The City of Bay City was faced with the challenge of meeting discharge limitations with an aging wastewater treatment facility, part of which was constructed in the 1950s. The City also had to meet a limitation for the toxic compound polychlorinated biphenyl (PCB), which frequently is found in the City's influent and sometimes in the effluent. With the NPDES permit limitation for PCB less than detection, new facilities were required to meet a consent judgment stipulation that the City provide the best available treatment for PCBs. The City of Bay City hired Hubbell, Roth & Clark, Inc. to prepare studies to evaluate the existing wastewater treatment facilities and to determine the most cost-effective renovations to continue to meet NPDES limitations for conventional pollutants and new facilities to meet the stringent PCB limitation.

The improvements to the Bay City WWTP included new influent pumps, primary settling tank mechanisms, secondary clarifier mechanisms, trickling filter distributor arms, new sludge disposal facilities to dewater and store solids for disposal to landfill, new laboratory and administrative building, new ultraviolet disinfection system, improvements to the City's existing five combined sewer overflow retention treatment basins, and the tertiary granular activated carbon filtration system for PCB removal. The facility treats an average daily flow of approximately 7 million gallons per day, with sustained peak flows of 18 MGD resulting from the dewatering operations of the City's five retention treatment basins.