Laserfiche WebLink
September 3, 2004 <br /> NOA Project Number: E04025A <br /> Page 5 <br /> For P-3 (1 foot diameter hole) <br /> CWR = 60 ft/day x (0.5 2 x 3.14) ft x 0.40 <br /> CWR = 19 ft lday <br /> CWR = 141 gal/day <br /> Adjust flow rate for a 5 foot diameter hole <br /> CWR = (5 ft x 141 gal/day)/0.5 ft <br /> CWR = 1,409 gal/day <br /> Average of three tests (5 foot dia.pit) <br /> CWR average = (410 gal/day+ 6,952 gal/day+ 1,409 gal/day)/3 <br /> CWR average = 2,924 gal/day <br /> Sewage Reduction Factor <br /> A sewage reduction factor should be applied to the clear water rate to adjust for suspended solids <br /> and biologic films which will grow on the sides of the seepage pits. These factors will cause the <br /> infiltration rates (flow rates) to reduce over the long term. Having proper tank capacity and <br /> retention time can help clean up the waste water allowing for a higher sewage reduction factor. <br /> Sacramento County calls for a standard 0.04 sewage reduction factor for their design for seepage <br /> pits. Table 2 presents sewage reduction factors and the resulting sewage flow rates. <br /> Table 2. <br /> Sewage Reduction Factor vs. Calculated Flow Rates <br /> Sewage Reduction Factor Average Clear Water Flow Rate Calculated Sewage Flow <br /> (CWR) (gal/day) Rate (gal/day) for 5-ft Dia. <br /> Seepage Pit <br /> 0.04 2,494 100 gal/day/pit <br /> (Sacramento County <br /> Standard Rate) <br /> 0.10 2,494 290 gal/day/pit * 2 ;W <br /> z <br /> 0.20 2,494 500 gal/day/pit <br /> 0.30 2,494 750 gal/day/pit <br /> Recommending the use 10% reduction factor. <br />