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(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 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. 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 HistoryHistory: CR 12-023: cr. Register October 2013 No. 694, eff. 11-1-13. NR 720.10NR 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 NoteNote: 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 NoteNote: 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 HistoryHistory: CR 12-023: cr. Register October 2013 No. 694, eff. 11-1-13. NR 720.12NR 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 NoteNote: 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: NR 720.12(3)(a)1.1. When the land use of a site or facility is classified as non-industrial, in accordance with s. NR 720.05 (5), all of the following shall apply: NR 720.12(3)(a)1.a.a. Incidental ingestion of soil shall be assumed to occur at the rate of 200 mg of soil per day for a 15 kg child for 350 days each year. NR 720.12(3)(a)1.b.b. Dermal absorption of soil shall be determined assuming a child’s daily exposed skin surface area of 2,800 cm2 with a skin-soil adherence factor of 0.2 mg/cm2 and a contaminant specific dermal absorption fraction. NR 720.12(3)(a)1.c.c. Inhalation of outdoor soil vapors shall be assumed to occur for each volatile contaminant at a 24-hour daily exposure rate determined by the volatile’s soil-to-air volatilization factor, and inhalation of particulate matter shall be determined assuming a particulate emission factor of 1.43 x109 m3/kg. NR 720.12(3)(a)1.d.d. An averaging period for exposure shall equal the default exposure duration of 6 years. NR 720.12(3)(a)2.2. When the land use of a site or facility is classified as industrial, in accordance with s. NR 720.05 (5), all of the following shall apply: NR 720.12(3)(a)2.a.a. Incidental ingestion of soil shall be assumed to occur at the rate of 100 mg of soil per day for a 70 kg adult worker for 250 days each year. NR 720.12(3)(a)2.b.b. Dermal absorption of soil shall be determined assuming an adult outdoor worker’s daily exposed skin surface of 3,300 cm2 with a skin-soil adherence factor of 0.2 mg/cm2 and a contaminant specific dermal absorption fraction. NR 720.12(3)(a)2.c.c. Inhalation of outdoor soil vapors shall be assumed to occur for each volatile contaminant at an 8-hour daily exposure rate determined by the volatile contaminant’s soil-to-air volatilization factor, and inhalation of particulate matter shall be determined assuming a particulate emission factor of 1.43 x109 m3/kg. NR 720.12(3)(a)2.d.d. An averaging period of exposure shall equal the default exposure duration of 25 years. NR 720.12(3)(b)(b) Carcinogens. When the contaminant is a carcinogen, the following default exposure assumptions shall be used: NR 720.12(3)(b)1.1. When the land use of a site or facility is classified as non-industrial, in accordance with s. NR 720.05 (5), all of the following shall apply: NR 720.12(3)(b)1.a.a. Incidental ingestion of soil shall be assumed to occur at the rate of 200 mg of soil per day for 350 days each year for 6 years for a 15 kg child and the rate of 100 mg per day for 350 days each year for 24 years for a 70 kg adult. NR 720.12(3)(b)1.b.b. Dermal absorption of soil shall be determined assuming a child’s daily exposed skin surface area of 2,800 cm2 with a skin-soil adherence factor of 0.2 mg/cm2, and an adult’s daily exposed skin-surface area of 5,700 cm2 with a skin-soil adherence factor of 0.07 mg/cm2 and a contaminant specific dermal absorption fraction. NR 720.12(3)(b)1.c.c. Inhalation of outdoor soil vapors shall be assumed to occur for each volatile contaminant at a 24-hour daily exposure rate determined by the volatile contaminant’s soil-to-air volatilization factor, and inhalation of particulate matter shall be determined assuming a particulate emission factor of 1.43 x109 m3/kg. For mutagenic contaminants, age segmented exposure durations shall be assumed when age adjusted cancer slope factors are available. NR 720.12(3)(b)1.d.d. An averaging period of 30 years of exposure consisting of 6 child years and 24 adult years shall be assumed during a 70 year lifetime. NR 720.12(3)(b)2.2. When the land use of a site or facility is classified as industrial, in accordance with s. NR 720.05 (5), all of the following shall apply: NR 720.12(3)(b)2.a.a. Incidental ingestion of soil shall be assumed to occur at the rate of 100 mg of soil per day for 250 days each year for a 70 kg adult worker. NR 720.12(3)(b)2.b.b. Dermal absorption of soil shall be determined assuming an adult outdoor worker’s daily exposed skin surface of 3,300 cm2 with a skin-soil adherence factor of 0.2 mg/cm2 and a contaminant specific dermal absorption fraction. NR 720.12(3)(b)2.c.c. Inhalation of outdoor soil vapors shall be assumed to occur for each volatile contaminant at an 8-hour daily exposure rate determined by the volatile contaminant’s soil-to-air volatilization factor, and inhalation of particulate matter shall be determined assuming a particulate emission factor of 1.43 x109 m3/kg. NR 720.12(3)(b)2.d.d. An averaging period of 25 years of exposure shall be assumed during a 70 year lifetime. NR 720.12 NoteNote: Department approval of alternative exposure assumptions for a site or facility may be based on consultation with the department of health services. If EPA makes changes to the default exposure assumptions, the department would generally use the revised values.
NR 720.12 NoteNote: 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 the direct contact pathway. 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 720.12(4)(4) Soil parameter values. Unless otherwise approved, when determining site specific residual contaminant levels, all the following soil parameter values shall be used: NR 720.12 NoteNote: These soil parameter values are the defaults used in Pub-RR-890, “Soil Residual Contaminant Level Determination Using the US EPA Regional Screening Level Web Calculator.” This guidance may be found at http://dnr.wi.gov/topic/Brownfields/Pubs.html. NR 720.12 HistoryHistory: CR 12-023: cr. Register October 2013 No. 694, eff. 11-1-13. NR 720.13NR 720.13 Other pathways of concern. Responsible parties shall consider human food chain, surface water quality, and terrestrial eco-system pathways of exposure, when those pathways of exposure are of concern at a site or facility. NR 720.13 NoteNote: In some cases, the potential for contaminant migration or exposure to contamination through other pathways may be of concern at a site or facility. These situations could include contaminated soil in close proximity to a surface water where the potential for runoff from the site or facility to cause an impact on surface water quality exists or contaminated soil where potential for bioaccumulation and uptake through the food chain resulting in adverse impacts to human health or terrestrial ecosystems exists. This section requires responsible parties to establish appropriate residual contaminant levels protective of these pathways when necessary.
NR 720.13 HistoryHistory: CR 12-023: cr. Register October 2013 No. 694, eff. 11-1-13.
