When testing indicates that chemical breakdown products (degradates) are present in groundwater, it is necessary to consider those breakdown products in a risk assessment. When no health risk limit or other health-based water value exists for a chemical breakdown product, due to absence or paucity of toxicity information on the chemical breakdown product, the health risk limit specified for the parent chemical in part 4717.7860 is the health risk limit for the chemical breakdown product. When a parent and one or more of its breakdown products are present, or when multiple breakdown products are present even in the absence of the parent, it is necessary to conduct a risk assessment for multiple chemicals, according to the procedures in parts 4717.7880 and 4717.7890.
MS s 103H.201
May 11, 2009
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