The department shall calculate Tier 1 action levels shown in Table 1 in this section based on the petroleum contamination in soil leaching to the groundwater pathway, with an excess lifetime cancer risk not exceeding 1:100,000 and a chronic noncancer risk not exceeding a hazard index of one. The department assumes there are receptors actually or potentially ingesting groundwater at the point of maximum soil contamination.
Table 1 is as follows:
TABLE 1
TIER 1 ACTION LEVELS FOR SOILS AT PETROLEUM RELEASE SITES
Chemical of Concern | Tier 1 Action Level (ppm = parts per million) |
Benzene | 0.2 ppm |
Toluene | 15 ppm |
Ethylbenzene | 10 ppm |
Xylene | 300 ppm |
Napthalene | 25 ppm |
S.D. Admin. R. 74:56:05:07
General Authority: SDCL 34A-2-93, 34A-2-99, 34A-2-101, 34A-12-7.
Law Implemented: SDCL 34A-2-99, 34A-2-101, 34A-12-10.