Preston Wastewater Treatment Plant Upgrade

Key Accomplishments

Johnston Construction Company

• Performed demolition and site modifications required to accommodate the new treatment systems.
• Constructed a new control building supporting the upgraded plant operations.
• Constructed a new influent screening building incorporating below-grade concrete process structures.
• Installed a new influent pumping system to convey wastewater into the upgraded biological treatment process.
• Furnished and coordinated a new programmed aeration treatment system designed for approximately 115,000 gallons per day.
• Constructed a new aeration reactor/pond within the existing lagoon system.
• Performed major earthwork and lagoon-embankment construction associated with the new aeration treatment area.
• Installed a textured geomembrane liner system for the new aeration lagoon.
• Coordinated installation of floating aeration chains, diffuser assemblies and associated process equipment.
• Installed positive-displacement blowers serving the aeration process.
• Incorporated dissolved-oxygen monitoring and automated air-flow control into the aeration system.
• Coordinated VFD-controlled operation of three aeration blowers.

Concrete Services Division

• Served as the concrete subcontractor to Johnston Construction Company for the Preston Wastewater Treatment Plant Upgrade.
• Furnished labor, tools, equipment and supervision for extensive concrete forming, reinforcing, placement and finishing work throughout the treatment facility.
• Performed concrete work associated with the Lagoon No. 1 overflow area, including a concrete pad, yard-hydrant pads and valve-box pads.
• Constructed concrete elements at the influent pump station, including the suction separation wall and associated fillets.
• Completed concrete work for the aerated lagoon, including liner-trench grout, spillway concrete and aerator deadmen.
• Provided grouting associated with the clarifier and RAS/WAS treatment structures as required by the subcontract.
• Constructed extensive reinforced-concrete elements for the barscreen building, including channel slabs, structural walls, beams and fillets.
• Formed and placed barscreen-building foundations, floor slabs, thickened slabs, door stoops and frost walls.
• Constructed equipment pads and the generator-pad slab and frost walls serving the barscreen building.
• Completed structural-concrete construction for the control building, including building footings, slab-on-grade, thickened slabs, door stoops and frost walls.
• Constructed control-building equipment pads and concrete generator-pad components.
• Performed major concrete construction for the filter tank, including bottom and intermediate slabs and multiple reinforced-concrete walls.
• Constructed the filter-tank launder slab, launder wall, stair slabs, stair footings, stairs and stair cheek wall.
• Constructed the grinder pump station anti-flotation pad.

B & R Electrical Contractors

• Performed the major electrical construction scope associated with the comprehensive Preston Wastewater Treatment Plant modernization.
• Furnished the labor, materials, tools, equipment and supervision required for BRE's electrical work.
• Installed conduit, conductors and electrical connections for both power and control systems shown on the project electrical drawings.
• Furnished and installed major electrical distribution equipment serving the new Influent Screen Building.
• Provided the Screen Building's main electrical distribution components, including a 200-amp main breaker.
• Furnished panelboard equipment associated with the Screen Building electrical system.
• Furnished and installed VFD-related equipment serving process equipment at the Screen Building.
• Furnished starter equipment and disconnects required for the Screen Building process loads.
• Installed electrical infrastructure serving wastewater-screening and influent-treatment equipment.
• Furnished and installed major electrical-distribution equipment serving the new Control Building.
• Installed a 400-amp service disconnect for the Control Building.
• Furnished and installed the 400-amp main breaker serving the Control Building electrical system.
• Furnished and installed MCC-A as part of the plant's motor-control infrastructure.
• Furnished a 25 kVA transformer serving required facility loads.