539 
TABLE I- ECONOMICS FOR 20-TON-PER-DAY SLUDGE DISPOSAL FACILITY* 
4 BASIS OF OPERATION 
Sludge with 20% Solids/80% Water 
Solid Waste (Incinerator Residue) with 80% Solids/20% Water 
350 Operating Days per Year 
Tons Per Year 
Dry Sludge Feed (20 tons per day) 7,000 
Dry Residue Feed (33.3 tons per day) 11,655 
Aggregate Production (32 Tons per day) 11,249 
$/Yr 
DIRECT COSTS 
Direct Labor: 2 Operators/shift, 7 days/wk @ $14.00/hr $235 ,200 
Electricity: 2,402,000 KWH @6¢ KWH 144 ,120 
Fuel Oil: 46,655 gal/yr @ $1.20/gal 55,986 
Gasoline: 2,640 gal/yr @ $1.30/gal 3,432 
$438 ,738 
INDIRECT COSTS 
Factory General: 1% Gross Fixed Assets ($2,867,106) $ 28,671 
Maintenance: 3% GFA 86,013 
Insurance: 1% 28,671 
Capital Charges: 10% GFA 286,711 
$430 ,066 
TOTAL OPERATING COSTS $868 ,804 
Cost per ton of Sludge $124 
REVENUES 
Aggregate: 11,249 tons @ $4.50/ton $ 50,621 
Credit for Solid Waste Disposal: 11,655 tons @ $12/ton 139 ,860 
Total Credits $190 ,481 
NET COST $678 ,323 
Net Cost per Ton of Dry Sludge Solids $97 
* - Tons of sludge on dry weight basis; costs based on pilot-plant experience; 
20 tons per day sludge: equivalent to the output for a city of 200,000 persons. 
