On August 25, 2016, EPA Region 6 issued a Consent Agreement and Final Order (CAFO) to Valero Refinery under its authority pursuant to sections 113(a)(3) and 113(d)(1)(B) of the Clean Air Act, to Valero Three Rivers Refinery located in Three Rivers, Texas. The CAFO was issued in response to violations pursuant to section 112(r)(1) of the CAA, 42 U.S.C. Sec. 7412(r)(1) where the Safety Instrumentation System (SIS) did not trip the heater as designed when the combustibles concentrated in the heater stack exceeded the designated trip set point due to it being disabled following instillation of the system. The heater experienced combustion difficulties causing a deflagration within the heater unit causing an emission, which was later determined to have been caused by the disability of the trip function for the stack analyzers. The emission released the following substances: Nitrogen Dioxide, Carbon Monoxide, Particulate Matter, Volatile Organic Compounds, Sulfur Dioxide, and Hydrogen Disulfide. The CAFO requires Valero to maintain a safe facility so as to prevent releases by accurately tracking preventative maintenance and repairs or routine inspections and pay a civil penalty of $37,500 to EPA Region 6 within 30 days.