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<br />8 | Final Report Bay Area Clean Water Agencies | City of San Leandro <br />Table 3–3. Flow and Load for Facility Upgrades (Projected to Permitted Capacity) <br />Criteria Unit Permitted Flow <br />Capacity, ADWF1,2 <br />Annual <br />Average <br />Dry Season MM <br />(May 1 – Sept 30)1,3 <br />Year Round <br />MM1,3 <br />Flow mgd 7.6 7.9 8.2 10.0 <br />BOD lb/d 34,800 34,300 39,200 45,600 <br />TSS lb/d 30,100 30,100 35,800 38,600 <br />Ammonia lb N/d 1,700 1,900 1,700 2,100 <br />TKN lb N/d 3,300 3,600 3,300 3,900 <br />TP lb P/d 440 490 440 530 <br />Alkalinity4 lb/d as CaCO3 - - - - <br />BOD mg/L 549 521 570 549 <br />TSS mg/L 475 457 520 464 <br />Ammonia mg N/L 27 29 25 25 <br />TKN mg N/L 52 55 48 47 <br />TP mg P/L 6.9 7.4 6.4 6.4 <br />Alkalinity4 mg/L as CaCO3 - - - - <br />1. ADWF = Average Dry Weather Flow and MM = Maximum Month. <br />2. ADWF is calculated as the average flow for the months of July, August, and September. <br />3. The dry season maximum month values are used to size facilities to treat dry season loads that operate year round; the year round maximum <br />month values are used to treat year round loads that operate year round. <br />4. Alkalinity data not available. <br />3.4 Basis for Cost Analysis <br />The approach to developing the estimated capital and O&M costs for the optimization strategies and <br />facilities upgrades was consistent for each of the 37 POTWs included in the study. <br />First, treatment options were analyzed to determine their feasibility and facility needs and the major <br />process facilities were identified on a site plan to show their respective footprint and location. The <br />need for additional major facilities such as pumping stations, significant transfer piping, chemical <br />feed facilities, and blowers were identified and the footprint for these facilities was located on the site <br />plan. Once the major facilities were defined, a parametric cost analysis was used to estimate the <br />construction costs for each facility. Allowances were included for undefined facilities, site conditions, <br />and contractor’s costs and profit. An allowance for engineering, construction management, legal and <br />other administrative costs was then applied to develop a total estimated capital cost. Appendix A <br />presents the various allowances that were included to estimate the capital cost. <br />The O&M costs for power, chemicals, and labor were also estimated using a parametric cost <br />analysis. Unit chemical costs were developed using information from the Bay Area Chemical <br />Consortium (BACC). The same unit costs were used for all the BACWA treatment plants to simplify <br />the analysis. See Appendix A for the unit costs used in the cost opinions. <br />The capital and O&M costs are presented in current dollars, referenced to the ENR SF CCI for <br />November 2017 at 12,015. In order to understand the relative costs for each of the 37 POTWs <br />included in the watershed permit, the capital and O&M costs were also expressed as unit costs: <br /> Unit capital cost per gallon ($/gpd) includes the capital cost for the treatment strategy to remove <br />ammonia, nitrogen and phosphorus.