Caldwell WWTP Improvements

Caldwell Final Comp 3Construct new aeration basin with flow splitting structure, final clarifier, scum box, and groundwater underdrain pump station, modify existing blowers, install new blower,  digester sludge circulation pump, hypochlorite facility with injection vault, fine screen and influent inclined screw pump, owner furnished equipment, associated valves, piping (including and chemical treatment piping and equipment), and appurtenances, HVAC, electrical, instrumentation, and site work. Owner requested additional work included emergency generator system, stainless steel digester gas piping, plumbing, vortex grit mechanism, stainless steel gates, and piping modifications.


  • Cost: $5,781,000
  • Owner: City of Caldwell
  • Designer: MWH Engineering
  • Construction Period: 11/2007 – 12/2009