Wis. Admin. Code Department of Natural Resources NR 720.08 - Procedures for establishing soil performance standards

(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.

Note: 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.

(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:

(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.

(b) Use of natural attenuation to contain and remediate the contaminants present.

(c) Operation of a system in compliance with ch. NR 724 until the lowest concentration that is practicable is achieved.

Note: 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.

(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:

(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.

(b) Operation of a system in compliance with ch. NR 724 until the lowest concentration that is practicable is achieved.

Notes

Wis. Admin. Code Department of Natural Resources NR 720.08

CR 12-023: cr. Register October 2013 No. 694, eff. 11-1-13.