2012/04/04 Council Agenda Packet

REQUEST FOR PROPOSALS General Contractor/Construction Manager Services for Water Pollution Control Facility Expansion-Phase C The advantage of using a GC/CM contracting approach is that it would allow the involvement of the contractor early during design with the intent of identifying and minimizing construction conflicts and leading the way to a more efficient phasing approach, centralized site management, and the successful coordination of commissioning of both processes. Under the guidance of a single contractor, project delivery could be expedited with fewer disruptions resulting in project cost savings. The City intends to use a single preconstruction contract with work tasks and activities specific to each phase. Completing Phase C1 (Liquid Stream) work is the highest priority for the City, therefore the preconstruction activities will initially focus on the liquid stream. B. Background: The City of Everett, Washington, located in Snohomish County, provides wastewater collection and treatment for a community of approximately 140,000 people. The Water Pollution Control Facility (WPCF) consists of two parallel treatment systems downstream from a common headworks structure. One of the treatment systems is an aeration/oxidation pond system, and the other is a trickling filter/solids contact process to treat wastewater. The lagoon-based system provides primary sedimentation, secondary treatment, stormwater treatment, disinfection, sludge digestion, and biosolids storage. The trickling filter system consists of two trickling filters, a solids contact tank, two secondary clarifiers, and a chlorine contact tank. The trickling filter plant provides secondary treatment and disinfection for up to 21 million gallons per day (mgd) of wastewater, and the aeration/oxidation pond system treats any wastewater in excess of the mechanical plant capacity. Effluent from the lagoon system is discharged to the Snohomish River and the effluent from the mechanical system is pumped across town and discharged into Port Gardner Bay. The facilities have relatively few process variables that can be manipulated to control the treatment process. Despite few process control variables, this combination of aeration pond and mechanical systems has performed satisfactorily, and effluent limitations have generally been met. Summary: The WPCF provides wastewater treatment for residential, commercial, and industrial customers within the City, and purveyors (water/sewer districts) located to the south of the City. In addition, the City is City of Everett Page 5 April 16, 2012 Water Pollution Control Facility Expansion-Phase C8