A Coviparative Study of Imhoff Tanks 
363 
5 — I inch bars at 80 feet (horizontal — brackets) = 340.0 
12 — I inch bars at 20 feet (partition) = 204.0 
12 — I inch bars at 6 feet (vertical — brackets) = 34.5 
12 — f inch bars at 4 feet (vertical — brackets) = 23.0 
5 — ^ inch bars at 40, 50, 60, 65, 70 feet (bottom — circular) = 242 .5 
6 — I inch bars at 4 feet (inlet channel) = 20.2 
2 — I inch bars at 4 feet (inlet channel) = 6.8 
12 — I inch bars at 12 feet (bottom radial) = 122.5 
6 — I inch bars at 6 feet (bottom radial) = 30.6 
Total 4567.1 
Excavation: 
350 cubic yards 
Steel: 
2 — 9 inch— 25 pound I-beams at lOJ feet long 
2 — 12 inch — 31 .5 pound I-beams at 17^ feet long 
200 square feet triangle mesh 
3 Plates — 6 x ^ inch — total length = 35 feet weir plates 
1 Plate 37 X 7 feet x \ inch 
Pipes and fittings : 
23 feet — 10 inch cast iron water pipe 
1 — 45 degree — 12 inch turn 
1 — 90 degree — 12 inch turn 
1 — 12 inch standard valve 
6 — ring pipe supports 
60 feet — 1^ inch water pipe — 32 feet long perforated | inch holes spaced 4 feet 
ESTIMATE OF COST FOR RECTANGULAR TANK 
Excavation : 
400 cubic yards at $0.45 $180.00 
Sheeting: 
100 linear feet at $1 .75 175 .00 
Placing cast iron sludge pipe: 
22 feet — 12 inch pipe at $2.00 44.00 
Setting valve 5.00 
Back filling and tamping sludge pipe trench 1 .50 
Placing reinforcement in floors : 
1000 pounds at 5 cents 50.00 
Concreting floors: 
13 .2 cubic yards at $12 .00 158.00 
Waterproofing: 
6| squares at $3 .50 22.70 
Reinforcement for Walls: 
5542 pounds at 5 cents 275.00 
Concrete for walls: 
46 .3 cubic yards at $12 .00 550.00 
