S.D. Admin. R. 74:56:05:07 - Tier 1 action levels - Criteria for calculation

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

Notes

S.D. Admin. R. 74:56:05:07

22 SDR 86, effective 12/18/1995; transferred from

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.