The district said Monday that its rule requires Bay Area refineries to operate fence line air monitoring systems that measure specific pollutants crossing their property lines. Refineries are required to monitor, record and publicly report concentration levels of multiple compounds, including hydrogen sulfide.
The district said that monitoring is already underway, and the data is available to the public in near real time.
The district said the refineries were required to update their monitoring plans to address requirements for monitoring hydrogen sulfide. Hydrogen sulfide is a colorless gas with the odor of rotten eggs. Exposure to hydrogen sulfide can induce tearing of the eyes, headaches, nausea and vomiting.
Fenceline air monitoring plans must include detailed descriptions of the equipment used for fence line monitoring; the siting, operation and maintenance of that equipment; procedures for implementing data quality assurance and quality control; and procedures for reporting the measured pollutant concentrations.
The district said following its disapproval of the plans, it will work with the refineries to make improvements in these areas.
Fenceline monitoring is one tool among many the air district uses to measure air pollutant concentrations and facility emissions. The district works to continually improve its emissions and air quality measurement programs as needs for air quality data evolve, particularly for communities that are disproportionately impacted by air pollution.
