Notice of Ambient Aquatic Life Water Quality Criteria for Tributyltin (TBT)-Draft

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of availability for ambient aquatic life water quality criteria for tributyltin (TBT)—draft and request for scientific and technical input.

SUMMARY:

Section 304(a)(1) of the Clean Water Act (CWA) requires the Environmental Protection Agency (EPA) to develop, and publish and, from time to time, revise criteria for water that accurately reflect the latest scientific knowledge. These criteria represent EPA's current recommendations to States, Territories, and authorized Tribes to use as technical information in establishing their water quality standards as state or tribal law or regulation. Such standards may form the basis for establishing water qualty-based controls. These water quality criteria are not regulations and do not impose legally-binding requirements on EPA, States, Territories, Tribes or the public. Today, EPA is announcing the availability of draft water quality criteria for tributyltin (TBT) for scientific and technical input.

EPA is notifying the public about the request for scientific and technical input on the draft criteria for TBT in accordance with the Agency's process for developing or revising criteria (63 FR 68354, December 10, 1998). As indicated in the December 10, 1998 FR notice, the Agency believes it is important to provide the public with opportunities to submit scientific information on criteria. Today, EPA is asking for input from the public on issues of science related to the information used in deriving the draft TBT criteria. These criteria constitute the Agency's current recommended section 304(a)(1) criteria for TBT. Based on its assessment of information received in response to this announcement and other available information, EPA will publish a notice containing the final criteria and informing the public how the final document can be obtained.

DATES:

EPA will accept significant scientific information submitted to the Agency on or before March 27, 2003. You should adequately document any scientific information and provide enough supporting information to indicate that acceptable and scientifically defensible procedures were used and that the results are reliable.

ADDRESSES:

Send an original and three copies of any written significant scientific information to W-02-03 Comment Clerk, Water Docket (MC4101T), USEPA, 1200 Pennsylvania Avenue NW., Washington, DC 20460. Information may be hand-delivered to the Water Docket, USEPA, Room B102, 1301 Constitution Avenue NW., Washington, DC 20460. Information may also be submitted electronically to OW-Docket@epa.gov. Information should be submitted as a WP5.1, 6.1 and/or 8.0 or an ASCII file with no form of encryption.

Copies of the criteria document entitled, Ambient Aquatic Life Water Quality Criteria for Tributyltin (TBT)—Draft (EPA-822-B-02-001) may be obtained from EPA's Water Resource Center by phone at (202) 566-1729, or by e-mail to center.water-resource@epa.gov or by conventional mail to EPA Water Resource Center, RC-4100T, 1200 Pennsylvania Avenue NW., Washington, DC 20460. The document is also available electronically at: http://www.epa.gov/waterscience/criteria/tributyltin.

FOR FURTHER INFORMATION CONTACT:

Frank Gostomski, Health and Ecological Criteria Division (4304T), U.S. EPA, 1200 Pennsylvania Avenue NW., Washington, DC 20460; (202) 566-1105; gostomski.frank@epa.gov.

SUPPLEMENTARY INFORMATION:

What Are Recommended Water Quality Criteria?

Recommended water quality criteria are the concentrations of a chemical in water at or below which aquatic life are protected from acute and chronic adverse effects of the chemical. Section 304(a)(1) of the Clean Water Act requires EPA to develop and publish, and from time to time revise, criteria for water accurately reflecting the latest scientific knowledge. Water quality criteria developed under section 304(a) are based solely on data and scientific judgments. They do not consider economic impacts or the technological feasibility of meeting the criteria in ambient water. Section 304(a) criteria provide technical information to States and Tribes in adopting water quality standards and provide a scientific basis for them to develop controls of discharges or releases of pollutants. The criteria also provide a scientific basis for EPA to develop Federally promulgated water quality standards under section 303(c). In this notice, EPA is announcing the publication and availability of EPA's most recent draft recommendations of water quality criteria for TBT and requesting scientific and technical input from the public.

What Is Tributyltin (TBT) and Why Are We Concerned About It?

TBT is one of several organotin compounds with various industrial uses. Environmental exposure occurs mainly from its application as a biocide in antifouling paints applied to ship hulls to keep barnacles and other fouling organisms from attaching to the hull. TBT remains effective over long periods because it is released from the hull into the water column over time. TBT is extremely stable and resistant to natural degradation in water. Because of TBT's high toxicity and the potential exposure of aquatic organisms to it, EPA has developed the following water quality criteria:

Freshwater: Aquatic life should not be affected unacceptably if the: One-hour average concentration of TBT does not exceed 0.46 ug/l more than once every three years on the average (Acute Criterion); and the Four-day average concentration of TBT does not exceed 0.063 ug/l more than once every three years on the average (Chronic Criterion).

Saltwater: Aquatic life should not be affected unacceptably if the: One-hour average concentration of TBT does not exceed 0.38 ug/l more than once every three years on the average (Acute Criterion); and the Four-day average concentration of TBT does not exceed 0.001 ug/l more than once every three years on the average (Chronic Criterion).

Definitions of Criteria Terminology

One hour average: the average of all samples taken during a one hour period by either continuous sampling or periodic grab samples.

Four day average: the average of all samples taken during four consecutive days by either continuous sampling or periodic grab samples. Also known as a 96-hour average.

Acute Criterion: A chemical concentration protective of aquatic organisms from short term exposure to fast acting chemicals or spikes in concentrations. For example exposure of a fish moving through an area for foraging but not residing in the area.

Chronic Criterion: A chemical concentration protective of aquatic organisms from longer term exposure to slower acting chemicals or relatively steady concentrations. For example, exposure of a fish that resides in an area.

Why Is EPA Notifying the Public About the Draft Criteria for TBT?

Today, EPA is requesting scientific and technical input on a new draft of the aquatic life criteria document for TBT. The new draft TBT criteria document incorporates scientific and technical input received in response to a draft criteria document which was announced in the Federal Register on August 7, 1997 (62 FR 42554). Based on submitted information and data, EPA has updated the draft recommended aquatic life criteria document for TBT. Today, EPA is soliciting views from the public on issues of science related to the information used to derive the draft criteria. EPA will review and consider significant scientific and technical information submitted by the public that might not have otherwise been identified during development of these draft criteria. Based on this information and any other new information available, EPA will decide whether to revise the draft criteria. EPA will publish a notice containing the final criteria and informing the public how the final document can be obtained.

Where Can I Find More Information on EPA's Revised Process for Developing New or Revised Criteria?

The Agency published detailed information about its revised process for developing and revising criteria in the Federal Register on December 10, 1998 (63 FR 68354) and in the EPA document entitled, National Recommended Water Quality-Correction (EPA 822-Z-99-001, April 1999). The purpose of the revised process is to provide expanded opportunities for public input and to make the criteria development process more efficient.