rxEPA
United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
Publication 9345.0-051
August 1992
ECO Update
Office of Emergency and Remedial Response
Hazardous- Site Evaluation Division (OS-230)
Intermittent Bulletin
Volume 1, Number 5
Briefing the BTAG: Initial Description of
Setting, History, and Ecology of a Site
For many Superfund sites, contaminants can cause
ecological harm as well as posing risks to human health. Pan
of the responsibility that a Remedial Project Manager (RPM)
must carry out during the site remediation process is to
assess whether ecological harm has occurred or may occur.
Many Regions have BiologicalTechnical Assistance Groups
(BTAGs) to assist RPMs in managing such assessments.1
This Bulletin focuses on the fust opportunity that an
RPM has for conferring with the BTAG about possible
ecological effects at a site. This meeting usually occurs early
in the planning stages of the Remedial Investigation (RI). At
this stage in the Superfund process, the RPM will have the
contractor review whatever information is readily available
about the site's setting, history, contaminants, and ecologi-
cal characteristics. The RPM then makes this information
available to the BTAG as a site description. This group's
input assists the RPM in providing the contractor with clear
direction for planning a well-focused investigation: that is,
one that has clear-cut objectives and that makes the most
efficient use of limited resources.2 The RPM should find
that expert input at this early stage results in long-term
savings in both the time and effort needed to evaluate a site's
ecological condition.
Although the initial meeting with the BTAG has the
same purpose and scope throughout EPA Regions, the
details of such ameeting can vary considerably from Region
to Region. When preparing the site description for this
meeting, the RPM should contact the Region's BTAG
coordinator to learn how the Region handles these briefings.
IN THIS BULLETIN
Objective of Initial Site Description 2
Sources of Information about the Site 2
Information in the Site Briefing 2
BTAG's Preview 5
The Meeting 5
BTAG's Recommendations 5
Meeting Follow-Up 5
Appendix A: Check Sheet 7
1 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 BTAG coordinator or other sources of
technical assistance in their Region. A more complete description
of BTAG structure and function is available in "The Role of
BTAGs in Ecological Assessment" (ECO Update Vol. 1, No. 1).
2 "Developing a Work Scope for Ecological Assessments"
(ECO Update Vol. 1, No. 4) discusses the process of planning and
designing ecological assessments.
ECO Update is a Bulletin series on ecological assessment of Superfund sites. These Bulletins serve as supplements to Risk Assessment Guidance
for Superfund. Volume II: Environmental Evaluation Manual (EPA/540-1 -89/001). The information presented is intended as guidance to EPA and
other government employees. It does not constitute rulemaking by tlie Agency, and may not be relied on to create a substantive or procedural right
enforceable by any other person. The Government may take action that is at variance with these Bulletins.
"Ip Printed an Recycled Paper
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The Objective of the Initial Site
Description: Assessing Whether
More Ecological Information is
Needed
The initial site description begins the process of evaluating
whether a site's contaminants have caused or could later cause
adverse ecological effects. By reviewing readily available infor-
mation about the site' s setting, history, contaminants, and ecologi-
cal characteristics, the.BTAG can assess whether the site requires
further investigation! Although little site-specific data may exist at
this stage of the RI, providing the BTAG with this information will
assist in evaluating the site.
What types of recommendations can an RPM expect to hear
after presenting the site to the BTAG? For some sites, the BTAG
may decide that no significant ecological impact has occurred or
is likely to occur and that consequently the site requires no further
ecological investigation. In other cases, the BTAG may advise the
RPM to pursue further ecological studies. In these instances, the
BTAG will be able to suggest
• What information is lacking,
• Which studies will elicit this information, and
• What level of effort is appropriate to obtaining the
information.
Sources of Information
about the Site
The investigator3 bases the site description for the initial
briefing on information about the site and its surroundings. Studies
and reports already in the site's record contain useful information.
For example, both the Preliminary Assessment (PA) and the Site
Inspection (SI) can provide a description of the site's geographical
setting, known or suspected contaminants, and general informa-
tion about the surrounding area.
The investigator may also find that State agencies or local
groups have useful information about the site. For example, if the
site contains a fishing stream, the State fish and game agency may
routinely monitor fish species. University researchers may have
conducted biological surveys at or near the site. Environmental
impact statements concerning nearby facilities or projects may
have additional data on natural resources in the area. Historical
societies, fish and game clubs, local or State chapters of such
organizations as the Audubon Society or Nature Conservancy, and
3 The term "investigator" refers to the individual charged with
responsibility for designing and/or carrying out any part of an
ecological assessment. Investigators can include government sci-
entists, contractors, or university scientists. However, the RPM
retains ultimate responsibility for the quality of the ecological
assessment.
local experts, such as foresters, soil conservation specialists, and
naturalists, also may have information relevant to a site descrip-
tion. In particular, such groups may have lists of habitats and
species found in the area.
In some Regions, field reconnaissance trips occur even at this
early stage, with the RPM, the contractor, and a BTAG member
visiting the site. Observing and studying the site enables the BTAG
member to carry back to the group an expert's first-hand observa-
tions. Such observations are especially helpful at this point in the
Superfund process when few, if any, ecological studies have
occurred. For example, a BTAG member may identify dense
growth of a species associated with polluted sites or, alternatively.
may note the absence of expected species.
RPMs need to be aware that Regions vary in their policies
concerning field reconnaissance visits. Consequently, an RPM
who wishes to have a BTAG member present on such a visit needs
to consult the BTAG coordinator to find out whether and when this
can take place.
The Information
in the Site Briefing
The information contained in a site briefing varies with the
nature of the site and its contaminants, the sources of information
available about the site, and the evaluations already performed
there. However, an RPM should keep in mind that the more the
BTAG learns about a site, the more specific direction it can offer.
The Appendix at the end of this Bulletin providesachecksheet that
RPMs may wish to use to make certain that the site description is
as detailed as possible, given the information that is readily
available to the contractor at this early stage. In most cases, the site
description will lack some of the information listed in the Appen-
dix. Such gaps can prove helpful in pointing to issues that may
require further investigation.
The Setting
A site's setting includes its geographical location (including
coordinates) and its surroundings. The setting should include the
site's town, county, and State and should describe the land use of
the area around it Land use upstream and downstream of the site
also constitutes important information about the setting. Land uses
may include industrial, business, residential, military, agricultural,
recreational, and undeveloped. The setting should note especially
such natural areas as parks, refuges, wetlands, and coastal zones.
The BTAG will also find helpful a description of the general
topography of the area associated with the site. Consequently, the
site description should include such information as whether the site
is wooded or open, flat or hilly, marshy or dry. The setting should
describe surface water associated with the site, along with such
related information as the water body's location, size, depth, and
flow rate, where applicable. A description of the aquifer, the
overlying strata, and the ground water discharge area is also
important to thesite'sdescription.Thesite'selevation, itssize. and
its accessibility may prove useful to know. Investigators can find
August 1992 • Vol. I, No. 5
ECO
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some of ttiis information in the topographical maps published by
the U.S. Geological Survey and in the National Wetlands Inven-
tory maps. Geographical Information Systems available in the
Regions may also provide additional information on natural re-
sources in the vicinity of the site. While the setting generally
contains several pieces of information, this description need not be
lengthy.
To appreciate the relevance of this information, consider the
following hypothetical examples:
An abandoned mine. One Superfund site consisted of land
containing a former nickel mine and the area that it bad contami-
nated, The RPM's description of the site's setting indicated that the
site occupied a steep mountain slope, which received heavy snow
cover in winter. Contaminants from the mine had leached into
streams that drained the area. These streams in turn emptied into
a larger stream, which local anglers fished for brook trout before
it flowed into a National Park. This description of the setting
alerted the BTAG to several important facts about the site:
• Because of the slope's steepness, at least part of the site was
not easily accessible, making it difficult and possibly costly
to assess the ecological condition of these parts of the site.
• Both heavy rains and the annual spring melt resulted in
continuing migration of contaminants into streams draining
the site.
• The presence of a National Park downstream from the site
indicated that site contamination bad the potential to ad-
versely affect a sensitive environment
An industrial site. This consisted of a small wooded area
bordered by several factories. The soil in the woodland had
become contaminated with refuse from the factories. No ponds or
streams occurred on this flat site. In addition, the site's geology
indicated that ground water lay below an impervious layer. Be-
cause industrial plants surrounded the site, the.site lacked surface
water, and its contaminants had no access to ground water, the
BTAG concluded that off-site migration of contaminants would
occur only through movement of biota.
A former landfill. This site consisted of a former landfill
operation located in a wetland that overlay a shallow aquifer.
Streams from the wetland fed a river protected by the State.
Residences and industrial facilities occupied the properties adja-
cent to the landfill. From this description, the BTAG concluded
that:
• As a wetland, this site merited special concern;
• The streams provided a means of off-site contaminant migra-
tion to the surrounding area;
• Migration of contaminants into the aquifer could occur, with
any discharge of ground water into surface water further
spreading the contaminants; and
• The river constituted a sensitive environment because it was
a body of water designated by the State for the protection of
aquatic life.
The Site's History
The site's history includes information about the events i
have resulted in its being designated a Superfund site. In gene
the PA and the SI recount the site's contaminant history, indicai
both the activities that caused the contamination and the lengtt
time over which these activities occurred. As with the setting, i
information helps the BTAG to develop a picture of the site.
addition, such information can indicate contaminants potentia
associated with the site. Consider again the three hypotheti.
Superfund sites described above.
The abandoned mine. The old mining site had been work
for 30 years before its closing. For more than 30 years, th(
tailings had been exposed on the mountainside. From this infonr
tion, the BTAG discerned that contaminants from the mine had h
many years to leach into the soil, the streams that drain t
mountainside, and the sediments in these streams and that co
lamination was on-going.
The industrial site. The contaminated woodland surroundt
by factories had had a shorter but more diverse history of contarr
nation than the nickel mine. Industrial activities, including electr
plating and plastics manufacture, had been occurring in the buil
ings surrounding the site for 15 years. In general, the plants h;
accurate records of the chemicals and the amounts they bad use
From this information, the BTAG concluded that it had a clear ar
complete account of the site's history and required no furthi
information on the site's history.
The former landfill. The landfill site presented a differei
picture. Few records existed to show which cHernicals the facilii
received and in what amounts. The RPM learned that the operatic
did not dispose of contaminants properly, frequently pourin
liquid wastes directly onto the ground. This sketchy history alerte
the BTAG that they could only guess at the precise nature an
extent of contamination.
The Contaminants of Concern
The BTAG will want to know what contaminants are associ
ated with the site and in which media and in what concentration
they occur. The RPM should also provide the BTAG with th<
results of chemical analyses that have already been performed a
the site. The BTAG will want to know where samples wen
collected and, where applicable, at what depth(s). The contracto
should research whether the contaminant levels exceed Federa
Ambient Water Quality Criteria, State Water Quality Standards, o.
other widely accepted screening values. The BTAG, in turn, ma}
compare a site's contaminant concentrations with concentration:
known to cause adverse ecological effects to biota.
If a site has a large number of contaminants, tracking all o:
them may prove unwieldy. The BTAG may be able to advise the
RPM as to which contaminants to choose as contaminants o
concern. Alternatively, the BTAG may advise that additiona
analyses be performed to document the presence of certain con
taminants at specific areas of the site or in various media.
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August 1992 • Vol. I, .V,>. ;
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The abandoned mine. At the old mining site, the BTAG
recognized that soil, surface water, and sediment were all poten-
tially contaminated with metals. Since the chemical analyses
performed during the SI concentrated mainly on surface water, the
BTAG advised chemical testing of soil and sediment In addition,
the analyses of surface water lacked a reference site, so the BTAG
suggested that future analyses include an upstream water sample.
The industrial site. Because of the variety of industrial
facilities adjacent to the site, the initial site chemistry included both
inorganics and organics. Since some of the organics were volatile,
the SI had analyzed air as well as soil. The variety of contaminants
present at this site made it advisable for any future ecological
assessment to focus on a subset of the contaminants. To this end,
the BTAG advised the RPM as to which chemicals to consider the
contaminants of concern.
The former landfill. Because of the sparse history of the
landfill, the BTAG regarded both organics and inorganics as
potential contaminants and soils, sediments, surface water, and air
as potentially contaminated media. Consequently, the BTAG
advised chemical analyses more extensive than those conducted as
part of the SI. The BTAG also suggested that the RI examine
contamination of the river. As at the woodland site, this site had a
large number of contaminants, and the BTAG offered the RPM
advice on selecting contaminants of concern.
Ecological Description
This pan of the site description helps the BTAG decide
whether the contaminants and their history at the site represent a
potential for ecological harm to the area associated with the site. In
preparing this description, the RPM should make full use of all
readily available information.
Central to an ecological description is a list of the habitats,
which are types of environments, associated with a site. These
include wetlands, woodlands, grasslands, open fields, ponds,
streams, estuaries, coastal zones, and other natural areas.
The ecological description also includes geological informa-
tion, such as hydrology, sediment types, and soil types. Conse-
quently, the RPM needs to describe all surface waters-lakes,
ponds, rivers, streams (including intermittent streams), and flood-
plains-in greater detail than was required for the site's setting. The
topographical maps published by the U.S. Geological Survey can
provide much of this information. Maps providing information
about floodplains include the Flood Insurance Rate Maps and the
Flood Hazard Boundary Maps published by the Federal Emer-
gency Management Agency. For areas largely owned by the State
or Federal government, the controlling agency generally has
information about floodplains. The SI may contain measurements
of soil and sediment parameters. Such information enables the
BTAG to decide whether the contaminants of concern are likely to
adsorb to the site's soil and sediment.
Whatever information the RPM has about plants and animals
in the site-associated area also belongs in the ecological descrip-
tion. In addition to species spending all or most of their time in the
site-associated area, this information should include migratory
species and species using the area during only pan of their lift
cycle. Some sites may have species of special interest, such a<
game species. Federal- or State-listed endangered or threatened
species, or species protected under other statutes.
The abandoned mine. An ecological description of the old
mining site showed that it bad no ponds or lakes but did contain a
number of fastflowing streams with hard, gravelly sediments. The
fishing stream into which these emptied had finer sediments. This
information led the BTAG to conclude that the streams with the
gravelly beds probably had little or no adsorbed contaminants but
the fishing stream's finer sediments may have adsorbed contami-
nants from the water column. As to the area's biota. State surveys
indicated that brook trout, minnows, dace, shiners, and suckers all
inhabited the streams. The local Audubon chapter provided a list
of bird species sighted in the area. Hunters routinely took deer and
occasionally bear. The team that made the site visit reported
spotting several squirrels and chipmunks and noted that vegetation
consisted largely of pine and birch trees with limited undergrowth.
The flora and fauna described for the site held no surprises for the
BTAG.
The industrial site. While researching the site, the investiga-
tor learned that a State-listed endangered species inhabited wood-
lands in this general area, raising the possibility that the site could
be home to members of this species. With respect-to vegetation,
pine trees dominated the site, which also contained grasses and
shrubs. In places the dry sandy soil was bare of vegetation. The
BTAG suggested that the RPM have additional chemical analyses
performed on soil samples from this part of the-site. No readily
available information existed as to the site's resident animals.
The former landfill. Because this area was a wetland, the
BTAG had concerns about potential cross-media contamination
between soil and surface water. With respect to vegetation, the SI
noted that shrubs and grasses dominated the area's vegetation and
that the pollution-tolerant marsh plant Phragmites grew abun-
dantly at the site.
Known Ecological Effects
In addition to the ecological description, the investigator may
have information about known or suspected ecological harm at a
site. For example, the site may have an abundance of a "nuisance"
or pollution-tolerant species. Alternatively, an expected species
may be absent, or present only in small numbers. Local sport and
nature groups or State agencies may have information about
changes in the condition or abundance of certain species.
The abandoned mine. In the course of routine surveys of the
fishing stream, the State noted that a decline in the population of
several species, including brook trout, had occurred over the past
ten years.
The industrial site. The bare areas of the woodland site gave
evidence of ecological impact.
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ECO Updai,
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The former landfill. The abundant growth of Phragmites,
known for its association with polluted wetlands, suggested a
disturbed ecological condition.
At this stage of the investigation, the available information
can only suggest possibilities for future study. Demonstrating a
causal link between site contaminants and ecological effects
requires considerably more evidence.
The STAG'S Preview
In marry cases, this briefing represents the first time that the
BTAG has encountered the site. Having materials ahead of time
enables the group's members to familiarize themselves with the
site. By providing these materials, the RPM enables the BTAG to
give more thoughtful and informed advice about handling the site.
BTAG coordinators have indicated that members sometimes take
this opportunity to consult additional outside experts.
Precisely which materials the BTAG members ask to preview
varies considerably among the Regions. These documents could
include the documents relating to the site, such as the PA and the
SI; all materials that will be used at the meeting; or a "distilled"
version of these materials. The RPM will need to check with the
BTAG coordinator to find out which materials to supply.
At the very least, however, the RPM should provide the
BTAG with a brief description and history of the site. Many BTAG
coordinators indicate that members find a copy of the SI helpful at
this time. In addition, a map of the site helps in following the details
of a site description. The RPM should include among the pre-
meeting materials the reasons for the site's listing and any addi-
tional information that has expanded the reasons for the listing.
The Meeting
EPA Regions have developed two ways of dealing with the
BTAG's first meeting concerning a site. In some Regions the RPM
introduces the site in a presentation that generally lasts no longer
than 30 minutes. The presentation covers the information that the
RPM has assembled; the site's setting, history, contaminants,
ecological description, and any evidence of ecological impact.
BTAG coordinators indicate that members find maps and photo-
graphs particularly useful visual aids at these briefings. Maps
should show the source of contamination, the direction in which it
is moving, and the nearest potentially exposed habitats (Figure 1).
In other EPA Regions, the BTAG gathers specifically to
discuss the SI or the document on which the RPM is currently
working. Here the RPM does not make a formal presentation.
Instead, he or she attends the meeting to answer questions and to
hear the BTAG's input first hand. Even in these Regions, however,
- the BTAG may expect the RPM to present a brief description of the
site's setting and a short account of its contaminant history.
The BTAG's Recommendations
An important part of this initial meeting is the open discus-
sion, during which BTAG members ask questions and develop
suggestions for the site. At this time, the BTAG will offer its
advice.
• The group may decide that a site does not pose a significant
present or future ecological risk. In such a case, the BTAG
will advise the RPM that the site does not require any further
ecological assessment.
• Before deciding what to recommend with regard to future
ecological studies, the BTAG may decide that the group
needs more information. In this case the BTAG's recommen-
dation will include suggestions as to the studies that could
provide the additional information.
• The BTAG's evaluation of the available data may lead it to
conclude that the site has a significant potentialf or ecological
impact and should undergo an ecological assessment The
BTAG will then offer advice on the types of studies that will
elicit pertinent information and the level of effort commensu-
rate with the adverse effect suspected.
Follow-Up of the Meeting
After the meeting has ended, the RPM will most likely want
a written record of the meeting's results. How such a record comes
into existence varies with the Region. In some Regions, the RPM
receives a copy of the minutes or a memorandum prepared by one
or more members of the BTAG. This document provides the RPM
with a copy of the BTAG's recommendations in the BTAG's own
words. Other Regions have the RPM prepare minutes, summariz-
ing both the presentation (if one occurred) and the BTAG's advice.
BTAG coordinators in these Regions say that this approach en-
ables them to confirm that the RPM has understood the group's
suggestions. Regardless of who prepares the record, it is generally
available no later than two weeks following the meeting.
The record of this first meeting constitutes a succinct descrip-
tion of the site, its contaminant history, and the BTAG's initial
recommendations. RPMs may wish to copy this record, along with
a map, to BTAG members to refresh their memories about a site the
next time it comes up for review. Alternatively, RPMs can accom-
plish the same end by copying the check sheet (see Appendix) to
BTAG members.
ECO Update
August 1992- Vol. I. No. 5
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0)
A Map Style Useful for the Initial Site Briefing
Figure 1
DLum's A S^^-v
flfc> \ \ *V '•*,'
Many BTAG members have found this style of map helpful in
visualizing a Superfimd site with which they are unfamiliar.
Arrows indicate the direction in which runoff flows.
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Appendix A: Check Sheet for Ecological Description of Site
Setting
1. What are the land uses/facilities in the vicinity of the site?
North
South
East-
.West
What directions do contaminant gradients follow?
Surface water, sediment '.
Soil
Ground wate
2. What is the site's highest elevation?.
What is its lowest elevation?
3. Is the site readily accessible? Yes No
If No, explain:
4. For each pair of descriptors, circle the one that best describes the site.
wooded/open. hilly/flat marshy/dry
Other
5. Does the site contain or drain into surface water? Yes No
IfYes,whattype(s)?
Pond or lake
Location
Area
Average Depth (or depth range).
ECO Update 7 August 1992 • Vol. I. No.
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Stream or river (including intermittent screams):
Location
Length
Average Width (or width range
Average Depth (or depth range
Type(s) of bottom
Row rate
Estuary/embayment:
Location
Area
Average Depth (or depth range).
Type(s) of bottom
List any known parameters of site-associated surface water.
pH Temperature Dissolved Oxygen.
Total Suspended Solids
Total Organic Carbon
Hardness
Salinity
Other (specify.
List any known sediment parameters of site-associated bodies of surface water.
Sediment type(s)
Grain Size pH ' Eh pE
Total Organic Carbon
Acid-Volatile Sulfides
Other (specify
(If more than one surface water body of each type, repeat information as needed.)
6. Does the site contain or drain into wetlands? Yes No
If Yes, what type(s) and size(s)? -
List any known surface water and sediment parameters of site wetlands, as in #5, above.
August 1992 • Vol. 1. No. 5 8 - ECO Update
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7. Describe sub-surface hydrology.
Overlying strata
Aquifer
Depth to aquifer
Location of groundwater discharge
Ecological Description
8. List and describe habitats that occur at the site.
Woodlands
Grasslands/open fields
Wetlands
Ponds
Streams.
Estuaries
Coastal zones
Flood plains _
Other natural areas _
List any known soil and sediment parameters for each terrestrial habitat.
Soil type(s
Grain Size pH Eh pE.
Total Organic Carbon
Total Phosphorus
Nitrogen forms ,
Other
9. Are any Federally or State listed endangered or threatened species known or suspected to occur on or near the
Yes No
If yes, list:
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10. Does the site have any game species or species of interest for another reason? Yes No
If yes, list:
Known Ecological Effects
11. Does the site show any evidence of adverse ecological effects? Yes No
If yes, describe:
12. Documentation attached:
Site map(s)
PA
SI
Contaminant concentration data
Species list(s)
Preliminary Natural Resources Survey (PNRS)
__ Other (specify
August 1992 • Vol. I, No. 5 10 ECO Update
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