Hubbell, Roth & Clark, Inc. (HRC) has provided engineering services to the City of Saginaw since the 1940s with the design of the City's interceptor system and first wastewater treatment plant.  HRC was also involved with the design and construction of the recently completed combined sewer overflow control program which consists of an extensive new collector sewer system and seven (7) retention treatment basins (RTBs).  Dewatering of these RTBs after storm events bring additional flow and solids loading to the City's 32 MGD WWTP.

The proposed plant improvements include two (2) additional primary settling tanks which will provide the additional primary treatment capacity necessary during CSO dewatering operations.  Following construction of the two new primary settling tanks, the existing four (4) settling tanks will be renovated with new collector mechanisms and improved sludge pumping systems to facilitate more reliable operation.

Other major improvements to the plant include the replacement of the automatically cleaned fine screens system and the addition of a centrifugal grit removal system to replace the existing drag flight grit removal system.  The last preliminary treatment system improvements include the addition of new magnetic variable speed drives which will help the pumping system better match the influent flow conditions which now vary more widely after the CSO improvements.  These air and water-cooled magnetic drives are the first of its type used in Michigan and one of the largest installations in the United States.