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 HistoryHistory: 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.

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)(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 NoteNote: 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.

NR 140.20 HistoryHistory: 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(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)(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.