(A) The minimum conduit diameter for sewer proposes (except building sewers) shall be eight inches. For sewers up to and including 24 inches in diameter, shall be designed for the above volumes of sewage with the sewer flowing half full. For sewers 27 inches in diameter, shall be designed for the above volumes of sewage with the sewer flowing at 0.6 depth and sewers 30 inches in diameter and larger shall be designed for the above volumes of sewage with the sewer flowing at 0.7 depth. Manning's Formula with an “n” factor of 0.014 in design shall be used.
(B) The minimum allowable slope shall be that which results in a velocity of two feet per second when the conduit flows at ¼ of full depth.
Size of Conduit (Inches) | Slope (Percent) |
Size of Conduit (Inches) | Slope (Percent) |
8 | 0.50 |
10 | 0.50 |
12 | 0.40 |
15 | 0.30 |
18 | 0.24 |
21 | 0.19 |
24 | 0.16 |
27 | 0.14 |
(Ord., passed 7-13-87) Penalty, see § 51.999