State expands program that has provided free replacement water for over 1,800 nitrate-impacted wells

SACRAMENTO – Building on the success of a groundbreaking program that has already helped thousands of Central Valley residents, the Central Valley Regional Water Quality Control Board is expanding its Nitrate Control Program (NCP) to eight more groundwater basins, ensuring thousands more households that rely on domestic wells have access to safe drinking water.

Launched in 2021, the Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) Nitrate Control Program has had a significant impact. Since the program began, over 9,000 wells have been sampled in Priority 1 basins – those groundwater basins identified as having the most serious contamination issues – and free replacement drinking water has been provided to over 1,800 households with nitrate- impacted wells. Additionally, over 3.7 million gallons of safe drinking water have been distributed through bottled water deliveries and eight public water filling stations across the region.

of this program, and the results speak for themselves,” said Patrick Pulupa, Executive Officer for the Central Valley Water Board. “Expanding into more zones means thousands more families will have the peace of mind that comes with knowing their water is safe—or getting immediate help if it’s not.”

Nitrate in drinking water can lead to serious health issues, especially for infants and pregnant women. It is considered a risk to human health when it is above 10 parts per million (ppm) of nitrate nitrogen, which is the primary maximum contaminant level (MCL), also known as the nitrate drinking water standard.

The Nitrate Control Program is a collaborative effort between the Central Valley Water Board, management zone leaders, and the regulated community. The Central Valley Water Board early last year issued over 900 notices to comply to dischargers in these areas—including growers, dairies, industrial facilities, and wastewater plants—requiring them to begin well testing and to provide free replacement water where nitrate contamination exceeds health standards. The starting date for compliance was Feb. 26, 2025.

This phase of the program will expand free well testing and drinking water assistance to residents across the following Priority 2 groundwater basins: Delta-Mendota, Eastern San Joaquin, Madera, Merced, Kern County (Poso & West-side South), Tulare Lake and Yolo.

In addition to addressing nitrate contamination, program partners, such as Valley Water Collaborative and the Kaweah Delta Water Conservation District have expanded their testing to screen for other harmful contaminants, including arsenic, uranium, and 1,2,3- TCP, through funding from the State Water Resources Control Board’s Safe and Affordable Funding for Equity and Resilience (SAFER) program.

Residents in the newly added management zones can expect outreach beginning in early 2025 with information on how to apply for free well testing. If their well water exceeds the nitrate drinking water standard (10 mg/L of nitrate nitrogen), they will qualify for free replacement drinking water through bottled water deliveries or filling stations.

Residents and dischargers can learn more about the CV-SALTS Nitrate Control Program at www.cvsalinity.org.

The Central Valley Regional Water Board is a state agency responsible for managing water quality and protecting surface and groundwater beneficial uses such as aquatic habitat and human health for 11,350 miles of streams, 579,110 acres of lakes, and the largest contiguous groundwater basin in California. It is the largest of nine regional boards, encompassing 60,000 square miles, or about 40 percent of the state. Thirty- eight of 58 counties are either completely or partially within the regional board's boundaries, formed by the crests of the Sierra Nevada on the east, the Coast Ranges and Klamath Mountains on the west, the Oregon border on the north, and the Tehachapi Mountains on the south