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Ecological Risk Assessment In NJDEP's Site Remediation
Program: Conducting A Baseline Ecological Evaluation
By: Nancy Hamill, Research Scientist and
Edward Demarest, Ph.D., Research Scientist
Division of Publicly Funded Site Remediation
Hazardous Site Science Element
Bureau of Environmental Evaluation and Risk
Ecological evaluations and risk assessments are
conducted at contaminated sites (1) to address actual
impacts or the potential for adverse ecological effects
resulting from site-related contamination, (2) to evaluate the
effects of alternative remediation strategies, and (3) to
establish clean-up levels for the selected remedy that
protect ecological receptors.
Ecological risk assessments have been performed for
National Priorities List (NPL) sites
since the early 1990s pursuant to National Contingency Plan (NCP)
With the passage of P.L. 1993, c.139 which includes the
Industrial Site Recovery Act (ISRA)
(N.J.S.A. 13:1K-6) and the Hazardous Site Remediation Act (N.J.S.A. 58:10B),
ecosystem protection has been integrated with current Site
Remediation Program (SRP) initiatives directed toward the
protection of human health; together they form the basis of
remedial decisions for all sites under its jurisdiction. P.L.
1993, c.139 established an "Environment Advisory Task
Force" that will consist of scientists and others from
industry, academia, public interest groups, and government.
The Task Force is charged with making recommendations
to the Department on the feasibility, development, and
application of ecologically-based remediation standards.
Until such recommendations are available, N.J.S.A. 58:10B
directs that the Department shall determine the need for and
application of remediation standards to protect the environment
on a case-by-case basis in accordance with USEPA
regulations and guidances. SRP's initiatives in ecological
evaluation and risk assessment are coordinated through the
Bureau of Evaluation and Risk Assessment (BEERA),
Environmental Toxicology and Risk Assessment Section
A tiered approach for conducting of ecological
evaluations and ecological risk assessments has been
developed by the SRP. Tier I, the Baseline Ecological
Evaluation (BEE), has proved to be an efficient and cost-effective
screening process and is required for all SRP sites.
A BEE assures that all sites are addressed for potential
ecological effects early in the remedial process; sites
without ecological concern are quickly eliminated from
further, more rigorous site-specific investigation. Only
those sites that present the potential for adverse ecological
effects are retained for further investigation and/or risk
assessment at the Tier II level. It is at the Tier II level that
definitive estimates of risk and the basis for determining
clean-up goals are provided.
While a BEE must be performed, evaluators are to use
best professional judgment based on USEPA guidance.
The purpose of this article is to provide further guidance on
how to perform a BEE and to provide direction on the
format and content of the final report delivered to the SRP.
The objective of the Baseline Ecological Evaluation is
to examine the site for the co-occurrence of (1) contaminants
of potential ecological concern, (2) environmentally
sensitive areas, and (3) a chemical migration pathway to
these sensitive areas. The intent is to use existing site
documents, existing analytical data, and the results of a
qualitative site visit to document these conditions in a brief
report submitted as part of the Site Investigation (SI) report
or as a stand-alone document if conducted outside of the SI.
A work plan is not required for Tier I investigations. The
BEE report should include, but is not limited to, the
A "Results and Discussion" section should summarize
and interpret findings of the evaluation and present a
reasonable decision regarding the need for further studies,
based on technical information and best professional
judgment. For example, a slight exceedance of a conservative
screening value for one compound in one media would
likely not warrant further investigation.
- 1. Contaminants of Potential Ecological Concern (COPEC)
Analytical data must be presented in a tabular format
according to media and chemical fraction. Sample
quantitative limits and data qualifiers should be
included. If an adequate number of samples were taken
and it is appropriate for the area of concern, the
arithmetic mean, maximum concentration detected, 95
percent upper confidence limit, concentration range,
and frequency of detection should be included. It is
important to report measurement of parameters
affecting toxicity to biota (e.g., total organic carbon,
particle grain size, alkalinity, hardness) was well as
standard field parameters (e.g., temperature, pH,
dissolved oxygen). No potential COPEC should be
excluded from consideration without proper justifica-tion
pursuant to USEPA guidance.
Maximum measured contaminant concentrations are to
be compared to ecotoxicologically-based benchmarks,
or screening values, using a "weight of evidence"
approach. If the measured concentration exceeds the
benchmark, further assessment may be warranted since
the potential for adverse ecological effects is indicated.
For contaminants typically considered to biomagnify,
concentrations below the screening values do not
necessarily negate the potential for adverse effects;
these should be evaluated on a case-by-case basis.
SRP currently recommends the media-specific screen-ing
values from the following references:
- a. Surface Water
- New Jersey Surface Water Quality Standards, N.J.A.C.7:9B
- Federal Ambient Water Quality Criteria for
Acute/Chronic Aquatic Life Protection, 40 CFR Part 131
- b. Sediment
- "Guidelines for the protection and management
of aquatic sediment quality in Ontario," Ontario
Ministry of the Environment, ISBN 0-7729-9248-7, 1993,
Persaud, D., R. Jaagumagi, and A. Hayton. (Fresh water sediments)
- "Incidence of adverse biological effects within
ranges of chemical concentrations in marine and
estuarine sediments,&qyuot; Environmental Management
19:81-97, 1995, Long, E.R., D.D. MacDonald, S.I. Smith,
and F.D. Calder. (Estuarine and marine sediments)
- "Briefing Report to the EPA Science Advisory
Board on the Equilibrium Partitioning Approach
to Generate Sediment Quality Criteria,"
- c. Soil
The scientific literature and various ecotoxicological databases
should be consulted. Suggested references include:
- "Contaminant Hazard Reviews," Fish and
Wildlife Service, U.S. Department of the
Interior, various publication dates, Eisler, R.
- "Toxicological Benchmarks for Wildlife: 1994,"
Oak Ridge National Laboratory, Oak Ridge, TN, Opresko,
D.M., B.E. Sample, and G.W. Suter.
- "Toxicological Benchmarks for Screening
Potential Contaminants of Concern for Effects
on Terrestrial Plants: 1994 Revision," Oak
Ridge National Laboratory, Oak Ridge, TN,
Will, M.E., and G.W. Suter.
Note that all benchmark values are intended to be used for
screening purposes only and must not be considered as regulatory
criteria or site-specific cleanup numbers. Any screening values
used should be presented alongside analytical summary data in
- 2. Environmentally Sensitive Areas
Environmentally sensitive areas are thoroughly described in
N.J.A.C. 7:1E-4.10. If present on-site, adjacent to the site, or
under the influence of the site in any manner, these areas should
be briefly described in the BEE report. Included should be a
qualitative description of land use and major ecological habitat
types, including natural and manmade areas (e.g., forested wetland,
old field, waste lagoons, wildlife refuge). A map indicating
sensitive area boundaries and an estimation of area covered by
these habitat types, etc., should be provided. More comprehensive
habitat and wildlife (plant and animal) surveys are usually
reserved for the Tier II process.
- 3. Contaminant Migration Pathways to Environmentally Sensitive Areas
The potential for contaminants to migrate from the source to
receptors must be evaluated during a site visit and documented in
the BEE report. The text should include a description of potential
chemical migration pathways. For example, surface impoundments may
affect a receptor via direct exposure, they may contaminate
groundwater that then discharges to a surface water body, and they
may contaminate surrounding soil or surface water bodies via
overflow and overland transport. It is appropriate to include a
qualitative comparison of contaminants in various media with known
In summary, the BEE is a streamlined evaluation
conducted with limited data using conservative assumptions
for parameters where site-specific data are lacking. While
the results of the BEE may overestimate actual risk, a "no
further action" decision can be supported without additional
investigation. If the results of the BEE indicate the realistic
potential for ecological risk at the site, the appropriate
conclusion will be that further site-specific investigation is
needed at the Tier II level, which must be conducted in
strict accordance with USEPA guidance ("Risk Assessment
Guidance for Superfund, Volume II, Environmental
Evaluation Manual," EPA/540/1-89/001, and the associated
supplementary guidance "Ecological Update Series").
For further information, please contact the Bureau of
Environmental Evaluation and Risk Assessment, Environmental
Toxicology and Risk Assessment Unit, at 609/633-1348.