The HRVOC GC system is designed for analytes recently targeted by the Texas Commission on Environmental Quality (TCEQ). Ethylene, propylene, 1,3-butadiene and butenes have been found to contribute to high ozone observed in the Houston area. It is believed that substantial emission reductions of these four compounds are likely to have a high impact on the rapid ozone formation and transient high ozone in the area. To that end, the TCEQ requires that facilities in the Houston/Galveston area with a vent gas stream, flare or cooling tower heat exchange system that emits HRVOCs (or has the potential to emit HRVOCs) continuously monitor their systems for composition and flow.