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Wastewater Treatment System ..i <br /> Engineering Report ! � FALL CREEK <br /> '�,� ENGINEERING,INC. <br /> 4.3. Organic Loading Rates <br /> %' Table 4.3 presents the results of the calculations for the organic loading rates for the proposed <br /> `, wetland treatment system under the 10-year plan flows. It also shows the hydraulic detention <br /> `, time of both the septic tank and the wetland. <br /> Table 4.3. Wetland Organic Loading Rates— 10-Year Plan Flow Rates <br /> %W Process Stormwater Wetland Wetland Septic <br /> %W Water Flow Flow Loadinq Det. Time Det. Time <br /> Qp (gal/mo)Qs (gal/mo) L (kg/ha-d) (day) (day) <br /> January 4,891 114,270 35 10 2 <br />`, February 16,565 107,548 109 9 2 <br />%1W March 18,340 82,561 106 12 2 <br /> April 17,748 36,093 103 23 4 <br />%" May 12,226 18,985 68 41 7 <br /> June 11,832 2,989 67 90 14 <br /> July 12,226 1,063 67 107 16 <br /> August 73,358 264 402 20 3 <br /> September 118,320 8,027 671 11 2 <br />�r October 103,924 34,220 572 10 2 <br /> November 47,328 61,413 272 12 2 <br /> December 48,906 80,050 274 10 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-day (100 lbs/ac-day). However, these rates are <br /> well within the successful experimental value 1650 kg/ha-day (1472 lbs/ac-day). There are some <br /> months with loading rates are as much as 6 times above the EPA's suggested level. However the <br /> average yearly loading rate is 230 kg BOD/ha-day (205 lbs BOD/ac-day), which is only twice <br /> the EPA value. There are also many months were the loading rate is much lower than the EPA <br /> value. <br /> Although the expected loading values are sometimes higher than the EPA's criteria, other <br /> wineries have used as high or higher loading rates to successfully treat process wastewater <br /> (Shepard, 2001). Therefore, the constructed wetland proposed for Jessie's Grove Winery is <br /> expected to function adequately even under higher loading conditions. FCE also notes that the <br /> hydraulic detention time under these higher flow conditions remains longer than six days at all <br /> times and BOD removal rates are expected to be high. <br />` 4.4. Detention Time <br /> The wetland's hydraulic detention times are shown in Table 4.3. The detention time ranges from <br /> 9 days during the height of the wet season to over 100 days during the dry season when little to <br /> r <br /> no process water is being generated. During crush it appears that the hydraulic detention time is <br /> approximately 10 days. All of these detention times are above the recommended 6 to 7 days. <br /> JESSIE's GROVE WINERY MAY 2002 <br /> ` 18 <br />