Ground level monitors (GLMs) measure hydrogen sulfide and sulfur dioxide in the ambient air from all sources including the refinery, mobile sources such as cars and trucks, and other stationary sources such as homes and businesses.
Fenceline monitors go a step beyond, by measuring specific pollutants that cross the facility’s fenceline in real time. The systems have the ability to monitor, record and report air pollutant levels of multiple compounds.
The Bay Area Air Quality Management District's Regulation 12-15 requires refinery fenceline monitoring by June of 2019. Valero's fenceline monitoring project will be completed by the end of November 2018. Once operational, fenceline monitoring data will be added to the above website for public availability.
