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CALIFORNIA LEGISLATURE— 2025–2026 REGULAR SESSION

94

Introduced by Senator Padilla

(Coauthor: Senator Blakespear)

January 8, 2025

An act to add Section 41514.7 to the Health and Safety Code, relating to air pollution.

Vote: majority   Appropriation: no   Fiscal committee: yes   Local program: no

LEGISLATIVE COUNSEL’S DIGEST

Existing law generally designates the State Air Resources Board as the state agency with the primary responsibility for the control of vehicular air pollution, and designates air pollution control districts and air quality management districts with the primary responsibility for the control of air pollution from all sources other than vehicular sources. Existing law requires the state board to inventory sources of air pollution within the air basins of the state, determine the kinds and quantity of air pollutants, and monitor air pollutants in cooperation with districts and other agencies.

Existing law requires the state board to adopt standards of ambient air quality for each air basin in consideration of the public health, safety, and welfare, including, but not limited to, health, illness, irritation to the senses, aesthetic value, interference with visibility, and effects on the economy. Existing law authorizes these standards to vary from one air basin to another.

This bill would require the state board, in consultation with specified entities, to develop, as provided, a response framework that establishes best practices and guidance for addressing fugitive and natural sources of hydrogen sulfide gas and for community preparation and response to hydrogen sulfide exposure events originating from these sources. The bill would require the state board, in developing the response framework, to conduct at least 3 public workshops, including at least one located in the Tijuana River Valley region, at least one located in the Salton Sea region, and at least one selected in consultation with a community that has experienced significant hydrogen sulfide exposure. The bill would require the Office of Environmental Health Hazard Assessment to update the acute and chronic reference exposure levels for hydrogen sulfide and to develop additional health guidance values for hydrogen sulfide, if the need is identified by the state board, in consultation with the office, during development of the response framework.

The people of the State of California do enact as follows:

SECTION 1.

The Legislature finds and declares all of the following:

(a) Hydrogen sulfide is a colorless, highly toxic gas with a strong odor detectable at very low concentrations.

(b) The state board adopted a one-hour ambient air quality standard of 0.03 parts per million (30 parts per billion) for hydrogen sulfide in 1969, primarily to address odor nuisances, rather than chronic or long-term public health effects.

(c) Exposure to hydrogen sulfide is associated with headache, nausea, respiratory irritation, nasal symptoms, and neurological effects, and current evidence indicates that chronic exposure can contribute to persistent respiratory and neurological impacts, with heightened susceptibility among children, older adults, and individuals with preexisting health conditions.

(d) Although the The state’s existing hydrogen sulfide standard has not been updated for 25 years and years, may not consider contemporary health science, cumulative exposure assessments, or community vulnerability, it and may also be insufficient in addressing public health impacts near hydrogen sulfide hotspots across the state.

(e) Monitoring data in regions such as the Tijuana River Valley in the County of San Diego and the Salton Sea in the Counties of Imperial and Riverside have shown exceedances of the state hydrogen sulfide standard; however, it is difficult to identify a responsible party that could be subject to plans to attain the standards.

(f) Thus, Therefore, there is a need for a response framework that can address local needs in response to harmful air quality.

(f) Modern scientific research conducted in the Tijuana River Valley shows that communities near the river experience prolonged and chronic low-level hydrogen sulfide exposures, with concentrations of hydrogen sulfide frequently exhibiting sudden increases above the current state standard in durations of less than one hour. These sudden increases are in part caused by episodic influxes of transboundary pollution and are not captured in the time-averaged concentrations made to compare to the one-hour standard.

(g) Health symptoms associated with exposure to hydrogen sulfide have been reported in the South Bay region and the cities of San Diego and Imperial Beach, and include respiratory and gastrointestinal issues, headaches, fatigue, nausea, skin irritation, and respiratory irritation.

(h) Monitoring data indicate that hydrogen sulfide concentrations near sensitive locations, including Berry Elementary School in the Tijuana River Valley, have exceeded the current standard, demonstrating that children and other vulnerable populations are exposed to elevated levels.

(i) Similarly, communities surrounding the Salton Sea experience frequent elevated and chronic low-level hydrogen sulfide concentrations, caused by anaerobic biological activity, decomposition of organic matter, and shoreline emissions, with recorded levels frequently exceeding the state standard.

(j) These exposures disproportionately affect vulnerable and environmentally overburdened communities, including low-income households, immigrant communities, Latino and tribal populations, and areas already experiencing elevated rates of respiratory and other health conditions, exacerbating existing health inequities.

(k) The Office of Environmental Health Hazard Assessment indicates that chronic exposure to hydrogen sulfide at levels below the current one-hour standard can adversely affect human health.

(l) Furthermore, factors such as concentration averaging times, local and regional climate, and indoor versus outdoor exposure should be considered in assessing concentration levels and their impacts to public health.

(m) Thus, the Legislature recognizes a need to develop additional threshold levels for hydrogen sulfide that consider these factors in conjunction with local agency response to address public health issues.

SEC. 2.

Section 41514.7 is added to the Health and Safety Code, to read:

41514.7.

(a) For purposes of this section, the following definitions apply:

(1) “Fugitive source” means any source of emissions of hydrogen sulfide gas that is not currently regulated as a stationary source by a local air pollution control district or air quality management district.

(2) “Local environmental and public health agencies” means any local entity that a health officer, as defined in Section 120100, serves, or any local environmental health agency.

(3) “Natural source” means a source of hydrogen sulfide occurring in nature as a result of environmental circumstances. circumstances that is not regulated as a stationary source by a local air pollution control district or air quality management district.

(b) The state board shall, in consultation with the local air pollution control districts and local air quality management districts, the Office of Environmental Health Hazard Assessment, the Office of Emergency Services, the State Department of Public Health, regional water quality control boards or other local or regional authorities, local environmental and public health agencies, universities and academic institutions, affected tribal governments, and community-based organizations, develop a response framework that establishes best practices and guidance for addressing fugitive and natural sources of hydrogen sulfide gas and for community preparation and response to hydrogen sulfide exposure events originating from these sources. The guidelines shall consider response framework shall:

(1) Consider cross-media releases, and develop releases.

(2) Develop integrated, multiagency approaches to identify and address fugitive and natural sources, and methods sources.

(3) Develop methods for reducing identified fugitive and natural sources of hydrogen sulfide gas in impacted communities. In developing the response framework, the state board shall consider and evaluate the inadequacies of the Acute, 8-hour, and Chronic Reference Exposure Levels for fugitive and natural sources of emissions for developing the response plan. The evaluation shall consider all of the following:

(d) In developing the response framework pursuant to subdivision (b), the state board shall conduct at least three public workshops located in all of the following:

(1) At least one in the Tijuana River Valley region.

(2) At least one in the Salton Sea region.

(3) At least one selected in consultation with a community that has experienced significant hydrogen sulfide exposure.