DEFINITION
National wastewater discharge standards that are developed by EPA on an industry-by-industry basis. These are technology-based regulations that strictly limit pollutant discharge.
Effluent Limitation Guidelines (ELGs) are national standards for wastewater discharges to surface waters and publicly owned treatment works (POTWs). The EPA issues these regulations for specific industrial categories based on the performance of treatment and control technologies.
Key Components
- BPT (Best Practicable Control Technology Currently Available): The baseline level of control for existing sources.
- BAT (Best Available Technology Economically Achievable): Sets the standard for toxic and non-conventional pollutants.
- PSES/PSNS (Pretreatment Standards): Standards for facilities discharging to municipal treatment plants rather than directly to surface waters.
Recent Updates
Recent ELG updates have focused heavily on Steam Electric Power Generating (aimed at coal ash and bottom ash transport water) and Metal Finishing categories, tightening limits on heavy metals and total suspended solids.