Locating a Coke Plant Emissions Source via Passive Air Monitoring


Air quality in the vicinity of a steel mill with an onsite coke plant and by-products processing area located in the Midwest was brought to the attention of the regional environmental authority. The facility was ordered to monitor ambient air concentrations of benzene emanating from the coke works area to ensure compliance with air quality standards. After completing several initial rounds of fence line monitoring, the facility began seeking out methodologies to locate the unknown source within the coke plant to allow remedy the issue. Handheld meters proved to be ineffective in locating potential source areas due to the complexity of the site infrastructure, changing process activities, and the dynamic nature of the fugitive emissions.


Cox-Colvin was requested to assist in locating the unknown source within the coke works, after having conducted the fence line monitoring using evacuated stainless steel “Summa” canisters. Due to the variable conditions and operations at the site, passive ambient air samplers equipped with a carbon adsorbent were selected. These samplers provided very low reporting limits for the target compound after a two-week deployment period. The sample results were provided as a time-weighted average, revealing areas of high concentration despite short term variations in site conditions. These “hot spots” were then further assessed by Cox-Colvin and ultimately led to a focused operational response by plant personnel. Targeted repair efforts resulted in reduced average ambient air concentrations.