Capital Improvement Program Projects
The following is a list of projects either completed or currently in construction.
- Digester Complex
- Clarifiers
- Aeration Basins
- Lagoon Relining
- Biocycle Farm Treet Planting
- Odorous Air Treatment
- Influent Pumping & Headworks Expansion
- Peak Flow Management
- Sodium Hypochlorite Conversion
Digester Complex
The digesters treat the solid by-products of the treatment process. The capacity of the existing facilities needed to be maximized in order to provide for future demands. The digesters were retrofitted with more efficient technology in order to increase the effective use of each digester and improve mixing and solids production.
Project Completed: 2008
Clarifiers
The clarifiers, where the solids settle out of the wastewater, needed to be improved and expanded to ensure that the facility could handle severe wet weather flows. The existing primary and secondary clarifiers received enhancements to increase treatment capacity and improve effluent quality and performance reliability. In addition, two new secondary clarifiers were constructed.
Project Completed: 2008
Aeration Basins
Aerations basins are used to reduce organics in the wastewater treatment process. During this part of the treatment process, oxygen and micro-organisms are introduced to the wastewater. The aeration basins project converted the "plug-flow" process to a more efficient and effective "step-feed" process. The improvements increased energy efficiency, increased the effectiveness of the biological treatment and increased capacity for high winter flows.
Project Completed: 2009
Lagoon Relining
The Biosolids Management Facility has four facultative lagoons for storing biosolids prior to beneficial reuse. The bentonite clay lining was reaching the end of its useful life span so a new liner made of high-density polyethylene (HDPE) was put in place.
Project Complete: Phase 1- 2008, Phase 2- 2010
Biocycle Farm Tree Planting
The Biocycle Farm was planted in three phases. A citizen advisory committee gave their input on reuse options for biosolids which led the MWMC to purchase land for the Biocycle Farm, providing more effective ways for biosolids and recycled water to be beneficially used. The Farm now totals approximately 88,000 hybrid poplar trees planted over 400 acres. More information is available on the Biocycle Farm page.
Project Completed: Phase 1- 2004, Phase 2- 2007, Phase 3- 2008
Odorous Air Treatment
The odorous air treatment is an important part of the MWMC's Good Neighbor Policy. The main reasons behind the upgrades were to accommodate increased air flow due to modifications to the influent pumping/headworks facility and the covering of primary clarifiers and the new system will be able to capture more air and provide more effective treatment.
The "fan farm" that moves the odorous air from its source to filtration was upgraded with new, larger fans and new above and below ground ductwork to transport the air.
In addition, the biofilter bark media was replaced with an engineered media that will last longer and is able to treat greater air flow. Higher efficiency media also allows for energy saving due to less work required to push air through it.
A cover system was also developed for the vactor pit. This is a small, but potent odor source. These odors will be treated with a small carbon filter. Two of the primary clarifiers were covered. Odors will be drawn off of the clarifiers with the new fans and transported to the biofilter for treatment.
Project Completed: 2010
Influent Pumping & Headworks Expansion
The Influent Pumping and Headworks Expansion Project will upgrade and expand the existing facilities to allow more flow to enter the plant during wet weather, high-flow events. Once complete, the project will help prevent sanitary sewer overflows from the collection system, including the nearby Willakenzie Pump Station, that might otherwise occur under extremely high flow conditions.
The project consists of improvements to the Willakenzie Pump Station, upgrades and expansion of the existing headworks facility and the addition of a new influent pump station.
Due to the time critical nature of this project, it was delivered using a Construction Manager/General Contractor (CM/GC) project delivery process.
Project Completed: 2010
Peak Flow Management
The Peak Flow Management Project provides flow management piping and diversion facilities to increase the amount of flow that can be treated at the plant during wet weather peak events. The improvements will make it possible to divert wastewater through an alternative route during high flows that occur with prolonged winter storms.
The project combines several project elements described in the 2004-Facilities Plan including: the Parallel Primary/Secondary Treatment project, the Bankside Outfall project, the Outfall Mixing Zone Study, and the design and construction of the high rate disinfection basins, which was pulled from the Sodium Hypochlorite Conversion project.
The project consists of four additions to the existing facilities: a 96-inch diameter pipeline to convey flow from the outlet of the headworks facilities to the inlet of the aeration basins, an 84-inch diameter pipeline to convey flow from the outlet of the aeration basins to the new high rate disinfection basin, also constructed as a part of this project, and finally, flow diversion structures, and flow control and measurement equipment is also included in the project.
Project Completed: 2010
Sodium Hypochlorite Conversion
New liquid sodium hypochlorite and sodium bisulfite systems are being built in order to replace the existing chlorine and sulfur dioxide gas systems used in the final (disinfection) stage of treatment. In addition, the improvements will increase the disinfection capacity from 175 million gallons per day to 277 million gallons per day in order to meet peak flow capacity requirements. Since the new systems will use liquids instead of extremely hazardous gasses, the project will improve operator and community safety.
Project Completed: 2010
