Regional board resumes Salton Sea water-quality monitoring; HABs and hydrogen sulfide raise public-health concerns

The Colorado River Basin Regional Water Quality Control Board told the State Water Board at the May 21 workshop that it has resumed systematic Salton Sea sampling after several years of limited access, but warned monitoring coverage still is constrained by funding and boat access.

Emma McCorkle, senior environmental scientist for the regional board, said the agency secured about $350,000 in U.S. EPA 205(j) funding to restart water-quality lab analyses and partnered with California Department of Fish and Wildlife (CDFW) and the Department of Water Resources (DWR) to use CDFW boats and DWR site coordination to collect samples beginning in November 2023. “If we could get funding for sampling, we could collect data again,” McCorkle told the board.

Why it matters: water quality at the Salton Sea affects recreation and may be linked to localized health problems. Harmful algal blooms (HABs), elevated nutrients and odors from hydrogen sulfide were raised repeatedly during the workshop by community groups.

What monitoring has shown so far - Preliminary results from the resumed sampling show very high salinity in the Sea: total dissolved solids measured in samples ranged roughly from 75 to 82 parts per thousand, compared with ocean salinity of about 35 parts per thousand. - The regional board and partners have taken sediment samples at rotating sites; sediment testing reported no detections of several legacy and current-use pesticides (DDT/degradates, chlorpyrifos, pyrethroids) in the samples referenced at the workshop. - The board is conducting HAB testing in periods of high recreational use and said HABs remain a persistent problem; agencies said additional funding and study are needed to understand bloom development and public-health risks.

Limitations and next steps cited at the workshop - Boat access: long-term sample collection was halted earlier because rising shoreline left historic ramps unusable. The SCH boat ramp restored practical sea access for the southern sites, but the northern shoreline remains difficult to access and requires more time and logistical coordination. - Funding timeline: regional board funding that supported the 2023–2026 sampling effort runs through 2026; additional funds will be needed to maintain or expand the work.

Community concerns raised at the workshop Multiple community organizations and speakers asked for more comprehensive and…