an experienced biologist/wetlands ecologist will
identify wetlands that are in the area of the proposed remedial
action. Impacts to wetlands will be avoided or mitigated. The
wetlands assessment is intended to comply with Section 404 of the
Clean Water Act.
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The New Castle Steel site in Delaware has released lead and other
metals (arsenic, cadmium, chromium, nickel) into a tidal marshland
along the Delaware River. The "no action" alternative was
selected based on the lack of human health and ecological risk.
Surface water samples from the marsh contained lead levels twice
as high as the AWQC, but background levels upstream are even
higher, indicating that the inactive landfill is not the major
source of contamination. Included in the no action alternative is
a plan to monitor lead concentrations in and around the marsh to
evaluate the potential adverse effects of lead and to identify the
principal contaminant sources. If continued efforts to reduce
lead discharges upstream make the site a relatively larger
contributor to contamination, further remedial action might be
required. Monitoring will continue until the site is deleted from
the NFL, or closed under Delaware's solid waste disposal
regulations. The ROD notes that NPL deletion does not disqualify
the site for Superfund financing of any remedial actions that may
be deemed necessary based on further monitoring.
The Crab Orchard site in Illinois is the site of a National
Wildlife Refuge. Elevated levels of lead have been detected in
terrestrial biota. In Crab Orchard Lake, both PCBs and mercury in
fish tissue have exceeded FDA action levels. PCBs and cyanide
levels in the surface water of Crab Orchard Lake have exceeded
AWQC for the protection of aquatic life. The sediments are also
contaminated with arsenic, PCBs, and other organics. The Crab
Orchard site is currently in the FS stage. Because the site is
owned by the Department of the Interior, DOI rather than EPA is
responsible for remedial actions.
The Munisport site in Florida, a landfill that has led to
contamination of a mangrove swamp, on-site lakes, and soils, is
currently in the FS stage. Although no explicit ecological risk
management decisions have been made at this site, it is noteworthy
with respect to its relatively detailed assessment of potential
effects on terrestrial species. A literature search was conducted
for the purpose of deriving information on the toxicity to
terrestrial life of several different compounds found at the site.
Information was collected on the toxicity of arsenic, chromium,
mercury, nickel, DDE, and PCBs to birds; and of cyanide,
manganese, phenol, and vanadium to mammals. These toxicity values
were then compared to expected exposure levels for the species of
concern. This types of quantitative assessment of potential
terrestrial effects has rarely been seen at CERCLA sites.
Although ecological risk management has not historically played a
significant role in remedy selection, it is clear that ecological concerns are
receiving increased attention in some of the EPA Regions. Biological
technical assistance groups have been formed in some EPA Regional offices to
assist CERCLA site managers in making sure that site activities fully consider
ecological risk. EPA Region 3 has had a biological technical assistance group
for about four years, a group has been operating for longer than a year in
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Region 2, and groups have been formed in Regions 1, 4, and 10. Regions 5, 6,
and 9 are well along in developing biological technical assistance groups, and
Region 8 is beginning to address how a group would be utilized if it were
organized. These groups have been supported through the Emergency Response
Division and the Hazardous Site Evaluation Division for over two years. The
goal of these groups is to provide specific technical recommendations to site
managers during the RI/FS process, and apparently to a lesser extent in the
actual selection of remedy. These recommendations may be accepted or rejected
at the discretion of site managers.
In order to ensure the efficient, coordinated communication of
ecological risk information essential to effective ecological risk management,
biological technical assistance groups comprise officials not only from EPA,
but also from agencies with responsibility for trusteeship of natural
resources under CERCLA (DOI, NOAA, and State government agencies). The
representation of these other agencies in the groups allows site managers to
make maximum use of their varied expertise, and to learn about the concerns of
the other agencies early enough in the remedial response process to allow them
to be fully addressed. Biological technical assistance groups can also be
used to resolve disagreements between agencies on the appropriate course of
action at a site.
After reviewing the current documentation for a site (usually an RI
workplan or a draft RI) and meeting with the manager for that site, biological
technical assistance groups generally (1) identify ecological concerns, (2)
determine data needs, and (3) make recommendations. The types of ecological
concerns identified include any CERCLA natural resources that may be affected
by the site (e.g., estuaries), and may therefore require a determination by
the relevant natural resource trustee regarding any liability of potentially
responsible parties (PRPs) for damages to those natural resources. In
addition, the group identifies the contaminants of ecological concern at the
site, and the pathways along which contaminants may migrate to ecological
receptors. The data needs usually pertain to the extent and the character of
contamination in specific areas (e.g., a stream), media, and pathways of the
site that are of ecological concern.
Biological technical assistance group recommendations to site managers
consist primarily of specific instructions to use particular endpoints and
assessment methods to satisfy the data needs spelled out earlier. These
recommendations are phrased in terms of monitoring activities, sampling plans,
toxicity tests, and other analytical techniques to be used with respect to
specific site areas and receptors (e.g., benthic infaunal communities in river
sediments). Recommendations can also identify specific ARARs that serve as
thresholds for action (and with which compliance is necessary), as well as
some of the beneficial and detrimental aspects of possible remedial
alternatives. For example, the biological technical assistance group in
Region 2 recommended that any discharge associated with a remedial alternative
selected for a particular site comply with specific State criteria for ocean
and river discharges. The same group also recommended that at another site,
any water that may be contaminated by sediments dredged from a lake (if
dredging is chosen as a remedial alternative) not be allowed to flow
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downstream through a spillway, and uhat AWQC for site contaminants not be
exceeded.
4.1.3 Discussion
It is apparent that although human health concerns have driven remedial
actions in the past, ecological considerations are being taken into account
more frequently in site-specific cleanup decisions.
Many factors have contributed to the past lack of consideration of
ecological risk in remedy selection. The most frequently cited cause for the
lack of effective ecological risk management is the absence of clear policy or
guidance that articulate the extent to which ecological data should be
collected and used in the remedy selection process. The absence of policy or
guidance in many cases is due to a lack of appropriate scientific knowledge
and data, and additional fundamental research addressing these data gaps
clearly is needed. However, some policy decisions could be reached given
current knowledge and data. For example, probably the most fundamental risk
management issue is the selection of appropriate biotic receptors and
ecological effects to evaluate. There is a virtually infinite number of
combinations of receptors and effects that can be considered at a site.
However, there currently is no policy or guidance for Superfund managers on
which receptors and endpoints should be assigned priority in terms of
evaluating and minimizing effects (e.g., Should impacts directly related to
human health concerns or involving species with economic value be given
priority?) Given current ecological knowledge, it should be possible to
identify a set of receptors, endpoints, and levels of concern to be assigned
priority at Superfund sites. In addition, limited policy and guidance exists
on how to interpret ecological survey and toxicity test results.2 Therefore,
even when extensive ecological assessments are conducted, site managers have
virtually no basis for judging the acceptability of ecological damages and
risks, or determining "how clean is clean."
A recent memorandum (dated December 28, 1988) from the Directors of OERR
and the Office of Waste Programs Enforcement to Regional Division Directors
provides a useful statement of policy concerning the need to evaluate
ecological issues in Superfund remedial actions and removals. The CERCLA
program is also currently in the process of revising some of its guidance
documents, and is preparing several new ones. However, neither the recent
policy statement nor the forthcoming guidance documents provide complete
answers to the kinds of questions outlined above. The extent to which these
documents address ecological risk is discussed below.
2Guidance for denoting levels of concern for toxicity tests has been
developed for the NPDES permitting process. (See two EPA Office of Water
reports; one entitled "Technical Support Document for Water Quality-Based
Toxics Control, September 1985, EPA-440/4-85-032; the other titled "Permit
Writer's Guide to Water Quality-Based Permitting for Toxic Pollutants," July
1987, EPA-440/4-87-005.)
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The 1985 version of the RI/FS guidance is being revised to
incorporate changes in SARA and the NCP. The latest revision,
"Guidance for Conducting Remedial Investigations and Feasibility
Studies Under CERCLA," August 1988, identifies general types of
environmental data that should be collected and possible sources
for some types of data. It emphasizes the need to examine
environmental threats as part of site characterization,
development and evaluation of alternatives, and baseline risk
assessment. It also identifies environmental protection as a
criterion in screening and comparing remedial action alternatives.
However, it does not address the major issues identified above as
important by CERCLA personnel. Although many of these issues
cannot be answered at the present time, the usefulness of the
guidance in promoting consideration of ecological risk in the
RI/FS process could be improved by: (1) adding language stressing
the need for some type of measure for comparing the effectiveness
of each remedial alternative in reducing environmental risk; (2)
emphasizing that a key planning step should be to investigate
various ecological assessment methods and attempt to select the
best method at an early stage; (3) emphasizing the need to
identify and coordinate with potentially affected natural resource
trustees; and (4) revising the baseline risk assessment discussion
to include expanded discussions on the types of ecological
receptors of possible interest, the types of endpoints that may be
addressed, and the level of impact that could be considered
significant.
OSWER's "Risk Assessment Guidance for Superfund -- Environmental
Evaluation Manual" (Draft Interim Final, March 1989) is intended
to help Remedial Project Managers and On Scene Coordinators manage
ecological assessments during the RI/FS and removal processes. The
manual discusses several important topics that should be
considered when managing an ecological assessment under Superfund,
including an overview of relevant statutory authorities and
guidance, basic ecological concepts, when and how to coordinate
with ecological experts, key types and potential sources for
environmental data, and basic questions that will commonly be
asked during an ecological assessment. The manual is an excellent
primer on ecology and ecological impacts, but does not provide
specific guidance on how to resolve key issues such as the
appropriate level of detail for an ecological assessment, how to
choose appropriate assessment methods, how to interpret the
results of an ecological assessment, and when it is appropriate to
take action to mitigate ecological concerns. Instead, the manual
emphasizes the need for site managers to coordinate with technical
experts to resolve these issues on a site-specific basis.
Two other guidance documents are being prepared as companions to
the Superfund Environmental Evaluation Manual: the OIRM
"Ecological Resource Information Directory" and the ORD
"Ecological Assessments of Hazardous Waste. Sites Methods Manual."
The OIRM directory will identify useful sources of ecological
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data, including experts in the field of ecology who can be
contacted for information, and the ORD manual will describe field
and laboratory methods for ecological assessments.
Several drafts of a revised ROD guidance document have been
produced to reflect changes in the NCP. The latest draft,
"Interim Final Guidance on Preparing Superfund Decision Documents:
The Proposed Plan ind Record of Decision," March 1988, appears to
contain only limited consideration of ecological risk.
Apparently, then, the consideration of ecological risk in ROD
guidance has not expanded and developed along with the
implementation of SARA and the expansion of ROD guidance in
general.
Guidance documents on identifying and complying with ARARs have
been drafted that include a brief discussion of ecological ARARs.
Although these guidance documents are still in draft form,
Regional personnel have already been trained to use them, and it
is likely they have already begun to be used for some site
selections of remedy.
A lack of ecological assessment data is also frequently cited as a major
hindrance to effective ecological risk management. For many ecological .risk
assessments, the level of analysis is minimal, and they ten4 to be qualitative
rather than quantitative. In addition, the assessment methods vary greatly
from site to site depending in part on the interests and backgrounds of site
managers. Assessments are usually limited to parts of, or adjuncts to human
health risk assessments. Assessment of ecological impacts at the population
and ecosystem levels has been particularly lacking. EPA Regional personnel
remarked that bioassessment (assessment of contaminant levels in sampled
biota) is done relatively infrequently, and that current bioassessment efforts
are incomplete and need improvement. Interviewees also suggested some of the
root causes of the current inadequacies in ecological risk assessment. These
include the lack of methods for assessing ecological effects quantitatively;
the inadequate implementation of good ecological risk assessment methods;
insufficient knowledge about ecosystems; a lack of personnel qualified to
perform ecological assessments; a lack of criteria by which to judge
ecological risk; and a lack of resources to do the field sampling necessary
for ecological risk assessments.
As discussed above, ecological risk management is being performed
increasingly in the remedy selection process through the formation of
biological technical assistance groups in several EPA Regions. The formation
of these groups has been encouraged by CERCLA program headquarters. The
influence of biological technical assistance groups has probably been
reflected in selections of remedies at a few sites. These efforts can be
expected to bring about further improvements in remedy selections in the near
future. Biological technical assistance groups may bring even greater
benefits in the longer term as their use expands to other Regions. However,
the useful guidance provided from these groups still suffers from limits on
available resources, personnel, and standards.
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5. SUMMARY/PROGRAM IMPLICATIONS
This section summarizes the results of the analysis and discusses
program implications, first for RCRA and then for CERCLA. The section
concludes with a discussion of cross-program ecological risk management
issues.
5.1 RCRA Programs
This analysis indicates that in general, ecological concerns have not
played a significant role in past regulatory development or site-specific
decisionmaking in the RCRA program. RCRA regulations have historically been
geared toward protection of human health, and have been justified in terms of
their benefits to human health. Ecological risk management has been virtually
non-existent in the listing and delisting of hazardous wastes, and there is no
indication that future listing and delisting decisions will consider the
inherent ecological toxicity of waste streams. In the permitting program,
ecological assessments are not required in permit applications for new
facilities. Ecological risk management in RCRA appears to be limited to ACL
demonstrations and Subpart S corrective action. Overall, it appears that
ecological concerns are addressed in the RCRA program only if there is
evidence of a past release.
To increase the consideration of ecological concerns in RCRA
rulemakings, program needs include:
clear statements of policy requiring the analysis of ecological
impacts in benefits and impacts assessments;
protocols for use over the short term for incorporating
qualitative measures of ecological impacts in rulemaking
decisions;
guidance and methods to be developed over the long term for
improving the quantitative measurement of ecological impacts; and
clear identification of the threshold levels of ecological impacts
that warrant rulemaking action.
To promote ecological risk management in site-specific decisions, needs
in the permitting program include:
providing a mechanism by which people with the appropriate
expertise (either from EPA or other agencies) can be brought into
permit reviews earlier in the process; and
requesting and reviewing more detailed ecological impact
information whenever human health impact data is considered as
part of a permit application.
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Management of ecological risks in the Subpart F corrective action
process could be improved by developing guidelines for assessing impacts to
ecosystems when human health damage is not a concern, and publishing criteria
to assist permit writers in evaluating the variety of data that may be
submitted with ACL petitions.
In the new Subpart S corrective action process, EPA should ensure that
sufficient data is collected during the RFA/RFI assessment stages to identify
ecological impacts accurately, and to guarantee that ecological impacts are
considered along with human health impacts when site-specific corrective
action priorities are set.
Improvements to the listing/delisting processes would include expanding
existing models to consider pathways other than ground-water transport,
setting TC regulatory levels at concentrations protective of ecological as
well as human health receptors, and evaluating delisting petitions in terms of
potential ecological effects.
5.2 CERCIA Program
The activities of the CERCLA remedial response process in which
ecological risk management can occur are of three basic types: collection of
information on site ecological concerns; analysis and evaluation of this
information; and decisionmaking based on the evaluations. Although only the
actual decisionmaking constitutes explicit ecological risk management,
information collection and evaluation can also be considered ecological risk
management activities because they provide the foundation on which ecological
risk management decisions rest.
The initial phase of the remedial response process, the Preliminary
Assessment and Site Inspection (PA/SI), primarily involves information
collection. A scoring evaluation of data from the PA/SI by the Hazard Ranking
System (HRS) is used to decide whether a site should be included on the
National Priorities List (NPL) of sites requiring more detailed investigation.
The inability of a site to score high enough to be included on the NPL based
on ecological impacts alone severely hinders effective ecological risk
management. Revisions to the HRS significantly expand its treatment of
ecological concerns, but it appears that sites will still have to pose
substantial human health threats in order to qualify for the NPL.
After being placed on the NPL, sites undergo a Remedial Investigation
(RI) that analyzes and evaluates site hazards in greater detail. Together
with the Feasibility Study (FS) of alternatives for remedial action, the RI
constitutes the base of information used in remedy selection for the site.
Unfortunately, ecological assessments are often incomplete, probably because
of an emphasis on human health versus the environment in the CERCLA program
generally, the lack of needed ecologically-based standards (ARARs) and
personnel trained to use them, and the fact that the funding available in the
CERCLA program cannot address all concerns at every site. The limited but
growing use of biological technical assistance groups in EPA Regional offices
has improved the consideration of ecological effects during the RI/FS phase
and should bring even more improvement in the future. However, the useful
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guidance provided by these panels still suffers from limits on available
standards, personnel, and resources.
The rationale for selecting a remedial action for a site is documented
in a Record of Decision (ROD). An examination of selected RODs supplemented
by observations from CERCLA program personnel reveals that while ecological
concerns are sometimes addressed thoroughly, most RODs omit at least some
important ecological considerations (e.g., AUQC), and many RODs contain little
or no explicit treatment of ecological impacts. Where ecological risk
management does occur, it usually involves decisions on (1) the effectiveness
of a remedy in achieving compliance with ecologically-based ARARs; (2) the
acceptability of adverse environmental effects created by the remedial action
(e.g., the dispersal of contaminants in a wetland due to excavation of
sediments); and (3) the trade-off between the need for remedial action at a
site and the availability of funds for remedial actions at other sites. Also,
toxicity testing of environmental receptors is being used more frequently as a
basis for determining the need for remedial action, or for identifying the
portions of a site requiring cleanup.
Consideration of ecological impacts in remedy selection can probably be
most improved by ensuring a more complete inclusion of ecological risk in the
RI/FS phase, and by indicating the importance of explicitly ecological
considerations in CERCLA guidance documents. Draft revisions to existing
CERCLA guidance, and new draft guidance documents such as the Superfund
Environmental Evaluation Manual, will encourage the extent to which ecological
impacts are investigated at sites. However, because the Superfund
Environmental Evaluation Manual provides little direction on how to interpret
the findings of ecological site investigations, it is not likely to resolve
(and might, in fact, exacerbate) inconsistencies in risk management decisions
among sites. Recommendations of the biological technical assistance groups on
ARARs and remedial alternatives have been helpful, and should be even more so
in the future.
5.3 Cross-Program Ecological Risk Management Issues
This section identifies some fundamental ecological risk management
issues that will need to be addressed as EPA attempts to incorporate
ecological concerns into its RCRA and CERCLA site and program activities.
Probably the most fundamental risk management issue is the selection of
appropriate ecological effects to evaluate. There is a virtually infinite
number of combinations of receptors and effects that can be considered at a
site. Which receptors and endpoints should be assigned priority in terms of
evaluating and minimizing effects? More specifically, should impacts directly
related to human health concerns (e.g., consumption of contaminated fish
tissue) or involving species with economic value be given priority? Another
important issue is whether the selection of appropriate receptors and
endpoints should be based on program-wide (or Agency-wide) policy, or whether
the decision should be made on a site-specific basis.
Once the appropriate receptors and endpoints have been identified, a
decisionmaker must determine the appropriate threshold for taking action. This
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requires a policy decision regarding the familiar "how clean is clean"
question, or the definition of a de minimis ecological risk. As above, it is
unclear as to whether this determination is made more appropriately on a
program-wide or site-specific basis.
Another major issue is the monetization of ecological damage. For
example, a valuation of ecological damage may include aesthetics, effects on
recreation, effects on agricultural production, overall public desire for
environmental quality, and the loss of societal well-being from species
extinction or other irreversible effects. When is it appropriate to express
ecological damage in dollar terms? Such analyses may be supported by the use
of the CERCLA Type B natural resource damage assessment methods developed by
the Department of the Interior.
Given that neither the RCRA nor the CERCLA program have unlimited
resources for carrying out their mandate to protect human health and the
environment, each program must set priorities for addressing ecological
concerns, both within and among sites. Priority-setting requires resolution
of a host of tradeoff issues. For example, when should ecological concerns be
incorporated into cleanup decisions, particularly in relation to concerns
related to human health; and what is the appropriate balance between the use
of resources for protecting human health versus the environment? In the
process of ranking sites or selecting remedial actions for a specific site,
which ecological impacts should be given priority? What is the appropriate
decision process in choosing between the need for immediate cleanup at a site
and the need for thorough and time-consuming evaluation of ecological threats
posed by a site?
An important institutional issue faced by both RCRA and CERCLA programs
is how to determine whether ecological risk management activities in the
programs are being conducted successfully.. Determinations should be made
periodically to verify the effectiveness of Agency actions in achieving policy
goals. For example, success in the CERCLA program can be defined in terms of
the number of sites at which remedial actions have been completed; this
measure does not, however, indicate the extent to which the program has
resulted in increased protection of the environment. How to evaluate the
performance of an ecological risk program as a whole needs to be defined.
More specifically, what are the appropriate endpoints and indicators (e.g.,
economic, social, and political) of effective ecological risk management?
What methods or guidelines should be established to weigh/rank the many
parameters that may be involved? Should management indicators of
effectiveness be used on a site-specific basis, on a program-wide basis, or
both? Several of these issues are being addressed by the CERCLA program as
part of the "Superfund indicators" project; they have not yet been addressed
for the RCRA program.
Finally, if ecological risk management is to be firmly incorporated into
EPA hazardous waste programs, impediments to ecological risk management that
arise from legal authorities must be identified. Do statutory and judicial
mandates, such as requirements to consider cost-effectiveness or to use a
particular type of technology, constrain effective ecological risk management?
CERCLA., RCRA, and the court cases bearing on these statutes may often conflict
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with and constrain risk reduction efforts, or they may affect the legal
defensibility of ecological risk management decisions. In particular, the
differing mandates of CERCLA and RCRA may make the consistency of ecological
risk management across the two programs difficult.
Many of the issues identified above have already surfaced in the CERCLA
program, and appear to be receiving increased attention in RCRA programs,
particularly with respect to RCRA corrective actions. As the discussions of
ecological risk management at CERCLA sites (Section 4.2) indicates, when
ecological risk management issues arise, they are generally resolved on a
site-by-site basis. If ecological risk-based decisionmaking is to be
conducted with some consistency both within and across programs, there is a
need for EPA to develop policies for addressing these important ecological
risk management issues.
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