As the Village of Danville’s wastewater treatment facility approached 25 years old, the Ohio EPA imposed new discharge limits on the facility requiring additional ammonia reduction during winter months. We designed facility modifications to allow for additional nitrification during extremely cold periods, though the need to maintain treatment during construction presented several interesting challenges for our team. First, the facility’s effluent is discharged into the East Branch Jelloway Creek: an exceptionally warm water habitat that’s strictly regulated. Second, two of the six lagoons were removed from service while they were being repurposed for nitrification. Through creative problem solving, we aided in converting the disinfection process from chlorination to ultraviolet, limiting water additives while answering the EPA standards.