- Agencies and Cadiz partner on groundwater cleanup.
- Focus on Rialto-Colton Basin and Cactus Basins recharge.
- New filtration systems will address perchlorate risks.
Tuesday, September 9, 2025 — On September 5, 2025, the San Bernardino Valley Municipal Water District, Fontana Water Company, and Cadiz Inc. announced a partnership
to address perchlorate contamination in the Rialto-Colton Groundwater Basin. The agreement supports the proposed Cactus Basins Recharge Program, which is intended to expand groundwater replenishment, improve water quality, and enhance water supply reliability in San Bernardino County.
Perchlorate, a chemical often linked to rocket fuel, fireworks, and explosives, has been found in groundwater across the United States, including parts of San Bernardino County. Because it dissolves easily in water and does not break down quickly, it can spread widely once released. The main health concern is its ability to interfere with the thyroid gland’s use of iodine, which can affect metabolism and development. (Sources: EPA, FDA)
How the Treatment Works.
Under the agreement, Cadiz will provide advanced filtration systems to Fontana Water Company. These systems, built by Cadiz’s subsidiary ATEC Water Systems, are designed to remove perchlorate from groundwater and prevent further migration of contamination as San Bernardino Valley begins recharging water through the Cactus Basins. The treatment systems are part of a broader 200,000 acre-foot water supply agreement between Fontana Water Company and Cadiz that was signed in 2024.
San Bernardino Valley CEO and General Manager Heather Dyer described the program as critical for long-term water reliability. “We are looking forward to exploring potential opportunities offered through this unique public-private partnership that could address legacy perchlorate contamination while also providing critical groundwater supply benefits to the communities depending on the Rialto-Colton Groundwater Basin,” she said.
Cadiz CEO Susan Kennedy emphasized the broader benefits. “By deploying cost-effective advanced treatment technology, we can unlock low-cost water supplies for the whole region,” she said, noting that the project could serve as a model for collaborative groundwater management.
Regional Water Supply Strategy.
San Bernardino County faces mounting challenges in securing reliable water supplies. Physical risks, climate variability, and uncertainty in State Water Project deliveries have put pressure on local supplies. At the same time, the region has struggled with impaired groundwater that requires cleanup before use.
The Cactus Basins Recharge Program would spread imported State Water Project water into the existing Cactus Basins, where it would filter into the Rialto-Colton subbasin. From there, water would be pumped through existing wells to supplement potable supplies. Planning has been delayed, however, due to concerns about contaminant migration, making the treatment partnership an important step forward.
San Bernardino Valley has invested in storage and recharge projects to strengthen drought resilience and maximize the use of imported water during wet years. The district’s integrated strategy also includes sustainable and equitable access to clean water across its service area, which serves communities from Fontana and Rialto to Redlands and Yucaipa.
About the Partners.
-
San Bernardino Valley Municipal Water District
was created in 1954 to plan long-term supplemental water supplies for the region and imports water through the State Water Project. -
Fontana Water Company
, a division of San Gabriel Valley Water Company, has provided water service to the City of Fontana for more than 75 years. -
Cadiz Inc.
, founded in 1983, is a California water solutions company with projects including the Mojave Groundwater Bank, a large storage and supply facility in the Mojave Desert.