Air Quality

 

In addition to the comprehensive air monitoring programs already deployed at our refineries as required by regulations and/or air permits, we have implemented advanced monitoring systems that go beyond regulations to identify and reduce air emissions. Ambient air readouts allow refineries to monitor the surrounding communities and take early response and mitigation actions even on small emissions sources. We have the following air monitoring programs:

1. GMAP Vans Equipped with Duvas DV3000 Instruments, a real-time mobile air monitoring and quality screenings. The vehiclemounted DV3000 is a monitoring instrument with a gas analyzer that uses ultraviolet spectroscopy and a meteorological station to identify and quantify up to 14 different gases, including benzene, SO2 and NOx, at low part-per-billion levels.
2. Continuous Emissions Monitoring Systems (CEMS) are placed in the outlet stacks of certain fired equipment (boilers and heaters) as well as process vents like the Fluid Catalytic Cracking Unit (FCCU). CEMS continuously measure the concentration of compounds, such as NOx and SO2, exiting the stack to confirm operations are within permitted limits.
3. Continuous Flare Monitoring Systems are installed on flares to measure the amount of process gases routed to the flare for destruction and track operational parameters to confirm the flare is operating properly.
4. Stack Testing is conducted periodically on equipment that does not require continuous emissions monitoring to confirm it is operating properly and within permitted limits.
5. Leak Detecting and Repair (LDAR) ensure our operating sites comply with the EPA's air quality regulations for reducing fugitive emissions. Inspections are conducted on a routine basis. Leaks identified are fixed and re-monitored to confirm repairs were effective. In 2023, we implemented an enhanced LDAR program using optical gas imaging, resulting in improved leak identification and cost savings.
6. Routine Optical Gas Imaging (OGI) Inspection of storage tanks, wastewater treatment operations and other equipment are performed using OGI cameras equipped with infrared technology capable of detecting VOC leaks that are not visible to the naked eye.
7. Unit Battery Limits Monitors placed around the perimeter of refinery process units continuously measure for target compounds. These stationary air monitors serve as an early warning system if elevated concentrations are detected.
8. Personal H2S Monitors are required to be worn by refinery personnel while in and around process units, continuously measuring for H2S, sounding an alarm and recording in the event elevated H2S is detected.
9. Five-Gas Monitors are routinely used by personnel within the refinery for measuring H2S, SO2, CO, oxygen and lower explosive limit levels for safety purposes and also as early detection to identify and correct issues that could impact ambient air quality.
10. Fenceline Benzene Monitors are located around a number of our refineries at designated intervals to collect composite samples. Additionally, stationary analyzers that detect total VOCs or specific compounds, such as benzene, are deployed at certain sites in areas at or inside the fenceline to allow for advanced notification of elevated concentrations.

For more information, see SASB report and the notes thereto beginning on page 76.

*Beginning in 2022, fresh water withdrawn includes volume that was withdrawn and sold. Values in prior years include only freshwater used in Valero's operations.