WATER / WASTEWATER
Salmon Creek WWTP
The Solid Handling Improvements project at Salmon Creek WWTP features construction of a new anerobic digester; new digester support equipment, including gas-hold covers, gas safety equipment, pumps, boilers, hot water circulation systems; and related piping for the new and existing digesters. Site work included dewatering/shoring of a 40 foot excavation for the new digester, as well as site sewer, storm, natural gas, and water utilities. Work also included construction of a new Lab/Office building over the existing chlorine contact basin; the addition of a truck loading bay, screw press/conveyor system, and truck scale; improvements and seismic modifications to existing equipment and structures; demolition of the unused structures and equipment; and electrical upgrades including a new electrical service, MCCs, and backup generator. Extensive coordination was needed to complete this project while maintaining critical plant operations throughout the entire process.
The Water Reclamation Facility, Phase 2 improvements, for the City of Snoqualmie, feature the addition of a headworks grit pump, clarifier replacement, oxidation ditch anaerobic replacement, grit and W3 piping improvement, control panel replacement, and headworks channel cover installation. Work included building a new decant facility as well as additions and improvements to Clarifier 1, the scum pump stations, the WAS pump and piping, and the addition of an in-ground biofilter. Tie-in and planned shut downs were required to complete the work. Improvements were also made to the site utilities, grading and surfacing throughout the jobsite.
The existing Sumner WWTP capacity was increased to 6.10 mgd through this project, which required significant planning and flow diversion to maintain seamless operations of the existing facility. The improvements included modifications to the existing influent pump stations, installation of new grit handling equipment, modifications to the existing primary sludge pump station and existing Aeration Basin Nos. 1 and 2, construction of Aeration Basin No. 3, installation of a fourth aeration blower, construction of a new secondary clarifier with aluminum dome cover, construction of a new RAS/Scum pump station and chemical storage building, installation of additional UV effluent disinfection equipment, construction of a new sludge truck canopy, construction of a new centrate pump station and new centrate holding tank, and construction of a new storage equipment building.
Gig Harbor WWTP
Both phases of construction significantly increased the capacity and treatment capabilities of the Gig Harbor Wastewater Treatment Plant. Located on an extremely small, sloped site, the work required extensive coordination between the construction, engineering and plant operation teams to facilitate success. The project included the following: Site clearing, grading, and major excavation; modification and demolition of existing facilities and structures; new process buildings, concrete tanks and retaining walls; extensive process piping and new equipment in all areas of the existing plant; installation of owner-supplied equipment; improvement to instrumentation, control, telemetry and power systems; fiber optic telemetry cable installation from the Wastewater Treatment Plant to the City’s Pump Station 2A, located at Ruth M. Bogue Park, and final surfacing and landscaping improvements.
Barton Pump Station
The small site located at the entrance to the congested Fauntleroy Ferry Terminal added unique challenges to the already difficult and technical work of the Project. The purpose of this project was to upgrade the existing pump station to extend the useful life of the facility, improve reliability, operability and safety. The work included rehabilitation of the existing pump station to include new structural and mechanical components, construction of a new valve room within a sheet pile cell attached to the existing pump station, construction of a new odor control structure to house equipment, wet well bypassing, demolition, jet grout soil improvement, pumps, ground anchors, and site improvements.
Ship Canal Pump Station
Located at the historic Ballard Locks, the Lake Washington Ship Canal Pump Station Project comprehensively rehabilitated the existing pump station, which is utilized to dewater the small and large locks for maintenance and cleaning. The project was severely complicated by its location within a 26-foot diameter by 65-foot deep dry basement well located directly below the Administration Building. All work required accommodating severe overhead height restrictions, limited side access and no direct vehicular access. Demolition included lead abatement work, removal of pipe up to 60 inches in diameter, removal of multiple valves up to 30 inches in size, and two 30 volute pumps. Supply and installation work included new pipe and valves up to 60 inches in diameter, a new 42-inch submersible pump set deep within the shaft, process pump control components complete with remove operation, new oil water separator system, a small lock pump and associated piping, replacement of 14 inch piping under the large locks to the small locks within a confined tunnel, reconstruction of multiple levels of platforms and provision of a new 480v unit substation and motor control center. In addition, Prospect partially disassembled historic motor casings and valve actuation machinery and retuned historical equipment components to their original locations upon completion of the contract.