ENTERGY ARKANSAS, LLC. - UNION POWER STATION Stormwater Outfall, El Dorado, Arkansas

ENTERGY ARKANSAS, LLC. - UNION POWER STATION is a stormwater outfall located at 6497 Calion Highway in El Dorado, Union County, Arkansas, United States. As a stormwater outfall associated with a power station, it is part of the industrial stormwater management infrastructure under the Clean Water Act. The facility operates under the National Pollutant Discharge Elimination System (NPDES) permitting framework, which regulates stormwater discharges from industrial activities. The NAICS code 221112 indicates it is a fossil fuel electric power generation facility, subject to EPA's Multi-Sector General Permit (MSGP) for stormwater discharges associated with industrial activity. Stormwater outfalls like this one play a critical role in managing runoff from industrial sites to prevent pollution of nearby water bodies. The facility's location in Union County, Arkansas, places it within the Ouachita River watershed, where stormwater management is important for protecting local water quality and aquatic habitats.

The stormwater outfall at Union Power Station discharges into the Ouachita River basin, a region with mixed land use including forest, agriculture, and urban areas. Industrial stormwater runoff can carry pollutants such as sediment, metals, and hydrocarbons. The facility's compliance with NPDES permit conditions, including stormwater pollution prevention plans and monitoring, is essential to minimize impacts on downstream water quality and aquatic ecosystems.