15. d
16. b
17. d
18. 4,800
4 min/in.=2.5 gal/sq ft/da
10,000 gal/da/2.5 gal/sq ft/da=4,000 sq ft
.20 x 4,000 sq ft = 800 sq ft (for garbage grinders)
4,000
4,800 sq ft
19. 1,600
4,800 sq ft/3 ft = 1,600 linear feet
20. 50
21. 4875
50 persons x 100 gal/person/da=5,000 gal/da
Enter Figure 1-13 at a flow of 5,000 gal/da
Read up to curve and interpolate tank capacity
Or use the formula V=1125 + 0.75Q = 1125 + 0.75 (5000)=
1125 + 3750 = 4875
22. Yes
capacity: 900 gal;
top of sludge is 22 in. from bottom;
The bottom of outlet device is 28 in. from bottom 60-(12+20). The top of
the sludge is 6 inches from the bottom of the outlet device (28-22) which is
less than recommended minimum of 7 inches.
23. Yes
1500 gal/da/0.9 gal/sq ft/da = 1667 sq ft
1667 sq ft/3 ft = 556 linear feet
24. d,e
percolation rate exceeds 60 min (30 min for seepage pits).
25. Disposal of the effluent (and chlorination, if necessary) (para 1-17b)
End of Lesson 1
MD0161
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