Delta Coves Chemical Feed Facility

We prepared project plans and specifications and performed construction oversight for the new chemical treatment facility located near Bethel Island. The facility was needed in preparation for a large subdivision at the boundary of the District’s existing distribution system. The distant location of the new subdivision introduced the possibility of chloramine disinfectant residuals to drop below desired levels prior to reaching the new development.

The facility consists of a liquid sodium hypochlorite and aqua ammonia treatment system to increase the concentration of chloramine disinfectant within the existing potable water supply from the distribution system prior to customer use. This project included the design and construction administration review for the following major facilities: (i) 100-gallon HDXPLE liquid sodium hypochlorite tank with storage reserve for up to an additional 450 gallons of sodium hypochlorite, (ii) 60-gallon stainless steel aqueous ammonia tank and neutralization tank, (iii) complete chemical pump skids with redundant metering pumps for backup chemical supply, and (iv) chemical treatment, analyzers, alarms, indicator, and other instrumentation.

The project required close interaction with multiple public agencies, including the Contra Costa Fire District, Bethel Island Municipal Improvement District, City of Oakley, County of Contra Costa, State Water Resources Control Board, and multiple engineering design team members.

Significant Project Elements

• Civil engineering design of treatment, storage, and distributionfacilities
• Construction management and site inspections of work performed
• Extensive commissioning and startup of new facilities to optimize chemical feed rates
• Facilitation of effective communication between state and local agencies and the public