McKim & Creed provided support and engineering services related to a National Pollutant Discharge Elimination System (NPDES) permit for a generating station. Work included a detailed analysis of water quality and flow data for water quality-based effluent limits (WQBELs), total maximum daily load (TMDL) program and effluent limitations guideline (ELG) revisions. McKim & Creed’s prepared, submitted and received approval for permit application renewal and modifications from the Pennsylvania Department of Environmental Protection.
Modifications included permitting a legacy mine water treatment facility and modifications to infrastructure to properly manage stormwater from the station’s coal piles. Engineering calculations and design documents were developed for diversion structures
and conveyance systems to allow the station’s coal pile desilting ponds to manage the 10-year storm event. These improvements included an automatic diversion system that limits discharge of stormwater for frequent storm events and provided safeguards for emergency overflows. Additional modifications included upgraded controls to level control pumping systems and interconnections for conveyance of other stormwater-driven flows in the future.