Some of California’s aquifers are contaminated with chemicals. One of the greatest dangers is nitrates, which leach from fertilizers, manure and sewage. Pesticides, oil waste, industrial solvents and other contaminants also pollute groundwater.

More than one million Californians have unsafe drinking water — the systems that provide their water have failed to meet state standards, according to a 2021 state audit. Most of these people are in the Central Valley, but large numbers are in San Bernardino and Kern counties, too. “Hundreds of failing water systems have been providing unsafe drinking water for years,” the audit says. “The State Water Board has demonstrated a lack of urgency to provide needed assistance.” About two-thirds of the failed water systems serve disadvantaged communities.

In 2012 Brown signed into law AB 685, the Human Right to Water Act, which aims to bring safe, clean water to all Californians. A 2019 law provided up to $130 million in 2020-21 funding to help water providers in small, low-income communities fix their failed systems.