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 public-facing data, stronger nutrient-management measures and faster regulatory action to protect public health. Leadership Council for Justice and Accountability and local community science groups pressed for clear public dashboards and asked whether nutrient loads and hydrogen sulfide exceedances are being tracked and addressed through regulatory tools such as TMDLs.

Speakers - Emma McCorkle — Senior Environmental Scientist, Colorado River Basin Regional Water Quality Control Board (government) - Crystal Otworth — Leadership Council for Justice and Accountability (nonprofit), speaking for local community interests - Representatives from CDFW and DWR who described cooperative sampling logistics

Authorities - type:other name:"Monitoring and Implementation Plan (MIP) for the Salton Sea" referenced_by:["salton-sea-water-quality-and-health-monitoring"] - type:statute name:"Clean Water Act (Section 303(d) / 303(d) listing and TMDL authority)" referenced_by:["salton-sea-water-quality-and-health-monitoring"]

Discussion vs. decision - Discussion only: agencies described resumed sampling, preliminary results and logistical constraints; community members raised concerns about HABs, hydrogen sulfide and the need for nutrient controls. - Direction/assignment: agencies will continue sampling where possible, seek additional funding, and coordinate with sister agencies to expand monitoring; no new regulatory measures were adopted at this meeting.

Clarifying details - Category:"sampling_start" detail:"Regional Water Board sampling resumed November 2023 using the SCH boat ramp; sampling has concentrated at 3 southern sites due to access constraints in the north" source_speaker:"Emma McCorkle" - Category:"salinity" detail:"Measured total dissolved solids about 75–82 parts per thousand in recent samples; ocean ~35 ppt" source_speaker:"Emma McCorkle" - Category:"funding_end" detail:"Regional board 205(j) funding for sampling runs through 2026; additional funding is required to sustain monitoring at current levels" source_speaker":"Emma McCorkle"},{"category":"HABs","detail":"Harmful algal blooms are a persistent issue; regional board conducts targeted HAB monitoring during higher recreation periods; fuller HAB program requires more funds","source_speaker":"Emma McCorkle"}],"proper_names":[{"name":"Colorado River Basin Regional Water Quality Control Board","type":"agency"},{"name":"Monitoring and Implementation Plan","type":"program"},{"name":"Leadership Council for Justice and Accountability","type":"nonprofit"},{"name":"California Department of Fish and Wildlife","type":"agency"}],"community_relevance":{"geographies":["Salton Sea shoreline","Bombay Beach","Coachella Valley"],"funding_sources":["U.S. EPA 205(j)","state grants"],"impact_groups":["recreational users","nearby residents with respiratory illness concerns"]},"meeting_context":{"engagement_level":{"speakers_count":8,"duration_minutes":35,"items_count":1},"implementation_risk":"high","history":[{"date":"2016-01-01","note":"Regional water board last collected routine Salton Sea samples prior to access loss"},{"date":"2023-11-01","note":"Regional board resumed sampling using SCH boat ramp"}]},"searchable_tags":["water quality","HABs","hydrogen sulfide","TMDL","salinity"],"provenance":{"transcript_segments":[{"block_id":"s10852.425-e10885.665","local_start":0,"local_end":260,"evidence_excerpt":"The regional water board has conducted water quality monitoring for decades as part of the surface water ambient monitoring program or SWAMP... The construction of the species conservation habitats included a boat ramp into the Salton Sea and regional water board staff saw an opportunity.","global_start":10852,"global_end":10885,"tc_start":"00:03:12","tc_end":"00:03:45","reason_code":"topicintro"},{"block_id":"s11108.226-e11145.79","local_start":0,"local_end":260,"evidence_excerpt":"Some preliminary results have shown that the Salton Sea has continued to increase in salinity as expected. Our data shows that the concentration of total dissolved solids to be between 75 and 82 parts per thousand... For comparison, the ocean has roughly 35 parts per thousand.","global_start":11108,"global_end":11145,"tc_start":"00:03:28","tc_end":"00:03:55","reason_code":"topicfinish"}]},"salience":{"overall":0.78,"overall_justification":"Water quality sampling and HABs are directly relevant to public health and recreation, and the resumed sampling after loss of access is a material program development.","impact_scope":"regional","impact_scope_justification":"Results matter to shoreline communities and regional health agencies.","attention_level":"high","attention_level_justification":"Community commenters raised health concerns; monitoring funding expires in 2026.","novelty":0.45,"novelty_justification":"Resumption of sampling is important but expected; preliminary salinity findings confirm known trends.","timeliness_urgency":0.82,"timeliness_urgency_justification":"Monitoring gaps and community health concerns mean additional funding and near-term action are timely.","legal_significance":0.55,"legal_significance_justification":"TMDL development and regulatory responses implicate Clean Water Act authorities.","budgetary_significance":0.30,"budgetary_signification_justification":"Resumed monitoring uses modest grant funds but requires sustained funding.","public_safety_risk":0.70,"public_safety_risk_justification":"HABs and hydrogen sulfide are local public-health concerns when they recur.","environmental_impact":0.60,"environmental_impact_justification":"High salinity and nutrient loading affect aquatic ecology and HAB formation.","affected_population_estimate":15000,"affected_population_estimate_justification":"Nearby shoreline communities and frequent recreational visitors; rough local estimate.","affected_population_confidence":0.5,"affected_population_confidence_justification":"Estimate is approximate; workshop did not provide a precise exposure population number.","budget_total_usd":350000.0,"budget_total_usd_justification":"Regional Water Board cited ~ $350,000 in EPA 205(j) funding for sampling efforts (2023–2026).","decision_deadline":"2026-12-31","decision_deadline_justification":"Regional board sampling grant described runs through 2026.","policy_stage":"implementation","policy_stage_justification":"Monitoring is active; larger regulatory actions (TMDLs) remain to be pursued.","follow_up_priority":1,"follow_up_priority_justification":"High priority to secure ongoing monitoring funding and to expand public data access.","fact_check_risk":0.25,"fact_check_risk_justification":"Preliminary lab results and funding amounts were described on the record; these should be verified in final datasets and grant documents.","uncertainty":0.5,"uncertainty_justification":"Sampling across the whole sea is limited by access and funding; HAB drivers are complex.","source_diversity":0.6,"source_diversity_justification":"Regional board, CDFW and community groups provided perspectives.","stakeholder_balance":0.6,"stakeholder_balance_justification":"Technical agencies and community advocates participated; tribal engagement was invited but no tribal speakers signed up."}},{