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� MOUND DESIGN WORK SHEET (For Flows u to 1200 d) <br /> A. Average Design FLOW A-1: Estimated Sewage Flows in Gallons per poy <br /> num er o <br /> Estimated �Sv gpd (see figure A-1) bedrooms Class I Class II Class III Class IV <br /> or measured '— x 1.5 (safety factor) _ — gpd 2 300 225 �so � <br /> 3 . 450 300 218 ,pf the <br /> 4 600 375 256 values <br /> B. SEPTIC TANK Capacity 5 750 450 294 ' in tne <br /> 6 900 525 332 Class I, <br /> 7 1050 600 370 II,or Iil <br /> I -la-�� � )—)000 gallons (see figure C-1) g �2pp 675 408 columns. <br /> C. SOILS (refer to site ez�aluation) 1��.�'�✓���'� C•l: Se ticTankCa acities(in allons <br /> S�-slG• J,•3 "1•`d Liquid capacity <br /> d z.! Number of Minimum Liquid Liquid capacity with W��disposal& <br /> 1. Depth to restricting layer = /,.s�I•i� t a.o feet B���� Capaciry garbagedisposal Iiftinside <br /> 2. Depth of percolation tests = I.o feet 2orless �so >>2s 15� <br /> 3. Texture ��-,�^� ��w� 3 0�a �000 tsoo z000 <br /> 5 or 6 1500 2250 3� <br /> Percolation rate I i-1 - � TI1P1 ��g°f 9 Z000 3000 <br /> 4. Soil loading rate ��� gpd/sqft (see figure D-33) <br /> 5. Percent land slope 3 % W�s-s. <br /> � <br /> D. ROCK LAYER DIMENSIONS <br /> 1. Multiply average design flow (A) by 0.83 to obtain required rock layer area. <br /> ��o gpd x 0.83 sqft/gpd = �a sqft -r����=�s�►�'� <br /> 2. Determine rock layer width = 0.83 sqft/gpd x linear Loading Rate (LLR <br /> 0.83 sqft/gpd x 1�— gpd/sqft= /o ft Mound LLR <br /> 3. Length of rock layer = area=width = <br /> �� sqft (Dl) = ►o ft (D2) = c�� ft < 120 M PI < � 2 <br /> E. ROCK VOLUME � � 2O M P I < C� <br /> 1. Multiply rock area (D1) by rock depth of 1 ft to get cubic feet of rock <br /> ��s sqft x 1 ft = ��_cuft <br /> 2. Divide cuft by 27 cuft/cuyd to get cubic yards <br /> lo�s • cuft + 27 cuyd/cuft = a�� cuyd <br /> 3. Multiply cubic yards by 1.4 to get weight of rock in tons <br /> �,� cuyd x 1.4 ton/cuyd = 35� tons <br /> D-33: Absorption Width Sizing Table <br /> F. SEWAGE ABSORPTION WIDTH Percolation Ra�e Loeding Ro�e <br /> in Minutes per Soil Texturc Gellons Absorytion <br /> Inch per day per Ratio <br /> MPI s uatt(oot <br /> Fastcr than 5 Coerx Sand 1.20 1.00 <br /> Medium$and <br /> Absorption width equals absorption ratio (See Figure D-33) Loamy Send <br /> times rock la er width (D2) 16 to 30 ��„ o.� z.� <br /> y 3��oas s�i�t.o.R, o.so 2.ao <br /> �•�X . �� ft -�ft 46 to 60 Si�CI�ayYLo�m 0.45 2.67 <br /> 61�0 120 Silty Clay 0.24 5.00 <br /> Sandy Clay <br /> I <br /> SlowerUien 120' <br /> •Sy�lem duiEned for Nue wlls rtu��be aLer or perform.xe <br />