Nearly 4 million people are served drinking water from the Los Angeles Department of Water and Power, making it one of the largest water utilities in the U.S. With the release of the 2025 update of EWG’s Tap Water Database, we took a closer look at this expansive system for the millions of Angelenos served by it, comparing it to the nation as a whole. In addition to information about L.A. drinking water quality, the Tap Water Database provides details about chemical and radioactive contaminants in the water of nearly 50,000 community systems nationwide. … Test results through 2024 showed 24 contaminants found in the L.A. system, with nine at levels above EWG’s health-based limits.