Water Quality


To ensure that water is safe to drink, the United States Environmental Protection Agency (EPA) and the State Water Resources Control Board (SWRCB) prescribe regulations that limit the amount of certain constituents in drinking water. To meet these regulations, the Los Angeles County Waterworks Districts (LACWD) contracts with a state-certified laboratory to conduct all water quality analyses. These tests are performed routinely on water samples taken from the distribution system. Several key locations within the distribution system have been selected to test for bacteria, color, turbidity, odor, and disinfectant level on a regular interval to ensure that you receive safe and high quality drinking water. Our contract laboratory is equipped with state-of-the-art instruments capable of detecting contaminants in very minute quantities.

There are two drinking water quality standards, primary drinking water standards and secondary drinking water standards. Primary drinking water standards are set for substances that are thought to pose a health risk at certain levels and are enforceable by law. Secondary drinking water standards are set for substances that do not pose a health risk and are intended to control the aesthetic qualities related to the public acceptance of drinking water such as taste and smell. Secondary drinking water standards are not enforceable by law.

LACWD is committed to serving you a reliable supply of high quality water that meets and exceeds all primary and secondary drinking water standards. We strive to ensure your water is healthy and meets your aesthetic needs.

For additional information regarding drinking water regulations, please visit the EPA Ground Water and Drinking Water or State Water Board Division of Drinking Water Programs websites.

Public Health Goals Reports

Los Angeles County Waterworks District No. 40 Regions 4 & 34 is required by California Environmental Protection Agency to prepare a triennial Public Health Goals (PHGs) report to inform consumers with information on the detection of any contamination above any Public Health Goals established by the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) or Maximum Contaminant Level Goals (MCLGs) set by the United States Environmental Protection Agency.

2016 Public Health Goals Report
2019 Public Health Goals Report
2022 Public Health Goals Report

2022 PHG Report Webinar

The 2022 Public Health Goal (PHG) Report Webinar recording is available upon request.

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