Ann Arbor, MI
$45.5 million
29.5 Million Gallons Per Day
General Contracting
City of Ann Arbor, Michigan
Greeley & Hansen, LLC

City of Ann Arbor WWTP

Residual Handling

New construction of a wastewater treatment plant residual handling complex. The project consisted of the following:
• Demolition of existing equipment including dewatering plates and frame presses and a biosolids incinerator.
• Installation of centrifuges for biosolids dewatering and gravity belt thickeners to separately thicken secondary biosolids.
• Rehabilitation of an existing gravity thickener for thickening primary biosolids and conversion of two existing gravity thickeners to covered tanks for blending thickened primary and secondary biosolids.
• Rehabilitation and modification of Solid Handling Building to accommodate new equipment, meet current building code requirements and construction of a building addition for loading trucks with processed biosolids and receiving chemical deliveries.
• Installation of new boiler system to service all facilities within the WWTP.
• Installation of odor control equipment to reduce WWTP staff exposure and off-site nuisance odors from residual handling equipments and facilities.
• Replacement of antiquated 4.8 KV electrical system with more efficient and maintainable 13.2 KV system.

Plant operations needed to be maintained 24-7 during construction, so project was accomplished in two phases:
• Phase one – construct the new addition and the renovations work, install all major mechanical and electrical equipment to be able to start up the thickening /dewatering system.
• Phase two – demolition of the existing equipment, re-build the structural floors and install the new odor control system.