How Clean Is My Drinking Water?
Water quality testing ensures that our drinking water is safe and meets federal and state drinking water standards. The US Environmental Protection Agency establishes federal standards that determine the maximum concentration allowable for specific contaminants in tap water. In California, the State Water Resources Control Board Division of Drinking Water is responsible for regulating drinking water. While tests are important for identifying potential health issues, the presence of some contaminants does not necessarily indicate the water is unsafe to drink for all populations.

How Can Contaminants Get into My Tap Water?
Water service providers are responsible for providing safe drinking water to water meters, and property owners/landlords are responsible for maintaining infrastructure from the meter to tap. In some cases, domestic water quality issues result from infrastructure that is the responsibility of the owner/landlord to maintain.
How often is my water tested and reported?
The State Water Resources Control Board Division of Drinking Water (DDW) requires community water systems to publish and make available an annual Consumer Confidence Report. Water agencies collect water samples from designated sampling points or wells quarterly, and report results in the annual report.
What is my water tested for?
The EPA has set maximum contaminant levels (MCLs) for more than 90 contaminants, and maintains a list of unregulated contaminants that may require thresholds in the future.
What is an exceedance?
An exceedance occurs when a concentration of a contaminant is above the established safe threshold and could potentially cause a threat to human health. When this occurs, agencies are responsible for sending an unsafe water notice to all customers and instructions on how to proceed when using tap water.
Are Property Owners Responsible for Water Quality?
Water service providers are responsible for providing safe water to water meters, and property owners/landlords are responsible for maintaining water infrastructure from the meter to tap. In some cases, domestic water quality issues result from infrastructure that is the responsibility of the owner/landlord to maintain.