[Federal Register Volume 65, Number 59 (Monday, March 27, 2000)]
[Notices]
[Pages 16200-16201]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-7454]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-6564-7]


Methods for Measuring the Toxicity and Bioaccumulation of 
Sediment-Associated Contaminants With Freshwater Invertebrates--Second 
Edition

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability of methods for measuring the toxicity 
and bioaccumulation of sediment-associated contaminants with freshwater 
invertebrates--second edition.

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SUMMARY: The Environmental Protection Agency (EPA) is publishing 
procedures for testing freshwater organisms in the laboratory to 
evaluate the potential toxicity or bioaccumulation of chemicals in 
whole sediments. This second edition updates methods originally 
published in 1994 (EPA/600/6-94/024). The second edition of the manual 
includes new methods for evaluating sublethal effects of sediment-
associated contaminants utilizing long-term sediment exposures. 
Procedures are described for testing the freshwater organisms in the 
laboratory to evaluate the potential toxicity or bioaccumulation of 
chemicals in whole sediments. Sediments may be collected from the field 
or spiked with compounds in the laboratory. Toxicity methods are 
outlined for two (2) organisms, the amphipod Hyalella azteca, and the 
midge Chironomus tentans. Toxicity tests with amphipods or midges are 
conducted for 10 days in 300-mL chambers containing 100 mL of sediment 
and 175 mL of overlying water. Overlying water is renewed daily and 
test organisms are fed during the toxicity tests. The endpoints in the 
10 day test with H. azteca and C. tentans

[[Page 16201]]

are survival and growth. Procedures are primarily described for testing 
freshwater sediments; however, estuarine sediments (up to 15\0/00\ 
salinity) can also be tested in 10 day sediment toxicity tests with H. 
azteca. Guidance is also provided for conducting long-term sediment 
toxicity tests with H. azteca and C. tentans. The long-term sediment 
exposures with H. azteca are started with 7-to 8-day old amphipods. On 
day 28 of the sediment exposure, amphipods are isolated from the 
sediment and placed in water-only chambers where reproduction is 
measured on day 35 and 42. Endpoints measured in the amphipod test 
include survival (day 28, 35, and 42), growth (on day 28 and 42), and 
reproduction (number of young/female produced from day 28 to 42). The 
long-term sediment exposures with C. tentans start with newly hatched 
larvae (24 hours old) and continue through emergence, reproduction, and 
hatching of the F1 generation (about 60 day sediment 
exposures). Survival and growth are determined at 20 days. Starting on 
day 23 to the end of the test, emergence and reproduction of C. tentans 
are monitored daily. The number of eggs/female is determined for each 
egg mass, which is incubated for 6 days to determine hatching success. 
The procedures detailed in this document include measurement of a 
variety of lethal and sublethal endpoints with Hyalella azteca and 
Chironomus tentans. Minor modifications of the basic methods can be 
used in cases where only a subset of these endpoints is of interest. 
Guidance for conducting 28 day bioaccumulation tests with the 
oligochaete Lumbriculus variegatus is also provided in the manual. 
Overlying water is renewed daily and test organisms are not fed during 
the bioaccumulation tests. Methods are also described for determining 
bioaccumulation kinetics of different classes of compounds during 28 
day exposures with L. variegatus.
    This guidance is designed to describe procedures for testing 
freshwater organisms in the laboratory to evaluate the potential 
toxicity or bioaccumulation of chemicals in whole sediments. This 
guidance document has no immediate or regulatory consequence. It does 
not in itself establish or affect legal rights or obligations, or 
represent a determination of any party's liability. The USEPA may 
change this guidance in the future.
    This guidance document has been reviewed in accordance with USEPA 
Policy and approved for publication. Any mention of trade names or 
commercial products does not constitute endorsement or recommendation 
for use.
    Availability of Document: Copies of the complete document, titled 
Methods for Measuring the Toxicity and Bioaccumulation of Sediment-
associated Contaminants with Freshwater Invertebrates--Second Edition 
(EPA/600/R-99/064) can be obtained from the National Service Center for 
Environmental Publications, P.O. Box 42419, Cincinnati, OH., 45242 by 
phone at 1-800-490-9198 or on their web site at  www.epa.gov/ncepihom/orderpub.html. A pdf version of this document will be made available to 
be viewed or downloaded from the Office of Science and Technology's 
home page on the Internet at www.epa.gov/OST/.

FOR FURTHER INFORMATION CONTACT: D. Scott Ireland, USEPA, Standards and 
Applied Science Division (4305), Office of Science and Technology, 
Ariel Rios Building, 1200 Pennsylvania Avenue, N.W., Washington, DC 
20460; or call (202) 260-6091; fax (202) 260-9830; or e-mail 
[email protected].

SUPPLEMENTARY INFORMATION:

Background Information

    Sediment contamination is a widespread environmental problem that 
can potentially pose a threat to a variety of aquatic ecosystems. 
Sediment functions as a reservoir for common chemicals such as 
pesticides, herbicides, polychlorinated biphenyls (PCBs), polycyclic 
aromatic hydrocarbons (PAHs), and metals such as lead, mercury, and 
arsenic.
    These methods provide consistent testing protocols for agency-wide 
use to evaluate risks and provide comparable data. They provide the 
basis for uniform cross-program decision making within the USEPA. Each 
program, however, retains the flexibility of deciding whether 
identified risk would trigger regulatory actions.

    Dated: March 22, 2000.
Geoffrey H. Grubbs,
Director, Office of Science and Technology.
[FR Doc. 00-7454 Filed 3-24-00; 8:45 am]
BILLING CODE 6560-50-U