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Pursuant to a congressional request, GAO examined the Environmental Protection Agency's (EPA) efforts to: (1) assess pesticides' leaching potential in groundwater; (2) regulate those pesticides that could leach into groundwater; and (3) consider human exposure to pesticides in groundwater when setting and reviewing limits for pesticide residues in food.

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Recommendations for Executive Action

Agency Affected Recommendation Status
Environmental Protection Agency 1. To help prevent groundwater contamination, the Administrator, EPA, should promptly require a groundwater advisory for all pesticides known to leach into groundwater from normal agricultural use to appear on labels under a prominent heading such as Groundwater Advisory, in order to alert the user to the problem.
Closed - Not Implemented
Groundwater advisories were previously added to about 12 pesticides. EPA recently contacted the registrants of four pesticides identified in the GAO report to discuss voluntarily adding groundwater advisories to those pesticides. EPA is evaluating general criteria for groundwater advisories to determine whether there are additional cases in which label statements can alert users to potential risks. Since EPA has not completed action and the recommendation is over 3 years old, GAO is deleting it from the open recommendations list.
Environmental Protection Agency 2. To help prevent groundwater contamination, the Administrator, EPA, should establish a percentage of the health advisory level as a criterion for prohibiting the use of a pesticide in any geographic area where the groundwater contamination from the normal agricultural use of that pesticide has reached that percentage.
Closed - Implemented
EPA does not support this recommendation but prefers to have the states identify the geographic areas of concern and devise specific, appropriate management measures.
Environmental Protection Agency 3. To help prevent groundwater contamination, the Administrator, EPA, should establish a pesticide's potential to leach or actual detection in groundwater as a criterion for requiring well setbacks.
Closed - Implemented
EPA believes that well setbacks need to be applied on a chemical-specific and site-specific basis, either through reregistration decisions or state management plans.
Environmental Protection Agency 4. To minimize further groundwater contamination, the Administrator, EPA, should, after acceptable data are obtained and reviewed, conduct a complete leaching assessment of pesticides with a potential to leach and provide specific information to applicators concerning the conditions that promote the leaching of those individual pesticides, including the soil characteristics and climatic conditions.
Closed - Implemented
Some information can be conveyed on labels, and some information needs to be delivered through training. EPA and state extension services have prepared a training module for applicator certification. For the most serious threats, detailed state-level management programs will be needed. EPA has taken no further action and, therefore, the recommendation is being closed.
Environmental Protection Agency 5. So that EPA can act preventively before contamination reaches potentially hazardous levels, the Administrator, EPA, should establish a criterion for initiating special reviews on the basis of pesticides' potential to contaminate groundwater.
Closed - Not Implemented
EPA disagrees with the recommendation and prefers to address cases with groundwater contamination as the primary concern through state management plans.
Environmental Protection Agency 6. During special reviews, EPA should consider risks to water resources resulting from groundwater contamination, and even if levels of a pesticide found in groundwater are well below the level currently considered to present a health risk, EPA should consider the pesticide's presence in groundwater to be a risk.
Closed - Not Implemented
EPA prefers to respond to concentrations posing significant risks rather than to respond to all detections through special reviews.
Environmental Protection Agency 7. In order to ensure that total dietary exposure does not exceed safe levels, the Administrator, EPA, should, in setting and reviewing tolerances for pesticides found in groundwater or identified through studies as likely to leach into groundwater, assess and take into account potential human exposure from contaminated groundwater.
Closed - Not Implemented
EPA agrees that the tolerance system should consider exposure through food and water when both exposures are likely. EPA disagrees with the first method GAO recommended and believes that the second method recommended is in line with current agency practice.
Environmental Protection Agency 8. To facilitate EPA ability to assess the leaching potential of known groundwater contaminants, the Administrator, EPA, should review the relevant studies submitted by registrants for List-A pesticides, which include the 13 groundwater contaminants in this report, on a priority basis.
Closed - Implemented
In the future, EPA will be reviewing key studies as they are submitted. List A pesticides are a priority for review.

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