Chapter 160

160.21(2)(a)1. 1. The regulatory agency shall establish a point of standards application at any location where groundwater is monitored for the purpose of determining whether the preventive action limit for a substance has been attained or exceeded.

160.21(2)(a)2. 2. The regulatory agency shall establish a point of standards application at the following locations for the purpose of determining compliance with enforcement standards, or determining whether design and management practice criteria established under s. 160.19 (2) (a) successfully maintain compliance with preventive action limits:

160.21(2)(a)2.a. a. Any point of present groundwater use;

160.21(2)(a)2.b. b. Any point beyond the property boundaries of the premises where the facility, activity or practice is located or undertaken; and

160.21(2)(a)2.c. c. Any point beyond the design management zone but within the property boundaries of the premises where the facility, activity or practice is located or undertaken.

160.21(2)(b) (b) If monitoring is not required under existing rules for a facility, activity or practice:

160.21(2)(b)1. 1. The regulatory agency shall establish a point of standards application at the following locations for the purposes of determining whether the preventive action limit or the enforcement standard is attained or exceeded:

160.21(2)(b)1.a. a. Any point of present groundwater use, except the regulatory agency may exempt points of nonpotable groundwater uses if the regulatory agency determines that the substance will not affect the nonpotable groundwater use; and

160.21(2)(b)1.b. b. Any point beyond the property boundary of the property where the facility, activity or practice is located or undertaken.

160.21(2)(b)2. 2. The regulatory agency may establish by rule additional points of standards application which the regulatory agency determines are necessary to protect future groundwater uses and the public interest in the waters of the state.

160.21(2)(c) (c) If facilities are subject to regulation under chs. 283 or 289 to 292, the department shall develop by rule and utilize points of standards application for purposes of facility design, the review of facility performance and enforcement as follows:

160.21(2)(c)1. 1. Rules promulgated by the department under s. 289.05 (1) relating to facility design shall establish design criteria which ensure compliance with s. 160.19 (2) at any point of present groundwater use, at property boundaries and at any point beyond a 3-dimensional design management zone within property boundaries established under general criteria specified by rule and applied to individual facilities.

160.21(2)(c)2. 2. The department shall consider any point at which groundwater is monitored and at which a preventive action limit is exceeded a point of standards application for purposes of facility performance review, including investigations and evaluation of specific sites. If the point is within the design management zone, the department shall evaluate the location of the point, specific characteristics of the site, the nature of the substance involved and the likelihood of substance migration in assessing the need for response activities.

160.21(2)(c)3. 3. The department shall establish the point of standards application for enforcement standards at any point of present groundwater use, at property boundaries and at any point beyond a 3-dimensional design management zone within property boundaries established under general criteria specified by rule and applied to individual facilities.

160.21(2)(d) (d) The department shall establish criteria for design management zones by rule for the facilities specified under par. (c). The rule shall take into account different types of facility designs. The design management zone which is applied to a facility utilizing the criteria in the rule may be adjusted based on the following factors:

160.21(2)(d)1. 1. Soil type, depth and permeability;

160.21(2)(d)2. 2. Type, depth and permeability of bedrock;

160.21(2)(d)3. 3. Volume and characteristics of the waste involved;

160.21(2)(d)4. 4. Mobility of contaminants;

160.21(2)(d)5. 5. Distance to property boundaries and surface waters;

160.21(2)(d)6. 6. Present and anticipated future uses of land and groundwater;

160.21(2)(d)7. 7. Expected useful life of the facility;

160.21(2)(d)8. 8. Depth, direction and velocity of groundwater and other hydrogeologic factors; or

160.21(2)(d)9. 9. Likely methods for abatement if an enforcement standard is exceeded.

160.21(2)(e) (e) The department and each regulatory agency shall enter into a memorandum of understanding setting forth the criteria for acceptable monitoring wells and sample handling for the point of standards application.

160.21(3) (3) Responses may include remedial actions, revisions of rules or criteria on facility design, location and management practices, prohibition of an activity or practice or closure of a facility. Remedial actions for a specific site may include, but are not limited to, investigations, relocation, prohibition of activities or practices which use or produce the substance, closure of a facility, revisions of operational procedures, monitoring or, if only a preventive action limit is attained or exceeded, no remedial action. Responses may vary depending on the type and age of the facility, the hydrogeological conditions of the site and the cost effectiveness of alternative responses that will achieve the same objectives under the conditions of the site. Responses shall take into account the background water quality at the site, the uses of the aquifer, the degree of risk, the validity of the data and the probability of whether, if a preventive action limit is exceeded, the enforcement standard will be exceeded at the point of standards application. In requiring a remedial action for a specific site, the regulatory agency shall use the authority and existing protections, including, but not limited to, due process provisions in other applicable statutes.

160.21(4) (4) In setting forth the range of responses and providing for implementation of appropriate responses under the rules promulgated under subs. (1) and (3), the regulatory agency shall consider, where applicable, the following:

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.