The Minnesota Depart of Health (MDH), Health Risk Assessment Unit has adopted revisions to the Rules relating to health risk limits (HRL) for groundwater standards in the Minnesota. The amendments add (to Part 4717.7860 of the rule) health-based guidance values for six chemicals that were not previously in the Health Risk Limit Rules for Groundwater. In addition, outdated HRL values (adopted in 1993 and 1994) for six chemicals are repealed (in Part4717.7500) and replaced (in Part 4717.7860) by new HRL values.
Chemicals with new or revised HRL values include:
- 6-Acetyl-1,1,2,4,4,7-hexamethyltetraline (AHTN).
- Carbamazepine.
- Carbon tetrachloride.
- 1,2-Dichloroethane.
- trans-1,2-Dichloroethene
- N,N-Diethyl-meta-toluamide (DEET).
- 1,4-Dioxane
- Metribuzin
- Naphthalene
- 1,2,4-Trichlorobenezene
- 1,2,3-Trichloropropane
- Tris(2-chloroethyl) phosphate
The new HRL values go into effect on Monday, September 30, 2013.