Under the Calderon-Sher Safe Drinking Water Act of 1996, public water systems with more than 10,000 service connections are required to prepare a report every three years for contaminants that exceed their respective public health goals (PHGs) (Health and Safety Code Section 116470[b]). This document contains health risk information on regulated drinking water contaminants to assist public water systems in preparing these reports. A PHG is the concentration of a contaminant in drinking water that poses no significant health risk if consumed for a lifetime. PHGs are developed and published by OEHHA (Health and Safety Code Section 116365) using current risk assessment principles, practices and methods.
The water systems’ report is required to present the numerical health risk for a contaminant, along with the category of health risk (e.g., carcinogenicity or neurotoxicity), and a plainly worded description of these terms. The cancer health risk, if any, is to be calculated at the PHG and at the California maximum contaminant level (MCL).