Project Updates

Groundwater Wellhead Treatment System Project

Since the discovery of the contaminant perchlorate in the Rialto-Colton groundwater basin in 2000, the public has become increasingly concerned of its effects on the community. In April 2002, the State of California Department of Public Health Services issued a Conditional Acceptance of “biological treatment as a means of removing perchlorate from source waters for distribution as a part of the public water supply.” West Valley Water District has teamed up with the City of Rialto to construct a “bioremediation” wellhead treatment system that would help stabilize water supplies in the Rialto-Colton groundwater basin.

What is bioremediation?

Bioremediation allows natural processes to clean up harmful chemicals in the water. Microscopic organisms, which are already present in the groundwater, consume certain harmful chemicals such as perchlorate. After allowing this natural process to occur, the water is sent through a traditional water treatment process before it enters the drinking water system. Bioremediation does not use harmful chemicals.

Why are we using bioremediation?

Contaminants, like perchlorate, exist in the water that is underground. We have been using an effective treatment to clean the water, but it is expensive. When the level of contaminants increases, the current method of treatment becomes even more expensive. Bioremediation, on the other hand, is proven safe, does not use harmful chemicals, and costs less.

How safe is this type of water treatment?

It has been successfully tested for safety and subsequently used at many locations in the western U.S. for years. After the water passes through the bioremediation treatment system, it then goes through a traditional water treatment system. Water quality testing occurs throughout the entire process.

Where is the bioremediation plant located?

The plant has been constructed and is operated by West Valley Water District at our site at the corner of Base Line Road and Cactus Avenue in Rialto.

Who will pay for the construction of the plant?

To date, WVWD has been awarded a total of $16.7 million collectively contributed by the State of California Department of Public Health Services ($10 million, Proposition 84), Santa Ana Regional Water Quality Control Board ($2.8 million, CAA Account), the Department of Defense ($2.9 million, ESTCP) and the Department of Water Resources ($1 million, Proposition 84) via Santa Ana Watershed Project Authority (SAWPA).