Facilities Renovations Project

The Facilities Master Plan was completed in 2004 and identified the need for improvements to the City of Ann Arbor’s Wastewater Treatment Plant (WWTP). The improvements include rehabilitating existing structures and replacing aging facilities with new facilities.

The needed renovations will allow the City to meet future flow and loading demands as well as regulatory requirements. The current WWTP has a design capacity of 29.5 million gallons per day (MGD), and consists of an older West Plant (constructed in the 1930’s) and a newer East Plant (constructed in the late 1970’s). Picture of East Aeration Tanks

The Facilities Renovations Project will develop detailed designs for improvements to the existing East Plant as well as demolition and reconstruction of the West Plant. Reconstruction of facility structures, such as the Administration and Maintenance Buildings, necessitated by the demolition of the West Plant facilities, will also be included in this project.

The City of Ann Arbor retained the engineering firm Malcolm Pirnie, Inc. to provide engineering design services for this Facilities Renovations Project. The design phase is expected to continue through August, 2009.

The tasks of this project include:

Field investigations, such as site surveys, subsurface geotechnical and hydrological investigations.

Infrastructure surveys to assess current conditions at the WWTP.

Detailed design of facility improvements, including development of construction sequencing and schedules, permit applications and opinions of probable cost.

The Facilities Renovations Project will be constructed in two phases. The first phase, Facilities Renovations Demolition Project, is a small demolition project that prepares the facility for major construction. The more substantial second phase, Facilities Renovations Project, includes considerable facilities replacement consisting of complete demolition and replacement of the old West Plant and improvements to the newer East Plant. Both projects are summarized below.

The Facilities Renovations Demolition Project includes:

Demolition of the Old Solids Storage Building
Demolition of the Reaeration Tank
Relocation of essential utilities prior to demolition
Electrical work to isolate the East Plant power from the Solids Handling Building
Installation of a waste activated sludge piping to convey sludge to the Solids Handling Building

The Old Solids Storage Building and the Reaeration Tank are located immediately adjacent to the Solids Handling Building. The early demolition of these structures in Phase 1 will facilitate construction of the Residuals Handling Improvements Project.

The Facilities Renovations Project includes:

Pre-demolition survey of hazardous and other waste materials
Concrete repair survey
Ferric chloride storage and feed system evaluation
East Plant biosolids sedimentation evaluation
Administration Building alternatives evaluation
Plant isolation gate valve evaluation
Geotechnical investigations
Hydrogeological investigations
Electrical one-line verification
PIC's field wiring survey
Rehabilitation of the East Plant aeration system, including installation of new blowers for the aeration tanks, new air piping, new diffused aeration system, new mixers and reconfiguration of the tank flow patterns
Modification of the East Electrical/Blower Building including removal of the standby generators and electrical gear, installation of a new sampler facility and replacement of return activated sludge pumps
Electrical improvements to the East Primary Building
Miscellaneous repairs to the East Plant secondary clarifiers
Tertiary Filter Blower Building addition
Demolition of old digester tanks
Demolition of West Plant primary and secondary clarifiers and aeration basins
Demolition of the Administration Building, Chlorine Building, Sulfur Dioxide Building, Fabrication Shop, Machinery Building, West Blower Building, Flow Splitter, Flocculation Basins and a portion of the Old Chlorine Contact Tank
Construction of new West Plant primary clarifiers, Primary Building, Secondary Building, aeration basins and secondary clarifiers
Construction of a new Administration Building and parts storage addition to the existing Maintenance Building
Construction of a new electrical facility for the Raw Sewage Lift Station
Construction of a new influent splitter/flow monitoring station
Construction of a new tunnel connecting the East and West Plants
Construction of a new East and West Plant ferric pumping facility
Replacement of the existing plant wide 4800 KV power distribution system with a 13.2 KV power distribution system
Construction of a new Central Electrical Building
Replacement of two old standby electrical generators with two new 2-megawatt generators located within the Central Electrical Building
Re-routing of existing site utilities
Reconfiguration of the existing storm water collection system
Relocation of overhead DTE power transmission lines
Installation of new roadways throughout the plant
Upgrading the existing SCADA system

Project Status

Facilities Renovations Demolition Project

Malcolm Pirnie, Inc. has completed design and construction documents and a MDEQ Part 41 Construction Permit was issued on February 20, 2008. MDEQ issued a Part 31 Floodplain Permit on April 30, 2008 and Ann Arbor Charter Township granted conditional approval of the project site plans on May 7, 2008. Conditional items needed to obtain full approval have been addressed and submitted to the township. The anticipated bid date for Phase 1 work is August 2008.

Facilities Renovations Project

This more substantial project includes considerable facilities replacement. Design documents are scheduled for completion in the spring/summer of 2009 and advertisement is scheduled to start in the fall of 2009.

Picture of ultra violet disinfection area

For more information on this project, please contact

Mike Amicangelo at MAmicangelo@A2gov.org