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E. SURFACE WATER INFORMATION AND CALCULATIONS <br /> NLS§3.2. As referenced,the subject facility occupies an APN with an acreage of 11.07 acres. <br /> The actual facility only encompasses 4.82 acres in area. An area size of 3.13 acres is the actual <br /> batch plant facility and 1.69 acres directly to the east is where stormwater runs to from the batch <br /> plant area, as I directly observed after a heavy rainfall. The proposed leachfield area is 0.24 acres <br /> of the 3.13 acres. These land use areas are delineated in an aerial photo found in Appendix F. <br /> The following Mass Balance Approach utilizes these area delineations correlated with Available <br /> Rainfall and Net Rainfall Recharge, which were provided by the EHD consultant,Norman <br /> Hantzsche, PE. <br /> Available Rainfall= 17.85" (1.49 ft) <br /> Net Rainfall Recharge=8.82" (0.735 ft) <br /> Pervious/runoff area comparable to a Retention Basin area= 1.69 ac: <br /> 1.69 ac+0.24 ac(LF Area)= 1.93 ac x 325,851 gals/ac-ft x 0.735 ft=462,236 gals (R1) <br /> Impervious areas: Buildings/batch plant/compacted/paved=3.13 ac - 0.24 ac=2.89 ac <br /> 1.49 ft x 325,851 gals/ac-ft=485,518 gals/ac x 2.89 ac= 1,403,147 gals runoff from buildings/batch <br /> plant/compacted/paved areas entering the 1.69 ac area (b) <br /> 1.69 ac x 0.735 ft= 1.24 ac-ft x 325,851 gals/ac-ft=404,756 gals rainfall directly onto runoff area(c) <br /> 17.85" - 8.82"=9.03" Lost to evaporation from runoff area <br /> 9.03" x 27,154 gals/ac-in x 1.69 ac=414,389 gals(d) <br /> (e)= 1,403,147 gals(b)+404,756 gals(c)-414,389 (d)= 1,393,514 (R2) <br /> R1.+R2=R=462,236 gals+ 1,393,514 gals= 1,855,750 gals=5.70 ac-ft <br /> i <br /> Page -5- <br /> Chesney Consulting <br />