B&N conducted an evaluation of chemical and biological phosphorus removal processes for the City of Wadsworth wastewater treatment plant (WWTP). BioWin® modeling was used to determine the effectiveness of both strategies. Although the biological model showed promise, a full-scale pilot test determined that phosphorus removal using this method was not sufficient enough to be cost effective. As a result, chemical treatment was selected.
Final design of a chemical storage and feed system was completed following the successful pilot testing of various coagulants. The final design included:
- New 5,000 gallon chemical storage tank
- New chemical feed pumps
- New chemical feed piping and multiple discharge locations
- SCADA system improvements and programming
- Start-up and testing of the system
Buildings were refurbished with new roofing materials along with installation of new doors and windows. The WWTP electrical system was completely renewed along with a new SCADA system. Plumbing and HVAC components also were replaced.
B&N also completed a needs evaluation, prepared a general plan of improvements, prepared construction documents, and provided engineering services during construction for the expansion of the Wadsworth WWTP from 3.0 mgd to 5.0 mgd. The final design allows for full treatment of peak daily flows up to 10 mgd, and primary and tertiary treatment of peak hourly flows up to 15 mgd, with capacity for future expansion to a peak hourly flow of 20 mgd.
The expansion project required temporary facilities and a detailed construction sequence so that the plant could remain operational throughout the three-year construction period.