EPA identified four counts of excess opacity in violation of the 20%, as a 6-minute standard during offsite monitoring activities on May 16, 2023 and September 5, 2023. EPA performed onsite inspections on May 17, 2023, and September 6, 2023 and determined GCS failed to maintain, repair, and operate its fugitive dust (PM) suppression control equipment from January 1, 2022, to June 30, 2023. GCS also did not establish a minimum water flowrate and moisture content of its slag products through the required routine bi-annual testing as far back as the Statue of Limitations (SOL) allows. This caused excess emissions of Particulate Matter (PM) and resulted in an exceedance of their 2.42 lb/hr PM limit identified in their Title V Permit. Additionally, GCS failed to keep the moisture content of its slag fines material above the required minimum of 1.5% at least 20 times from 2020 ? 2023. GCS did not perform the required periodic sampling and monitoring of its stockpiled production materials resulting in, at a minimum, 652 record keeping and monitoring violations from 2020 - 2023. GCS failed to utilize its portable water truck to mitigate dust from unpaved surfaces at the facility and did not properly monitor and record the daily usage of water from their functional wet suppression system and their water truck. EPA issued a NOV on January 9, 2024.
This ACO requires GCS to install new control equipment to reduce its fugitive emissions, and increase the moisture content of its slag mat