Guidance For Sediment Quality Evaluations
November
1998
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1.0 Introduction
The purpose of this document is to establish
practical guidance for the evaluation of sediment quality
to be used in the ecological risk assessment process associated
with contaminated sites under the jurisdiction of the Site
Remediation Program (SRP) in the New Jersey Department of
Environmental Protection. Presented are procedures and references
that form a framework for qualitative and quantitative determinations
of actual or potential adverse ecological effects and provide
the basis for remedial decision-making and evaluation of
injury to natural resources in sediment media. The information
presented in this document is based on State and Federal
regulations and guidances, in particular Ecological Risk
Assessment Guidance for Superfund, Process for Designing
and Conducting Ecological Risk Assessments (EPA 540-R-97-006)
and Risk Assessment Guidance for Superfund, Volume II,
Environmental Evaluation Manual (EPA/540/1-89/001).
It is intended to be consistent with, and supplementary
to, the Technical Requirements for
Site Remediation, N.J.A.C. 7:26E. References are presented
at the end of each major section for ease of use.
In accordance with N.J.A.C. 7:26E-3.8 (b),
the collection of sediment samples is required when it is
evident that a discharge to a surface water body has occurred
pursuant to N.J.A.C. 7:26E-3.8 (a). Successful
evaluation and risk management of contaminated sediments
requires knowledge of the nature, concentration and areal
extent of contamination, as well as site-specific variables
that affect the expression of environmental impacts. There
are three components of a complete assessment of sediment
quality:
(1) measurement of contaminant concentration,
via standard or special analytical laboratory procedures;
(2) measurement of toxicity and bioavailability,
via tissue analysis, sediment toxicity testing, etc.;
and
(3) assessment of resident biota, via
community bioassessment/survey procedures.
These three components, measured at potentially
site-impacted and reference locations, provide complementary
data, because no single component can be used to predict
the measurement of the other components. For example, sediment
chemistry provides information on the identification and
extent of contamination but not on biological effects. Sediment
toxicity testing provides direct evidence of sediment toxicity
but cannot discriminate among contaminants nor predict actual
in-situ responses. In-situ responses of resident biota,
measured by in-fauna community surveys can provide direct
evidence of contaminant-related effects, but only if confounding
effects unrelated to contamination can be excluded, such
as differences in habitat quality. Thus, a sediment evaluation
program must be based on this "triad" approach
to provide a weight of evidence for determining if adverse
effects are occurring, and if so, whether they are due to
the site in question.
For sediment quality evaluations at SRP
sites, this "triad" investigation is accomplished
pursuant to the tiered approach described in N.J.A.C. 7:26E-3.11 and 4.7. In the Baseline Ecological Evaluation
(BEE), the site is examined for the co-occurrence of chemicals
of potential ecological concern, environmentally sensitive
areas, and complete chemical migration pathways, to assess
the potential for ecological risk. If this initial evaluation
indicates the potential for adverse ecological effects,
a subsequent, more rigorous evaluation will be required
for the full Ecological Risk Assessment (ERA) to further
characterize risk.
References
- N.J.A.C. 7:26E. Technical Requirements
for Site Remediation.
- U.S. Environmental Protection Agency. March,
1989. Risk assessment guidance for Superfund, volume
II, environmental evaluation manual. EPA/540/1-89/001.
Office of Emergency and Remedial Response. Washington.
- U.S. Environmental Protection Agency. June,
1997. Ecological risk assessment guidance for Superfund,
process for designing and conducting ecological risk assessments. EPA 540-R-97-006. Office of Solid Waste and Emergency Response.
Washington.
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