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The gravel bed on top of the sand media shall also be tested for conformance with the following <br /> size distribution: 3/8 in. washed pea gravel to 1.5 in. washed drain rock. A geotextile filter fabric <br /> must be placed over the top of the gravel bed. <br /> AGGREGATE ABSORPTION AREA WIDTH(A) <br /> A=Linear Loading Rate=Sand Media Loading Rate <br /> =6 gals/day/ft . 0.6 gal/ft'= 10 ft <br /> AGGREGATE ABSORPTION AREA LENGTH(B) <br /> B=Design Flow Rate . Linear Loading Rate <br /> B=375 gpd_6 gals/day/ft=63 ft <br /> BASAL AREA WIDTH(A+I+J) <br /> A+I+J=Linear Loading Rate—Basal Loading Rate(Based on Long-Term Acceptance Rate-LTAR) <br /> =6 gals/day/ft=0.2 gallons/W/day <br /> =30 ft <br /> Use A= 10ft, I= 10fit and J= loft <br /> MOUND FILL DEPTH <br /> Sand Fill depth north side of Aggregate Absorption Area= 1.5 ft. <br /> Sand Fill depth south side of Aggregate Absorption Area= 1.5 ft. (Mound must be level). <br /> MOUND DEPTHS <br /> Aggregate Absorption Area thickness=9 in. <br /> (6 in. of aggregate below the laterals, I in.for pipe height and 2 in. for cover over pipe=9 inches) <br /> Thickness of Topsoil(Fill and Cap)at the north and south edges of Aggregate Absorption Area = 12 in. <br /> Thickness of Topsoil(Fill and Cap)at the center of the Aggregate Absorption Area= 18 in. <br /> NORTH DOWN-SLOPE WIDTH(1) <br /> Mound side slope of 3:1. <br /> Height of mound=(18 in.Fill+9 in.Aggregate Absorption Area + -15 in.Avg.Topsoil thickness) <br /> Height=3.5 ft. vertical x 3 horizontal= 10.5 ft. Use 10 ft as referenced above. <br /> SOUTH UP-SLOPE WIDTH (,I) <br /> Mound side slope of 3:1. <br /> Height of mound=(18 in.Fill+9 in.Aggregate Absorption Area + -15 in.Avg. Topsoil thickness) <br /> Height=3.5 ft.vertical x 3 horizontal= 10.5 ft. Use 10 ft as referenced above. <br /> END-SLOPE LENGTHS AT EAST AND WEST ENDS(K) <br /> mound end slope of 3:1 <br /> K=3((18 in.+ 18 in.)—2+9 in. + 18in.) <br /> K= 11.3 ft. Use 11.Oft <br /> OVERALL LENGTH AND WIDTH(L+W) <br /> L=B+2K <br /> L =63ft+2(llft) <br /> L=85ft <br /> W=A+I+J <br /> W = 10ft+ 10ft+ 10ft <br /> W=30ft <br /> 17 <br /> Chesney Consulting <br />