[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validation studies that comprise Appendix I of the March 1991 draft 
guidance document entitled: Assessment and Control of Bioconcentratable 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validation studies that comprise Appendix I of the March 1991 draft 
guidance document entitled: Assessment and Control of Bioconcentratable 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in the draft guidance document.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requested the draft guidance document ``Assessment and Control of 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1955 for a copy of Appendix I or a copy of the March 1991 draft 
guidance document ``Assessment and Control of Bioconcentratable 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]
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