Chapter NR 140

NR 140.16(2) (2) The laboratory shall select the analytical methodology which:

NR 140.16(2)(a) (a) Is specified in rules or approved by the regulatory agency, and

NR 140.16(2)(b) (b) Is appropriate for the concentration of the sample, and

NR 140.16(2)(c) (c) Is one of the following:

NR 140.16(2)(c)1. 1. Has a limit of detection and limit of quantitation below the preventive action limit, or

NR 140.16(2)(c)2. 2. Produces the lowest available limit of detection and limit of quantitation if the limit of detection and limit of quantitation are above the preventive action limit.

NR 140.16(3) (3) If the owner or operator of a facility, practice or activity believes that a sample result does not represent groundwater quality in the vicinity of the facility, practice or activity, the owner or operator shall resample the appropriate well or wells to obtain a representative sample at the earliest possible time. All sample results shall be submitted to the department and the appropriate regulatory agency with an explanation of why the owner or operator believes that all or some of the results are invalid.

NR 140.16(4) (4) The department may reject groundwater quality data that does not meet the requirements of the approved or designated analytical methods.

NR 140.16(5) (5) The owner or operator of the facility, practice or activity shall report the limit of detection and the limit of quantitation with the sample results. If a substance is detected below the limit of quantitation, the owner or operator shall report the detected value with the appropriate qualifier to the regulatory agency.

NR 140.16 History History: Cr. Register, September, 1985, No. 357, eff. 10-1-85; am. (1), Register, September, 1990, No. 417, eff. 10-1-90; am. (1), r. and recr. (2), Register, March, 1994, No. 459, eff. 4-1-94; (5) renum. from NR 140.14 (3) (c), cr. (4), Register, August, 1995, No. 476, eff. 9-1-95; r. and recr. (1), Register, December, 1998, No. 516, eff. 1-1-99; CR 22-061: am. (1) (d) Register July 2023 No. 811, eff. 8-1-23.

subch. III of ch. NR 140 Subchapter III — Evaluation and Response Procedures

NR 140.20 NR 140.20 Indicator parameter groundwater standards.

NR 140.20(1) (1) Establishing background water quality. Background water quality at a facility, practice or activity at which monitoring is required shall be established by sampling one or more monitoring points at locations and depths sufficient to yield groundwater samples that are representative of background water quality at or near the facility, practice or activity. Background water quality shall be determined for indicator parameters specified by the department. Background water quality for indicator parameters shall be established by averaging a minimum of 8 sample results from each well. The department may exclude any sample result which is nonrepresentative of background water quality. In making the calculations required in this section, the department may use as many representative sample points as are available.

NR 140.20(2) (2) Establishing preventive action limits for indicator parameters. For each indicator parameter, except total coliform bacteria, for which groundwater monitoring is required by the department, the preventive action limit shall be established based upon a change of water quality with respect to background water quality according to the methodology specified in any of the following:

NR 140.20(2)(a) (a) For field pH, the preventive action limit shall be one pH unit above or below the pH of the background water quality.

NR 140.20(2)(b) (b) For field temperature, the preventive action limit shall be 3 standard deviations or 10ºF (5.6ºC), whichever is greater, above or below the temperature of the background water quality.

NR 140.20(2)(c) (c) For all other indicator parameters, the preventive action limit shall be the background water quality for that parameter plus 3 standard deviations or the background water quality plus the increase of that parameter listed in Table 3, whichever is greater.

NR 140.20 Note Note: The standard deviation for a group of samples is equal to the square root of: the value of the sum of the squares of the difference between each sample in the sample group and the mean for that sample group divided by the number of samples in the sample group where the sample group has 30 or more samples and by one less than the number of samples in the sample group where the sample group has less than 30 samples.

NR 140.20(3) (3) Total coliform bacteria indicator parameter. The preventive action limit for total coliform bacteria is 0. If the source of total coliform bacteria is determined to be from a regulated facility, practice, or activity, response actions under s. NR 140.24 may be required.

Table 3
Methodology for Establishing Preventive Action Limit for Indicator Parameters

NR 140.20 History History: Cr. Register, September, 1985, No. 357, eff. 10-1-85; am. table 3, Register, October, 1990, No. 418, eff. 11-1-90; am. Table 3, Register, December, 1998, No. 516, eff. 1-1-99; CR 09-102: am. Table 3 Register December 2010 No. 660, eff. 1-1-11; CR 22-061: am. (2) (intro.), cr. (3), am. Table 3 Register July 2023 No. 811, eff. 8-1-23.

NR 140.22 NR 140.22 Point of standards application for design and compliance.

NR 140.22(1) (1) Design. Except as specified in sub. (1m), facilities, practices or activities regulated by the department, including remedial actions, shall be designed to minimize the level of substances in groundwater and to comply with the preventive action limits to the extent technically and economically feasible at all the following locations:

NR 140.22(1)(a) (a) Any point of present groundwater use.

NR 140.22(1)(b) (b) Any point beyond the boundary of the property on which the facility, practice or activity is located.

NR 140.22(1)(c) (c) Any point within the property boundaries beyond the 3-dimensional design management zone if one is established by the department at each facility, practice or activity under sub. (3).

NR 140.22(1)(d) (d) Every point at which groundwater is monitored to determine if a preventive action limit or enforcement standard has been attained or exceeded for sites identified under s. NR 140.22 (2) (c).

NR 140.22(1m) (1m) Design of asr systems; specified substances. The point of standards application to determine if the design of an aquifer storage recovery system, regulated under ch. 280 or 281, Stats., complies with the preventive action limits for a specified substance is 1,200 feet from an aquifer storage and recovery well and at any other well that is not part of the ASR system and that is within 1,200 feet of an aquifer storage recovery well.

NR 140.22(2) (2) Compliance.

NR 140.22(2)(a) (a) Except as specified in par. (d), the point of standards application to determine if a preventive action limit has been attained or exceeded is any point at which groundwater is monitored.

NR 140.22(2)(b) (b) Except as specified in par. (d), the point of standards application to determine whether an enforcement standard has been attained or exceeded shall be the following locations:

NR 140.22(2)(b)1. 1. Any point of present groundwater use;

NR 140.22(2)(b)2. 2. Any point beyond the boundary of the property on which the facility, practice or activity is located;

NR 140.22(2)(b)3. 3. Any point within the property boundaries beyond the 3 dimensional design management zone if one is established by the department at each facility, practice or activity under sub. (3).

NR 140.22 Note Note: The boundary beyond which the enforcement standards apply is the closer of the property boundary or the design management zone boundary to the waste boundary for the facility, practice or activity.

NR 140.22(2)(c) (c) For discharges, releases, sites or facilities regulated under s. 292.11, 291.29 or 291.37, Stats., or s. NR 600.07, for which a design management zone has not been established in sub. (3), Table 4, the point of standards application shall be every point at which groundwater is monitored to determine if a preventive action limit or enforcement standard has been attained or exceeded.

NR 140.22 Note Note: Section NR 600.07 no longer exists.

NR 140.22(2)(d) (d) The point of standards application to determine if a preventive action limit or enforcement standard for a specified substance has been attained or exceeded at an aquifer storage recovery well, regulated under ch. 280 or 281, Stats., is 1,200 feet from the aquifer storage and recovery well and at any other well that is not part of the ASR system and that is within 1,200 feet of the aquifer storage recovery well.

NR 140.22(3) (3) Design management zone.

NR 140.22(3)(a) (a) The design management zone for facilities, practices or activities subject to regulation by the department shall be an area enclosed by vertical boundaries which extend from the land surface downward through all saturated geological formations. The design management zone shall extend horizontally beyond the waste boundary or ASR displacement zone to the distance indicated in Table 4 for the specific type of facility, practice or activity. The waste boundary shall be the outermost limit at which waste from a facility, practice or activity has been stored, applied or disposed of, or permitted or approved for storage, application or disposal. For hazardous waste facilities regulated under ch. 291, Stats., the waste boundary shall include the horizontal space taken up by any liner, dike or other barrier to contain waste.

NR 140.22(3)(b) (b) In issuing or reissuing a permit, license or approval, the department may consider an expansion or reduction of the design management zone at a regulated or proposed facility, practice or activity by a horizontal distance not to exceed 50% of the distance listed in Table 4.

NR 140.22(3)(c) (c) The department shall consider the following factors in determining whether to expand or reduce the design management zone:

NR 140.22(3)(c)1. 1. Nature, thickness and permeability of unconsolidated materials, including topography;

NR 140.22(3)(c)2. 2. Nature and permeability of bedrock;

NR 140.22(3)(c)3. 3. Groundwater depth, flow direction and velocity;

NR 140.22(3)(c)4. 4. Waste volume, waste type and characteristics, including waste loading;

NR 140.22(3)(c)5. 5. Contaminant mobility;

NR 140.22(3)(c)6. 6. Distances to property boundary and surface waters;

NR 140.22(3)(c)7. 7. Engineering design of the facility, practice or activity;

NR 140.22(3)(c)8. 8. Life span of the facility, practice or activity;

NR 140.22(3)(c)9. 9. Present and anticipated uses of land and groundwater; and

NR 140.22(3)(c)10. 10. Potential abatement options if an enforcement standard is exceeded.

NR 140.22(3)(d) (d) The design management zone may not be expanded or reduced unless it has been demonstrated to the satisfaction of the department that the preventive action limits and enforcement standards will be met at the adjusted design management zone. The design management zone may not be expanded unless it has been demonstrated to the satisfaction of the department that the preventive action limits and enforcement standards cannot be met at the design management zone specified in Table 4.

Table 4

NR 140.22 History History: Cr. Register, September, 1985, No. 357, eff. 10-1-85; am. (1) (b), Register, October, 1988, No. 394, eff. 11-1-88; am. (4) and table 4, Register, January, 1992, No. 433, eff. 2-1-92; am. (1), cr. (1) (d), renum. (2) to (5) to be (2) (a), (b), (c) and (3) and am. (2) (b) 3., Register, March, 1994, No. 459, eff. 4-1-94; CR 02-134: am. (1) (intro.), (2) (a), (b) (intro.), (3) (a) and Table 4, cr. (1m) and (2) (d) Register June 2003 No. 570, eff. 7-1-03; correction in Table 4 made under s. 13.93 (2m) (b) 7., Stats., Register November 2006 No. 611.

NR 140.24 NR 140.24 Responses when a preventive action limit is attained or exceeded.

NR 140.24(1) (1) Notification and assessment. If the concentration of a substance, including indicator parameters, in groundwater attains or exceeds a preventive action limit at a point of standards application as described in s. NR 140.22 (2):

NR 140.24(1)(a) (a) The owner or operator of the facility, practice or activity shall notify the department in writing when monitoring data is submitted that a preventive action limit has been attained or exceeded in accordance with any deadlines in applicable statutes, rules, permits or plan approvals. Where no deadlines are imposed, the owner or operator shall notify the department as soon as practical after the results are received. When the results of any private well sampling attain or exceed a preventive action limit, the owner or operator of the facility, practice or activity shall notify the department within 10 days after the results are received. The notification shall provide a preliminary analysis of the cause and significance of the concentration.

NR 140.24 Note Note: Section 292.11 (2) (a), Stats., requires that the department be notified immediately of hazardous substance discharges.

NR 140.24 Note Note: See s. NR 140.27.

NR 140.24(1)(b) (b) Upon receipt of the notice under par. (a), the department shall evaluate the information and, if further information is required to make the assessment under par. (c), direct the owner or operator to prepare and submit a report by a specified deadline. The report shall assess the cause and significance of the increased concentration based on a consideration of the factors identified in par. (c) and shall propose a response to meet the objectives of sub. (2).

NR 140.24(1)(c) (c) The department shall assess the cause and significance of the concentration of the substance in determining the appropriate response to meet the objectives of sub. (2). In addition to all other relevant information, the department shall consider the information submitted under par. (b) and the following factors where applicable:

NR 140.24(1)(c)1. 1. Background water quality.

NR 140.24(1)(c)1.a. a. The department shall compare background water quality data and monitoring data from wells downgradient of the facility, practice or activity to determine if downgradient water quality is adversely affected. If the background water quality at a facility, practice or activity is not known or is inadequately defined, the department may require additional sampling of existing wells, or installation and sampling of additional wells, or both.

NR 140.24(1)(c)1.b. b. Except for substances which are carcinogenic, teratogenic or mutagenic in humans, before requiring a response at a site where the background concentration of a substance is determined to be equal to or greater than the preventive action limit, the department shall determine that the proposed remedial action will protect or substantially improve groundwater quality notwithstanding the background concentrations of naturally occurring substances.

NR 140.24(1)(c)2. 2. Reliability of sampling data. As part of its review of the quality of the sampling data, the department shall evaluate the sampling procedures, precision and accuracy of the analytical test, size of the data set, and the quality control and quality assurance procedures used. If there is insufficient information to evaluate the reliability of the sampling data, the department may require additional samples or other changes in the monitoring program at the facility, practice or activity.

NR 140.24(1)(c)3. 3. Public health, welfare and environmental effects of the substance. The department shall consider the public health, welfare and environmental effects of the substance, including but not limited to its mobility in the subsurface, environmental fate, the risks considered when the standard was adopted and whether it is carcinogenic, mutagenic, teratogenic or has interactive effects with other substances.

NR 140.24(1)(c)4. 4. Probability that a preventive action limit or an enforcement standard may be attained or exceeded outside the design management zone. In evaluating the probability that a preventive action limit or an enforcement standard may be attained or exceeded outside the design management zone, the department shall consider, at a minimum, geologic conditions, groundwater flow rate and direction, contaminant mobility in the subsurface and environmental fate.

NR 140.24(1)(c)5. 5. Performance of the facility, practice or activity. The department shall consider whether the facility, practice or activity is performing as designed in accordance with the design requirements in s. NR 140.22 (1). The department shall consider the type, age and size of the facility, practice or activity; the type of design, if applicable; the operational history; and other factors related to performance of the facility, practice or activity as appropriate.

NR 140.24(1)(c)6. 6. Location of the monitoring point. The department shall consider the location of the monitoring point in relation to the facility, practice or activity and the design management zone in assessing the appropriate response.

NR 140.24(1)(c)7. 7. Other known or suspected sources of the substance in the area. If other known or suspected sources are present in the vicinity of a facility, practice or activity of concern, the department shall evaluate the probability of contributions from other sources of the substance. The department shall consider, at a minimum, the number, size, type and age of nearby sources; the groundwater flow patterns; and the substances involved.

NR 140.24(1)(c)8. 8. Hydrogeologic conditions. The department shall consider the geologic and groundwater conditions, including but not limited to the nature, thickness and permeability of the unconsolidated materials; the nature and permeability of bedrock; the depth to the water table; groundwater flow gradients, both vertical and horizontal; the position of the facility, practice or activity within the groundwater flow system; and the present and potential groundwater use in the vicinity of the facility, practice or activity at which an exceedance occurs. If there is insufficient hydrogeologic information, the department may require additional information.

NR 140.24(1)(c)9. 9. Extent of groundwater contamination. The department shall consider the current and anticipated future extent of groundwater contamination in 3 dimensions. If water supplies are affected or threatened, the department shall evaluate the existing effects and potential risks of the substance on the potable water supplies. If the extent of contamination is not known, the department may require further documentation of the extent of contamination.

NR 140.24(1)(c)10. 10. Alternate responses. The department shall evaluate alternate responses, including consideration of the technical and economic feasibility of alternate responses from Table 5 or 6 or both, the practicality of stopping the further release of the substance and the risks and benefits of continued operation of the facility, practice or activity and the ability of a response to meet other applicable environmental protection laws.

NR 140.24(2) (2) Response objectives. Based on its evaluation of the report required under sub. (1), and the assessment criteria of sub. (1) (c), the department shall specify the responses to be implemented by the owner or operator of the facility, practice or activity designed to the extent technically and economically feasible to prevent any new releases of the substance from traveling beyond the design management zone or other applicable points of standards application described in s. NR 140.22 and restore contaminated groundwater within a reasonable period of time, considering the criteria specified in s. NR 722.07. Both the source control and the groundwater restoration components of the response shall be designed and implemented to:

NR 140.24(2)(a) (a) Minimize the concentration of the substance in groundwater at the point of standards application where technically and economically feasible;

NR 140.24(2)(b) (b) Regain and maintain compliance with the preventive action limit. If the department determines that compliance with the preventive action limit is either not technically or economically feasible, the owner or operator shall achieve compliance with the lowest possible concentration which is technically and economically feasible; and

NR 140.24(2)(c) (c) Ensure that the enforcement standard is not attained or exceeded at the point of standards application.

NR 140.24(3) (3) Range of responses for indicator parameters. Except as otherwise provided in this subsection, the range of responses that the department may take or may require if a preventive action limit for an indicator parameter identified in Table 3 has been attained or exceeded, is one or more of the responses in items 1 to 4 in Table 5. If total coliform bacteria are detected at a facility, practice, or activity groundwater monitoring point, that monitoring point shall be sampled for E. coli bacteria. The range of responses that the department may take or may require if a preventive action limit for total coliform bacteria has been attained or exceeded, is one or more of the responses in Table 5. The range of responses is one or more of the responses in items 1 to 6 of Table 5 in the event the department determines that:

NR 140.24(3)(a) (a) There is a threat to public health or welfare as a result of a preventive action limit for an indicator parameter being attained or exceeded; or

NR 140.24(3)(b) (b) The results demonstrate a significant design flaw or failure of the facility to contain substances, such that the facility can be expected to emit one or more of the substances on Table 1 or 2 in excess of a preventive action limit at a point of standards application.

NR 140.24(4) (4) Range of responses for substances of public health or welfare concern. The range of responses which the department may take or may require the owner or operator of a facility, practice or activity to take if a preventive action limit for a substance of health or welfare concern has been attained or exceeded are listed in Table 5. More than one response may be taken or required by the department.

NR 140.24(5) (5) No action response criteria. For facilities, practices and activities with a design management zone specified in s. NR 140.22 (3) Table 4, the department may determine that no response is necessary and that an exemption under s. NR 140.28 is not required when either of the following conditions is met:

NR 140.24(5)(a) (a) The concentration of a substance within a design management zone is detected above the preventive action limit, the enforcement standard has not been attained or exceeded within the design management zone, and the department determines that there is no indication that the preventive action limit will be attained or exceeded at any point outside the design management zone, or

NR 140.24(5)(b) (b) The background concentration of a substance is greater than the preventive action limit, the anticipated or detected incremental increase in the concentration of a substance which results from a specific facility, practice or activity is not greater than the preventive action limit, and the anticipated or detected concentration is not greater than the enforcement standard either within or outside of the design management zone.

NR 140.24(6) (6) Prohibition and closure criteria. The department may not impose a prohibition on a practice or activity or require closure of a facility which produces the substance unless the department:

NR 140.24(6)(a) (a) Bases its decision upon reliable test data;

NR 140.24(6)(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;

NR 140.24(6)(c) (c) Establishes the basis for the boundary and duration of the prohibition; and