&EPA
United States
Environmental
Protection
Agency
Office of
Solid Waste and
Emergency Response
Publication 9345.0-051
May 1992
ECO Update
Office of Emergency and Remedial Response
Hazardous Site Evaluation Division (OS-230)
Intermittent Bulletin
Volume 1, Number 4
Developing A Work Scope For Ecological
Assessments
This Bulletin is intended for Remedial Project
Managers (RPMs), to help them plan and manage
ecological assessments of sites as part of the Remedial
Investigation and Feasibility Study (RI/FS) process. : As
used here, the generic term work scope describes the
process of specifying the work to be done for ecological
assessment, as part of the overall RI Work Plan. The term
encompasses project scoping, development and approval
of the Work Plan, and preparation of the Statement of
Work (SOW) for contractors (at Fund-lead sites).
The outcome of a successfully executed work scope
should be an ecological assessment that includes four
essential components: problem formulation, exposure
assessment, ecological effects assessment, and risk
characterization. A work scope should also provide for
close oversight of individual tasks. This will ensure that
the assessment accomplishes its objectives within
reasonable budget and schedule limitations.
Need for Clarity, Specificity, and
Completeness
SOWs and Work Plans should clearly state the studies
needed at each phase of the assessment. In addition, they
should include other parameters concerning an assessment,
such as sample collection, data analysis, and reports.
Specifically, SOWs and Work Plans should describe:
1 Although the primary focus of this document is on the RI/FS
process, On-scene Coordinators may find much of the information useful
in evaluating sites during the removal process.
Ecological Assessment ofSuperfund Sites: An Overview (ECO
Update Vol., 1, No. 2).
Which studies should be conducted;
Why they should be conducted;
When and where they should be conducted;
What data should be collected;
How samples should be collected, handled, and
analyzed;
How data should be evaluated; and
What reports should be produced.
IN THIS BULLETIN
The Role Of The Biological Technical Assistance
Group 2
Points To Consider In Developing A Work Scope 2
Elements Of An Ecological Assessment Work
Scope 4
Ensuring Contractor Capability To Do Work 7
Review Of Interim And Final Products 8
Sample Work Scope 8
Conclusion 9
Appendix 10
Preparing a clear, specific, and
thorough SOW will avoid such
problems as the following:
May 1992Vol. l,No. 4
ECO Update
-------
Too much work,
Too little work,
Incorrect work, and
Inadequate QA/QC.
The work scope should also detail how decisions will
be made about the need for additional studies.
Preparing a clear, specific, and thorough SOW will
avoid such problems as the following:
Too much work. In the absence of clear
direction, a contractor may do considerably more
work than is required to characterize the ecological
risks at the site, wasting both time and money.
The studies could be valid, well-designed, and
complete, but unnecessary given the nature of the
site and its contaminants.
Too little work. An improperly designed study
can result in inadequate attention to potentially
important habitats or species associated with the
site, too few sampling stations to characterize the
habitat, or too few data points for meaningful
statistical analysis. Such shortcomings could
result in the need to conduct additional studies and
cause delays in producing an acceptable RI/FS.
Incorrect work. If the SOW is not specific
enough as to what work is needed or what the
objectives of the studies are, the contractor may
conduct studies that fail to meet the needs of the
RI/FS decision-making process. In this case,
valuable time may be lost as the correct studies are
rescheduled.
Inadequate QA/QC. If the SOW does not specify
data quality objectives (DQOs) then, the data may
not meet the level of quality required to make
decisions on risk or remedial actions. As above, a
delay in the RI/FS process may result.
The Role of the Biological Tech-
nical Assistance Group (BTAG)
Most EPA Regional Offices have established groups of
biologists to advise site managers on ecological assessment
in the RI/FS from the Work Plan stage onward. These
Biological Technical Assistance Groups (BTAGs)3 provide
valuable help in the development of a a work scope.
3 These groups are sometimes known by different names, depending
on the Region, and not all Regions have established BTAGs. Readers
should check with the appropriate Superfund manager for the name of the
RPMs should contact the Regional BTAG Coordinator
as early in the process as possible, certainly before the
Work Plan has been developed. The RPM should provide
appropriate documentation on the site and its contaminants
to BTAG members before the group meets to discuss the
site. In addition, the BTAG may find a brief oral
presentation on the site and its history helpful at this time.
(A future ECO Update will provide guidance on how to
provide the BTAG with useful information in this initial
briefing.) Following this initial review of site data, the
BTAG can make recommendations on the need for studies
to characterize the ecological risks posed by the site.
When the draft Work Plan has been developed, BTAG
review may elicit further helpful comments.
The BTAG should also be consulted when interim
products (reports, data summaries, etc.) are delivered.
Based on the data in such a product, the BTAG may
recommend modifications to the original work scope.
Because this kind of "mid-course correction" can save a
project time and money, the RPM is well advised to
schedule time for such reviews in the Work Plan.
Points to Consider in Developing a
Work Scope
Definition of Objectives
The work scope for the ecological assessment of a
Superfund site requires an overall objective to provide the
assessment with direction. When an assessment has a
clear objective, the RPM can readily determine which
studies will further the assessment. For example, at a site
where chemicals from mine tailings contaminated the cold
mountain streams that flow through the area, the work
scope had for one of its objectives to determine whether
resident fish had suffered adverse impact. Consequently,
the work scope specified studies that concerned fish and
their environment. These studies included aquatic toxicity
tests, a fish survey, and bioaccumulation4 studies using
resident fish.
The overall assessment objective may be clear from the
outset, based on data from previous studies or on an
evaluation of the concentrations and known effects of site
contaminants. More likely, some preliminary studies,
including a site visit and collection of screening-level data,
will be needed to identify and specify the objective of the
ecological assessment. Where possible, these preliminary
studies should incorporate the need for future work.
BTAG Coordinator or other sources of technical specialized facilities,
and specialized equipment necessary to carry out the work. If not,
qualified subcontractors should be sought for those tasks where their
qualifications are needed.
4 Bioaccumulation is the accumulation of a substance in an
organism's tissues as a result of respiration, absorption, or feeding.
May 1992Vol. l,No. 4
ECO Update
-------
Just as an ecological assessment gains direction from
having an overall objective, each study that the work scope
specifies also should have a clear objective, such as filling
a data gap or testing a hypothesis about the effects of the
site's contaminants on resident organisms. By stating a
study's objective, an RPM provides guidance for designing
the study. For example, the work scope for the mining site
described above called for aquatic toxicity testing to
determine whether the water was toxic to freshwater fish
that thrive at low temperatures. This study objective
provided specific direction in planning the toxicity tests.
Assessment Design
The work scope lays out the design for an ecological
assessment. Assessment designs vary tremendously from
site to site depending on:
The objective and the assessment;
The size, location, and accessibility of the site;
The site's ecologywhat is already known and
what needs to be known; and
The site' s contaminant history.
In an ecological assessment, the individual studies are
the pivotal elements. If the overall objective gives an
ecological assessment a purpose, the studies are the
vehicles by which it attains its purpose. Studies can
include chemical analysis of media or biota, toxicity
testing of laboratory or resident organisms, biological field
studies, and analyses of organisms' physiological or
pathological condition. However, because a work scope
indicates only those studies necessary for assessing a
specific site, any one assessment need not include all of
these types of studies. The assessment design specifies not
only which studies to perform but also the level of effort
for each. For example, the work scope developed for the
mining site described above included toxicity testing, but
only of one medium (surface water) and with only one
type of test organism (fathead minnow). At another site,
toxicity testing might include evaluation of soil, sediment,
and surface water using several different organisms.
The complexity of an ecological assessment makes it
essential that trained ecologists have responsibility for its
design. The RPM can consult the BTAG for advice as to
which media to analysis, which studies to perform, and at
what level of effort. The RPM can include this
information in the SOW. As discussed below, since the
contractor has responsibility for developing the Work Plan
from the SOW, the RPM needs to consider whether the
contractor's staff has the required expertise. After a
contractor has prepared the Work Plan the BTAG can
review it and advise the RPM whether or not to approve it.
The phased approach ensures that:
Only the necessary work
will be done, and
All the necessary work will
be done.
Phased Approach
Implementation
to
Task
For most sites, a phased approach with expert review at
each phase results in the most efficient use of resources.
With the phased approach data or observations from one
phase determine whether further studies are needed to
meet the assessment's objectives and, if so, what these
studies are. At some sites, the phased approach might
result in a low level of effort adequately characterizing
ecological risks. At others, the phased approach might
indicate that the assessment should be expanded to include
studies of specific habitats of contaminants in order to
evaluate the risks. At still other sites, the phased approach
could identify areas originally not considered at risk. In
this case, the RPM would want to expand the work scope
to include an assessment of the newly identified area.
Review of interim products, such as a report on the levels
of contaminants of concern or a field survey of resident
species, can contribute to the phased approach. Careful
review of interim products can help to ensure that the
assessment remains focused on those studies most
important for evaluating the site's ecological effects.
To summarize, the phased approach ensures that:
Only the necessary work will be done, and
All the necessary work will be done.
The value of the phased approach can sometimes be
outweighed by other factors. For example, seasonality
affects when certain types of studies, such as loristics
surveys, can occur. In some cases, budgetary restrictions
and time constraints may be incompatible with the phased
approach. RPMs may need to consider such factors when
planning studies.
In practical terms, the phased approach requires an
RPM to decide when a contractor should proceed from one
task to the next and whether the contractor should proceed
with one alternative task or another. In making these
determinations, the RPM interprets information from
completed studies. The BTAG can assist the RPM in
identifying criteria appropriate for evaluating data. (See
Figure 1.)
May 1992Vol. l,No. 4
ECO Update
-------
An ecological assessment should be
designed to contribute to remedial
decisions at the site.
As an example of the phased approach, consider the
following hypothetical case. (See Figure 1.) An RPM has
a field reconnaissance done in order to identify and map
potentially exposed habitats at a site. The RPM then uses
the results of this study to decide on the number and
placement of sampling stations for initial chemistry data.
After the first round of sampling for contaminant levels at
these stations, the chemistry data indicates that
contaminant levels are high enough in some areas of the
site to warrant collection of biological data from the field,
along with additional data on site chemistry. The field
data collected indicate the advisability of toxicity testing at
certain stations, but not at others. In other parts of the site,
the low level of contaminants indicate that now further
biological investigation is required. Thus, in this
hypothetical example, use of the phased approach results
in there as most in need of study receiving the most
attention.
An ecological assessment involves
problem formulation, exposure assess-
ment, ecological effects assessment, and
risk characterization.
Relating Ecological Information to
Remedial Decision-Making
While an ecological assessment of a Superfund site
might extend our knowledge of the environment and the
effects of contaminants on it, the assessment is not
intended as a research project. Rather, it should be
designed to contribute to remedial decisions at the site.
Ecological assessments serve this function when they
determine whether remediation is needed, indicate the
conditions (if any exist) requiring remediation, suggest
technologies for achieving remediation, and/or estimate the
environmental effects of proposal remedial alternatives.
At the earliest stages of Work Plan development, the RPM
and BTAG should consider what types of ecological
information will contribute to remedial decisions. For
example, the site manager may need to know:
If remediation goals are protective of
environmental receptors,5
If ecological risk considerations will affect the
definition of the area to be remediated,
If special measures need to be taken during
remediation to protect natural habitats, and
What monitoring will be needed to ensure
protection of environmental receptors during and
after remediation and to evaluate the effectiveness
of remedial actions.
Questions such as these should form part of the initial
scoping session, where the RPM and the BTAG select
appropriate studies and study designs.
Elements of an Ecological
Assessment Work Scope
As described in Ecological Assessment of Superfund
Sites: An Overview (ECO Update Vol. 1, No. 2) an
ecological assessment involves problem formulation,
exposure assessment, ecological effects assessment, and
risk characterization. To ensure that an assessment fulfills
its objectives, the work scope should use its elements to
accomplish these tasks. In addition, the work scope should
identify data quality indicators to ensure that established
DQOs are met.
Problem Formulation
Problem formulation defines the assessment's
objectives and also involves a thorough description of the
site. This qualitative description must occur before
deciding on any substantial quantitative work.
An initial site description should include citations from
existing site literature (such as the Preliminary
Assessment, Site Inspection, or any studies conducted in
support of removal actions) relating to site history,
physical features of the site, species expected at or near the
site, and known or anticipated effects of site contaminants
on receptors. Investigators should determine whether
threatened or endangered species are known or suspected
to occur at or near the site. Descriptions of potentially
affected habitats should include as much detail as possible.
For instance, stream habitats vary considerably depending
on stream depth and width, type of stream bottom, aid
types of vegetation in and adjacent to the stream.
Information pertaining to these types of characteristics
could affect both the kinds of studies required to evaluate
possible effects and the level of effort needed to conduct
the studies.
5 Receptors are individuals, populations, or communities/habitats that
may be exposed to a contaminant.
May 1992Vol. l,No. 4
ECO Update
-------
This qualitative description of the site helps to indicate
whether further studies are needed and, if they are, what
these studies should be. For example, if scientific
literature or databases indicate that a site's contaminant
concentrations consistently fall below levels likely to cause
adverse ecological effects, additional analyses may be
unnecessary. On the other hand, if contaminant
concentrations suggest a need for further investigation, the
initial site description may identify potential exposure
routes useful in targeting the additional studies to media
and areas of greatest concern. Targeting studies make the
most efficient use of the time and money available for the
ecological assessment.
A site visit should form part of the initial site
description phase. In addition, the RPM may decide to
characterize the site's ecology further by conducting
limited field studies. These studies could include aerial
photography, evaluation of habitats' suitability for
wildlife, functional evaluation of wetlands,6 qualitative or
semi-quantitative examination of the environment for
evidence of stress (e.g., stressed or dead vegetation, bare
soil and erosion, dominance by pollution-tolerant species),
and field verification of the presence of absence of key
species. At some sites, the existence of site descriptions
made prior to contamination may enable the RPM to
assemble a "before and after" picture of the site.
Figure T. The Phased Approach
As this hypothetical cccici&csi
assessment llustrstes, thephsGvct
appn&ch results r> ths arsss most
ri need of stud/ recer/rig the most
attention.
6 A functional evaluation of wetland determines the importance of
the wetland for such values as wildlife habitat, pollution abatement, and
flood control. This type of study helps to establish the value of a
particular wetland as it relates to the need for remediation. Another type
of study, a wetland delineation, defines the boundaries of a wetlandbasad
on soil type, vegetation, and hydrology. The delineation aids in the
selection and evaluation of remedial alternatives. Site managers should
consult with their BTAGs to determine which of these studies are
appropriate, if at all, and when they should be conducted.
Based on the information developed in this initial site
description, the investigator (under the direction of the
RPM and with BTAG consultation) should specify:
The receptors (habitats and species) most likely to
be exposed to site contaminants,
The contaminants most likely to be of ecological
concern,
The ecological effects most likely to be important
with regard to the site, and
The studies needed to characterize actual or
potential adverse effects associated with site
contaminants and, where applicable, the
hypothesis that the study will test.
Exposure Assessment
Since exposure assessment quantifies the actual or
potential exposure of receptors to contaminants, the work
scope must plan for studies that gather appropriate data on
both receptors and contaminants. Evaluation of chemical
and biological data will indicate which receptors and
contaminants are appropriate subjects of study and how
best to evaluate exposure at a particular site. And, as in all
other decisions of this type, the RPM can consult the
BTAG before committing resources.
Fiari suiviy Bfenlifcis lcc:nns r-L
A! [e
pn^ninly-nc|viGol hviSKS m|unii] .blBm^d mmics! .n.iy
FI r<3i FRI rn m n
-------
could specify receptors for further study because they are
of concern for statutory or other reasons (e.g., those
species protected under Federal law). When the RPM has
satisfied these criteria for choosing receptors, he or she can
then consider which of the species are most amenable to
rapid and inexpensive field evaluation. Field, laboratory,
and literature studies conducted in the Problem
Formulation phase can also aid in selecting and
characterizing receptors. The exposure assessment should
include information on feeding habits, life history, and
habitat preferences of receptors.
To study exposure to contaminants, the work scope
might include additional chemical analyses and the
measurement or estimation of exposure point
concentrations. Chemical analysis of plant and animal
tissues is one useful technique for determining whether
exposure to contaminants has taken place. For
contaminants known to bioaccumulate, analysis of tissues
from organisms representing different trophic levels (e.g.,
plant, herbivore, and carnivore) also permits measurement
of dietary exposure for species that feed on contaminated
organisms. Biochemical, physiological, and histological
studies can also provide information about exposure of
receptors to site contaminants.
The work scope could also specify studying exposure
by means of fate-and-transport models. Fate concerns the
ultimate chemical disposition of a contaminant, such as
remaining stable, undergoing photodegradation, or
combining with another substance. Transport, or
migration, refers to the movement of a contaminant from
one medium to another, from one location to another
within the same medium, or into biota. Site
characteristics, contaminants' physical and chemical
properties, and bioaccumulation studies provide
information useful in predicting the fate and transport of
site contaminants.
Ecological Effects Assessment
Ecological effects assessment links concentrations of
contaminants to adverse effects in receptors. Literature
reviews, field studies, and laboratory studies provide the
information for making this link. However, the ecological
assessment of a site may not require all three of these types
of studies.
Field studies of populations and communities7
support ecological effects assessment by providing
information on the condition of populations of resident
species and on any contaminant-related changes in
ecological communities. In their focus on resident
populations, field studies play a central role in identifying
receptors. Such studies also can allow investigators to
collect samples for laboratory analysis.
7 A population is a group of organisms belonging to the same species
and inhabiting a contiguous area. A community consists of populations
of different species living together.
Generally, habitats that are potentially or actually
exposed to contaminants require some field study.
Consulting with the BTAG will enable the RPM to select
the methods and level of effort appropriate to the site and
its remedial objective. Whenever possible, the work scope
should specify standard or commonly accepted field
methods. A future ECO Update will provide information
about field studies useful at Superfund sites.
Level of effort depends on the choice of qualitative,
semi-quantitative, or quantitative studies. In some cases,
qualitative studies will adequately describe the habitats and
species at risk. However, most sites with suspected
adverse effects will require some semi-quantitative or
quantitative approach for evaluating effects of stream
pollution might sufficiently characterize differences in
species composition between contaminated and
uncontaminated areas of stream. But another site might
require a more detailed quantitative analysis to discern
such differences.
An important task in preparing a work scope involves
coordinating different types of studies. In an ecological
effects assessment, simultaneous collection of site
chemistry data and biological field data allows the analysis
to show clearly whether a correlation exists between
contaminant presence and ecological effects.
Toxicity tests (bioassays) constitute a major type of
study used in assessing ecological effects at Superfund
sites. Toxicity tests expose selected organisms to water,
soil, or sediment from the site to determine whether the
medium adversely affects the organisms. Most commonly,
technicians perform these tests in laboratories using
standard test organisms. However, toxicity tests also can
occur on-site and can use resident organisms.
Especially for a site with only one or a few
contaminants, toxicity tests can contribute to the weight of
evidence linking the contaminants to biological effects.
Specifically, while chemical analyses indicate the presence
of contaminants, they do not indicate whether
contaminants are bioavailable.8 In order to have a toxic
effect, a contaminant must be both bioavailable and toxic.
The relationship between toxicity and site contaminants is
less easily interpreted for sites with a more complicated
contaminant picture.
The work scope should coordinate the collection of site
chemistry data and toxicity data. When the work scope
specifies that toxicity tests will occur in the laboratory,
field scientists should collect samples for chemical
analyses and toxicity tests at the same time and in the same
place. When the work scope calls for in situ toxicity tests,
chemical sampling should happen concurrently and at the
same locations. In this way, analysis of the data can most
clearly evaluate correlations between toxicity results and
contaminant levels.
8 Unavailability is the presence of a substance in a form that
organisms can take up.
May 1992Vol. l,No. 4
ECO Update
-------
Consulting closely with the BTAG can help the RPM
decide which tests are appropriate and the specific
conditions under which to conduct the tests. A future ECO
Update will focus on using toxicity tests in ecological
assessments.
Risk Characterization
In ecological assessments, risk characterization
evaluates the evidence linking site contaminants with
adverse ecological effects. To characterize risk, the
investigator evaluates all of the chemical and biological
data relating to the site, comparing the results of the
exposure assessment with the results of the ecological
effects assessment. In particular, fate and transport studies
can provide evidence of links between site contaminants
and observed or predicted effects.
Also relevant to risk characterization are the results of
the chemical analyses of media, toxicity testing, and field
studies. At some sites RPMs will have had these studies
conducted along contaminant gradients. Where risk
characterization establishes a link between contaminants
and adverse effects, it should also describe the qualitative
or quantitative ecological significance of these effects.
A successful work scope is one that correctly
anticipates the types of studies that will provide the data
needed for risk characterization.
The results of an ecological assessment
support the remedial decision-making
process only if the data are
scientifically defensible.
Quality Assurance
The results of an ecological assessment support the
remedial decision-making process only if the data are
scientifically defensible. Usually, this means that the data
should be (1) accurate and (2) amenable to statistical
analyses (for quantitative studies). Data quality objectives
are qualitative and quantitative statements of the overall
level of uncertainly that a decision-maker is willing to
accept. Consequently, data quality objectives reflect the
statistical design of the study and the level of significance
needed to support any conclusion that might be drawn
from the study. For example, the SOW should specify a
sample size large enough to account for natural variability
to ensure that DQOs are met. In reviewing the Work Plan,
the RPM should ensure that minimum sample sizes are
specified for statistically valid analyses, that significance
criteria meet the needs for remedial decision-making, and
that quality control procedures are in place to ensure
accuracy and precision.
Before approving a Work Plan, the
RPM should make certain that the
contractor has the trained personnel,
specialized facilities, and specialized
equipment necessary to carry out the
work. If not, qualified subcontractors
should be sought for those tasks where
their qualifications are needed.
Quality assurance is the set of procedures that ensure
that the quality of data meets the needs of the user. The
Work Plan establishes quality assurance for field work and
laboratory analyses by specifying criteria for such items as
sample collection, sample handling, and numbers of
replicate analyses. Selecting standard methods specified in
EPA or other federal agency manuals (subject to EPA
approval), when these methods are appropriate, can
provide confidence of a stated level of quality assurance
because they have built-in quality control activities.
Laboratories that conduct standard toxicity tests, such
as those required under the National Pollutant Discharge
Elimination System (NPDES), have in place quality
control procedures that are readily subject to review and
audit. Contractors experienced in conducting field studies
should also have standard procedures for ensuring
accuracy and reproducibility in their work. As an example
of quality control in a field study, a survey of benthic
invertebrates could require an independent taxonomist to
classify a randomly selected sub-set of the organisms
identified by the study's field or laboratory staff.
When the work scope specifies clear and appropriate
quality assurance procedures, the data collected should
satisfy the specified data quality indicators of precision,
accuracy, representativesness, completeness, and
comparability.
Ensuring Contractor Capability To Do
Work
Ecological studies trained personnel, and some studies
also require specialized facilities and equipment. Before
approving a Work Plan, the RPM should be satisfied that
the contractor proposing to carry out the work can do so.
If not, qualified subcontractors should be sought for those
tasks where their qualifications are needed.
May 1992Vol. l,No. 4
ECO Update
-------
Personnel
In selecting a contractor, a RPM must look for a direct
match between contractor qualifications and the scope of
work. To this end, the RPM should request information on
the specific training and experience of proposed
individuals with respect to the specific tasks to be
undertaken. For example, if a Work Plan calls for
sampling benthic invertebrates in a stream, those
conducting the study should:
Be familiar with the types of equipment (e.g.,
Surber sampler, artificial substrates) appropriate to
the study site;
Know how and where to collect samples (e.g.,
what kinds of stream bottoms support which
species);
Know what kinds of environmental data to collect
along with the biological and chemical samples
(e.g., water temperature, pH, dissolved oxygen,
hardness); and
Have the requisite taxonomic expertise to identify
the organisms (principally the larval stages of
insects) collected.
On the other hand, these same individuals may lack
qualifications for conducting other types of studies, such as
wetland assessments or the collection of small mammals
for tissue analysis. Although some experienced biologists
have developed considerable expertise working in a wide
variety of habitats and with a broad range of species, many
others are specialists in their fields and do not know the
details of conducting studies outside their specialty.
Consequently, the RPM must ask for evidence of specific
individuals' capabilities to carry out proposed tasks. This
evidence can consist of results of similar studies conducted
in the past. These results should demonstrate that the
contractor performed studies correctly and that the
resulting data served its intended purpose.
Facilities and Equipment
The RPM also should require a contractor to
demonstrate capability in terms of any specialized facilities
and equipment needed to conduct the studies selected for a
particular site. For example, most of the toxicity tests
used to evaluate aquatic systems are standard procedures
developed for NPDES. Many States have certification
programs for laboratories that conduct NPDES toxicity
tests. If the work scope calls for such tests at a site, the
RPM can ask that the contractor use a laboratory certified
in at least one state (if possible, the State where the site is
located), and that the laboratory show proof that it has
conducted the same or similar tests in the recent past.
Alternatively, where a State and its neighboring States
have no certification program, the RPM can obtain the
name of an appropriate laboratory from the State agency
charged with regulating NPDES permittees. In the case of
field sampling, the BTAG or Regional field biologists can
evaluate a contractor's capabilities.
Figure 2. Order Task to an Ecologfeal Assessment
An mvesSsf&orcan conduct srnultansausly somsafthe task that t- Waft Plan dstais for
w flco'e^e' vssessmement. AS in&pteitbei-?
-------
In all cases, contractors must possess both the
appropriate equipment and staff trained on that equipment.
For instance, a commonly used method for collecting fish
involves electroshock equipment that stuns the fish,
causing them to float to the surface. Electroshock
equipment ranges in size from small backpack units to
large boat-mounted units. For both safety and efficacy, it
is essential to use the right size of equipment manned by a
crew familiar with its operation and safety requirements.
Review of Interim and Final
Products
In keeping with the suggested phased approach, the
RPM should plan for BTAG review of interim products
such as initial site description, initial field surveys, and
reports on specific studies such as the basis for revising the
work scope to account for the new findings.
In addition to the interim products mentioned above,
the RPM should have the BTAG review the draft Work
Plan and the draft ecological assessment before the
contractor proceeds with the final version. With regard to
the draft ecological assessment, the RPM should
particularly request the BTAG to comment on the quality
of studies and the validity of their findings. The RPM will
also want to know whether the data support any
conclusions about proposed remedial actions at the site.
Sample Work Scope
The Appendix presents an example of the kinds of
components likely to occur in a typical work scope. Of
course, work scopes designed for particular sites will differ
significantly from the general one in the Appendix. An
RPM will find it necessary to tailor the work scope to the
specific conditions and objectives at an individual site.
The example in the Appendix also demonstrates how
BTAG review of interim products can alter the scope and
level of effort for succeeding tasks. The example always
states that products are subject to review and approval by
the site manager, because the BTAG has no official
authority to approve or disapprove contractor work.
Nevertheless, wherever appropriate, the RPM should ask
the BTAG for review and advice on each product. In
scheduling a project, RPMs need to allow time for the
review process. In fact, some Regional BTAGs require a
minimum review period.
In addition to the general work scope in the Appendix,
RPMs in several Regions have available to them generic
work statements or other guidance material prepared by
their BTAGs. RPMs should check with the BTAG
coordinator in their Region to obtain any such guidance.
Conclusion
This Bulletin has summarized the issues and RPM
needs to address in developing work scopes for the
ecological assessment of Superfund sites. Because every
site presents a unique combination of study problems,
RPMs should consider the expert advice of BTAG
members as an essential part of the planning process for
these assessments. These specialists should be consulted
as early as possible in the planning stages for a site, and
should remain involved in the planning and oversight
throughout the life of the project. By involving the BTAG
in this way, the RPM can be assured that ecological as well
as human health effects will receive the full attention
called for in the law and in Agency policy directives.
May 1992Vol. l,No. 4
ECO Update
-------
APPENDIX
SUGGESTED TASKS IN PLANNING AND EXECUTING AN
ECOLOGICAL ASSESSMENT
The following tasks can help a contractor in assembling an acceptably detailed and focused ecological assessment. Wherever
possible, these tasks should be coordinated with the human health assessment and any hydrogeologic investigations.
A site's ecological assessment may not require all of the tasks. For example, with site description (Task 1) and the
reconnaissance visit (Task 2) complete, the RPM may decide that the Work Plan can be drafted (Task 4) without any further site
characterization (Task 3).
Note also that an investigator can conduct certain tasks simultaneously rather than sequentially, greatly enhancing the efficiency
of the process (Figure 2). Precisely which tasks can occur simultaneously and which the investigator must conduct sequentially
depend upon the site.
Task 1. Site Description
Purpose: Preliminary screening of the extent of contamination and the potential effects.
Description: Qualitatively describe site based on existing data from the Preliminary Assessment, Site Inspection, and other
sources, including:
1. Physical description of the site and its surroundings, including photos and detailed maps;
2. Nature and extent of contamination by medium and contaminant type;
3. Site-associated habitats potentially exposed to contaminants; and
4. Initial toxicity assessment of site contaminants with respect to environmental receptors, including comparison
to criteria and other benchmarks.
Submit interim report to site manager for review.
Task 2. Site Reconnaissance Visit
Purpose: Gather first-hand expert opinion of site's condition and suggestions about what, if any, studies are needed.
Description: If authorized by site manager, prepare plan for site reconnaissance, including:
1. Chemical and biological data needed for more complete initial site description;
2. Methods to be used to collect necessary data; and
3. Criteria for deciding whether and what future studies might be necessary.
Submit reconnaissance plan to site manager for review.
Task 3. Site Screening
Purpose: With limited studies, identify and characterize habitats and characterize exposure and ecological effects. [For some
sites, information will suffice for risk characterization.]
Description: If authorized by site manager, further characterize sie based on field observations, including, as appropriate:
1. More detailed habitat identification and evaluation;
a. Suitability for wildlife, including an endangered species consultation with State and Federal agencies
May 1992 Vol. 1, No. 4 10 ECO Update
-------
b. Ecosystem value and function (e.g., wetland functional analysis)
2. Qualitative and semi-quantitative surveys of flora and fauna;
3. Toxicity tests;
4. Additional chemical sampling;
5. Identification of appropriate references sites for comparison to each potentially exposed habitat; and
6. Simple modeling of transport and exposure.
Submit interim report to site manger for review.
Task 4. Draft of Work Plan
Purpose: Develop a plan that will provide any additional information about exposure and ecological effects that is needed to
characterize risk.
Description: Draft detailed Work Plan for any further site investigations needed, including overall assessment objective and, as
appropriate:
1. Qualitative, semi-quantitative, and quantitative surveys of flora and fauna in potentially exposed habitats and
reference sites;
2. Chemical sampling of media and biota in potentially exposed habitats and reference sites;
3. Laboratory and in situ toxicity testing;
4. Tissue analyses, enzyme studies, and bioaccumulation studies; and
5. Simple modeling of fate and transport.
For each proposed study above, provide:
a. Objectives of the study, effects to be measured, and relevance to overall risk assessment objectives at the site;
b. Proposed field or laboratory methods and their risk-based detection limits (where appropriate), with appropriate
references to Agency guidelines or other source;
c. Criteria for determining sampling locations, expected sampling locations (including detailed maps), sampling
dates, and sample sizes;
d. Benchmark, or background values, where appropriate;
e. Statistical methods to be used and data quality indicators to meet statistical significance criteria; and
f. Quality assurance procedures and quality control techniques.
Submit Work Plan to site manager for review and approval. Revise per site manager's direction.
Task 5. Data Collection
Purpose: Gather necessary data regarding exposure and ecological effects
Description: Conduct those studies approved by site manager for immediate execution. Submit interim reports to site manager
for review.
Task 6. Final Data Collection
Purpose: Based on findings of studies conducted, identify and collect any final data needed to assess exposure and ecological
effects.
Description: Revise Work Plan per site manager's direction. Conduct next phase of studies as approved by site manager. Submit
interim reports to site manager for review. Repeat this step as needed. Task 6 is an iterative process that will
lengthen or shorten, depending on the results of studies.
Task 7. Risk Characterization
Purpose: Validate the data and their interpretations, and characterize risk.
May 1992 Vol. 1, No. 4 11 ECO Update
-------
Description: Prepare the following for review by site manager:
1. Summary of biological and chemical data; and
2. Detailed outline of ecological assessment.
Task 8. Report Preparation
Purpose: Prepare data for presentation.
Description: Prepare draft ecological assessment.
NOTE: Depending on the scope and level of effort decided on by the site manager, not all of the elements listed below may
appear in a given assessment. For instance, not all sites will require toxicity testing or the full array of quantitative
field studies. The following outline should be modified to account for the studies actually undertaken at the site
with the approval of the site manager.
1. Initial site description and potential receptors (include detailed maps wherever appropriate)
a. Physical description of the site
b. Nature and extent of contamination by medium and contaminant type
c. Potentially exposed habitats
(i) Surface water habitats
(ii) Wetlands
(iii) Terrestrial habitats
(iv) Sensitive or critical habitats
d. Potentially exposed species
(i) Vegetation
(ii) Invertebrates
(iii) Vertebrates
(iv) Special concern species
2. Selection of contaminants, species, and ecological effects of concern
a. Contaminants of concern and rationale for selection
b. Species of concern and rationale for selection
c. Ecological effects of concern, acceptable and unacceptable levels of effects, temporal and spatial scales or
concern, and rationale for selection
3. Exposure assessment
a. Sources and exposure pathways of contaminants of concern
b. Fate and transport analysis
c. Exposure scenarios
d. Estimated exposure point concentrations by habitat, species and exposure scenario
e. Uncertainty analysis
4. Ecological effects assessment
a. Known effects of contaminants of concern (from literature)
b. Site-specific toxicity testslaboratory and in situ
c. Existing toxicity-based criteria and standards
d. Uncertainly analysis
5. Risk Characterization
May 1992 Vol. 1, No. 4 12 ECO Update
-------
a. Observed adverse effects in potentially exposed habitats compared to reference sites
(i) Mortality and morbidity
(ii) Vegetation stress
(iii) Habitat degradation
(iv) Presence or absence of key species
(v) Population assessment of key species
(vi) Community indices
(vii) Ecosystem function, such as decomposition or nutrient recycling
b. Analysis of contaminant concentrations in relation to observed adverse effects
c. Analysis of bioaccumulation studies
d. Analysis of toxicity test results in relation to observed adverse effects
e. Comparison of estimated exposure point concentrations with criteria and standards
f Comparison of estimated exposure point concentrations with toxicity data and/or toxicity values from
literature, as appropriate
g. Likely ecological risks associated with present and future land use scenarios
h. Ecologically relevant ARARs
i. Ecological consideration in selecting remedial alternatives (including no action)
j. Uncertainly analysis
Submit draft ecological assessments to site manager for review.
Task 9. Report Revision
Purpose: Prepare final presentation of ecological assessment.
Description: Revise draft ecological assessment per site manager's review comments and submit final ecological assessment for
inclusion in RI/FS.
May 1992 Vol. 1, No. 4 13 ECO Update
------- |