1. Risk Factor: Implications of Stringent Drinking Water Standards Water Quality Water Supply Water Cost

2. Safe Drinking Water Quality Act of 1974 Regulates drinking water quality in the U.S. Ensures U.S. EPA controls substances with greatest risk at lowest cost Prevents contamination of source water Informs consumers of contaminant levels and health risks Helps states develop local regulations

3. Range of Contaminants Common Pollutants Perchlorate MTBE Cryptosporidium Chromium-6 Disinfectant and disinfectant byproduct rule (D/DBP) Volatile organic compounds (VOCs) Compounds of Emerging Concerns (CECs)

4. The Debate About Regulation of Perchlorate and Chromium-6 Southern California Water Coalition Advocates: Proper regulations augmented by best science available Risk factors for contaminants must be based on hard findings alone Regulations should be reconciled with feasibility of compliance

5. Implications for the San Gabriel Valley Water Quality San Gabriel Basin WQA lead agency to clean up contaminated groundwater but $700 million funding gap Water Supply Uncertainty about SWP and concerns about CR reliability Water Cost Imported water costs will continue to increase