Laserfiche WebLink
River Islands Development at Lathrop January 2021 <br /> Final River Islands Potable Water Technical Report—Rev 3 #6520 <br /> 2.6 Potable Water Pumping Capacity Requirements — Proposed Phase II City of Lathrop Potable <br /> Water Storage and Booster Pump Station at River Islands <br /> As of November 2020, the total PHD for Phase I and II is 10,372 GPM which is greater than the MDD + <br /> Fire Flow. With Phase I BPS's 10,000 GPM firm pumping capacity, the minimum required firm pumping <br /> capacity of the proposed Phase 11 pump station is 372 GPM. However, as discussed further in Section 3, <br /> the Phase I site alone will not be able to provide the required PW storage for the development. Additional <br /> PW storage will need to be provided in Phase 11 to offset the storage deficiencies under full buildout <br /> conditions. Because the River Islands distribution system requires booster pump stations to draw from <br /> localized storage to pressurize the distribution system, installing a 372 GPM booster pump station with the <br /> proposed 3.47 MG of storage will not be ideal as the booster pump station will not be able to adequately <br /> draw and transmit the stored PW. <br /> As shown in Table 2-8, it is recommended that the Proposed Phase 11 City of Lathrop PW Storage and <br /> Booster Pump Station at River Islands (also referred to as Phase 11 BPS) be sized with a minimum firm <br /> pumping capacity of 4,000 GPM from 2 duty + 1 standby pumps. A firm pumping capacity of 4,000 GPM <br /> will not only satisfy the firm pumping capacity requirement of 10,372 GPM, but will also be able to <br /> supplement PW demands and fire flows in Phase 11, should an emergency situation occur at the Phase I <br /> BPS. <br /> Table 2-8: Proposed Phase II City of Lathrop Potable Water Storage and Booster Pump Station at <br /> River Islands - Firm Pumping Capacity <br /> Pumping <br /> Capacity Motor <br /> (gpm) @ Rated Motor <br /> Pump Number 197' TDH Horsepower Drive Status <br /> Variable <br /> Phase 11 —Small Booster Pump#1 2,000 125 Frequency Duty <br /> Drive <br /> Variable <br /> Phase 11 —Small Booster Pump#2 2,000 125 Frequency Duty <br /> Drive <br /> Variable <br /> Phase II —Small Booster Pump#3 2,000 125 Frequency Standby <br /> Drive <br /> Total Firm Pumping Capacity Phase II 4,000 <br /> Total Firm Pump Capacity Phase I + Phase 14,000 <br /> I I <br /> Notes: <br /> 1. Proposed Phase II BPS will be designed to operate in a 2 duty+ 1 standby configuration with Small Booster <br /> Pump#3 designed as standby. <br /> 12 <br />