NR 720.07(1)(c)(c) In addition to meeting the requirements of par. (b), a soil cleanup standard developed under this chapter shall comply with all the following requirements:

NR 720.07(1)(c)3.3. Residual soil contamination at the site or facility may not concentrate through plant uptake and adversely affect the food chain.

NR 720.07(1)(c)4.4. Residual soil contamination at the site or facility may not result in vapor concentrations reaching a substance’s lower explosive limit.

NR 720.07(2)(a)(a) Contaminant concentrations in soil samples shall be determined using a department-approved and appropriate analytical method and reported on a dry weight basis. An appropriate analytical method shall have limits of detection or limits of quantitation, or both, at or below soil cleanup standards where possible. Responsible parties shall report the limit of detection and the limit of quantitation with sample results. The department may require that supporting documentation for the reported limit of detection and limit of quantitation be submitted

NR 720.07(2)(b)(b) Unless an alternative approach for determining standards exceedances is approved by the department, if a soil contaminant concentration in a sample exceeds the soil cleanup standard at or above the limit of quantitation for that soil contaminant, the soil cleanup standard shall be considered to have been exceeded.

NR 720.07 NoteNote: When evaluating the direct contact pathways, it may be possible to average measured soil sample concentrations to determine whether the calculated residual contaminant level has been exceeded or not. If averaging of soil concentrations is being considered, the department recommends seeking department approval of the proposed sampling plan and analysis methodology as soon as possible, but prior to submitting a case closure request in order to avoid delays and other potential problems.

NR 720.07 NoteNote: Averaging soil concentrations is not appropriate as the sole method for addressing sites with areas of significant soil contamination.

NR 720.07(2)(c)(c) If a soil cleanup standard for a soil contaminant is between the limit of detection and the limit of quantitation, the soil cleanup standard shall be considered to be exceeded if the soil contaminant concentration is reported at or above the limit of quantitation.

NR 720.07(2)(d)2.2. If a soil contaminant is reported above the limit of detection but below the limit of quantitation, the responsible party may accept the results and the soil cleanup standard shall be considered to have been exceeded, or the responsible party may choose to have the soil sample reanalyzed by the use of an appropriate analytical method. If the soil contaminant is confirmed to be present between the limit of detection and the limit of quantitation, the soil cleanup standard shall be considered to have been exceeded. If the soil contaminant is not detected upon reanalysis of the soil sample, the soil cleanup standard shall not be considered to have been exceeded.

NR 720.07(3)(3) Background. If the background concentration for a substance in soil at a site or facility is higher than the residual contaminant level for that substance determined using the procedures in this section, the background concentration in soil may be used as the residual contaminant level for that substance. The background concentration for a substance in soil shall be determined using a department-approved and appropriate method.

NR 720.07 NoteNote: Naturally occurring background concentrations of arsenic in soil, for example, may be higher than the calculated residual contaminant level for arsenic. In such instances, the naturally occurring background concentration could be used as the soil cleanup level.

NR 720.07 HistoryHistory: Cr. Register, March, 1995, No. 471, eff. 4-1-95; CR 12-023: am. (title), (1) (a) to (c), cr. (1) (c) 4., am. (2) (b), (d) 2., cr. (3) Register October 2013 No. 694, eff. 11-1-13.

NR 720.08(1)(1) General. If a responsible party selects this option, performance standards shall be established and maintained so that the residual contaminants in the soil do not pose a threat to public health, safety, or welfare or the environment.

NR 720.08 NoteNote: Guidance document RR-528 indicates that it may not be necessary to determine numeric residual contaminant levels for contaminants as long as all contaminant pathways for all contaminants of concern are addressed by the remedial action, the extent of contamination is fully defined, the remedy remains in place, is maintained as appropriate and remains effective. For example, if a cover is placed that addresses all pathways for the contaminated soil, then it isn’t necessary to determine the numeric residual contaminant levels for as long as the cover adequately addresses the pathway and remains protective. It may be necessary to determine residual contaminant levels in the future if the remedy is changed or replaced.

NR 720.08(2)(2) Protection of groundwater. Acceptable performance standard options to address the soil to groundwater pathway may include any of, or any combination of, the following:

NR 720.08(2)(a)(a) Placement of a permanent engineering control such as a cap or cover to limit infiltration and thereby minimizing the leaching of soil contaminants to groundwater that is constructed and maintained until the threat to groundwater no longer exists.

NR 720.08 NoteNote: As explained in more detail in guidance document RR-528, if there is no threat to groundwater from soil contamination, a soil remedy is not necessary. The lack of groundwater contamination may not always be sufficient to establish there is not threat to the groundwater pathway. An analysis to determine whether sufficient time has passed for the soil contamination to have reached the locations where groundwater is being monitored may be necessary. The factors that may need to be considered include: the age of the contaminant release, type of contaminants, geologic setting, depth to groundwater, and the proximity of the monitoring wells to the source of contamination.

NR 720.08(3)(3) Protection from direct contact. Acceptable performance standard options to address the direct contact pathway may include either of, or a combination of, the following:

NR 720.08(3)(a)(a) Placement of a permanent engineering control such as a cap or cover that is constructed and maintained until the direct contact threat no longer exists.