Chapter NR 720

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 Note Note: EPA's regional screening level user's guide provides a table containing contaminant specific dermal absorption factors and soil to air volatilization factors. The document can be found at: http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/usersguide.htm.

NR 720.12 Note Note: 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 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 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(4)(a) (a) For direct contact:

NR 720.12(4)(a)1. 1. A dry soil bulk density of 1.5 gm/cm3.

NR 720.12(4)(a)2. 2. An air filled soil porosity of 0.28.

NR 720.12(4)(a)3. 3. A total soil porosity of 0.43.

NR 720.12(4)(a)4. 4. A water filled porosity of 0.15.

NR 720.12(4)(a)5. 5. A soil particle density of 2.65 gm/cm3.

NR 720.12(4)(a)6. 6. A soil organic carbon content of 0.006.

NR 720.12(4)(b) (b) For soil to groundwater:

NR 720.12(4)(b)1. 1. A dry soil bulk density of 1.5 gm/cm3.

NR 720.12(4)(b)2. 2. An air filled soil porosity of 0.13.

NR 720.12(4)(b)3. 3. A total soil porosity of 0.43.

NR 720.12(4)(b)4. 4. A water filled porosity of 0.30.

NR 720.12(4)(b)5. 5. A soil particle density of 2.65 gm/cm3.

NR 720.12(4)(b)6. 6. A soil organic carbon content of 0.002.

NR 720.12 Note Note: 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 History History: CR 12-023: cr. Register October 2013 No. 694, eff. 11-1-13.

NR 720.13 NR 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 Note Note: 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 History History: CR 12-023: cr. Register October 2013 No. 694, eff. 11-1-13.