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C7—deAverage Daily Flow(ADF) was calculated to be 1,700 gals on Sundays and a signed olume for Monday through Saturday. The new mound system basal area must be pt the highest daily flow,which would be Sundays. The Application Rate at the of 24 inches was determined to be 0.800 gals/ft'/day and 0.686 gals/ftZ/day at the 36-inch depth. Taking an average of these two rates= 0.743 gals/ft2/day. With a mound system basal area of 50 ft x 130 ft=6,500 ftZ x 0.743 gals/ft'/day=4,829 gals/day. An anticipated Long- Term Acceptance Rate (LTAR) of 0.2 gals/ft2/day still gives an ADF of. 6,500 ft' x 0.2 gals/ft'/day = 1,300 gals/day, every day of the week. The effluent pumps will operate under a"demand dose" system and not a"time dose" system. This is due to the fact that the septic system will be under use during the entire week,just not on Sundays. Otherwise, if effluent was generated exclusively on Sundays, it could be stored in a surge tank and time-dosed throughout the week. �LS§4.�The nitrate loading potential calculated on Page 12 indicates the percolating effluent ay'have a resultant nitrate-nitrogen concentration of 6.0 ppm, which is six-tenths of the drinking water Maximum Contaminant Level (MCL). By sampling and testing the effluent from the second existing septic tank, a very accurate Total Kjeldahl Nitrogen (TKN) concentration was determined. This quantifies the total nitrogen and makes the loading calculations more accurate. MAINTENANCE A maintenance program must be established for the entire wastewater disposal system. As referenced, the septic tank pump-out interval has been calculated to be between 2.5 and 3.0 years. However, this is a theoretical pump-out interval and should be field verified by a sewage contractor after the first year of project completion. Clean-outs must also be installed at the distal ends of each lateral as noted on the attached plan detail notes. By using a long"bottle-brush" arrangement,the interiors of the laterals can be cleaned of potential biomat build-up. Severe biomat build-up was observed in the existing laterals after more than 15 years of operation. Accurate "as-builts"of the septic system must be supplied to the Environmental Health Department. It is imperative to recognize that all septic systems and disposal areas have a lifespan. This lifespan is unpredictable due to the numerous operational and environmental factors involved. A critical lifespan issue is controlling the on-site water use as much as possible. This may be accomplished by using the required low flow toilets and sink faucets. Restricting water use also includes checking for water leaks in toilets, dripping faucets, etc. on a regular monthly basis. 17 Chesney Consulting