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<br />I
<br />MOUND DESIGN WORKSHEET
<br />, (For Flows up to 1200 gpd)
<br />A. FLOW
<br />Estimated c.po gpd (see pages D-7 or 1-3, 4, 5)
<br />or measured ___ gpd.
<br />B. SEPTIC TANK UQUID VOLUMES
<br />l -I oo D gallons (see pages C-3 or C-5)
<br />C. SOILS (refer to site evaluation)
<br />I/
<br />1. Depth to restricting layer = 1 6 ,, -ro \ $ inches
<br />2. Depth of percolation tests = I ~ '1 inches
<br />3. Percolation rate 1 1 . "3 mpi
<br />4. Land slope -;, / o %
<br />D. ROCK LA YER DIMENSIONS
<br />1. Multiply flow rate by 0.83 to obtain required area of rock
<br />layer: A x 0.83 =
<br />000 gpd x 0.83 sq. ft./gpd =~sq. ft. -\ I oS>o
<br />2. Select width of rock layer (10 feet or less)= / o ft.
<br />3. Length of rock layer = area + width = .
<br />£ y '.J sq. ft. + Jo ft. = ,<:;.:_:; ft.
<br />E. ROCK VOLUME
<br />1. Multiply rock area by rock depth to get cubic feet of rock;
<br />~ sq. ft. X l.:J2...:S... ft. = £1.!d_ CU. ft.
<br />2. Divide cu. ft. by 27 cu. ft./cu. yd. to get cubic yards;
<br />:£1.!:L cu. ft. + 27 = -2,l_ cu. yd.
<br />3. Multiply cubic yards by 1.4 to get weight of rock in tons;
<br />.s;2_L cu. yd. x 1.4 ton/ cu. yd. = 2.:::;.... tons.
<br />F. ADSORPTION WIDTH
<br />1. Percolation rate in top 12 inches of soil is l '7 .3 mpi
<br />2. Select allowable soil loading rate from table on page E-16;
<br />·½ gpd/ft2
<br />3. Calculate adsorption width ratio by dividing rock layer
<br />loading rate of 1.20 gpd/ft2 by allowable soil loading rate;
<br />1.20 gpd/ft2 + . (c2 gpd/ft2 = J.0 .
<br />Check this value on page E-16.
<br />4. Multiply adsorption width ratio by rock layer width to get
<br />required adsorption width;
<br />~ X _j_Q__ ft = ~ 0 ft
<br />E-19
<br />D-7
<br />ESTIMATED -'1.0WI IN ~9 I'll! DIii'
<br />NIM[R TYi'! OF IIDIDENC[ •
<br />Of
<br />IEOftOOMS I n m Dt
<br />I IICO -IIIO 1011
<br />ll •IIO 300 111 ., .. 800 !TS -,.._ ,.
<br />9 190 4IIO -"ttL • 800 5211 an
<br />T ,oeo IIOO sro 1n • !too 8?5 --C-3
<br />SEPTIC TANK CAPACmES, IN GALLONS
<br />-1/# --UOUID CA,AOl'T
<br />l OIII.III "' tOIU ttH
<br />10111 Hit
<br />?,1,0III ....
<br />$'4 0 .::;t:t f''\,
<br />Rock Bed
<br />•;,;;,,;;,9;,,;;,;J";;,;;,,;J,iJ';,I'. ,.,.,.,.,.,.,.,., ... -~ '•J'•,l'•rl'•J'•.f•-1'•.r•.--, ..
<br />19: ,-: J,8:;. ": ;:: ,-: ;, ":;.9:;.": ,: ,., .......... , .... ,.,.
<br />·-.-~,~,l',!,f~,t~J'~J',!,~-1'.•
<br />E-16
<br />-DA'<•Oll"f
<br />wmtOAIIIIII._
<br />DlaPOIAL
<br />1111
<br />ttll .... ....
<br />___ ... °' .... __ ----.... -------_, ........... .. , .. . ... .... . ... , ...
<br />I • 11 .. ,. '·" l,t\ '·" ti -to uo .... . ... , ...
<br />11 • •• . ... . ... . ... . .... ...... o.•• 0.11 ,.u •.. ,
<br />•• •tit .... . ... .... . ...
<br />________ .,.._.,..~,=-• ""''"'~-~....,,__~~--~ -R ~--.. (11kt ' ,ill)~
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