Michigan Administrative Code
Department - Environmental Quality
Remediation and Redevelopment Division
Environmental Contamination Response Activity
CLEANUP CRITERIA REQUIREMENTS FOR RESPONSE ACTIVITY
Section R. 299.20 - Generic cleanup criteria for soil based on direct contact
Universal Citation: MI Admin Code R. 299.20
Current through Vol. 25-4, March 15, 2025
Rule 20.
(1) Cleanup criteria for soil based on direct contact shall be calculated for the generic residential category according to the following algorithms, except as provided in R 299.34(3):
EQUATION FOR CARCINOGENS:
| where, | ||
| DCC | (Direct contact criterion) | = chemical-specific, ug/kg or ppb |
| TR | (Target risk level) | = 10-5 |
| AT | (Averaging time) | = 25,550 days (70 years x 365 days/year) |
| CF | (Conversion factor) | = 1E+9 ug/kg |
| SF | (Oral cancer slope factor) | = chemical-specific (mg/kg-day)-1 |
| EFi | (Ingestion exposure frequency) | = 350 days/year |
| IF | (Age-adjusted soil ingestion factor) | = 114 mg-year/kg-day* |
| AEi | (Ingestion absorption efficiency) | = chemical-specific or default specified at R 299.20(3) |
| EFd | (Dermal exposure frequency) | = 245 days/year |
| DF | (Age-adjusted soil dermal factor) | = 353 mg-year/kg-day** |
| AEd | (Dermal absorption efficiency) | = chemical-specific or default specified at R 299.20(3) |
EQUATIONS FOR NONCARCINOGENS:
| where, | ||
| DCC | (Direct contact criterion) | = chemical-specific (ug/kg or ppb) |
| THQ | (Target hazard quotient) | = 1 |
| RfD | (Oral reference dose) | = chemical-specific mg/kg-/day |
| AT | (Averaging time) | = 10,950 days (30 years x 365 days/year) |
| CF | (Conversion factor) | = 1E+9 ug/kg |
| RSC | (Relative source contribution) | = 1 |
| EFi | (Ingestion exposure frequency) | = 350 days/year |
| IF | (Age-adjusted soil ingestion factor) | = 114 mg-year/kg-day* |
| AEi | (Ingestion absorption efficiency) | = chemical-specific or default specified at R 299.20(3) |
| EFd | (Dermal exposure frequency) | = 245 days/year |
| DF | (Age-adjusted soil dermal factor) | = 353 mg-year/kg-day** |
| AEd | (Dermal absorption efficiency) | = chemical-specific or default specified at R 299.20(3) |
and,
| where, | ||
| IRsoil/age 1-6 | (Soil ingestion rate) | = 200 mg/day |
| EDage 1-6 | (Exposure duration) | = 6 years |
| BWage 1-6 | (Body weight) | = 15 kg |
| IRadult | (Soil ingestion rate) | = 100 mg/day |
| EDadult | (Exposure duration) | = 24 years |
| BWadult | (Body weight) | = 70 kg |
and,
| where, | ||
| SAage 1-6 | (Skin surface area) | = 2,670 cm2/dayevent |
| EV | (Event frequency) | = 1 event/day |
| AFage 1-6 | (Soil adherence factor) | = 0.2 mg/cm2 |
| EDage 1-6 | (Exposure duration) | = 6 years |
| BWage 1-6 | (Body weight) | = 15 kg |
| SAadult | (Skin surface area) | = 5,800 cm2/dayevent |
| AFadult | (Soil adherence factor) | = 0.07 mg/cm2 |
| EDadult | (Exposure duration) | = 24 years |
| BWadult | (Body weight) | = 70 kg |
(2) Cleanup criteria for soil based on direct contact shall be calculated for the generic nonresidential category according to the following algorithms, except as provided in R 299.34(3):
EQUATION FOR CARCINOGENS:
| where, | ||
| DCC | (Direct contact criterion) | = chemical-specific, ug/kg or ppb |
| TR | (Target risk level) | = 10-5 |
| BW | (Body weight) | = 70 kg |
| AT | (Averaging time) | = 25,550 days (70 years x 365 days/year) |
| CF | (Conversion factor) | = 1E+9 ug/kg |
| SF | (Oral cancer slope factor) | = chemical-specific (mg/kg-day)-1 |
| ED | (Exposure duration) | = 21 years |
| EFi | (Ingestion exposure frequency) | = 245 days/year |
| IRs | (Soil ingestion rate) | = 100 mg/day (residential) |
| AEi | (Ingestion absorption efficiency) | = chemical-specific or default specified at R 299.20(3) |
| EFd | (Dermal exposure frequency) | = 160 days/year |
| SA | (Skin surface area) | = 3,300 cm2/day event |
| EV | (Event frequency) | = 1 event/day |
| AF | (Soil adherence factor) | = 0.2 mg/cm2 (nonresidential) |
| AEd | (Dermal absorption efficiency) | = chemical-specific or default specified at R 299.20(3) |
EQUATION FOR NONCARCINOGENS:
| where, | ||
| DCC | (Direct contact criterion) | = chemical-specific, ug/kg or ppb |
| THQ | (Target hazard quotient) | = 1 |
| RfD | (Oral reference dose) | = chemical-specific, mg/kg-/day |
| BW | (Body weight) | = 70 kg |
| AT | (Averaging time) | = 7,665 days (21 years x 365 days/year) |
| CF | (Conversion factor) | = 1E+9 ug/kg |
| RSC | (Relative source contribution) | = 1 |
| ED | (Exposure duration) | = 21 years |
| EFi | (Ingestion exposure frequency) | = 245 days/year |
| IRs | (Soil ingestion rate) | = 100 mg/day |
| AEi | (Ingestion absorption efficiency) | = chemical-specific or default specified at R 299.20(3) |
| EFd | (Dermal exposure frequency) | = 160 days/year |
| SA | (Skin surface area) | = 3,300 cm2/day event |
| EV | (Event frequency) | = 1 event/day |
| AF | (Soil adherence factor) | = 0.2 mg/cm2 (nonresidential) |
| AEd | (Dermal absorption efficiency) | = chemical-specific or default specified at R 299.20(3) |
(3) Absorption efficiencies used to calculate generic direct contact criteria are as follows:
(a) Chemical-specific data may be
submitted to the department to support development of a new generic criterion
under R 299.6(9) or (10) and shall be used in this rule if determined by the
department to be the best available information.
(b) If chemical-specific data are not
available, then the following default absorption efficiencies shall be used:
(i) AEi shall be 50%
for organic hazardous substances which exhibit a log octanol water partitioning
coefficient greater than 5 and a molecular weight greater than 200 grams per
mole or which are not ionizing organic compounds, and 100% for all other
organic hazardous substances.
(ii)
AEi shall be 50% for inorganic hazardous
substances.
(iii)
AEd shall be assumed to be 10% for organic hazardous
substances.
(iv)
AEd shall be assumed to be 1% for inorganic hazardous
substances.
(4) To demonstrate compliance with generic direct contact criteria, the criteria shall be applied without regard to the depth of contaminated soil.
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