1. (a) A person otherwise responsible for an exposure to a listed chemical which involves the use of drinking water, including the use of drinking water in food or any other consumer product, does not “expose” an individual within the meaning of Section 25249.6 of the Act to the extent that the person can show that the listed chemical was contained in drinking water which was received from:

   1. (1) a public water system, as defined in Section 116275 of the Health and Safety Code (1997);
   2. (2) a commercial supplier of drinking water; or

   3. (3) a source of drinking water in compliance with all applicable primary drinking water standards for all listed chemicals and the chemical in question is the result of treatment of the water in order to achieve compliance with primary drinking water standards.

      Where the source of the listed chemical is in part from such drinking water and in part from other sources, “exposure” can occur only as to that portion of the listed chemical from sources other than such drinking water.

2. (b) For purposes of subsection (a), the amount of a listed chemical contained in drinking water shall be determined by sampling of the drinking water at the point of delivery and by testing pursuant to Section 25901. If sampling and testing is impractical, the amount of a listed chemical shall be based on test results of the most recent sample of the drinking water taken by the public water system or the commercial drinking water supplier, provided that all sampling and testing has been conducted at the frequency and in the manner required by law, or alternatively, such amount shall be calculated at five percent of the maximum contaminant level set forth in the primary drinking water standard for the listed chemical.

Note: Authority cited: Section 25249.12, Health and Safety Code. Reference: Sections 25249.6 and 25249.11, Health and Safety Code.

History

1. New section filed 7-10-89; operative 8-9-89 (Register 89, No. 30).

2. Amendment filed 1-7-2003; operative 2-6-2003 (Register 2003, No. 2).

3. Change without regulatory effect renumbering title 22, section 12502 to title 27, section 25502, including amendment of subsection (b), filed 6-18-2008 pursuant to section 100, title 1, California Code of Regulations (Register 2008, No. 25).