To evaluate the risk of effects other than cancer from multiple chemicals detected in groundwater, a health risk index for each health endpoint must be calculated for each duration period using the procedure specified in this part.
Chemicals must be grouped according to health endpoints, other than cancer, specified in part 4717.7860, and according to duration except that:
chemicals for which no health endpoint is specified will not be grouped; and
a chemical will be included in the group for each health endpoint listed for that chemical.
Using the following equation, a noncancer health risk index must be determined for each group of two or more chemicals that have a common health endpoint and common duration period.
|Noncancer health risk indexduration=C1/nHRL1duration+C2/nHRL2duration+...+CN/nHRLNduration|
CN represents the concentration expressed as µg/L of the first through Nth chemical. In the case of a chemical that has been detected but cannot be quantified, CN is determined by standard statistical procedures.
MS s 103H.201
May 11, 2009
Copyright © 2009 by the Revisor of Statutes, State of Minnesota. All rights reserved.