[Federal Register Volume 59, Number 120 (Thursday, June 23, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-15308]
[[Page Unknown]]
[Federal Register: June 23, 1994]
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ENVIRONMENTAL PROTECTION AGENCY
[OW-FRL-5003-8]
Bioconcentratable Contaminants in Surface Waters; Assessment and
Control; Document Availability
AGENCY: Environmental Protection Agency.
ACTION: Notice of availability and request for comment on two field
validation studies that comprise Appendix I of the March 1991 draft
guidance document entitled: Assessment and Control of Bioconcentratable
Contaminants in Surface Waters.
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SUMMARY: This notice announces the availability of the two field
validation studies that comprise Appendix I of the March 1991 draft
guidance document entitled: Assessment and Control of Bioconcentratable
Contaminants in Surface Waters. The Environmental Protection Agency
solicits comments from the public on the Five Mile Creek and Louisiana
field studies and the possible repercussions for the methodologies used
in the draft guidance document.
DATES: Comments should be received by EPA on or before August 22, 1994.
ADDRESSES: Copies of the draft Appendix I were mailed to people who
requested the draft guidance document ``Assessment and Control of
Bioconcentratable Contaminants in Surface Waters.'' Others who want to
obtain a copy of Appendix I should contact Ms. Irene Suzukida Dooley,
Office of Wastewater Enforcement and Compliance (4203), U.S. EPA, Tel:
(202) 260-1955. Please provide your name, telephone number, and mailing
address and request ``Appendix I.'' Written comments should be
submitted to Ms. Lynn Feldpausch, Office of Science and Technology
(4304), U.S. Environmental Protection Agency, 401 M Street, SW.,
Washington DC 20460, Tel: (202) 260-8149. In addition, EPA encourages
commenters to provide one copy of their comments in electronic format,
preferably 5.25'' or 3.5'' diskettes compatible with WordPerfect for
DOS.
FOR FURTHER INFORMATION CONTACT: Irene Dooley, U.S. EPA, at (202) 260-
1955 for a copy of Appendix I or a copy of the March 1991 draft
guidance document ``Assessment and Control of Bioconcentratable
Contaminants in Surface Waters,'' which both have limited copies
remaining. For technical information contact Dr. Lawrence P. Burkhard,
U.S. EPA, Duluth, at (218) 720-5554.
SUPPLEMENTARY INFORMATION:
I. Availability of Document for Comment
The draft Appendix I being announced today contains two field
evaluation reports: the Louisiana study and the Five Mile Creek Study.
The two draft reports contain summary tables of the field data, such as
in-stream concentrations of the chemicals, tissue residues, and
predicted vs. measured tissue concentrations. Each draft study is
followed by an appendix of individual or raw field data, which were
included for comment and review. The final guidance will not include
the two draft field data appendices, so reviewers are encouraged to
keep these sections for future reference.
At this time EPA is not asking for additional comments on the
entire contents of the 1991 draft guidance document ``Assessment and
Control of Bioconcentratable Contaminants in Surface Waters,'' since
EPA announced the availability of the draft guidance document on March
29, 1991 (56 FR 13150) for comment and extended the comment period to
July 26, 1991 (56 FR 26411). Comments on the draft guidance document
were taken into account when EPA applied its methodology in the April
16, 1993 ``Proposed Water Quality Guidance for the Great Lakes System''
(58 FR 20802). For instance, on page II-5 of the draft guidance
document, ``Assessment and Control of Bioconcentratable Contaminants in
Surface Waters,'' EPA recommended use of BCF values calculated from the
log P values preferentially over measured BCF values. Commenters
suggested that measured BAFs and BCFs take precedence over calculated
values, and EPA agreed with this comment. Therefore EPA modified the
approach before deriving human health and wildlife bioaccumulation
factors in the Great Lakes proposal (58 FR 20802). Finally, EPA will
evaluate comments received on the bioaccumulation methodology in the
``Proposed Water Quality Guidance for the Great Lakes System'' (58 FR
20802) before preparing the final guidance document for
bioconcentratable contaminants.
II. Background Information
On March 29, 1991, the U.S. Environmental Protection Agency
announced the availability of the draft guidance document ``Assessment
and Control of Bioconcentratable Contaminants in Surface Waters'' for
review and comment in a Federal Register notice (56 FR 13150). This
1991 draft bioconcentration factor guidance did not contain ``Appendix
I: Field Evaluation Studies of Residue Prediction Procedures.''
EPA developed the methodology in the March 1991 draft document,
``Assessment and Control of Bioconcentratable Contaminants in Surface
Waters,'' to provide guidance on assessing, and where necessary,
controlling the release of bioconcentratable pollutants in effluents.
The principal components of the approach are: (1) analytical procedures
for detecting and identifying bioconcentratable chemicals in effluents,
receiving water, and organisms; (2) prediction of the bioconcentration
factor (BCF) from the n-octanol water partition coefficient (P) using
quantitative structure activity relationships (QSAR); (3) prediction of
the bioaccumulation factor (BAF) from the chemical's BCF and log P, and
the trophic status of the organism of concern; (4) prediction of
residues in aquatic organisms using the BCF or BAF and concentration of
the chemical in the receiving water; and (5) calculation of allowable
ambient water or tissue residue concentrations for bioconcentratable
chemicals based upon human consumption of contaminated fish and
shellfish. The protocol combines these procedures to arrive at effluent
discharge concentrations for bioconcentratable chemicals which will
limit residues in aquatic organisms used for human consumption.
III. Objectives of the Field Validation Studies
The objective of the two field validation studies was to determine
how well tissue residue concentrations can be predicted in field
discharge situations using the guidance procedures. In order to predict
residues in receiving water organisms, the concentration of the
chemicals in the receiving water must be known, and these
concentrations (in the receiving water) must be relatively constant for
a 20- to 40-day period. Without these conditions, successful evaluation
of field data will be nearly impossible since the organisms will never
come to steady-state conditions with the receiving water.
This field validation effort was not designed to verify a) the
accuracy of the allowable tissue residues, b) the analytical procedures
associated with the tissue alternative, c) the prediction of residues
where exposure is intermittent, d) the prediction of residues where
exposure is difficult to estimate, or e) the derivation of acceptable
human uptake levels.
A. Five Mile Creek Field Study
Residue levels in vertebrates and invertebrates were predicted by
estimating the in-stream chemical concentrations and using this data in
the residue prediction procedure. Effluent chemical concentrations were
determined from four seven-day effluent composites taken consecutively
over a 28-day period. During this 28-day period, stream and discharge
flows were also measured. Using the flow and effluent data, the
receiving water concentrations were estimated for each chemical.
Subsequently, the estimated receiving water concentrations were
multiplied by chemical-specific bioaccumulation factors (approximated
using procedures in the draft guidance document) to predict tissue
residue concentrations.
The Five Mile Creek, Alabama field study report contains the
evaluation methods; an abbreviated description of the residue
prediction technique from the draft guidance document, ``Assessment and
Control of Bioconcentratable Contaminants in Surface Waters;'' sampling
procedures; brief descriptions of the analytical procedures listed in
Appendices A and B of the draft guidance document; the analytical
methods used for the chemicals under investigation; previous mixing
studies; data on variability in flows; and interpretation of data. The
report lists predicted stream and discharge flows and in-stream
effluent concentrations; concentrations of target chemicals in ambient
water and tissue data; concentrations of the target chemicals with
coefficients of variation; tissue residues in parts per billion; values
used to calculate bioaccumulation factors (BAFs); predicted vs.
measured tissue concentrations for both caged and indigenous fish and
an invertebrate; a statistical presentation of the predicted vs.
observed tissue residues; and a discussion of the conditions causing
varying exposure concentrations.
The objective of the site study was to determine how well tissue
residues could be predicted in field discharge situations using the
guidance procedures. Biphenyl, phenanthrene, anthracene, fluoranthene,
and pyrene, all of which were detected by the effluent procedure, were
studied. For the indigenous invertebrate Decapoda organisms, the
observed and predicted residues differed by no more than a factor 3 for
9 of the 10 predicted residues. All of the measured Decapoda tissue
residues were within the bounds of the 99% confidence limits for the
predicted residues. For the indigenous fish Lepomis sp., the observed
and predicted residues differed by no more that a factor of 3 for 6 of
the 10 predicted residues. For each chemical, similar agreement between
the measured and predicted Lepomis sp. tissue residues was observed for
both sampling stations. For the caged Ictalarus punctatus, data from
these exposures could not be used to evaluate the residue prediction
procedure due to experimental problems.
The chemicals under investigation in this study can be metabolized
by aquatic vertebrates such as fishes. The observed residues in the
Lepomis sp. were consistent with this process. The observed residues
were lower than predicted and the more easily metabolized chemicals had
lower observed residues than the less easily metabolized chemicals. For
aquatic invertebrates, metabolism of the five chemicals under
investigation was (or should have been) essentially nonexistent. The
data for the Decapoda organisms were consistent with this metabolic
behavior as similar differences between the measured and predicted
residues were observed for all chemicals at each sampling station.
This study demonstrates that tissue residue concentrations in field
discharge situations can be predicted within a factor of 3 using the
developed residue prediction procedure provided the chemicals are not
easily metabolized. When metabolism is important, residues predicted
using the guidance procedure will be too large. The rate of metabolism
will directly influence the difference between the measured and
predicted residues.
The prediction of tissue residues within a factor of 3 for ``non-
metabolizable'' chemicals, in field discharge situations, strongly
demonstrates the validity of the developed residue prediction
procedure.
B. Louisiana Field Study
This site was selected because (a) the effluent contained
bioconcentratable chemicals detectable by the effluent analytical
method, (b) the flow regime of the site was reasonably simple and had
short flow times, and (c) native populations of fish and shellfish were
available. Furthermore, preliminary calculations suggested that
concentrations of the chemicals in the receiving water were high enough
to result in measurable tissue residues in the indigenous organisms.
Prior to the site study, the effluent analytical method was performed
on grab samples. This method detected and identified a number of
chlorinated organics, i.e., chloro-benzenes and chloro-butadienes, and
a few polycyclic aromatic hydrocarbons (PAHs).
The thirteen chemicals selected for evaluation were:
Hexachloroethane (HCE); Tetrachlorobutadiene #1 (TeCBD #1);
Tetrachlorobutadiene #2 (TeCBD #2); Pentachlorobutadiene #1 (PeCBD #1);
Pentachlorobutadiene #2 (PeCBD #2); Hexachlorobuta-1,3-diene (HCBD);
1,2,3-Trichlorobenzene (1,2,3-TrCB); 1,2,4-Trichloro-benzene (1,2,4-
TrCB); 1,2,4,5- and 1,2,3,5-Tetrachloro-benzene (TeCB Mix); 1,2,3,4-
Tetrachlorobenzene (1,2,3,4-TeCB); Pentachlorobenzene (PeCB); and
Hexachlorobenzene (HCB). The chemicals selected for the site study were
typical of the chemicals from the discharge. Their calculated BCFs
ranged from 140 to 6,420.
The Louisiana field study report contains the evaluation methods;
an abbreviated description of the residue prediction technique from the
draft guidance document, ``Assessment and Control of Bioconcentratable
Contaminants in Surface Waters;'' sampling procedures; brief
descriptions of the analytical procedures listed in Appendices A, B,
and C of the draft guidance document; and the analytical method used
for the chemicals under investigation. The report lists concentrations
of target chemicals in ambient water, sediment, and tissue data;
calculates bioaccumulation factors (BAFs) using the guidance procedure;
compares and predicts tissue concentrations for three species of fish
and an invertebrate using the guidance procedure; compares predicted
and measured tissue concentrations; discusses the conditions causing
varying exposure concentrations; and discusses the effects of measured
vs. estimated log P values.
The chemicals predicted to be larger than their measured tissue
concentrations for the Callinectes sapidus (blue crab), in general,
were HCE, PeCBDs, and HCBD. In contrast, no chemicals were predicted to
be larger for the fishes, e.g., none of 156 predicted tissue
concentrations were greater than their measured residues by a factor of
10 or more.
The guidance technique predicted tissue concentrations which were
smaller than the measured concentrations by a factor of 1.1 and 5.3 on
average (geometric average) for the C. sapidus and fishes,
respectively. For the C. sapidus, 32 and 53 of 72 predicted tissue
residues were within a factor of 3 and 10 of the measured tissue
concentrations, respectively. For the fishes, 48 and 111 of 156
predicted tissue residues were within a factor of 3 and 10,
respectively.
The guidance technique provided more accurate tissue concentrations
for chemicals with the highest quality log P values and with the least
variable exposure concentrations. The best predictability was observed
for the chlorinated benzenes (chemicals with the highest quality log P
values), and the poorest predictability was observed for the
chlorinated butadienes (chemicals with the lowest quality log P
values).
The measured and predicted tissue concentrations were in agreement
with the expected trends for metabolic behavior for the site study
chemicals for the fishes and for most compounds in C. sapidus. However,
for the C. sapidus, HCE, PeCBDs, and HCBD diverged from their expected
metabolic behavior in that their measured concentrations were
substantially lower than predicted.
Dated: June 5, 1994.
Robert Perciasepe,
Assistant Administrator for Water.
[FR Doc. 94-15308 Filed 6-22-94; 8:45 am]
BILLING CODE 6560-50-P
