01-23753. Notice of Availability of Draft Aquatic Life Criteria Document for Atrazine

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of availability of draft aquatic life criteria document for atrazine.

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 accurately reflecting the latest scientific knowledge. These criteria provide EPA's recommendations to states and authorized tribes as guidance in establishing their water quality standards as state or tribal law or regulation. Today, EPA is notifying the public about the availability of the draft aquatic life criteria document for atrazine.

EPA is notifying the public about the availability of this draft document 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 an opportunity to submit scientific information on draft criteria. EPA is soliciting views from the public on issues of science pertaining to the information used in deriving the draft criteria. EPA is also soliciting input from the public on harmonizing risk assesssment methods used by the Office of Water (OW) in its draft aquatic life criteria document for atrazine and by the Office of Pesticide Programs (OPP) in its Preliminary Ecological Fate and Effects Risk Assessment for Atrazine, published elsewhere in this issue of the Federal Register.

DATES:

All significant scientific information must be submitted to the Agency under docket number W-01-10. All significant scientific information submissions are requested to be submitted within 60 days after publication of this notice. The Administrative Record supporting this draft guidance document is available at the Water Docket, Room EB 57, Environmental Protection Agency, 401 M Street SW, Washington, DC 20460 on Monday through Friday, excluding Federal holidays, between 9 a.m. and 4 p.m. For access to docket materials call [phone] for an appointment. A reasonable fee will be charged for photocopies.

ADDRESSES:

Send an original and three copies of any written significant scientific information to W-01-10 Comment Clerk, Water Docket (MC4101), USEPA, 1200 Pennsylvania Ave., NW., Washington, DC 20460. Information may be hand-delivered to the Water Docket, USEPA, Room EB 57, 401 M Street, SW, Washington, D.C. 20460. Information may also be submitted electronically to [e-mail]. 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 Atrazine may be obtained from EPA's Water Resource Center by phone at [phone], or by e-mail to [e-mail] or by conventional mail to EPA Water Resource Center, RC-4100, 1200 Pennsylvania Ave., Washington, DC 20460. Alternatively, consult www.epa.gov/​OST/​standards for download availability.

FOR FURTHER INFORMATION CONTACT:

Frank Gostomski, Health and Ecological Criteria Division (4304), US EPA, 1200 Pennsylvania Avenue NW, Washington, D.C. 20460; [phone]; [e-mail]

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 guidance 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).

What Is Atrazine and Why Are We Concerned About It?

Atrazine is an organic chemical used as an herbicide throughout the U.S. for control of weeds in agricultural crops. Environmental exposure occurs mainly from its application as an herbicide but may also occur from industrial manufacture, distribution releases, precipitation, field runoff, and drift. Atrazine is moderately volatile and soluble in water, and resistant to natural degradation in water. Because of atrazine's chemical properties and widespread use as an herbicide, concerns have been raised over the potential risks posed by exposure of aquatic organisms to it. For these reasons, EPA has developed the following water quality criteria:

Freshwater

Aquatic life should not be affected unacceptably if the:

One-hour average concentration of atrazine does not exceed 350 ug/l more than once every three years on the average (Acute Criterion); and

Four-day average concentration of atrazine does not exceed 12 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 atrazine does not exceed 760 ug/l more than once every three years on the average (Acute Criterion); and

Four-day average concentration of atrazine does not exceed 26 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.

How Has EPA Coordinated Development of Ecological Risk Assessments on Atrazine Between the Office of Water (OW) and the Office of Pesticide Programs (OPP)?

Concurrent with OW's release of the Draft Aquatic Life Criteria Document for Atrazine, OPP is releasing its Preliminary Ecological Fate and Effects Risk Assessment for Atrazine. Both offices shared their aquatic toxicity data bases for atrazine in the development of their risk assessment documents. OW and OPP are currently consulting on their respective ecological risk assessment methodologies. Although there are similarities in the approaches, differences remain. When the consultation is completed, there may be revisions to this assessment. While the consultation is underway, both offices are making their respective ecological risk assessments for atrazine available to the public and requesting comment on their respective methodologies. It would be helpful if comments regarding a methodology that are made to one office are also made available to the other. OW and OPP will share comments received on their respective risk assessment methodologies and will coordinate review of those comments.

Why Is EPA Notifying the Public About the Draft Atrazine Criteria Document?

Today, EPA is notifying the public about the availability of the draft aquatic life criteria document for atrazine to expand the public's involvement in the criteria development process. EPA notified the public of its intent to develop aquatic life criteria for atrazine in the Federal Register on October 29, 1999 (64 FR 58409). At that time EPA made available to the public all references identified by a recent literature review and solicited any additional pertinent data or scientific views that would be useful in developing the aquatic life criteria for atrazine. EPA is now making the draft aquatic life criteria document for atrazine available for public review.

As indicated in the December 10, 1998 FR notice, the Agency believes it is important to provide the public with an opportunity to submit scientific information on draft criteria. EPA is soliciting views from the public on issues of science pertaining to the information used to derive the draft criteria. EPA will review and consider significant scientific information submitted by the public that might not have otherwise been identified during development of these criteria.

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.

Dated: August 8, 2001.

Geoffrey H. Grubbs,

Director, Office of Science and Technology.