SU0006571 SSNL - Laserfiche WebLink

Home Browse Search

r econdly, various researchers place the nitrogen reduction occurring in septic tanks at 10% to 20%.rom the May 8, 2003 Symposium "Onsite Wastewater Treatment-Nitrogen Removal,"Dr. Stuartakley of Chico State University states that"approximately 20% of the total nitrogen generated is removed in the septic tank." As noted above, a conservative estimate of 10% was used for the proposed septic tanks. Thirdly, the biomat does have the beneficial property of removing approiimately 10%of the nitrogen from disposal systems. This figure was not used in the nitrate ,loading calculations also to maintain a conservative loading concentration. C. SEPTIC SYSTEM OPERATIONAL PARAMETERS AND COMPONENTS SSS§ 3.7. Discussion of efficient operation, disposal field longevity, and environmental protection are based upon the environmental parameters discussed below. An overview of the system operation is as follows: Influent waste from the residential structure and the Store will gravity to an exisitng septic tank. This effluent will then gravity into a new 2,000 gallon tank. Effluent from this tank will then gravity flow into a distribution, or"D-Box"to be evenly distributed between three - 50 ft long leachlines with sumps at each end. /EPTIC TANKS Septic tanks store the accumulated sludge, scum and effluent(clear zone)volumes, which in turn affect treatment of nitrogen within the tanks. In the following calculation,the pump-out interval factor times the QAVE times the peaking factor(PF)correlate the pump-out time interval in years with the recommended tank capacity. The peaking factor value for this project is estimated to be 2.5. It is anticipated that the existing, original septic tank is 1,200 gallon capacity. Since effluent from this tank will flow into new tank to be installed, the recommended tank capacity for this new tank must be calculated. Recommended tank capacity for a potential pump-out interval of three years after operation: 2.8(pump-out interval factor) (QAVE)x Peaking Factor(PF=2.5)=2.8 (215 gpd)x 2.5 = 1,500 gals. Anticipated total septic tank capacity=2,000 gallon tank. Detention Time: Detention Time=2.000 gal total tank capacity x 0.70 (30%volume lost to sludge/scum accumulation) 2.5 (Peaking factor)x 215 gals/day(ADF) Detention Time=2.6 days. The minimum acceptable detention time is 1.0 day. Therefore, a 2,000 gallon septic tank is applicable for sufficient detention time with an adequate safety factor. 11 Chesney Consulting