Under the U.S. Environmental Protection Agency’s (EPA) Residual Risk and Technology Review (RTR) rules, affected facilities must monitor benzene emissions along their facility boundaries using EPA Method 325. This regulation utilizes a network of passive, diffusive sorbent tubes deployed at specific intervals to collect ambient air samples continuously over a rolling 14-day period. The tubes are then analyzed to calculate the facility’s net benzene contribution (Dc). If the rolling annual average Dc exceeds the strict regulatory action level of 9 micrograms per cubic meter, facilities are legally mandated to initiate a formal Root Cause Analysis (RCA) to pinpoint and remediate the underlying emission source. However, because Method 325 relies on time-integrated, 14-day average data, it inherently lacks the real-time resolution needed to spot an active leak, meaning traditional field investigations are often performed weeks after the actual emission event took place.
To resolve this critical delay, the Opgal Sentinuum24 offers an automated, real-time solution for instantaneous RCA. Rather than waiting for fortnightly laboratory results, low-cost sensors distributed across the facility can instantly detect a benzene emission event, immediately triggering the Sentinuum24 fixed optical gas imaging (OGI) system. Powered by advanced AI analytics, this 24/7 fixed solution continuously monitors, visualizes, and isolates volatile organic compound (VOC) plumes the moment they escape, efficiently eliminating regulatory blind spots. For comprehensive site verification, operators can back up the fixed system with Opgal’s mobile OGI units: the handheld EyeCGas Multi can be deployed to safely pinpoint leaks at closer ranges, while the drone-based EyeCGas Fly provides aerial source localization across complex asset infrastructure. This interconnected ecosystem transforms the RCA process from a delayed, retrospective investigation into an immediate, proactive protocaol against fugitive emissions.
This automated response capability has become even more vital with the EPA’s recent Hazardous Organic NESHAP (HON) rule amendments, which expand mandatory fenceline monitoring beyond petroleum refineries to over 200 chemical manufacturing facilities nationwide. The HON rule tightens industry accountability by targeting six key air toxics, including benzene, 1,3-butadiene, ethylene dichloride, vinyl chloride, chloroprene, and ethylene oxide, and requiring stringent quarterly public reporting of any action-level exceedances via the EPA’s CEDRI system. Because the HON rule subjects chemical plants to strict compliance timelines and intense public scrutiny, the Opgal Sentinuum24 suite serves as a crucial compliance safeguard. The specific Sentinuum24 VOC model is tailor-made to capture broad industrial volatile organic compound leaks, while specialized models like the Sentinuum24 Ammonia system address adjacent chemical processing demands, giving operators the exact automated foresight needed to suppress hazardous plumes before they ever cross the fenceline.
