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r <br /> MOUND DESIGN WORK SHEET (For Flows up to 1200 gpd) <br /> ' A. A'veraQe Design FLOW <br /> � ���y-g�,^�,�,��q,}�N-, ,�-�;�, �. ,.�op ,t�,� ���µ� A-l: Estimoted Sewage Flows in Gallons per Day <br /> ��,�� �� �I 3'�:�'� �- 3ac� �:i�Ijolk� num ero <br /> ESdmateC� 7 d� gpd (see figure A-1) bedrooms Class I Class II Class III Class IV <br /> or easur d x 1.5 (safety factor) = gpd 2 300 225 lso bo% <br /> ���;��„�,,. 3 . 450 300 218 of the <br /> 4 600 375 256 values <br /> B. SEPTIC TANIC Capacity 5 750 450 294 in the <br /> �..-> 6 900 525 332 Class I, <br /> ,,`�a,cr����!�'bc� "�-`��t�� f.-` <br /> �,-�l o�� gallons (see figure G1) ��"1�' �-�''���- � �o�0 60o s�o n, o�ui <br /> 8 1200 675 408 columns. <br /> I c�ca o ��,� �t�ti�� ����`►�� �1 `i`i`�,��-°�'. <br /> C. SOILS (refer to site evaluation) C-1: 5e ticTank Ca acities(in ailons <br /> Number of Minimum Liquid Liquid capacity wilh Liquid capacit} <br /> Bedrooms Ca aci arba e dis osal W��disposal& <br /> 1. Depth to restricting layer = ���. S, I.� feet P ry g g p lift inside <br /> 2. Depth of percolation tests = la c� feet zo��e55 �so �izs 15� <br /> 3. Texture G�-R� �.t��1 5 or 6 is�oo iiso 3� <br /> Percolation rate /r� . 9' mpi �,s o�9 z000 3000 <br /> 4. Soil loading rate •`-�l:� gpd/sqft (see figure D-33) <br /> 5. Percent land slope .� % <br /> D. ROCK LAYER DIMENSIONS <br /> 1. Multiply average design flow (A) by 0.83 to obtain required rock layer area. <br /> `�� � gpd x 0.83 sqft/gpd = �S'� I sqft <br /> 2. Determine rock layer width = 0.83 sqft/gpd x linear Loading Rate (LLR <br /> 0.83 sqft/gpd x 1'��, gpd/sqft= / G� ft Mound LLR <br /> 3. Length of rock layer = area =width = <br /> S `� i sqft (D1) = p� ft (D2) _ �;�� ft < 120 M PI < � 2 <br /> E. ROCK VOLUME > 120 M PI < 6 <br /> 1. Multiply rock area (D1) by rock depth of 1 ft to get cubic feet of rock <br /> ,�� I sqft x 1 ft = ���1 cuft <br /> 2. Divide cuft by 27 cuft/cuyd to get cubic yards <br /> ����' 1 cuft = 27 cuyd/cuft = �,�, cuyd <br /> 3. Multiply cubic yards by 1.4 to get weight of rock in tons <br /> . 2, � cuyd x 1.4 ton/cuyd = �� 1 tons <br /> D-33: Absorption Wid[h Sizing Table <br /> F. SEWAGE ABSORPTION WIDTH Pcrcolation Ra�c Loading Rale <br /> in Minulcs per Soil 7�ex�ure Gallons Absorption <br /> Inch • per day per Ratio <br /> MPI s uare foot <br /> Faster than 5 Coarse Sand 1.20 1.00 <br /> Mcdium Sand <br /> Absorption width equals absorption ratio (See Figure D-33) LoamySend <br /> Finc Sand <br /> times rock layer width (D2) 16 to 30 Lo�„ o.�o Z� <br /> 31 to 45 Silt Loam 0.50 2.40 <br /> o�•, (�r) X �� ft = �,�lj• / ft 46to60 SandyQayL,o 0.45 2.67 <br /> , Sil�y Clay Loem <br /> 6l to 120 Silty Clay 0.24 5.00 <br /> Sandy Clay <br /> Cle <br /> Slowerthan 120• <br /> •Sys�em duigned(ar Nese soils rws�be wtier or peAommrce <br />