Johnston Construction Co.

Owner:

Solar Power Industries, Inc

General Contractor:

Johnston Construction Company

Scope Of Work

Johnston Construction Company, as an integrated design-build team member, provided engineering, construction, and commissioning services under a fixed price contract of $133,000 for the construction of the packaged 115,000 gpd Siemens Water Technologies wastewater treatment system.

The Solar Power wastewater treatment system is a flocculation/gravity settling separation system, which was selected in lieu of other wastewater treatment technologies such as ion exchange or microfiltration, followed by reverse osmosis (RO) for wastewater recycling.

The Siemens equipment includes a 1,000 gallon HDPE waste collection sump tank that receives process wastewater and wash-down with a mixer and ultrasonic level sensor; a 10,500 gallon HDPE influent equalization tank; various pump skids; a 2,000 gallon chemical mixing and reaction tank for sulfuric acid; a MemClean Solids Separator unit consisting of a 100 gallon flash mix tank with mixer unit, a 1,000 gallon flocculation tank that receives lime slurry from an adjacent 275 gallon FRP lime-slurry tank with compressed air piping, mixer unit and transfer pump, a large 600 sf settling tank piped to a sludge-transfer pump; a multi-media filter skid; sludge thickening and filter press for solids removal; a surge tank with chemical mixing for RO pretreatment; an RO system for treated water recycling; and PLC controls for the integration of the various treatment equipment.

The project started in January 2009 and was completed in March 2009.