E8-24414. Guidance for Conducting Prospective Ground-Water Monitoring Studies, Response to Public Comments and Final Guidance; Notice of Availability

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice.

SUMMARY:

This document announces the availability of the final Guidance for Conducting Prospective Ground-Water (PGW) Monitoring Studies and EPA’s response to public comments on the development of the final PGW monitoring studies guidance. This PGW monitoring study, which is required on a case-by-case basis, is conducted in a controlled setting and provides EPA with data for evaluating the impact of legal pesticide use on ground-water quality. The PGW guidance document describes how to conduct a PGW monitoring study, milestones for consulting with EPA, and how to report results to EPA. Data generated from these field studies have proven valuable to EPA scientists and risk managers as they are specifically designed to relate pesticide use indicated on the label to measurements of the pesticide and its degradates in ground water used as a source of drinking water.

FOR FURTHER INFORMATION CONTACT:

Betsy Behl, Environmental Fate and Effects Division (7507P), Office of Pesticide Programs, Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number: [phone]; fax number: [phone]; e-mail address: [e-mail].

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

You may be potentially affected by this action if you are an agricultural producer, food manufacturer, or pesticide manufacturer. Potentially affected entities may include, but are not limited to:

• Crop production (NAICS code 111).
• Animal production (NAICS code 112).
• Food manufacturing (NAICS code 311).
• Pesticide manufacturing (NAICS code 32532).

This listing is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be affected by this action. Other types of entities not listed in this unit could also be affected. The North American Industrial Classification System (NAICS) codes have been provided to assist you and others in determining whether this action might apply to certain entities. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed under FOR FURTHER INFORMATION CONTACT.

B. How Can I Get Copies of this Document and Other Related Information?

1. Docket. EPA has established a docket for this action under docket identification (ID) number EPA-HQ-OPP-2007-1163. Publicly available docket materials are available either in the electronic docket at http://www.regulations.gov, or, if only available in hard copy, at the Office of Pesticide Programs (OPP) Regulatory Public Docket in Rm. S-4400, One Potomac Yard (South Bldg.), 2777 S. Crystal Dr., Arlington, VA. The hours of operation of this Docket Facility are from 8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The Docket Facility telephone number is [phone].

2. Electronic access. You may access this Federal Register document electronically through the EPA Internet under the “Federal Register” listings at http://www.epa.gov/​fedrgstr.

II. Background

A. What Action is the Agency Taking?

The PGW monitoring study, which is required on a case-by-case basis (40 CFR 158.1300), is conducted in a controlled setting and provides the Agency with data for evaluating the impact of legal pesticide use on ground-water quality. After assessing the overall environmental fate of a pesticide, the Agency may require the pesticide manufacturer (registrant) to conduct a PGW monitoring study, with input from EPA on key aspects of the PGW monitoring study design. The Agency’s assessment is based on a review of laboratory data on mobility and persistence of the compound, estimates of potential exposure, available monitoring and modeling information, and a consideration of the potential for risk from drinking-water exposure. Data generated from these field studies have proven valuable to EPA scientists and risk managers as they are specifically designed to relate pesticide use indicated on the label to measurements of the pesticide and its degradates in ground water used as a source of drinking water. The PGW guidance document describes how to conduct a PGW monitoring study, describes milestones for consulting with EPA, and describes how results should be reported to EPA. EPA uses the results of PGW monitoring studies to help answer questions such as:

1. Will the pesticide leach in portions of the pesticide use area that are similar to the field study area?

2. How do pesticide residues change over time?

3. What measures might be effective in mitigating the pesticide leaching?

Monitoring data generated in these PGW monitoring studies provide a time-series of concentrations that can be used in exposure and risk assessments as a reasonable surrogate for pesticide concentrations in drinking water drawn from shallow private wells in agricultural areas. PGW monitoring studies have been used to test alternative mitigation strategies for pesticides that have adversely affected ground-water quality to determine, for example, if a reduction in application rate or specific irrigation technology will reduce or eliminate the impact. Data from these PGW monitoring studies have also been used to develop the EPA regression screening model, Screening Concentration in Ground Water (SCI-GROW) (http://www.epa.gov/​oppefed1/​models/​water/​models4.htm#scigrow), which is used to estimate screening-level pesticide concentrations in ground water used as a source of drinking water. Currently, the results of these PGW monitoring studies are being used to evaluate models of subsurface pesticide transport, and as a basis for model scenarios for estimating pesticide concentrations in shallow-ground water.

The original draft guidance for PGW monitoring studies was developed primarily in the early 1990s and has been subjected to substantial public review and comment, including a public workshop sponsored by EPA in 1995 (Ref. 1), a Scientific Advisory Panel (SAP) review in 1998 (Ref. 2), and a request for final public comments in January 2008 (Ref. 3). From the January 2008 final request for comments, two public comments were received: California Department of Pesticide Regulation and Florida Department of Agriculture and Consumer Services (Ref. 4). Conference calls were held with these two commenters to discuss proposed revisions in response to their comments. The comments received during the workshop (Ref. 1) and SAP meeting (Ref. 2) provided valuable suggestions from both a technical and practical perspective and were used to revise the PGW monitoring studies guidance document and to address other issues identified in the Agency’s review of PGW monitoring studies conducted for the registration of over 50 pesticides. EPA incorporated comments solicited from industry, academia, and consultants into the revised PGW monitoring studies guidance document. The recommendations in the PGW monitoring studies guidance document also represent the Agency’s substantial experience, over the last decade, in developing and articulating effective procedures for collecting high-quality data on pesticide movement into ground water.

B. What is the Agency's Authority for Taking this Action?

This action is issued under the authority of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), section 3.

III. References

1. EPA. Prospective Ground-Water Monitoring Study 1995 Workshop Notes. Document Number: EPA-HQ-OPP-2007-1163-0009. Available on-line at: http://www.regulations.gov.

2. EPA. FIFRA Scientific Advisory Panel Meeting, October 14-15, 1998, Report. SAP Report No. 98-01. I—Review of Guidance Document for Small-Scale Prospective Ground-Water Monitoring Studies. November 19, 1998. Available on-line at: http://www.epa.gov/​scipoly/​sap/​meetings/​1998/​october/​final.pdf.

3. EPA. Guidance for Conducting Prospective Ground-Water Studies; Notice. Federal Register (73 FR 2910, January 16, 2008) (FRL-8347-5). Available on-line at: http://www.epa.gov/​fedrgstr.

4. EPA. Response to Public Comments Document on the Guidance for Conducting Prospective Ground-Water Monitoring Studies. Document Number: EPA-HQ-OPP-2007-1163-0005. Available on-line at: http://www.regulations.gov.

List of Subjects

• Environmental protection
• Ground-water monitoring studies
• Pesticides and pests

Dated: October 8, 2008.

Donald J. Brady,

Director, Environmental Fate and Effects Division, Office of Pesticide Programs.