The Verdantas Team (formerly PBI) is providing design services for numerous high-profile capital improvements to the Copper Cove Water System. The first project includes 1) a replacement for the Redwood tank at the B Tank Site 2) a new Copper Cove Water Treatment Plant (WTP) clearwell 3) rehabilitation of the existing steel B-tank and 4) the rehabilitation of the existing clearwell. 

The existing B zone Redwood tank is a 50-year-old .3MG storage tank made of redwood and is in unacceptable condition and in need of immediate replacement. The redwood has deteriorated to the point where water is leaking through the walls. Our team designed the new, second clearwell near the existing clearwell and a design for a new .5 MG steel tank to replace the existing .3MG redwood tank. 

The new clearwell as well as the new .5MG steel tank will be equipped with cathodic protection. The existing clearwell is a welded steel storage tank located in the Copper Cove WTP site at a ground elevation of 780 feet. The clearwell has numerous identified deficiencies including corrosion of interior components and roof as well as a failing exterior coating. The B zone steel tank is a 40-year-old 65-foot diameter .75MG welded steel storage tank. The tank sits at a ground elevation of 983 feet MSL, 200 feet higher than the WTP clearwell. The two B zone tanks must be the same height upon completion of the phase 1 and phase 2 projects. Therefore, the B zone piping must also be reconfigured to allow the two tanks to run in parallel upon completion of the projects, as they can currently only operate in series. It is recommended that both the Steel B tank and the existing WTP clearwell be rehabilitated in lieu of replacement due to the lower estimated costs and shorter construction times. 

The second design project addresses the need to replace the B-C Zone Booster Pump Station (BPS) and construct a new C Tank BPS and transmission main. The existing B-C Zone BPS pump capacities are insufficient to meet the existing maximum day demand of 1,555 gallons per minute (gpm) for the C Zone. The two existing effluent pumps supplying the B-C Zone BPS will be replaced with two high-head pumps. All of the high-head pumps will be sized to meet maximum day demands for B Zone, C Zone, and Copperopolis. The C Tanks would then gravity feed the B Tanks via the existing 10-inch main. PBI’s recommendation is to abandon the B-C Zone BPS following completion of the C Tank BPS. 

Verdantas is also addressing problems caused by the existing C tank overflow alignment. The C Tank overflow has historically discharged overflow water into a ditch that is not adequately sized to contain the overflow volume and has historically discharged overflow water onto neighboring parcels. Our team has recommended installing an altitude valve on the inlet piping to the C Tank to control the water level in the tanks and avoiding overflow events. The altitude valve will be hydraulically controlled to cut off flow to the C Tank before it overflows, thereby avoiding overflowing the tank instead of trying to redirect the existing overflow. 

The final design project address system redundancy. Approximately 750 domestic water customers on the east side of Lake Tulloch (Zone B4) are provided service via a single 10-inch distribution main that crosses underneath the bottom of Lake Tulloch. In the event this distribution main were to fail, the entire community on the east side of Lake Tulloch would be left without a water supply. The Lake Tulloch Intertie will serve as the primary water supply from the C Zone Tanks to these B4 Zone customers, replacing the current distribution main and minimizing the risk of catastrophic failure. The proposed transmission main will include a PRV station to drop the pressure from the C Zone to the appropriate hydraulic grade line to supply the B4 Zone.