Wastewater Treatment Plant Expansion, Liberty Lake Sewer and Water District

Liberty Lake, Washington

Century West provided design engineering services for the Liberty Lake Sewer and Water District for the expansion of this plant. The plant capacity was expanded from 1 MGD to 2 MGD capacity and converted to a biological nutrient and phosphorous removal method of treatment. Improvements were made to the headworks grit removal process. New facilities/structures include an aeration basin with anaerobic and anoxic sections, mixed liquor pump stations, two secondary clarifiers, a blower building, and a sludge dewatering building. Sludge is now dewatered with the use of a new belt filter press and hauled off-site for composting. The existing aeration basin was upgraded to be compatible with the new method of treatment. The existing equalization basin was converted to an anaerobic selector. Existing process piping was modified to accommodate new waste streams.

Century West also provided construction management services, which included submittal review, answering Contractor requests for information and clarification, special inspection of structural concrete and steel reinforcement, coordination of materials testing, and schedule monitoring.