Construction Management for Design/Build of Wastewater Treatment Plant
Mountain House Community Services District, California

Mountain House’s Wastewater Treatment Plant (WWTP) was built in three phases and completed by means of a design-build project delivery method. West Yost provided full-time, onsite construction management (CM) services for all three phases of the project, which consisted of a new and subsequently expanded WWTP, civil/site work, roadways, utilities, and appurtenant facilities.

The Phase I treatment facility had a design capacity of 0.45 mgd and included screening, an influent lift station, aerated treatment lagoons, dissolved-air floatation clarifiers, contact flocculators, gravity sand filters, and a chlorination/dechlorination disinfection system. The Phase II treatment facility has a design capacity of 3 mgd. The facility has replaced the Phase I aerated lagoons with a hybrid sequential batch reactor (SBR) activated sludge treatment system with new tertiary filtration and ultraviolet disinfection compatible with California Title 22 requirements. In addition, the facility provides advanced biological nutrient removal of nitrogen. The Phase III expansion will provide 6 mgd of capacity.

West Yost’s CM team paid careful attention to the documentation of time and material charges on the Mountain House projects to assure overcharges to the client did not occur. Work performed by the contractor to accelerate their schedule for their convenience was not paid; saving the client money.

In addition, West Yost provided assistance with payment applications, which was necessary because various funding sources were involved, and assured that charges were adequately billed to the right source.

The Mountain House projects involved PG&E coordination to expedite the setting of gas and electric meters to speed the installation of these critical facilities. West Yost CM staff also coordinated with County inspectors to bring them up to speed and to assure that the facilities are in the right condition to make the County inspector’s visit productive and to keep the project on schedule.