Wisconsin Administrative Code
Department of Agriculture, Trade and Consumer Protection
ATCP 20-54 - Agricultural Resource Management
Chapter ATCP 31 - Groundwater protection program
Section ATCP 31.07 - Pesticide use; groundwater contamination exceeding enforcement standard or preventive action limit; site-specific response

Universal Citation: WI Admin Code § ATCP 31.07

Current through August 26, 2024

(1) SITE-SPECIFIC RESPONSE; GENERAL. If, upon investigation under s. ATCP 31.04(2), the department finds that the concentration of a pesticide substance in groundwater attains or exceeds an enforcement standard or preventive action limit, and that the concentration has resulted from or may be affected by a pesticide use, the department shall implement an appropriate site-specific response to regulate the pesticide use, pursuant to the applicable provisions of ss. 160.21(3), 160.23 and 160.25, Stats., and this section. A site-specific response may take any of the forms described under sub. (2). A site-specific response may be implemented to regulate a pesticide use, whether or not the pesticide use violates an existing statute or rule administered by the department. Except as otherwise provided under s. 160.23 or 160.25, Stats., the site-specific response shall be designed to minimize the concentration of the pesticide substance where technically and economically feasible and to restore and maintain compliance with the preventive action limit at the point of standards application, and at other downgradient points to which the pesticide substance may migrate. A site-specific response may be implemented pursuant to substance-specific rules adopted under s. ATCP 31.09.

(2) SITE-SPECIFIC RESPONSE; FORM OF REGULATORY ACTION.

(a) Special orders.

1. A site-specific response may include one or more special orders issued under s. 94.71(3) (c), Stats. The department may issue a special order to a respondent, whether or not the respondent has previously engaged in the use of the pesticide, if the department finds that the special order is necessary to achieve the objectives under sub. (1). The department may, by substance-specific rules under s. ATCP 31.09, prescribe the scope and contents of special orders, and the conditions under which special orders are to be issued. Special orders may be issued on a summary basis, according to criteria set forth under s. 94.71(3) (c), Stats., and any substance-specific rules adopted under s. ATCP 31.09. Summary special orders are subject to a right of hearing before the department upon request. Special orders required by rule may be signed by a department employee designated in the rule. All other special orders shall be signed by the secretary, or a person individually designated by the secretary.

2. A special order may include:

a. A prohibition against the use of a pesticide, subject to s. ATCP 31.08.

b. Limitations on the purposes for which a pesticide may be used, including limitations on the crops or target pests for which a pesticide may be used.

c. Limitations on the rate at which a pesticide is applied.

d. Limitations on the time or frequency of pesticide use.

e. Limitations on the method of pesticide use.

f. Requirements for the training or certification of pesticide applicators or other persons using a pesticide.

(b) Rules applicable to a specific locality. A site-specific response may include the adoption of rules whose geographic scope is limited to a specific locality if, in the department's judgment, the conditions in that locality justify the geographically limited rules. Within the designated locality, rules shall be general in their application, and may not be limited to a single pesticide user. Rules may be adopted on an emergency basis as necessary, pursuant to s. 227.24, Stats. Site-specific rules under this paragraph may supplement, or be incorporated into more general substance-specific rules under s. ATCP 31.09. Site-specific rules may include any of the provisions set forth under s. ATCP 31.09(2), as applicable.

(c) Denial, suspension or revocation of permits. If a permit is required by statute or rule for the use of a pesticide, a site-specific response may include the denial, suspension or revocation of pesticide use permits for the locality covered by the site-specific response. The department may, by substance-specific rules under s. ATCP 31.09, prescribe the terms and conditions under which permits are to be denied, suspended or revoked. If the denial, suspension or revocation of a pesticide use permit is required by rule under certain conditions, the order denying, suspending or revoking the permit may be signed by a department employee designated in the rule. All other orders denying, suspending or revoking permits shall be signed by the secretary, or by a person individually designated by the secretary. Where necessary in an emergency, permits may be summarily suspended, pursuant to s. 227.51, Stats. Circumstances constituting an emergency may be specified by rule. The denial, suspension or revocation of a permit is subject to a right of hearing before the department upon request.

Note: In addition to any of the site-specific regulatory responses identified under this paragraph, the department may take other actions in response to a finding of pesticide contamination which attains or exceeds an enforcement standard or preventive action limit. The department may, for example:

1. Review its rules governing pesticide use, pursuant to s. 160.19, Stats., and s. ATCP 31.09

2. Disseminate information concerning the groundwater contamination, and notify affected persons.

3. Notify state or local health authorities and county agricultural extension agents of the groundwater contamination.

4. Initiate or recommend further investigation or research concerning the groundwater contamination.

(3) SITE-SPECIFIC RESPONSE; MAXIMUM GEOGRAPHIC SCOPE. A site-specific response required under this section does not include a regulatory action which extends beyond the groundwater recharge zone of the aquifer from which the groundwater sample was collected at the point of standards application. If the pesticide substance has migrated, or may migrate through more than one aquifer, a site-specific response may extend, at a maximum, to the boundary of the outermost recharge zone providing recharge to an affected aquifer. If the natural boundary of a groundwater recharge zone is not readily definable, a site-specific response may extend, at a maximum, to the whole of every land parcel which, in the judgment of the department, may be wholly or partially located within the relevant groundwater recharge zone. All or a portion of any land parcel may be exempted from a site-specific response upon proof that the parcel or portion is located outside the groundwater recharge zone to which the site-specific response is applicable. Within the maximum geographic limits specified under this section, the department may determine the geographic scope of the site-specific response, based on the objective of restoring and maintaining compliance with the preventive action limit and minimizing the concentration of the pesticide substance in groundwater where technically and economically feasible, at the point of standards application and other downgradient points to which the pesticide substance may migrate. For purposes of administrative efficiency, the geographic scope of a site-specific response may be delineated according to a regular geometric pattern.

(4) SITE-SPECIFIC RESPONSES; FACTORS TO BE CONSIDERED.

(a) In the department's choice of a site-specific response, or in its adoption of substance-specific rules under s. ATCP 31.09 prescribing nondiscretionary site-specific responses, the department shall consider the general risks and benefits of the possible actions to the extent authorized by relevant law, and shall consider the following specific factors to the extent feasible:

1. The concentration of the pesticide substance in groundwater at the point of standards application, and any known changes in concentration.

2. The concentration of the pesticide substance at other points of standards application, if known, and any known changes in concentration.

3. The extent, age and reliability of groundwater sample data indicating the presence of the pesticide substance in groundwater.

4. The specific activities or practices from which the pesticide contamination originated, if known, and the locations at which the source activities or practices are conducted.

5. The previously demonstrated propensity, if any, for the pesticide substance to leach to groundwater as a result of normal use.

6. Environmental conditions which may reasonably affect the risk of groundwater contamination, including soil conditions, depth to groundwater, and subsurface geological conditions. Differences in local environmental conditions may not be used to justify a difference in site-specific responses between localities unless the differences in environmental conditions are reasonably known to affect the relative risk of groundwater contamination between localities.

7. Differences in local pesticide use practices which are reasonably known to affect the risk of groundwater contamination.

8. The environmental fate of the pesticide substance in soil and groundwater, to the extent known.

9. The direction and rate of groundwater movement within the affected groundwater recharge zone, if known.

10. The potential uses of the affected groundwater.

11. The extent and likelihood of human exposure to the pesticide substance in groundwater.

12. The alternative measures which are available to prevent or control groundwater contamination, the relative cost and effectiveness of each alternative, and the risks associated with each alternative including the risk of adverse environmental effects.

(b) Except as otherwise required by law, the department is not required to make a written record of its consideration under this subsection. This subsection may not be construed to limit the department's responsibility under s. 160.19 or 160.25, Stats.

(5) SITE-SPECIFIC RESPONSE; PROHIBITIONS AGAINST PESTICIDE USE. If a site-specific response under this section prohibits a pesticide use in the locality covered by the site-specific response, the prohibition shall comply with the applicable provisions of s. ATCP 31.08.

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