vvEPA
                 United States
                 Environmental Protection
                 Agency
                        Office of
                        Solid Waste and
                        Emergency Response
Publication 9345.0-12FSI
EPA 540/F-95/038
PB95-963324
January 1996
ECO    Update
 Office of Emergency and Remedial Response
                                          Intermittent Bulletin
                                          Volume 3, Number 2
                   Ecotox  Thresholds
        This Bulletin provides an overview
  of the development and  use of Ecotox
  Threshold  (ET)  benchmark values  in
  Superfund  ecological  risk  assessments
  (ERAs).  ETs are defined as media-specific
  contaminant concentrations above which
  there  is  sufficient concern  regarding
  adverse  ecological  effects  to  warrant
  further site investigation.   The  bulletin
  describes how ETs  are to  be used for
  screening purposes in the Superfund ERA
  process,   and   summarizes  the
  methodologies used to  calculate ETs for
  each medium.
        IN THIS BULLETIN

Introduction	  1

Format of ETs	  2
                            Using ETs in the Superfund ERA Process . .  2

                            Limitations of ETs  	  3

                            Media-Specific Methods for Calculating ETs .  4

                            References	  8



                            INTRODUCTION

                              The  ecological  risk  assessments  (ERAs)
                            performed in  the  Superfund  program  often
                            include a procedure to determine which, if any,
                            of the contaminants found at a site are present in
                            concentrations that may be harmful to ecological
                            receptors. In this step, the maximum measured
                            contaminant concentration at a site is compared
                            to an ecotoxicologically-based benchmark; if the
                            concentration exceeds the benchmark,   further
                            assessment  is  warranted to  determine the
                            ecological risk posed by the contaminant. This
                            screening step is often useful at Superfund sites,
                            where a large number of contaminants may be
 ECO Update is a Bulletin series on ecological risk 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 to provide technical information to EPA and other government employees. It does not
 constitute rulemaking by the 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.

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detected.  While exceeding the benchmark does
not indicate the  level or type of risk involved,
concentrations below the benchmark should not
result in significant adverse effects to ecological
receptors   when  appropriately  conservative
benchmarks are used.
   The Superfund program has initiated a project
to develop media-specific benchmark values for
those chemicals  commonly found  in surface
water, sediment, or soil samples at  sites.  The
values  are  referred  to  as Ecotox  Thresholds
(ETs),    and  are  defined  as media-specific
contaminant concentrations above which there is
sufficient  concern  regarding  adverse ecological
effects to warrant further site investigation. ETs
are designed to provide Superfund site managers
with a tool to efficiently identify contaminants
that  may  pose a threat  to ecological receptors
and   focus  further  site  activities  on  those
contaminants and the media in which they are
found.  ETs are  meant to be used for screening
purposes only; they are not  regulatory criteria,
site-specific cleanup standards, or remediation
goals.
FORMAT OF ETs

   The list of ET values and the equations used
to calculate them will also soon be  available
electronically as computer application  software,
via the Internet at HTTP://WWW.EPA.GOV.
   As  data  on  more  contaminants  become
available, and as new methods are included, the
number of ETs will grow and some values will
change.  Having the  list available electronically
will  allow EPA to make regular updates while
minimizing the  expense  of generating and
distributing hard copies.
   The   toxicity  of many  contaminants  is
dependent upon some physical property of the
medium (e.g., hardness and pH of water, organic
carbon content of sediment).  The  application
software permits the  user to supply site-specific
values for these parameters, and then calculates
site-specific ETs.
   If site-specific values are not available, the
ETs presented in Table 2 of this Bulletin should
be used.  These values are based  on standard
default values of 100 mg/L hardness as CaCO3,
a pH of 7.8, and a  sediment  organic  carbon
content  of 1 percent.
USING ETs IN  THE SUPERFUND
ERA PROCESS

   ETs were developed for use  as  benchmark
screening values in the first step of the baseline
risk assessment. However, ETs may be useful for
decisions aking earlier in the Superfund process,
such as during the Preliminary Assessment/Site
Investigation (PA/SI) or  in the  Superfund
Accelerated  Cleanup  Model (SACM) integrated
site  assessment.   If  early analytical  results
indicate that a contaminant exceeds its ET value
for a medium,  future  site activities  can be
focused to gather information sufficient to assess
the ecological  risk,  if  any,  posed  by  that
contaminant.
   To the extent  practicable, established, peer-
reviewed EPA protocols and verified data have
been used to develop ETs, and are listed as the
"preferred methods" for calculating ETs later in
this  Bulletin.    However,  due  to  resource
constraints and/or insufficient data, EPA has not
used these protocols to develop formal "criteria"
for many of the contaminants found at Superfund
sites.     These   available   protocols  are   not
appropriate for all situations.  To fill this void,
methods  developed by other federal  agencies to
calculate  screening values have been included.
For  some contaminants, values  are available
from  both  a preferred EPA protocol  and an
alternative source (e.g., EPA's Sediment Quality
Criteria  [EPA,  1993a;  1993b;  1993c;  1993d;
1993e] and Long et al. [1995] Effects Range ~
Low  [ERLs] for sediment contaminants).   In
instances where multiple benchmark values are
available for a  specific  contaminant,  the  ET
derived by EPA  protocol  is preferred for use,
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                                 ECO Update

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regardless of whether it is higher or lower than
the alternative value.
   Because  ETs are to be  used for screening
purposes, the maximum site concentration  of
each  contaminant  in each medium should  be
compared to its medium-specific ET value.  If
the maximum site concentration of a contaminant
is less than its ET, the contaminant is not  an
ecological contaminant of concern, and further
assessment for the  contaminant for the purposes
of the ERA is generally not warranted  unless
additional site  information suggests otherwise.
If the maximum site concentration exceeds the
ET, further  investigation is  warranted.   The
nature and scope of this investigatory work is a
site-specific decision to  be  made  by the site
manager  in consultation  with  the  Regional
Biological Technical Assistance Group (BTAG).
For instance, the spatial distribution of measured
concentrations can be examined  to  determine if
contamination is widespread across the site  or
limited  to  discrete "hot spots,"  and  further
investigation can be planned accordingly.
   While ETs  will  help  focus  future  site
activities  on  the   potential  contaminants  of
concern, they should be used in conjunction with
any other information about the site to assess the
ecological risks posed by contaminants.   Risk
assessors should consider site-specific physical
and chemical conditions that may influence the
bioavailability  (and  thus,   the   site-specific
toxicity) of a contaminant, as the protocols used
to develop ETs may not be protective of all plant
and animal  species  at  all  sites  under  all
circumstances.  Site conditions that may  affect
the bioavailability  of contaminants  at a site,  or
the degree of protectiveness  of ETs, include the
following:

•   For   surface    water:      hardness,   pH,
   suspended/dissolved organic matter, salinity,
   flow rate, and temperature

•   For  sediment:   pH, organic  matter  content
   (i.e., total organic carbon), clay  content and
   clay  type, grain size, and redox potential
•   Surface water/groundwater hydrology patterns

•   Presence of:

   -  Endangered, threatened,  or rare species
   -  Species  particularly  sensitive  to   the
      contaminants detected at a site
   -  Species  of  economic   or  recreational
      importance
   -  Critical or sensitive habitats

   The  Superfund  site  manager should  also
review  the  site  analytical  data  used in  the
screening  process to ensure that:  1) the number
of samples taken is sufficient to characterize site
contamination, and 2) analytical detection limits
are below the ET value.
   At  some Superfund  sites,  the naturally-
occurring  background concentrations of metals
may exceed calculated ETs.   However, due to
physiological adaptations of  resident  biota or
reduced  bioavailability  due  to  physical  or
chemical  conditions,  the  naturally-occurring
concentrations  may  not  result  in  adverse
toxicological effects.   In these instances,  it is
suggested that a statistical comparison between
the background concentrations (reported  from
unimpacted   reference   locations)  and   the
maximum  measured  site  concentrations   be
completed. The results of the comparison would
provide the  site manager with the information
needed to make decisions regarding the need for
additional site investigation.
LIMITATIONS  OF  ETs

   The limitations of using ETs  as benchmark
values are summarized below.

1)   The  ETs  represent  a measure  of direct
toxicity  to  exposed  organisms,  based  upon
studies reported in the scientific literature.  The
endpoints that  form  the basis  for these values
typically are limited to reductions in  survival,
growth, or reproduction of the tested organisms
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                    January 1996 • Vol. 3, No. 2

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in either laboratory single-species or small-scale
mesocosm  studies, or small-scale field studies.
Indirect adverse effects to  wildlife  species via
bioaccumulation/biomagnification through food
chains are not addressed in  this project.
   While Superfund recognizes that failure to
address adverse effects to wildlife is a serious
shortcoming for this project, established, national
methods to address this issue are not currently
available.   These ETs may not be low enough
for those chemicals (e.g., methyl mercury, PCBs,
DDT, dioxins) where significant bioaccumulation
in the food chain may occur at the site.

2)   Although  there is substantial  interest in
integrating the human health risk assessment and
ERA processes, ETs were developed to address
toxicity to ecological receptors only, and are not
intended to be protective of human health.

3)  For Superfund sites located in states  where
state-mandated   screening  guidelines   are
available,  the  state  guidelines will generally
supersede the ETs recommended in this Bulletin.
MEDIA-SPECIFIC METHODS FOR
CALCULATING  ETs

Surface Water

Preferred  Method - Ambient  Water Quality
Criteria

   The  preferred  surface water  ETs  are  the
chronic  Ambient   Water   Quality   Criteria
(AWQC), developed by EPA's Office of Water
(OW).  AWQC are developed under the Clean
Water Act Section 304  (EPA, 1986a,  1986b,
1987, 40 CFR 131) for the protection of aquatic
life   for   both   freshwater   and   saltwater
environments. Development of a criterion for a
chemical in either fresh  or  salt water requires
results of at least eight acute toxicity tests from
eight different families and three  chronic tests.
Freshwater AWQC are applicable in waters with
salinity less than or equal to  1 part per thousand
(ppt), 95  percent or more of the time.  Saltwater
AWQC are to be used  in waters with salinity
greater than or equal to 10  ppt, 95 percent or
more of the time.    For waters  with salinity
between  1 and 10 ppt, the more stringent of the
freshwater  or saltwater  AWQC is  used, unless
site-specific information on species  inhabiting
the water body indicates a different preference.
   According to OW policy (October 1, 1993,
memorandum on Office of Water Policy  and
Technical  Guidance  on  Interpretation   and
Implementation of Aquatic Life Metals Criteria
[EPA, 1993fJ; and Revised Aquatic Life Metals
Criteria in  EPA's National Toxics Rule [EPA,
1995a]), concentrations of dissolved metal, rather
than total  metal, should be used to  set  and
measure   compliance  with   water  quality
standards,  because   dissolved   metal
concentrations more  closely  approximate  the
bioavailable fraction of  metal  in the water
column.  For this reason, the surface water ETs
for   metals   are    expressed   as  dissolved
concentrations, and many of them are slightly
different  than the published AWQC.
   Freshwater  AWQC  for  many metals  are
dependent on water hardness. For these criteria,
the ETs shown in Tables 1 and 2 correspond to
a total hardness  of 100 mg/L as CaCO3.  The
following equation  is  to be  used with  site-
specific hardness data to calculate a site-specific
ET criterion for the six metals shown in Table 1:
       .-, .,   .     (mJ\a.(hardness)] +/)„)  .-,,-,
       Cntenon=e  c           c *CF
where:
   m  =
   b  =
slope
y intercept
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Table 1: Calculation of Freshwater ETs for Metals
Chemical
Cadmium
Copper
Chromium III
Lead
Nickel
Zinc
Slope (m)
0.7852
0.8545
0.8190
1.273
0.8460
0.8473
y Intercept (b)
-3.490
-1.465
1.561
-4.705
1.1645
0.7614
Criterion (ET)1
1.0
11
180
2.5
160
100
Conversion
Factor
0.909
0.960
0.860
0.791
0.997
0.986
1Assumes hardness of 100 mg/L as CaCO3.
   CF =   conversion  factor,  ratio  of  total
           recoverable   concentration   to
           dissolved concentration

   Allowable  hardness  values  (expressed  as
mg/L CaCO3) must fall  within the range of 25
mg/L - 400 mg/L.   If the actual measured
hardness value  falls outside this range,  the
respective  minimum  or maximum  allowable
value is used in the calculation.
   The  freshwater  AWQC  for  pentachloro-
phenol is pH-dependent; the default ET criterion
was  calculated to correspond with  a pH of 7.8.
The equation for calculation of a site-specific ET
criterion for pentachlorophenol is:
          Criterion=e[LQ05(pH)-5.29Q]


   For several of the contaminants reported in
Table 2 (i.e., DDT, dieldrin, endrin, heptachlor,
methyl mercury, and  PCBs), the AWQC were
based  on  levels  that  would  result  in  an
exceedance of a Food and Drug Administration
action level  for fish consumed  by humans.
Since ETs are based solely on direct ecotoxicity
effects, the use of these values is not appropriate.
Consequently, the  final  chronic values (FCVs)
reported by OW are used for these chemicals.
When  there  are no human  fish consumption
concerns and there is no final residue value, the
FCV  is the  AWQC.   The  inorganic mercury
FCV  is reported in the AWQC document for
mercury, while the dieldrin and endrin FCVs are
reported  in the subsequent Proposed Sediment
Quality Criteria documents (EPA, 1993b; 1993c).

A Itemative Method - Great Lakes Water Quality
Initiative (GL WQI) Tier I and Tier II

   Because non-residue based AWQC have been
developed  only   for  a  limited  number  of
contaminants, ETs are also calculated using the
methodology presented in the Great Lakes Water
Quality Initiative (GLWQI) (40 CFR 122 et al.).
The GLWQI Tier I method is  identical to the
national  AWQC  method  when  final  residue
values are not used, and is used where enough
data are now available (e.g., diazinon), but where
AWQC have not been formally produced.
   Using the Tier  II methodology, ETs  can  be
calculated with less than the  complete minimum
data (e.g., tests for  species from eight families of
aquatic  organisms) required  for  a  Tier  I
calculation.   The  Tier II  methodology  uses
statistically   derived   "adjustment    factors"
described by Host et al. (1991) to  calculate a
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Tier II value.  The  adjustment factor decreases
as  the  number  of  representative  families
increases. The methodology is described in 40
CFR 132, Appendix A. The data set used in the
calculation   must include  a  daphnid test and
must meet the acceptability criteria outlined in
Appendix C of the revised aquatic life guidelines
(EPA,  1994).
   To date, OW has calculated GLWQI  Tier II
water  quality  values  and prepared  support
documents  for seven chemicals,  four of which
are on the ET list:  DDT,  heptachlor, lead, and
toxaphene (EPA, 1992a).    Because a  chronic
AWQC value  is available  for lead, its GLWQI
value is not used. The GLWQI values for DDT,
heptachlor,  and toxaphene values are used.
   OW has also used the GLWQI Tier II method
to  calculate   18  additional  values  for ETs,
including three chemicals for which AWQC had
been  published:   endosulfan, malathion, and
methoxychlor. OW believed that these new Tier
II values, based on more recent toxicity data, are
more appropriate  than the older AWQC  values.
Technical support documents have  not been
prepared for these chemicals.
   The 34 remaining values used are taken from
Suter and Mabrey (1994).  These benchmarks
were  developed  using the  GLWQI Tier  II
method,  and were reviewed by EPA to verify
their accuracy. A copy of the procedure used to
conduct the accuracy review  is available from
EPA OW by request.   EPA will not present an
ET value based  upon data that  do not meet
existing standards for use in developing criteria.
   Tier II values for marine surface waters have
not been calculated. While  Superfund may elect
to develop  such values using the Great Lakes
Tier II methodology  and  appropriate  marine
species in the future, the current procedure is to
accept the freshwater ETs  as  being appropriate
for use  in  a saltwater environment.   Using
AWQC as a model, the ETs  for salt water are
higher  than   the freshwater ETs  for nine
chemicals, and lower than the freshwater ETs for
seven  chemicals.   For each chemical  except
selenium, the  difference between the saltwater
and  freshwater value is  less than an order of
magnitude.

Sediment

Preferred Method - Sediment Quality Criteria

   Proposed  Sediment Quality Criteria (SQC)
have been published by OW (Federal Register,
Jan  18, 1994) for acenaphthene, dieldrin, endrin
fluoranthene, and  phenanthrene (EPA,  1993a;
1993b; 1993c;  1993d;  1993e).   These values
were derived using the equilibrium partitioning
(EqP)  method,  as described in  Technical Basis
for  Deriving Sediment Quality  Criteria  for
Nonionic  Organic   Contaminants   for  the
Protection  of  Benthic  Organisms  by   Using
Equilibrium Partitioning (EPA, 1993g). The EqP
method  quantifies the  hydrophobicity  of the
chemical by using the  octanol/water partition
coefficient,  Kow,  and determines the sorption
capacity of the sediment by the mass  fraction of
organic  carbon for  the sediment,  /oc.   The
relationship  between Kow   and the  sediment
organic carbon partitioning coefficient,  Koc, is
described by the  following  equation (Di Toro,
1985):

      log10Koc = 0.00028 +  0.983 log10Kow

Thus, the equation for the SQC is:

             SQC=foc*Koc*FCV

where:

   foc   =   mass fraction of organic  carbon for
            the sediment
   Koc  =   organic carbon  partition coefficient
   FCV =   final  chronic value,  from chronic
            AWQC

The  sediment  values  used in the  ETs  are
normalized to 1 percent organic carbon.
   Superfund has elected to use the lower limit
of the  95 percent confidence interval presented
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in the criteria documents as the ET, rather than
the central tendency value. This step was taken
to maintain an appropriate level of conservatism
for screening purposes.

Alternative  Method  1  -  Sediment   Quality
Benchmarks

   While  the   SQC  for  the  five chemicals
discussed  above have  been published in draft
form, EPA has also derived Sediment Quality
Benchmarks  (SQBs)  using   the  same EqP
approach as a joint effort between OW and  the
Office of Solid Waste (OSW).  SQBs are being
used for OW's National Sediment Inventory and
OSW's Hazardous Waste Identification Rule as
well as this project.  The SQB is calculated in
the same manner as the SQC except that a Tier
II surface water ET is substituted for the AWQC
or FCV in the  calculation.
   The SQB method is appropriate for nonionic
organic compounds with log Kow values between
2.0 and  5.5.   The  log Kow  values  used  to
calculate  SQBs  were  supplied  by   Samuel
Karickhoff and J. MacArthur Long of the EPA
Environmental  Research Laboratory -  Athens,
GA  as  an unpublished  internal report (EPA,
1995b).  Karickhoff and Long reviewed  available
literature Kow values from a variety of methods,
including  shake flask, slow  stir, reverse-phase
high performance liquid chromatography, and
generator column,  as  well as estimated values
generated by the SPARC and CLOGP models.
Generally,  data from  a slow-stir test were
preferable,  followed by estimation by  SPARC,
and others. For Kow values less than 4, the shake
flask method was preferable.  In most cases,  an
average  value  was calculated from a variety of
acceptable methods.
   All sediment ETs  presented in Table 2  are
normalized  to  1  percent  organic  carbon  in
sediment.
Alternative Method 2 - ERL  Values

   If neither an SQC nor an  SQB has been
calculated, the Effects Range Low value (ERL)
will  be used as the  sediment ET.   ERLs  are
included in the "effects range approach" initially
developed  for  the   National   Oceanic  and
Atmospheric Administration's (NQAA's)National
Status and Trends  Program,  by  Long  and
Morgan (1990).  The Long and Morgan method
was  revised  by MacDonald (1992)  and  the
values shown in Table 2 are from Long et al.
(1995), using the revised method.
   The Long and  Morgan (1990) values were
based  on  data from  freshwater,  estuarine, and
marine sediments.  Long et al.  (1995) derived
values on data from  estuarine and marine
sediments using modeling techniques, as well as
laboratory and field studies.  Trace metals data
were taken only from studies in which a strong
acid  digestion method was used.
   The procedures used to produce the ERLs  are
described  by Long and Morgan  (1990;  EPA,
1992b).   For  each  chemical,  the  ranges  of
chemical concentrations associated with observed
adverse biological  effects were determined and
ordered by weight  of evidence.  The data were
used to develop no-effects, possible-effects, and
probable-effects  ranges.     The  ERL  value
represents   the   lower   lOth-percentile
concentration associated  with  observation  of
biological effects.  According to this  method,
concentrations below the ERL should rarely be
associated with adverse effects.
   It  should be noted that there  is a relatively
low correlation, and consequently low accuracy,
between  the  incidence  of  effects  and  the
concentrations of mercury, nickel, total PCBs,
and DDT (Long et al., 1995). The sediment ETs
for  these  four chemicals  should  be  used
cautiously.
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                   January 1996 •  Vol. 3, No. 2

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Soil

   Methods to address toxicity in soils have not
been sufficiently developed to include them in
this  document.    The  Superfund program  is
currently evaluating options in this area and will
produce soil ETs when appropriate methods and
necessary resources are available.
REFERENCES

40 CFR 9, 122,  123,  131, and 132.  Tuesday,
   March  23,  1995.    Final  Water Quality
   Guidance for the Great Lakes System', Final
   Rule.

Di Toro,  D.M.,  1985.  A particle interaction
   model   of  reversible   organic   chemical
   sorption.  Chemosphere 14 (10):  1503-1538.

Host, G.E., R.R. Regal and C.E. Stephan.  1991.
   A nalyses of A cute and Chronic  Data for
   Aquatic Life.    Office  of  Environmental
   Processes  and  Effects Research, Office  of
   Research   and   Development,   U.S.
   Environmental  Protection Agency.   PB93-
   154714.

Long, E.R.,  D.D.  MacDonald,  S.L. Smith and
   F.D.  Calder.  1995.  Incidence  of Adverse
   Biological  Effects  Within   Ranges   of
   Chemical  Concentrations  in  Marine  and
   Estuarine   Sediments.       Environmental
   Management 19 (1): 81-97.

Long, E.R.  and L.G.  Morgan.   1990.   The
   Potential for Biological Effects of Sediment-
   Sorbed Contaminants Tested in the National
   Status  and Trends  Program.  NOAA  Tech.
   Memo. NOS OMA 62. National Oceanic and
   Atmospheric Administration, Seattle, WA.

MacDonald, D.D.  1992.  Development  of an
   Integrated Approach  to the Assessment  of
   Sediment Quality  in Florida.  Prepared for
   Florida   Department   of   Environmental
   Regulation.    MacDonald   Environmental
   Services, Ltd. Ladysmith, British Columbia.

Suter,  G.W.,  II  and  J.B.  Mabrey.    1994.
   Toxicological  Benchmarks  for  Screening
   Potential Contaminants of Concern for Effects
   on Aquatic Biota:  1994 Revision.   Oak
   Ridge National Laboratory, Oak Ridge, TN.
   ES/ER/TM-96/R1.

U.S. Environmental  Protection  Agency (EPA).
   1986a.      Quality   Criteria  for   Water.
   EPA440/5-86-001.

U.S. Environmental  Protection  Agency (EPA).
   1986b.   Update #1  to  Quality Criteria for
   Water.

U.S. Environmental  Protection  Agency (EPA).
   1987.   Update #2 to Quality Criteria for
   Water.

U.S. Environmental  Protection  Agency (EPA).
   1992a.  Great Lakes  Water Quality Initiative
   Tier II Water Quality Values for Protection of
   Aquatic  Life in Ambient Water:  Support
   Documents. November 23, 1992.

U.S. Environmental  Protection  Agency (EPA).
   1992b.    Sediment  Classification Methods
   Compendium.  EPA  823-R-92-006.

U.S. Environmental  Protection  Agency (EPA).
   1993a.   Sediment Quality Criteria for the
   Protection   of  Benthic   Organisms:
   Acenaphthene.  September 1993.

U.S. Environmental  Protection  Agency (EPA).
   1993b.   Sediment Quality Criteria for the
   Protection of Benthic Organisms:  Dieldrin.
   September 1993.

U.S. Environmental  Protection  Agency (EPA).
   1993c.   Sediment Quality Criteria for the
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   Protection of Benthic Organisms:
   September 1993.
Endrin.
U.S. Environmental Protection Agency (EPA).
   1993d.  Sediment Quality  Criteria for the
   Protection   of   Benthic  Organisms:
   Fluoranthene.  September 1993.

U.S. Environmental Protection Agency (EPA).
   1993e.  Sediment Quality  Criteria for the
   Protection   of   Benthic  Organisms:
   Phenanthrene.  September 1993.

U.S. Environmental Protection Agency (EPA).
   1993f. Office of Water Policy and Technical
   Guidance   on   Interpretation   and
   Implementation  of Aquatic  Life  Metals
   Criteria. Memorandum from M.G. Prothro to
   Water Management Division Directors, ESD
   Directors, Regions I-X. October 1.
U.S. Environmental Protection Agency  (EPA).
   1993g.    Technical  Basis  for  Deriving
   Sediment  Quality  Criteria  for Nonionic
   Organic Contaminants for the Protection of
   Benthic Organisms  by   Using Equilibrium
   Partitioning.  EPA-822-R-93-011.

U.S. Environmental Protection Agency  (EPA).
   1994.  Guidelines for Deriving Water Quality
   Criteria for the Protection of Aquatic Life and
   Its Uses - Revised.  Internal draft.

U.S. Environmental Protection Agency  (EPA).
   1995a. Revised Aquatic Life Metals Criteria
   in EPA 's National Toxics Rule. EPA-822-F-
   95-001. April 1995.

U.S. Environmental Protection Agency  (EPA).
   1995b.   OW/OSWER  Joint  Work  Group,
   internal working document.
ECO Update
                                 January 1996 •  Vol. 3, No. 2

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Table 2: Ecotox Thresholds for 67 Chemicals Commonly Found At Superfund Sites
CAS
Number
Chemical
Surface Water (ug/L)
Freshwater
AWQC or
FCV1
Tier II2
Marine
AWQC
or FCV1
Sediment (mg/kg)
EPASQC3
Fresh-
water
Marine
EPA
SQB4
ERL5
Metals (20)
22569728
17428410
7440393
7440417
7440439
1308141
18540299
7440484
7440508
7439896
7439921
7439965
7439976
22967926
7439987
7440020
7782492
7440622
7440666
57125
Arsenic III
Arsenic V
Barium
Beryllium
Cadmium
Chromium III
Chromium VI
Cobalt
Copper
Iron
Lead
Manganese
Mercury, inorganic
Mercury, methyl
Molybdenum
Nickel
Selenium
Vanadium
Zinc
Cyanide
190



1.0 h
180 h
10

11 h
1000
2.5 h

1.3


160 h
5.0

100 h
5.2

8.1 *
3.9 *
5.1 *



3.0 *



80 *

0.003 *
240 *


19 *


36



9.3

50

2.4

8.1

1.1


8.2
71

81
1.0




























































8.2 t



1.2
81 t


34

47

0.15 t


21


150

Organic Compounds (47)
83329
71432
50328
92524
117817
Acenaphthene
Benzene
Benzo(a)pyrene
Biphenyl
Bis(2-ethylhexyl)phthalate
23 S





46 *
0.014 *
14#
32 *
40 S




0.62




1.1





0.057

1.1

0.016

0.43


January 1996 • Vol.  3, No. 2
10
ECO Update

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Table 2 (continued)
CAS
Number
101553
85687
108907
50293
333415
132649
95501
541731
106467
75343
60571
84662
84742
115297
959988
33213659
72208
100414
206440
86737
76448
67721
58899
121755
72435
91203
608935
87865
Chemical
Bromophenyl phenyl ether, 4-
Butylbenzyl phthalate
Chlorobenzene
DDT
Diazinon
Dibenzofuran
Dichlorobenzene, 1,2-
Dichlorobenzene, 1,3-
Dichlorobenzene, 1,4-
Dichloroethane, 1,1-
Dieldrin
Diethyl phthalate
Di-n-butyl phthalate
Endosulfan, mixed isomers
Endosulfan, alpha
Endosulfan, beta
Endrin
Ethylbenzene
Fluoranthene
Fluorene
Heptachlor
Hexachloroethane
Lindane/Hexachlorocyclohexane
Malathion
Methoxychlor
Naphthalene
Pentachloro benzene
Pentachlorophenol
Surface Water (ug/L)
Freshwater
AWQC or
FCV1




0.043 F





0.062 S





0.061 S

8.1 S



0.08




13 pH
Tier II2
1.5#
19#
130 *
0.013 +

20 *
14#
71 #
15#
47 *

220 *
33 *
0.051 #
0.051 #
0.051 #

290 *

3.9 #
0.0069 +
12 #

0.097
0.019*
24 *
0.47 #

Marine
AWQC
or FCV1










0.11 S





0.01 S

11 S








7.9
Sediment (mg/kg)
EPASQC3
Fresh-
water










0.052





0.02

2.9









Marine










0.095





0.0035

1.4









EPA
SQB4
1.3
11
0.82

0.0019
2.0
0.34
1.7
0.35


0.63
11
0.0054
0.0029
0.014

3.6

0.54

1.0
0.0037
0.00067
0.019
0.48
0.69

ERL5



0.0016














0.6






0.16


ECO Update
11
January 1996 • Vol. 3, No. 2

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Table 2 (continued)
CAS
Number
1000
11096825
85018
129000
79345
127184
56235
108883
8001352
75252
120821
71556
79016
108383
Chemical
Polynuclear aromatic
hydrocarbons
Polychlorinated biphenyls
Phenanthrene
Pyrene
Tetrachloroethane, 1,1,2,2-
Tetrachloroethylene
Tetrachloro methane
Toluene
Toxaphene
Tribromomethane
Trichlorobenzene, 1,2,4-
Trichloroethane, 1,1,1-
Trichloroethylene
Xylene, m-
Surface Water (ug/L)
Freshwater
AWQC or
FCV1


6.3 S











Tier II2

0.19 *


420 *
120 *
240 #
130 *
0.011
320 #
110#
62 *
350 *
1.8#
Marine
AWQC
or FCV1


8.3 S





0.21





Sediment (mg/kg)
EPA SQC3
Fresh-
water


0.85











Marine


1.1











EPA
SQB4




0.94
0.53
1.2
0.67
0.028
0.65
9.2
0.17
1.6
0.025
ERL5
4.0
0.023
0.24
0.66










1USEPA chronic ambient water quality criteria (AWQC) or EPA-derived final chronic values (FCVs) (USEPA, 1986a, 1986b, 1987). Metals
concentrations are for total dissolved chemical.
2Values calculated using Great Lakes Water Quality Initiative Tier II methodology (40 CFR 9 et al.).
3USEPA Sediment Quality Criteria (SQC). Assumes 1 percent organic carbon (USEPA, 1993g). Values are lower limit of 95 percent
confidence interval.
4Sediment quality benchmarks (SQBs) by equilibrium partitioning. Assumes 1 percent organic carbon. (USEPA, 1995b).
5ERL = Effects Range - Low (Long et al., 1995).
Notes:
ug/L = micrograms per liter.
mg/kg = micrograms per kilogram.
h = hardness-dependent ambient water quality criterion (100 mg/L as CaCO3 used).
pH = pH-dependent ambient water quality criterion (7.8 pH used).
S = final chronic value derived for EPA Sediment Quality Criteria documents (EPA, 1993a, b, c, d, e).
F = final chronic value calculated using Great Lakes Water Quality Initiative Tier I methodology.
t = value is for total of all chemical forms.
* = value as calculated in Suter and Mabrey, 1994.
+ = value with EPA support documents.
# = value calculated for this project.
January 1996 • Vol. 3, No. 2
12
ECO Update

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