NR 720.03(15)
(15) “Soil cleanup standard" means either a residual contaminant level determined in accordance with
ss. NR 720.10 or
720.12, or a soil performance standard determined in accordance with
s. NR 720.08.
NR 720.03(16)
(16) “Soil saturation concentration" or “Csat" means the contaminant concentration in soil at which the absorptive limits of the soil particles, the solubility limits of the soil particles, the solubility limits of the soil pore-water, and saturation of soil pore-air have been reached. At concentrations greater than Csat, the soil contaminant may be present in free phase for contaminants that are liquid at ambient soil temperatures and pure solid phases for compounds that are solid at ambient soil temperatures.
NR 720.03 History
History: Cr.
Register, March, 1995, No. 471, eff. 4-1-95; corrections in (12) (c) made under s. 13.93 (2m) (b) 7., Stats.,
Register September 2007 No. 621;
CR 12-023: cr. (1m), (3m), am. (4), (8), r. (9), cr. (9m), r. (10), (12), cr. (12m), am. (14), cr. (15), (16)
Register October 2013 No. 694, eff. 11-1-13.
NR 720.05(1)(1)
Remedial action. Responsible parties shall select and implement a remedial action to address soil contamination when, after any of the following investigations has been completed, information collected during the investigation indicates that a remedial action to address soil contamination is necessary to achieve compliance with the requirements of this chapter:
NR 720.05(1)(b)
(b) Solid waste site investigation report prepared in accordance with the requirements of
ch. NR 508.
NR 720.05(1)(c)
(c) Investigation done under a hazardous waste closure plan or a RCRA facility investigation report, developed in accordance with the requirements of subchs.
G and
H of ch. NR 664 or
s. NR 664.0100.
NR 720.05 Note
Note: Remedial actions at some types of sites or facilities, such as the abandonment of wastewater lagoons, may only have to comply with ch.
NR 720 and not other requirements in the NR 700 series, such as the minimum site investigation requirements in ch.
NR 716. In this case, the department or responsible parties may choose to use the other chapters of the NR 700 rule series as guidance for complying with ch.
NR 720.
NR 720.05(2)
(2) Residual contaminant levels or performance standards. Remedial actions conducted by responsible parties to address soil contamination shall be designed and implemented to restore the contaminated soil to levels that, at a minimum, meet the residual contaminant levels or performance standards for the site or facility determined in accordance with this chapter.
NR 720.05(3)
(3) No further action. If all soil contaminant concentrations meet applicable residual contaminant levels or performance standards after a remedial action is completed, the department may not require further remedial action for soils, unless the department determines that the residual soil contamination:
NR 720.05(3)(a)
(a) Presents a threat to public health, safety, or welfare or the environment at the site or facility;
NR 720.05(4)(a)(a) Unless otherwise directed by the department, submittals under this chapter shall be included in the site investigation report or the draft remedial action options report required under
s. NR 700.11 (1).
NR 720.05(4)(b)
(b) Submittals to the department under this chapter shall include all of the following:
NR 720.05(4)(b)1.
1. Complete background information and supporting documentation for the procedure to be used.
NR 720.05(4)(b)2.
2. Documentation that the application of the procedure is valid for the site or facility under consideration.
NR 720.05(4)(b)3.
3. Necessary data and documentation needed to fully evaluate the submittal.
NR 720.05(4)(b)4.
4. Legible copies of source documents or pertinent portions of source documents.
NR 720.05 Note
Note: In order to facilitate department review of submittals, legible copies of entire source documents or the pertinent portions of source documents sufficient to evaluate the method or procedure used should be included with the submittal.
NR 720.05(5)(a)(a) Responsible parties shall identify the current land use and zoning for the site or facility by the time the remedial action is selected, unless otherwise directed by the department.
NR 720.05(5)(b)
(b) Responsible parties shall classify the land use of a site or facility as industrial if all of the following criteria are met:
NR 720.05(5)(b)1.
1. The site or facility is currently zoned for, or otherwise officially designated for, industrial use.
NR 720.05 Note
Note: Typically, a site or facility is officially designated for industrial use by the issuance of a conditional use or special exception permit that allows an industrial use of that site or facility in a non-industrial zoning district or by the designation of an area as industrial in a county development plan or a municipal master plan, among other means.
NR 720.05(5)(b)2.
2. More stringent non-industrial residual contaminant levels for soil are not necessary to protect public health on or off the site or facility.
NR 720.05 Note
Note: Situations where a non-industrial classification would apply include site or facilities which could otherwise be classified as industrial, but where proximity to a non-industrial land use, such as residential housing located across the street, makes a non-industrial classification more appropriate.
NR 720.05(5)(c)
(c) An industrial land use classification may be applied to restricted access areas unless more stringent residual contaminant levels are necessary to protect public health on or off the site.
NR 720.05 Note
Note: Under ch.
NR 726, a continuing obligation will be imposed as part of the case closure letter if residual contaminant levels are based on industrial exposure or if a soil performance standard is used.
NR 720.05 History
History: Cr.
Register, March, 1995, No. 471, eff. 4-1-95; corrections in (1) (c) made under s. 13.93 (2m) (b) 7., Stats.,
Register September 2007 No. 621;
CR 12-023: cr. (1) (title), am. (1) (b), (c), cr. (2) (title), am. (2), cr. (3) (title), am. (3) (intro.), cr. (4), (5)
Register October 2013 No. 694, eff. 11-1-13.
NR 720.07
NR 720.07
General requirements when establishing soil cleanup standards applicable to a site or facility. NR 720.07(1)(a)(a) Responsible parties shall use information from the sources listed in
s. NR 720.05 (1) to determine the residual contaminant levels or performance standards for each exposure or migration pathway of concern for each soil contaminant of concern at a site or facility in accordance with this chapter.
NR 720.07(1)(b)
(b) In addition to meeting the requirements of
par. (c), responsible parties shall establish the soil cleanup standard for each soil contaminant of concern at the site or facility as one of the following:
NR 720.07(1)(b)1.
1. The residual contaminant level of each contaminant in soil which is the lowest concentration from among the following as applicable: the ceiling limit concentration, the soil saturation concentration if the contaminant is a volatile, a land use specific direct contact level, a groundwater quality protective level, a concentration calculated for a pathway of concern set forth in s. NR 720.13 all of which are determined in accordance with the requirements of this chapter.
NR 720.07 Note
Note: For a single contaminant, a numeric land use specific residual contaminant level is determined based on aggregate exposure through incidental ingestion of soil, inhalation of soil vapors and particulates, and dermal contact with soil. When more than one contaminant is present, the residual contaminant level is determined based on cumulative exposure and may have to be adjusted downward so that the cumulative risk does not exceed an excess cancer risk of 1-in-100,000 or a hazard index of 1 for non-carcinogens.
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)1.
1. Residual soil contamination at the site or facility may not adversely affect surface water.
NR 720.07(1)(c)2.
2. Residual soil contamination at the site or facility may not adversely affect a sensitive environment.
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 Note
Note: 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 Note
Note: 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)
(d) The following applies when a soil cleanup standard for a soil contaminant is below the limit of detection:
NR 720.07(2)(d)1.
1. If a soil contaminant is not detected in a sample, the soil cleanup standard shall not be considered to have been exceeded.
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 Note
Note: 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 History
History: 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
NR 720.08
Procedures for establishing soil performance standards. 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 Note
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.
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(2)(b)
(b) Use of natural attenuation to contain and remediate the contaminants present.
NR 720.08(2)(c)
(c) Operation of a system in compliance with
ch. NR 724 until the lowest concentration that is practicable is achieved.
NR 720.08 Note
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.
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.
NR 720.08(3)(b)
(b) Operation of a system in compliance with
ch. NR 724 until the lowest concentration that is practicable is achieved.
NR 720.08 History
History: CR 12-023: cr.
Register October 2013 No. 694, eff. 11-1-13.
NR 720.10
NR 720.10
Procedures for determining residual contaminant levels based on protection of groundwater. NR 720.10(1)(1)
General. If a responsible party selects this option, residual contaminant levels for soil based on protection of groundwater shall be developed using the enforcement standards established in
ch. NR 140 or using procedures consistent with the methodology in ss.
160.13 and
160.15, Stats., and the criteria in
s. NR 722.09 (2) (b) 2. when there is no enforcement standard as the target concentrations in groundwater. If the department of health has not developed a recommended enforcement standard and a federal maximum contaminant level exists, that value may be used for calculating a soil residual contaminant level.
NR 720.10 Note
Note: In developing a residual contaminant level, any relevant information may be considered, including public welfare concerns for groundwater, such as taste and odor, and drinking water health advisory levels.
NR 720.10(2)
(2) Methods. Responsible parties shall use one or more of the methods listed in this section based on scientifically valid procedures that are subject to department review and approval and site-specific geological, physical and chemical conditions to establish residual contaminant levels:
NR 720.10(2)(b)
(b) Leaching tests appropriate for the site or facility in both application and extent.
NR 720.10(2)(c)
(c) Any other appropriate method approved by the department for that specific site or facility, or other appropriate method suggested in department guidance.
NR 720.10 Note
Note: Guidance document RR-890 provides detailed instructions on one method the department considers scientifically valid for purposes of calculating site specific residual contaminant levels that are protective of groundwater quality. A table of residual contaminant levels that are calculated using the standard default exposure assumptions can be found at:
http://dnr.wi.gov/topic/Brownfields/professionals.html#tabx2.
NR 720.10 History
History: CR 12-023: cr.
Register October 2013 No. 694, eff. 11-1-13.
NR 720.12
NR 720.12
Procedures for determining residual contaminant levels based on protection of human health from direct contact with contaminated soil. NR 720.12(1)(1)
General. If a responsible party selects this option, residual contaminant levels for soil based on protection of human health from direct contact shall be developed using the following criteria:
NR 720.12(1)(a)
(a) For individual compounds using an excess cancer risk of 1x10
-6 and a hazard quotient for non-carcinogens of one; and
NR 720.12(1)(b)
(b) The cumulative excess cancer risk will not exceed 1x10
-5 and the hazard index for non-carcinogens will not exceed one for the site or facility.
NR 720.12(1)(c)
(c) Risks for carcinogens and hazard quotients for non-carcinogens are presumed to be additive within each category, unless there is specific information that demonstrates that an alternative approach is more appropriate.
NR 720.12(1)(d)
(d) If toxicological values for both carcinogenic and non-carcinogenic end points exist for a substance, both shall be evaluated and the method that generates the lowest residual contaminant level shall be used for the site or facility.
NR 720.12(2)
(2) Methods and procedures. Responsible parties shall determine a residual contaminant level to protect public health from direct contact with soil contamination using scientifically valid procedures and toxicological values approved by the department and the default exposure assumptions identified in
sub. (3) or alternative assumptions specifically approved by the department in writing.
NR 720.12 Note
Note: The department will generally consider toxicological values in the following order: U.S. EPA's Integrated Risk Information System (IRIS); U.S. EPA's Provisional Peer Reviewed Toxicity Values (PPRTV); Agency for Toxic Substances and Disease Registry (ATSDR); California EPA (Cal EPA); U.S. EPA's Health Effects Assessment Summary Tables (HEAST); other pertinent toxicological information.
NR 720.12(3)(a)(a)
Non-carcinogens. When the contaminant is not a carcinogen, the following default exposure assumptions shall be used:
