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1.. <br /> FALL.CREEK <br /> REPORT OF WASTE DISCHARGE io ENGINEERING.INC. <br /> %' efficiency (assumed to be 20%), d is the number of days per month, and A is the area of the <br /> `, wetland in hectares (0.0891 ha). Table 4.4 presents the results of the calculations for the organic <br /> `w loading rates for the proposed wetland treatment system under the current expansion plans. It <br /> also shows the hydraulic detention time of both the septic tank and the wetland. <br /> �. Table 4.4. Wetland Organic Loading Rates—Current Flow Rates <br /> L <br /> %W Process Stormwater Wetland Wetland Septic <br /> Water Flow Flow Loading Det. Time Det. Time <br /> Qp (gal/mo) Qs (gal/mo) L (kg/ha-d) (day) (day) <br /> %„ January 2,055 106,963 19 11 1 <br /> February 6,962 103,967 50 10 1 <br /> March 7,707 79,566 48 14 2 <br /> April 7,459 33,848 45 30 4 <br /> `. May 5,138 17,154 29 58 7 <br /> June 4,973 2,797 28 173 19 <br /> July 5,138 994 28 236 25 <br /> August 30,830 236 169 48 5 <br /> `. September 49,725 6,762 282 25 3 <br /> ` October 43,675 26,402 241 20 2 <br /> November 19,890 60,063 117 16 2 <br /> December 20,553 78,100 118 13 2 <br /> ` Projected wetland loading rates during the months of crush are expected to be higher than the <br /> EPA's suggested BOD loading rate of 112 kg/ha-d. However, these rates are well within the <br /> successful experimental values of 1650 kg/ha-d. In addition, even though there are some months <br /> with high loading rates, the average yearly loading rate is only 98 kg/ha-d, and there are many <br /> months where the loading rate is much lower. It is expected that some of the low loading months <br /> will help to balance the high loading months. <br /> FCE then calculated the expected removal efficiency for the proposed subsurface flow wetland. <br /> %W A first order equation was used to model pollution removal, as follows: <br /> %r Ce = eI-KT!) <br /> Co <br /> vft.. where Ce is effluent BOD, Co is influent BOD, KT is a temperature dependent first-order rate <br /> 14- constant, and t is the hydraulic detention time. KT was calculated from the following equation; <br /> ,*UK Kr = K200-1)(T-20)K20(1.1)(T-20) <br /> where K20 was assumed to be 1.104 d-I, and the temperature was assumed to be 15°C (59°F). <br /> �' Figure 4.3 shows the expected BOD removal based on these equations. From this it appears ppears that <br /> �. virtually no BOD is expected to remain after 6 days. As Table 4.4 shows, all projected detention <br /> %„ times are higher than 6 days therefore the removal efficiency of the wetland is expected to be <br /> %W very high. <br /> %W JESSIE'S GROVE WINERY 18 FEBRUARY 2004 <br />