California Attorney General Rob Bonta issued an enforcement advisory letter to landlords on Mar. 12, urging compliance with Assembly Bill 2454, which requires participation in free water testing and treatment programs for domestic wells. The advisory targets properties in areas covered by well testing programs and aims to protect tenants in rural and disadvantaged communities from contaminated drinking water.
The issue is significant because more than one million Californians rely on private domestic wells, many of which have never been tested for contamination. According to the State Water Board’s 2025 Drinking Water Needs Assessment, nearly one-third of California’s domestic wells are at risk of failing to provide safe drinking water. Groundwater contaminants such as nitrates, arsenic, pesticides, and per- and polyfluoroalkyl substances can cause serious health problems including cancer and thyroid dysfunction.
“Access to safe drinking water is a fundamental human right. Everyone deserves clean, safe water in their home. Without systematic testing, contamination can remain hidden, leaving households unknowingly exposed and cut off from solutions that already exist,” said Attorney General Rob Bonta. “AB 2425 ensures that free, accessible water testing and treatment programs are available, so no one is left in the dark about their water quality and every community has the opportunity to protect their health and well-being. I urge landlords with drinking water wells to follow the law and test their wells to provide safe drinking water to protect public health and the environment from the threat of water contamination.”
Assemblymember Alex Lee said: “California recognizes the universal human right to safe drinking water. But rural and disadvantaged communities that rely on domestic wells remain disproportionately exposed to contaminated water. AB 2454 protects the health of tenants who depend on well water by ensuring free and existing domestic well programs are effective, accessible, and equitable. Participating in these programs is essential to preventing exposure to toxic contaminants. We must ensure that everyone has access to clean water.”
Yvonne West, Director of the Office of Enforcement for the State Water Resources Control Board said: “Protecting public health is our top priority, and a huge part of achieving that is ensuring people have information about potential health risks in their environment, especially in their homes. Compliance with this new law means that tenants will get the benefit of available well testing and alternative water supply programs, at no cost to landlords. It is an important step toward strengthening the protection of public health in these communities.”
The advisory explains that AB 2454 took effect in September 2024 and requires landlords with rental properties using domestic wells to participate in state or regional board-administered or funded testing programs. Landlords must provide tenants with test results within ten days along with interpretation guidance; they must also join any available remediation efforts such as bottled water delivery or connection to safer sources without charging tenants extra fees or raising rent due to participation.
Research shows Latino populations face higher risks: a ten percent greater Latino population correlates with a thirteen-to-twenty-three percent higher likelihood of elevated contaminant levels in drinking water. The Central Valley counties—Fresno, Sonoma, San Joaquin, Tulare—have been identified as having high numbers of at-risk wells.
The California Attorney General’s office promotes transparency through tools like OpenJustice for publishing criminal justice data according to its official website. The office forms an integral component of California’s executive branch as outlined by the state constitution according to its official website. It serves as chief law enforcement authority focusing on enforcing laws related to civil rights, consumer protection, economic security, environmental justice according to its official website, under leadership by Rob Bonta according to its official website. Its authority extends statewide according to its official website.
Landlords seeking more information about eligibility for free testing can visit https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/private-domestic-well-testing.html.
