California opens $46 million grant program for border water quality projects

California has opened a $46 million grant program aimed at addressing water quality issues tied to transboundary pollution along the U.S.-Mexico border, while renewing calls for federal action to resolve ongoing wastewater infrastructure problems in the Tijuana River watershed.

The funding, announced by Governor Gavin Newsom, is being made available through Proposition 4, a voter-approved bond measure passed in 2024. The grant program will support projects that reduce bacteria and trash pollution, address public health concerns, improve sediment management, and advance restoration efforts in waterways impacted by cross-border contamination.

The funding comes as California continues to press federal agencies to complete upgrades to the South Bay International Wastewater Treatment Plant, which treats wastewater originating from Tijuana. State officials noted that EPA Administrator Lee Zeldin pledged a "100% solution" to the long-running Tijuana River pollution crisis in 2025, but California argues that a permanent fix has yet to be delivered.

According to the state, California has already committed approximately $38 million since 2019 toward projects addressing Tijuana River pollution, including sediment and trash capture systems, habitat restoration, water quality monitoring, and air quality mitigation efforts.

Under the new program, implementation projects can receive up to $10 million in funding, with larger awards of up to $20 million possible with approval from the State Water Board. Applications will be accepted through Aug. 31, 2026.

The announcement comes amid continued concerns about sewage-contaminated flows entering the Tijuana River and Pacific coastline, creating public health risks and prompting ongoing wastewater infrastructure investments on both sides of the border.