As You Sow v. Conbraco Industries

This appeal concerns the Safe Drinking Water and Toxic Enforcement Act of 1986 (Health & Saf. Code, §§ 25249.5-25249.13), adopted by the vote of the people at the November 1986 election as Proposition 65 (hereafter referred to as the Act or Proposition 65). The Act regulates the discharge of specific toxins into California’s drinking water. A plaintiff alleging an unlawful discharge bears the burden of proving that a discharge has in fact occurred.

California Code of Regulations, title 22, former section 12901 (hereafter Regulation 12901), which was adopted pursuant to the Act, previously established a hierarchy of testing methods, called “methods of analysis,” to be used in determining whether there has been a discharge. Any testing method, other than a “method of analysis,” could not be used to prove a discharge under the Act.

In this case, plaintiff alleged that plumbing parts manufactured and/or distributed by defendants discharged lead into sources of California drinking water. The sole issue tried below was whether, in its reliance upon a particular designated testing method, plaintiff met its burden of proving, under Regulation 12901 and therefore under…