- You are Here
- Home
- Departments
- Water Quality
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.
Annual Reporting
The District provides an annual update to the community on water quality in the Consumer Confidence Report. View the most recent report (PDF).
Water Quality Sampling
The District collects water samples weekly, monthly, quarterly, annually and tri-annually to ensure the safety and quality of the water served. Sample frequency depends on State regulations and health risk factors.
Click here to view the District’s sampling pyramid, which provides an example of the various samples and frequency of collection.
Consumer Confidence Report
Providing the community with the opportunity to access information about the quality of your drinking water, detected contaminants, and possible health risks is an important job for all water suppliers. State and federal regulations currently in place are very important, and EVWD makes every effort to present this detailed information in a simplified manner.
The Consumer Confidence Report is made available to all customers each spring. Results found are based on an average of all samples collected throughout the year.
Most Recent Report (PDF) | View All Reports
Home Sampling
To ensure the safety of water being delivered to customers, East Valley Water District routinely samples water for harmful contaminants. Samples collected by the District are representative of the water quality being delivered to customers through the meter. Results from samples may not be representative of the water found in the home like plumbing, treatment equipment, and fixtures vary in each home.
For information regarding home water sampling please contact the Water Quality Department at (909) 806-4222.
Total Trihalomethanes
Total Trihalomethanes (TTHMs) are a group of four chemicals that are formed during the water treatment process when chlorine reacts with organic materials such as leaves, plants, and soil in the untreated water. The District regularly conducts water quality testing, including for Trihalomethanes or TTHM. To view quarterly testing results, click here.
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.
Granular Activated Carbon
The District made enhancements to its Surface Water Treatment Plant, known as Plant 134, to include Granular Activated Carbon (GAC) technology. GAC is proven technology that serves as an additional treatment process to further remove a wide range of contaminants from drinking water. This process is highly effective at capturing organic material using activated carbon to attract and adsorb contaminants as water flows through it.
Water System Flushing
Water Main Flushing is a process in which pipes are cleaned by forcing water through at high speeds. Flushing removes sediment that can cause water to appear dirty or discolored, helping to improve the water’s taste and appearance. East Valley Water District water quality staff will open fire hydrants and allow water to flow out uninterrupted for 5-10 minutes. This is an important part of maintaining a healthy drinking system. To view an interactive map with flushing and valve exercising activities occurring in the District, click here.
Tank Mixing
Water storage is an important part of the District's water distribution system. The District currently maintains approximately 30 Million Gallons of potable water storage. This storage capacity allows the District to provide surplus water for fire protection and maintain water delivery during emergencies. Recently, the District has added some tank mixing equipment to multiple tanks to improve water quality and reduce water age to ensure the water delivered to our customers is reliable and uniform in quality.
Valve Exercising
Valve exercising allows the District to isolate areas for necessary repairs in the event of an emergency and are an important element to maintaining the distribution system. To ensure proper operation, valves are routinely exercised. During this process, it may be necessary to flush the lines to eliminate any particles that may have collected in the valve. Click here to see where staff may be performing valve maintenance and exercising.
Frequently Asked Questions
Have questions about your water pressure or cloudy water? Click here for answers to water quality frequently asked questions.
Cross-Connection Control
East Valley Water District currently maintains a Cross-Connection Control program under Title 17 of the State of California Administrative Code by conducting site surveys and inspections of customers' properties to determine if any potential hazards exist that would require the need of backflow protection.
Cross-Connection also oversees the annual testing and maintenance of currently installed backflow prevention assemblies.
Backflow Prevention
The District requires the annual testing and maintenance of all currently installed backflow devices. Beginning April 3, 2017, EVWD will be offering backflow device testing for only $60 per year, a service that can be prorated on your account at $5 per month.
Please visit the Backflow Prevention page for complete program information and application.