A growing population and the arrival of new industry meant challenges for the Yorkville-Bristol Sanitary District wastewater treatment plant.
The district, based in Yorkville, Illinois, serves a population of 22,000 and discharges to the Fox River. The treatment plant (3.62 mgd design, 2.0 mgd average) was using a single-stage nitrifying activated sludge process.ity would likely exceed its rated organic capacity. At the same time, the district had to comply with a new total phosphorus effluent limit of 1 mg/L. The plant needed an upgrade to deal with both conditions.To meet its dual objectives, the district in 2017 completed an $8 million renovation
