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) 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 soil cleanup standards for the site or facility determined in accordance with this chapter.
NR 720.05(3)
(3) If all soil contaminant concentrations meet applicable soil cleanup 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 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.
NR 720.07
NR 720.07 Procedures for 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
ss. NR 720.09 to
720.19.
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:
NR 720.07 Note
Note: Numeric residual contaminant levels are determined separately for each exposure or migration pathway of concern at a site. These residual contaminant levels are not the soil cleanup standard for the site. The soil cleanup standard for the site is determined by selecting the lowest concentration from among the individual residual contaminant levels determined for each pathway.
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 the following requirements:
NR 720.07(1)(c)1.
1. Residual soil contamination at the site or facility shall not adversely affect surface water;
NR 720.07(1)(c)2.
2. Residual soil contamination at the site or facility shall not adversely affect a sensitive environment; and
NR 720.07(1)(c)3.
3. Residual soil contamination at the site or facility shall not concentrate through plant uptake and adversely affect the food chain.
NR 720.07 Note
Note: It is the department's intention to adopt in the future soil cleanup standards based on protection of human food chain exposures, protection of surface water quality and protection of terrestrial ecosystems after exposure assumptions and methods have been developed to allow the department to calculate soil cleanup standards for these pathways of exposure. Responsible parties are required by ss.
NR 720.07 (2) and
720.19 (6) to consider human food chain exposures, the protection of surface water quality and the protection of terrestrial ecosystems, if these pathways are of concern, when determining a residual contaminant level at a site or facility.
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) 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(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 soil cleanup standard shall be considered to have been exceeded if the presence of that soil contaminant has been confirmed by the use of an appropriate analytical method.
NR 720.07 History
History: Cr.
Register, March, 1995, No. 471, eff. 4-1-95.
NR 720.09
NR 720.09
Determination of residual contaminant levels based on protection of groundwater. NR 720.09(1)
(1)
Criteria and process using generic residual contaminant levels. If all of the following criteria are met, responsible parties may use one of the methods in
sub. (3) and, where applicable, the standards in
sub. (4) to determine residual contaminant levels based on groundwater protection for a site or facility:
NR 720.09(1)(a)
(a) An investigation has been conducted and completed in accordance with applicable administrative rules, as specified in
s. NR 720.05 (1);
NR 720.09(1)(b)
(b) The contaminants of concern are listed in Table 1, except that at sites or facilities with petroleum contamination where gasoline range organics (GRO) or diesel range organics (DRO), or both, are the only contaminants of concern present other than contaminants listed in Table 1, the standards in
sub. (4) (a) may be used for non-specific GRO or DRO contamination in addition to the methods in
sub. (3) which are applicable to contaminants listed in Table 1;
NR 720.09(1)(c)
(c) The horizontal and vertical degree and extent of contamination is defined;
NR 720.09(1)(d)
(d) The vertical distance from the base of the contaminated soil to carbonate bedrock (limestone or dolostone) or fractured bedrock is one meter (3.28 feet) or greater;
NR 720.09(1)(e)
(e) The vertical thickness of the residual soil contamination is 6 meters (19.69 feet) or less; and
NR 720.09(1)(f)
(f) None of the residual contaminants or combinations of residual contaminants at the site or facility are known to contribute to facilitated transport or cosolvent effects.
NR 720.09 Note
Note: In some cases, a contaminant or combination of contaminants may contribute to an increased potential for migration of contaminants to groundwater by facilitated transport or by acting as a solvent for other contaminants, which would make the use of the values in Table 1 inappropriate. An example of facilitated transport might be polychlorinated biphenyls (PCBs) in the presence of an oily phase. An example of cosolvency might be polycyclic aromatic hydrocarbons (PAHs) in the presence of alcohols, where the alcohol acts to increase the solubility of the PAHs.
NR 720.09 Note
Note: If a site or facility meets the criteria in sub. (1), responsible parties are not required to use the methods for generic residual contaminant levels in sub. (3). The procedure in s.
NR 720.19 may be used to determine site-specific soil cleanup standards even when the site or facility meets the criteria in sub. (1).
NR 720.09(2)
(2) Site-specific process. If any of the criteria in
sub. (1) are not met, responsible parties shall use the procedure in
s. NR 720.19 to determine soil cleanup standards specific to a site or facility based on groundwater protection.
NR 720.09(3)
(3) Methods for determining generic residual contaminant levels. Responsible parties may select one of the following methods to determine residual contaminant levels based on groundwater protection for sites or facilities that meet all of the criteria in
sub. (1) in addition to meeting the requirements of
sub. (4), if applicable:
NR 720.09(3)(a)
(a) Method 1. Responsible parties may use the residual contaminant levels based on protection of groundwater listed for each substance in Table 1.
NR 720.09(3)(b)1.1. Responsible parties may determine the residual contaminant levels based on protection of groundwater using the baseline concentration for each substance listed in Table 1 multiplied by a groundwater dilution factor specific to the site or facility determined using parameter values from the site or facility determined in accordance with
subd. 2. and a groundwater mixing zone depth of 5 feet (152.4 cm) in the following equation:
-
See PDF for diagram 
-
See PDF for table NR 720.09(3)(b)2.
2. Parameter values specific to the site or facility shall be determined as follows:
NR 720.09(3)(b)2.a.
a. Hydraulic conductivity shall be determined as the geometric mean of values determined from appropriate aquifer tests. Appropriate aquifer tests may include slug tests and pumping tests, and shall be properly performed using accepted practices.
NR 720.09(3)(b)2.b.
b. Hydraulic gradient shall be determined using water level measurements from a minimum of 3 groundwater monitoring wells whose screens intersect the same hydrogeologic unit using the procedures specified in
s. NR 716.13 (8). In cases where the magnitude of the hydraulic gradient is known to vary, an average value shall be used.
NR 720.09 Note
Note: Section
NR 716.13 (8) requires that water levels be measured and recorded to the nearest 0.01 foot prior to obtaining a groundwater sample from the well.
NR 720.09(3)(b)2.c.
c. Horizontal extent of contaminated soil parallel to the hydraulic gradient shall be determined as the maximum lateral extent from the information listed in
s. NR 720.05 (1) and direction of the hydraulic gradient determined in
subd. 2. b. In cases where the direction of the hydraulic gradient is known to vary, the longest appropriate dimension shall be used.
NR 720.09(3)(b)2.d.
d. Average groundwater recharge rate shall be determined using an appropriate method or a default value of 0.07 cm/day.
NR 720.09 Note
Note: The default value of 0.07 cm/day is equivalent to an average annual recharge rate of 10 inches/year (25.4 cm/year).
NR 720.09 Note
Note: Average groundwater recharge rate can be approximated from the infiltration rate less the evapotranspiration rate. Appropriate methods may include the review of literature sources applicable to the site or facility or the use of field measurements, analytical solutions for estimating infiltration rate combined with analytical or empirical equations for estimating of evapotranspiration, or water balance approaches, among others. It is preferable to overestimate the average groundwater recharge rate rather than underestimate it.
NR 720.09 Note
Note: In some cases, use of Method 2 will yield residual contaminant levels lower than those for Method 1. In such cases, the residual contaminant level for Method 1 can be used.
NR 720.09(4)(a)1.1. For sites or facilities with petroleum contamination where
subd. 2. is not applicable, the soil cleanup standard for gasoline range organics (GRO) or diesel range organics (DRO) is a concentration in soil that may not exceed 100 milligrams per kilogram for either GRO or DRO.
NR 720.09(4)(a)2.
2. For sites or facilities with petroleum contamination where contaminated soils and soils below the contaminated soil for a depth of 3 meters have a hydraulic conductivity of 1x10-6 cm/s or less, the soil cleanup standard for gasoline range organics (GRO) or diesel range organics (DRO) is a concentration in soil that may not exceed 250 milligrams per kilogram for either GRO or DRO.
NR 720.09 Note
Note: Milligrams per kilogram (mg/kg) is equivalent to parts per million (ppm) in soil.
NR 720.09(4)(b)
(b) Site-specific determination. For sites or facilities with petroleum contamination where the concentration of gasoline range organics or diesel range organics, or both, is greater than the concentration specified in
par. (a), Table 1 may be used to determine the residual contaminant levels for the compounds listed in Table 1 and soil cleanup standards for gasoline range organics and diesel range organics may be determined using the procedure in
s. NR 720.19.
Table 1
Baseline Concentrations, Dilution Attenuation Factors and
Residual Contaminant Levels Based on Protection of Groundwater
-
See PDF for table NR 720.09 Note
Note: Micrograms per kilogram (mg/kg) is equivalent to parts per billion (ppb) in soil. Soil concentrations are on a dry weight basis.
NR 720.09 Note
Note: The residual contaminant levels for Method 1 listed in Table 1 represent concentrations of contaminants that can remain in soil at a site and not cause a violation of a ch.
NR 140 preventive action limit in groundwater. These residual contaminant levels are based on the baseline concentration for a substance multiplied by the dilution attenuation factor for that substance listed in Table 1.
NR 720.09 Note
Note: The residual contaminant levels in Table 1 are based on protection of groundwater. These concentrations of hazardous substances in soil may not be protective of other pathways of concern.
NR 720.09 History
History: Cr.
Register, March, 1995, No. 471, eff. 4-1-95.
NR 720.11
NR 720.11
Determining residual contaminant levels based on protection of human health from direct contact with contaminated soil. NR 720.11(1)(a)(a) Responsible parties shall determine an appropriate land use classification for the site or facility in compliance with
pars. (b) to
(d), unless otherwise directed by the department.
NR 720.11(1)(b)
(b) Responsible parties shall classify the land use of a site or facility as non-industrial unless all of the following criteria are met:
NR 720.11(1)(b)1.
1. The site or facility is currently zoned for, or otherwise officially designated for, industrial use.
NR 720.11 Note
Note: A site or facility may be 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 720.11(1)(b)2.
2. The site or facility is expected to be used for industrial purposes due to zoning, statutory or regulatory restrictions, comprehensive plans, adjacent land use or other relevant factors.
NR 720.11(1)(b)3.
3. More stringent residual contaminant levels for soil are not necessary to protect public health on or off the site or facility.
NR 720.11 Note
Note: Situations where s.
NR 720.11 (1) (b) 3. would apply include site or facilities which could otherwise be classified as industrial, but where proximity to a nonindustrial land use, such as residential housing located across the street, makes a nonindustrial classification more appropriate.
NR 720.11(1)(c)
(c) The land use of a site or facility may be classified as industrial if all of the criteria in
par. (b) are met and if a deed restriction which meets the requirements of
s. NR 726.05 (8) is recorded within 30 days after remedial action is initiated at the site or facility.
NR 720.11(1)(d)
(d) The industrial column in Table 2 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 720.11 Note
Note: A deed restriction must be recorded if soil cleanup levels based on industrial exposure are used.
NR 720.11(2)
(2) Criteria and process for using generic residual contaminant levels. If all of the following criteria are met for a site or facility, responsible parties may use the residual contaminant levels based on protection from direct contact listed for each substance in Table 2 which are appropriate for the site or facility in accordance with the land use classification determined in
sub. (1), unless
sub. (3) or
(5), or both, applies:
NR 720.11(2)(a)
(a) An investigation has been conducted in accordance with applicable administrative rules, as specified in
s. NR 720.05 (1);
NR 720.11(2)(b)
(b) The contaminants of concern present at the site or facility are listed in Table 2; and
NR 720.11 Note
Note: For example, at a site where soils are contaminated with diesel fuel, polynuclear aromatic hydrocarbon (PAH) compounds are present and may be considered contaminants of concern. With the exception of naphthalene, PAH compounds are generally only of concern for direct contact due to their relatively low migration potential.
NR 720.11(2)(c)
(c) The horizontal and vertical degree and extent of contamination is defined.
NR 720.11 Note
Note: If a site or facility meets the criteria in s.
NR 720.11 (2) responsible parties are not required to use the procedure for generic residual contaminant levels in sub. (2). The procedure in s.
NR 720.19 may be used to determine site-specific soil cleanup standards even when the site or facility meets the criteria in sub. (2).
NR 720.11(3)(a)(a) The cumulative excess cancer risk may not exceed 1x10-5 and the hazard index for non-carcinogens may not exceed one for the contaminants of concern at a site or facility.
NR 720.11(3)(b)
(b) Risks for carcinogens and for non-carcinogens are presumed to be additive within each category. The residual contaminant levels in Table 2 shall be prorated downward to keep the cumulative risk below the levels specified in
par. (a).
NR 720.11 Note
Note: The residual contaminant levels for non-industrial land use in Table 2 are based on an excess cancer risk of 1x10-7 for carcinogens or a hazard quotient of 0.2 for noncarcinogens. These levels are intended to be analogous with the preventive action limits in ch.
NR 140.
NR 720.11(4)
(4) Site-specific process. Except as provided in
sub. (5), if one or more of the criteria in
sub. (2) are not met, responsible parties shall use the procedure in
s. NR 720.19 to determine soil cleanup standards specific to a site or facility based on protection from direct contact.
NR 720.11(5)(a)(a) For sites contaminated with petroleum products discharged from petroleum storage tanks:
