Water Quality

East Valley Water District staff regularly monitors the water system quality. Throughout each year, the District collects over 3,200 water samples and flushes 680 fire hydrants in order to maintain the high quality drinking water supply. 

For More Information


If you are curious about chlorine levels at your house or have questions about water quality, please contact the District’s Water Quality Team at (909) 806-4222.

Water Treatment


East Valley Water District’s primary water quality goal is to protect public health and safety. In order to ensure the water is free of harmful bacteria and other microorganisms, levels of chlorine that meet State and Federal guidelines are added to the water distribution system, which can range from 0.2- 4 parts per million (PPM). 

The District chlorinates all water wells to a target level of 0.8 to 1.2 ppm and tries to maintain storage reservoirs at this chlorine level. We are required to maintain chlorine levels at every point in the water distribution system as proof that the entire system is protected against harmful microorganisms.

Many people are able to taste or smell extremely low concentrations of chlorine in water and may be able to detect the levels we try to maintain in our water system. In order to keep an adequate chlorine residual throughout the water system customers who are located closer to the treatment location may detect some chlorine taste and odor. The District strives to balance the need for ensuring adequate protection for the drinking water against the possibility of customers experiencing chlorine taste and odor.

Water Sources


Drinking water within the District’s service area comes from three difference water sources: groundwater, surface water from the Santa Ana River, and imported water from Northern California. Customers may notice a difference in taste and hardness (mineral and organic content) at different times of year, depending on the water supply in use. This natural variation is a common occurrence with water systems that have the ability to use different water supply sources, and it does not impact the quality of the drinking water.

Annual Reporting

The District provides an annual update to the community on water quality in the Consumer Confidence Report. View the most recent update