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1A21 <br /> Project North Sound Behavioral Health 2170857.10 <br /> Project No. ['Page of ffl <br /> Subject Sewer Pump Calculations Phone 206.267.2425 ❑Meeting Minutes <br /> With/To FAX# ['Telephone Memo _ —�A <br /> ❑Calculations <br /> Address #Faxed Pages A H B L <br /> ❑Memorandum <br /> Date 05/07/2020 By Yi Yang ['Fax <br /> Occupancy of facility = 214 (level 1) + 61 (level 2-N) + 62 (level 2-R) = 337 people <br /> maximum (See Architect Plan A1.03B and A1.04B); <br /> Pump flows: <br /> Per WSDOE Criteria for Sewage Works Design, Table G2-2, consider facility type as <br /> "school with showers and cafeteria". We picked this classification because the <br /> Orange Book does not have a classification that adequately captures the use of the <br /> facility. We felt the gallons per day per person for the "school with showers and <br /> cafeteria" was more representative of the project than a "doctors office." <br /> - Discharge Flow = 16 gal/day/person (from Table G2-2) structural Snc1n yr_ <br /> —> Qavg = 337 people * 16 gal/day/person = 5392 gal/day Landscape Architects <br /> = 5392 gal/day * (1 day/24hr)*(1 hr/60min) = 3.74 gal/min <br /> Community Planners <br /> Per WSDOE Criteria for Sewage Works Design, Figure C1-1: <br /> -and surveyors <br /> -� Peak factor = Qpeak hourly/ Qavg <br /> = (18+ P^0.5)/(4+P^0.5) (P in thousands, Qpeak in gph, Qavg in gpm) °`e'ghb"rs <br /> = (18+0.337^0.5)/(4+0.337^0.5) <br /> = 4.06 <br /> -* Qpeak = Qavg * peak factor = 5392 gal/day * 4.06 = 21891.52 gal/day <br /> = 21891.52 gal/day * (1 day/24hr)*(1 hr/60min) = 15.20 gal/min <br /> Input for calculating total dynamic head (TDH): <br /> Pump Off Elevation = 84.51 ft <br /> High Point Elevation = 100.88 ft <br /> Differential Elevation = 16.37 ft <br /> Pipe length = 259 ft <br /> Pipe material = 2" HDPE SDR 11 <br /> I.D = 1.917" <br /> -* TDH = 52.00 ft <br /> Friction Losses in Pipe -(Hazen and Williams Formula): <br /> f = 0.2083 * (100/C)^1.85 * (q^1.85/d^4.8655); <br /> C = 140 for new pipe; SEA TTLE <br /> q = flow in gallons per minute; 1200 6th Avenue <br /> d = I.D =1.917" <br /> Suite 1620 <br /> Seattle,WA 98101-3117 <br /> -* f avg = 0.2083 * (100/140)^1.85 * (3.74^1.85/1.917^4.8655) = 0.05 206.261.2425 <br /> TEL <br /> —> f peak = 0.2083 * (100/140)^1.85 * (15.201\1.85/1.917^4.8655) = 0.72 <br /> ahbi <br /> If this does not meet with your understanding,please contact us in writing within seven days. THANK YOU. <br />