The legislature recognizes that prior to May 11, 1984, most groundwater regulatory programs were not based on numerical standards. The legislature intends, by the creation of this chapter, to minimize the concentration of polluting substances in groundwater through the use of numerical standards in all groundwater regulatory programs. The numerical standards, upon adoption, will become criteria for the protection of public health and welfare, to be achieved in groundwater regulatory programs concerning the substances for which standards are adopted. To this end, the legislature intends that:

      (a)    A drinking water standard or maximum contaminant level, by the federal environmental protection agency;

      (b)    A suggested no-adverse-response level, by the federal environmental protection agency; or

      (c)    For oncogenic substances, a concentration based on a risk level determination by the federal environmental protection agency or a concentration based on a probability of risk model determined by the national academy of sciences. See Wisconsin Statutes 160.01

Groundwater: means any of the waters of the state, as defined in…. See Wisconsin Statutes 160.01

Point of standards application: means the specific location, depth or distance from a facility, activity or practice at which the concentration of a substance in groundwater is measured for purposes of determining whether a preventive action limit or an enforcement standard has been attained or exceeded. See Wisconsin Statutes 160.01

Preventive action limit: means a numerical value expressing the concentration of a substance in groundwater which is adopted under…. See Wisconsin Statutes 160.01

Regulatory agency: means the department of agriculture, trade and consumer protection, the department of safety and professional services, the department of transportation, the department of natural resources and other state agencies which regulate activities, facilities or practices which are related to substances which have been detected in or have a reasonable probability of entering the groundwater resources of the state. See Wisconsin Statutes 160.01

State: when applied to states of the United States, includes the District of Columbia, the commonwealth of Puerto Rico and the several territories organized by Congress. See Wisconsin Statutes 990.01

Substance: means any solid, liquid, semisolid, dissolved solid or gaseous material, naturally occurring or man-made chemical, parameter for measurement of water quality or biological organism which, in its original form, or as a metabolite or a degradation or waste product, may decrease the quality of groundwater. See Wisconsin Statutes 160.01

   (1)   This chapter will establish an administrative process which will produce numerical standards, comprised of enforcement standards and preventive action limits, for substances in groundwater. As more specifically provided in this chapter, administrative procedures also provide for minimizing the concentration of substances in groundwater.

   (2)   The enforcement standards and preventive action limits will be adopted under the authority of this chapter, independent of any regulatory programs concerning the substances for which enforcement standards and preventive action limits are adopted.

   (3)   This chapter supplements the regulatory authority elsewhere in the statutes, whether the regulatory programs exist under current statutes on May 11, 1984, or are created after that date. Regulatory agencies will continue to exercise the powers and duties in those regulatory programs, consistent with the enforcement standards and preventive action limits for substances in groundwater under this chapter. This chapter provides guidelines and procedures for the exercise of regulatory authority which is established elsewhere in the statutes, and does not create independent regulatory authority.

   (4)   In order to comply with this chapter, a regulatory agency is not required to adopt a particular type of regulation; regulatory agencies are free to establish any type of regulation which assures that regulated facilities and activities will not cause the concentration of a substance in groundwater affected by the facilities or activities to exceed the enforcement standards and preventive action limits under this chapter at a point of standards application. A regulatory agency may adopt regulations which establish specific design and management criteria for regulated facilities and activities, if the regulations will ensure that the regulated facilities and activities will not cause the concentration of a substance in groundwater affected by the facilities or activities to exceed the enforcement standards and preventive action limits under this chapter at a point of standards application.

   (5)   The enforcement standards and preventive action limits adopted under this chapter provide adequate safeguards for public health and welfare. However, this chapter does not prevent regulatory agencies from adopting regulations under regulatory authority elsewhere in the statutes based on the best currently available technology for regulated activities and practices which ensure a greater degree of groundwater protection.

   (6)   Where necessary to comply with federal statutes or regulations, the department of natural resources may adopt rules in regulatory programs administered by it which are more stringent than the enforcement standards and preventive action limits adopted under this chapter.

   (7)   A regulatory agency may take any actions within the context of regulatory programs established in statutes outside of this chapter, if those actions are necessary to protect public health and welfare or prevent a significant damaging effect on groundwater or surface water quality for present or future consumptive or nonconsumptive uses, whether or not an enforcement standard and preventive action limit for a substance has been adopted under this chapter. Nothing in this chapter requires the department of health services or the department of natural resources to establish an enforcement standard for a substance if a federal number or state drinking water standard has not been adopted for the substance and if there is not sufficient scientific information to establish the standard.

   (8)   Preventive action limits shall serve as a means to inform regulatory agencies of potential groundwater contamination problems, to establish the level of groundwater contamination at which regulatory agencies are required to commence efforts to control the contamination and to provide a basis for design and management practice criteria in administrative rules. A preventive action limit is not intended to be an absolute standard at which remedial action is always required.