Who Do We Serve?

West Valley Water District serves approximately 82,000 customers in the communities of Bloomington, Colton, Fontana, Rialto, parts of unincorporated areas in San Bernardino, and a portion of Jurupa Valley in Riverside County.

Where Is Our Water From?

West Valley Water District is composed of three water sources: groundwater, surface water and imported water.

Groundwater (46%)

The majority of our water supply comes from groundwater.  Approximately 46% of the total water supply is from the District’s groundwater wells, located in five local groundwater basins:

  • Chino Basin
  • Bunkerhill Basin
  • Lytle Creek Basin
  • North Riverside Basin
  • Rialto-Colton Basin

Surface Water (13%)

The District receives approximately 13% of our total water supply from Lytle Creek in the San Bernardino Mountains, and is treated through our Oliver P. Roemer Water Filtration Facility. The water goes through several treatment processes and disinfection prior to delivery. 

Imported (41%)


The District purchases water from the Baseline Feeder Project through San Bernardino Valley Municipal Water District. This water comes from water pumped to Rialto from wells in San Bernardino, which makes up approximately 24% of our total water supply.

Surface Water

The District also purchases approximately 17% of our total water supply from the State Water Project through San Bernardino Valley Municipal Water District. Also treated through our Oliver P. Roemer Water Filtration Facility.

How Often Is Our Water Tested?

Our water quality staff collects samples on a weekly, monthly, quarterly, annual and triennial basis using EPA and State Water Resources Control Board – Division of Drinking Water (DDW) regulations. We test for over 80 contaminants to ensure strict standards of water quality. 

How Safe Is Our Water?

West Valley Water District vigilantly safeguards its water supplies. Our water meets all Federal and State Regulations. We are proud that the District always meets, and exceeds, these standards.

What Is The District Doing To Protect Our Water?

We are committed to improving water quality through innovative technologies. The District operates and maintains several treatment plants to ensure we deliver clean and safe water to our consumers: 

  • The Groundwater Wellhead Treatment System, a new, first-in-the-nation project, using ground-breaking, cost-effective technology called bioremediation, was approved to remove perchlorate from drinking water supplies.  The Groundwater Wellhead Treatment System utilizes Fluidized Bed Biological Reactors (FBRs) to remove perchlorate and nitrate from District Well No. 11 and Rialto Well No. 6. This treatment facility using FBR technology began delivering clean water to our customers in September 2016. The next treatment system that is currently under construction uses Fixed Bed Reactors (FXBs) for perchlorate, nitrate, and trichloroethylene removal.  The FXB technology began construction in summer 2016 and will start delivering clean water to our customers in 2018.
  • The Oliver P. Roemer Water Filtration Facility treats surface water from Lytle Creek and State Project Water delivered through Lake Silverwood. 
  • The Arsenic removal treatment plant treats water from Well No. 2.
  • Several Ion Exchange Treatment Systems remove perchlorate from Well Nos. 16, 17, 18A, and 42.

What Contaminants Are Being Tested? 

West Valley Water District tests according to Title 22 of the California Code of Regulations, Safe Drinking Water Act. Click here to read Title 22

The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally-occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity. Contaminants that may be present in source water include:

  • Microbial contaminants, such as viruses and bacteria that may come from sewage treatment plants, septic systems, agricultural livestock  operations, and wildlife.
  • Inorganic contaminants, such as salts and metals, that can be naturally-occurring or result/ram urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
  • Pesticides and herbicides that may come from a variety of sources such as agriculture, urban storm water runoff, and residential uses.
  • Organic chemical contaminants, including synthetic and volatile organic chemicals that are by-products of industrial processes and petroleum production, and can also come from gas stations, urban storm water runoff, agricultural application, and septic systems. 
  • Radioactive contaminants that can be naturally-occurring or be the result of oil and gas production and mining activities. 

In order to ensure that tap water is safe to drink, the US. Environmental Protection Agency (USEPA) and the State Water Resources Control Board (State Board) prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. State Board regulations also establish limits for contaminants in bottled water that provide the same protection for public health. 

Who is most vulnerable to contaminants in drinking water?

Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. USEPA/Centers for Disease Control (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (1-800-426-4791).

Where can I get more information about water contaminants?

To view completed source water assessments, you may visit our District office located at: 855 W Base Line, Rialto, California, 92376 or call (909) 875-1804.  You may also call the USEPA’s Safe Drinking Water Hotline to discuss local drinking water quality, drinking water standards, contaminants, and potential health effects at 1-800-426-4791.

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the USEPA’s Safe Drinking Water Hotline (1-800-426-4791).