Chapter 160

160.21(4)(a) (a) Risk-benefit considerations including, but not limited to:

160.21(4)(a)1. 1. Uses and substances alternative to the present use of the particular substance.

160.21(4)(a)2. 2. Risks and benefits of the alternative uses or substances.

160.21(4)(a)3. 3. Reliability and comprehensiveness of the information available for assessing such risks and benefits.

160.21(4)(b) (b) Hydrogeological considerations including, but not limited to:

160.21(4)(b)1. 1. The depth to groundwater.

160.21(4)(b)2. 2. The soil characteristics.

160.21(4)(b)3. 3. Groundwater gradients and flow direction.

160.21(4)(c) (c) Management and practice considerations including, but not limited to:

160.21(4)(c)1. 1. Reliability of sampling data.

160.21(4)(c)2. 2. The geographic extent of the substance if detected in groundwater and the size of the population affected.

160.21(4)(c)3. 3. The efficacy of label restrictions and other practical measures to minimize the concentration of the substance in the groundwater.

160.21(4)(c)4. 4. The existing effects and potential risks of the substance on potable water supplies.

160.21(4)(c)5. 5. The risks considered when the standard at issue was established or adopted.

160.21(4)(c)6. 6. The known depth of the substance in the groundwater.

160.21(4)(c)7. 7. Data and information provided by the manufacturer on the environmental fate of the substance.

160.21 History History: 1983 a. 410; 1995 a. 227.

160.21 Cross-reference Cross-reference: See also ch. NR 140, Wis. adm. code.

160.23 160.23 Implementation of responses for specific sites; preventive action limits.

160.23(1) (1) If the concentration of a substance in groundwater attains or exceeds a preventive action limit at a point of standards application, the regulatory agency shall assess the cause of the increased concentration, taking into account background concentrations, if known, and other known or suspected contributors in the area and shall evaluate the significance of the concentration of the substance and shall implement responses for a specific site designed to:

160.23(1)(a) (a) Minimize the concentration of the substance in the groundwater at the point of standards application where technically and economically feasible;

160.23(1)(b) (b) Regain and maintain compliance with the preventive action limit, unless, in the determination of the regulatory agency, the preventive action limit is either not technically or economically feasible, in which case, it shall achieve compliance with the lowest possible concentration which is technically and economically feasible; and

160.23(1)(c) (c) Ensure that the enforcement standard is not attained or exceeded at the point of standards application.

160.23(2) (2) A regulatory agency shall take responses with respect to a specific site in accordance with rules promulgated under s. 160.21.

160.23(4) (4) The regulatory agency may not impose a prohibition on the substance or the activity or practice which uses or produces the substance unless the regulatory agency:

160.23(4)(a) (a) Bases its decision upon reliable test data;

160.23(4)(b) (b) Determines, to a reasonable certainty, by the greater weight of the credible evidence, that no other remedial action would prevent the violation of the enforcement standard at the point of standards application;

160.23(4)(c) (c) Establishes the basis for the boundary and duration of the prohibition; and

160.23(4)(d) (d) Ensures that any prohibition imposed shall be reasonably related in time and scope to maintaining compliance with the enforcement standard at the point of standards application.

160.23(6) (6) 

160.23(6)(a) (a) A regulatory agency shall consider the existence of the background concentration of a naturally occurring substance in evaluating response options to the noncompliance with a preventive action limit for that substance. Before a regulatory agency may order a remedial action under sub. (2) or issue a prohibition for a specific site where the background concentration of a substance is determined to be equal to or greater than the preventive action limit, the regulatory agency shall determine that the proposed remedial action will result in the protection of or substantial improvement in groundwater quality notwithstanding the background concentrations of naturally occurring substances.

160.23(6)(b) (b) Paragraph (a) does not apply to a substance which may be carcinogenic, teratogenic or mutagenic in humans.

160.23(7) (7) If the concentration of a substance in groundwater attains or exceeds a preventive action limit at a point of standards application and if a waste facility subject to the waste management fund incurs costs for repairing environmental damage which arises from these occurrences which are not anticipated in the plan of operation and which poses a substantial hazard to public health or welfare, those costs may be paid as provided under s. 289.68.

160.23(8) (8) An action under this section with respect to a specific site does not constitute a major state action under s. 1.11 (2).

160.23 History History: 1983 a. 410; 1989 a. 56; 1995 a. 227.

160.25 160.25 Implementation of responses for specific sites; enforcement standards.

160.25(1) (1) 

160.25(1)(a) (a) If an activity or practice is not subject to regulation under chs. 283 or 289 to 292 and if the concentration of a substance in groundwater attains or exceeds an enforcement standard at a point of standards application, the regulatory agency shall take the following responses unless it can be shown to the regulatory agency that, to a reasonable certainty, by the greater weight of the credible evidence, an alternative response will achieve compliance with the enforcement standard at the point of standards application:

160.25(1)(a)1. 1. Prohibit the activity or practice which uses or produces the substance; and

160.25(1)(a)2. 2. Implement remedial actions with respect to the specific site in accordance with rules promulgated under s. 160.21.

160.25(1)(b) (b) A regulatory agency shall impose a remedial action for a specific site which is reasonably related in time and scope to the substance, activity or practice which caused the enforcement standard to be attained or exceeded at the point of standards application.

160.25(2) (2) If a facility is subject to regulation under chs. 283 or 289 to 292 and if the concentration of a substance in groundwater attains or exceeds an enforcement standard at a point of standards application, the department shall require remedial actions for a specific site in accordance with rules promulgated under s. 160.21 as are necessary to achieve compliance with the enforcement standard at the point of standards application.

160.25(3) (3) If nitrates or any substance of aesthetic concern only attains or exceeds an enforcement standard, the regulatory agency is not required to impose a prohibition or close a facility if it determines that:

160.25(3)(a) (a) The enforcement standard was attained or exceeded, in whole or in part, because of high background concentrations of the substance; and

160.25(3)(b) (b) The additional concentration does not represent a public welfare concern.

160.25(4) (4) If compliance with the enforcement standard is achieved at the point of standards application, s. 160.23 applies.

160.25(5) (5) 

160.25(5)(a) (a) A regulatory agency shall consider the existence of background concentrations of naturally occurring substances in evaluating response options to the noncompliance with an enforcement standard for that substance. A regulatory agency may not order remedial action under sub. (1) or (2) at a site where the background concentration of a substance is determined to be equal to or greater than the preventive action limit, unless the regulatory agency determines that the proposed remedial action will result in the protection of or substantial improvement in groundwater quality notwithstanding the background concentrations of naturally occurring substances.

160.25(5)(b) (b) Paragraph (a) does not apply to a substance which is carcinogenic, teratogenic or mutagenic in humans.

160.25(6) (6) If the concentration of a substance in groundwater attains or exceeds an enforcement standard at a point of standards application and if a waste facility subject to the waste management fund incurs costs for repairing environmental damage which arises from those occurrences which are not anticipated in the plan of operation and which poses a substantial hazard to public health or welfare, those costs may be paid as provided under s. 289.68.

160.25(7) (7) An action under this section with respect to a specific site does not constitute a major state action under s. 1.11 (2).

160.25 History History: 1983 a. 410; 1995 a. 227.

160.255 160.255 Exceptions for private on-site wastewater treatment systems.

160.255(1) (1) In this section, “private on-site wastewater treatment system” has the meaning given in s. 145.01 (12).

160.255(2) (2) Notwithstanding s. 160.19 (1), (2) and (4) (b), a regulatory agency is not required to promulgate or amend rules that define design or management criteria for private on-site wastewater treatment systems to minimize the amount of nitrate in groundwater or to maintain compliance with the preventive action limit for nitrate.

160.255(3) (3) Notwithstanding s. 160.19 (3), a regulatory agency may promulgate rules that define design or management criteria for private on-site wastewater treatment systems that permit the enforcement standard for nitrate to be attained or exceeded at the point of standards application.

160.255(4) (4) Notwithstanding s. 160.21, a regulatory agency is not required to promulgate rules that set forth responses that the agency may take, or require to be taken, when the preventive action limit or enforcement standard for nitrate is attained or exceeded at the point of standards application if the source of the nitrate is a private on-site wastewater treatment system.

160.255(5) (5) Notwithstanding ss. 160.23 and 160.25, a regulatory agency is not required to take any responses for a specific site at which the preventive action limit or enforcement standard for nitrate is attained or exceeded at the point of standards application if the source of the nitrate is a private on-site wastewater treatment system.

160.255 History History: 1995 a. 27; 2011 a. 146.

160.257 160.257 Exceptions for aquifer storage and recovery systems.

160.257(1) (1) In this section:

160.257(1)(a) (a) “Aquifer storage and recovery system” means all of the aquifer storage and recovery wells and related appurtenances that are part of a municipal water system.

160.257(1)(b) (b) “Aquifer storage and recovery well” means a well through which treated drinking water is placed underground for the purpose of storing and later recovering the water through the same well for use as drinking water.

160.257(1)(c) (c) “Municipal water system” means a community water system, as defined in s. 281.62 (1) (a), that is owned by a city, village, town, county, town sanitary district, utility district, public inland lake protection and rehabilitation district, or municipal water district, or by a privately owned water utility serving any of the foregoing.

160.257(1)(d) (d) “Specified substance” means one of the following:

160.257(1)(d)1. 1. Chloroform.

160.257(1)(d)2. 2. Bromodichloromethane.

160.257(1)(d)3. 3. Dibromochloromethane.

160.257(1)(d)4. 4. Bromoform.

160.257(1)(e) (e) “Treated drinking water” means potable water that has been treated so that it complies with the primary drinking water standards promulgated under ss. 280.11 and 281.17 (8).

160.257(2) (2) Notwithstanding s. 160.19 (1) and (2), the department is not required to promulgate or amend rules that define design or management criteria for aquifer storage and recovery systems to minimize the amount of a specified substance in groundwater or to maintain compliance with the preventive action limit for a specified substance, however, the department shall promulgate rules that define design or management criteria for aquifer storage and recovery systems to maintain compliance with drinking water standards promulgated under ss. 280.11 and 281.17 (8).

160.257(3) (3) Notwithstanding s. 160.21 (2), the point of standards application for an aquifer storage and recovery well with respect to a specified substance is 1,200 feet from the aquifer storage and recovery well and at any other well that is within 1,200 feet from the aquifer storage and recovery well.

160.257 History History: 2001 a. 109.

160.26 160.26 Enforcement. Regulatory agencies shall enforce the provisions of this chapter in accordance with enforcement procedures and subject to the penalties established by statute for activities and practices regulated by the regulatory agency.

160.26 History History: 1983 a. 410.

160.27 160.27 Substances in groundwater; monitoring.

160.27(1) (1) The department, with the advice and cooperation of other agencies and the groundwater coordinating council, shall develop and operate a system for monitoring and sampling groundwater to determine whether substances identified under s. 160.05 (1) are in the groundwater or whether preventive action limits or enforcement standards are attained or exceeded at points of standards application.

160.27(2) (2) At a minimum, the monitoring system shall include the following components:

160.27(2)(a) (a) Problem assessment monitoring to detect substances in the groundwater, including substances identified under s. 160.05 (1), and to assess the significance of the concentrations of the detected substances;

160.27(2)(b) (b) Regulatory monitoring to determine if preventive action limits or enforcement standards are attained or exceeded and to obtain information necessary for the implementation of responses with respect to specific sites under ss. 160.21, 160.23 and 160.25;

160.27(2)(c) (c) At-risk monitoring to define and sample at-risk potable wells in areas where substances identified under s. 160.05 (1) are detected in the groundwater or where preventive action limits or enforcement standards are attained or exceeded;

160.27(2)(d) (d) Management practice monitoring for establishing the management practices necessary to meet the requirements of ss. 160.19 and 160.21. The regulatory agency responsible for a particular management practice has primary responsibility for monitoring that practice and the department shall ensure that the monitoring specifications meet the needs of the regulatory agency; and

160.27(2)(e) (e) A monitoring plan for collecting, managing and coordinating the monitoring components specified under pars. (a) to (d) with the monitoring information from other regulatory agencies.

160.27(3) (3) The department shall notify the regulatory agency and the department of health services when monitoring data indicate that:

160.27(3)(a) (a) A substance is detected in groundwater;

160.27(3)(b) (b) The concentration of a substance, by a reasonable degree of scientific certainty, is determined to be changing; or

160.27(3)(c) (c) The concentration of a substance attains or exceeds a preventive action limit or an enforcement standard at a point of standards application.

160.27(4) (4) The department shall coordinate the collection of groundwater monitoring data and the exchange of these data among agencies for the purpose of this chapter and shall ensure, with the advice and cooperation of other agencies, the technical accuracy of the monitoring data used in the administration of this chapter.

160.27(5) (5) Notwithstanding subs. (1) to (3), a regulatory agency may develop and operate a system for monitoring and sampling groundwater to determine compliance with this chapter. This section does not affect the authority of the department to require groundwater monitoring by owners or operators of solid or hazardous waste facilities, water systems or wastewater systems under chs. 280 to 285 or 289 to 299.