(A) General requirements.
(1) No plat will be approved covering any property located within the corporate limits of the city until such time as sewer service has been made available for every lot within the subdivision.
(2) The subdivider shall extend the public sanitary sewer to the subdivision and shall install adequate sewerage facilities subject to the specifications and approval of the Public Works Director.
(2012 Code, § 77-211)
(B) Design criteria for sanitary sewers. Sanitary sewer systems shall meet the requirements of the city.
(1) These design criteria are not intended to cover extraordinary situations. Deviations will be allowed and may be required. Final designs for water and sewage service must be approved by the city’s Public Works Director. Design criteria provided herein is informational and is not to be construed as final design requirements.
(2) Sewers shall be designed for the total tributary area using the following criteria:
Source Classification | Remarks | Daily sewage flow gallon per person | Daily B.O.D. 5 lbs/person |
Source Classification | Remarks | Daily sewage flow gallon per person | Daily B.O.D. 5 lbs/person |
Drive-in theater | Per car space | 5 | 0.01 |
Factory | With showers | 25 | 0.07 |
Factory or office building | No showers | 20 | 0.06 |
Hospitals | Per bed | 200 | 0.35 |
Mobile home park | 3 persons/trailer | 100 | 0.17 |
Motor lodge | W/toilet and bath | 50 | 0.12 |
Municipality | Residential | 100 | 0.17 |
Nursing homes | Per bed | 90 | 0.20 |
Recreation parks | Swimmers | 40 | 0.10 |
Campers | 5 | 0.01 | |
Boaters | 10 | 0.03 | |
Restaurant | Per meal served | 5 | 0.02 |
Schools | Elementary, high | 15 | 0.04 |
Subdivision | Residential | 100 | 0.17 |
Trailer park, transient | 2-1/2 persons/trailer | 50 | 0.12 |
(3) These design factors shall apply to watersheds of 300 acres or less. For areas larger than 300 acres, registered engineers must submit design calculations for approval. The state’s Health Department criteria shall govern design preparation.
(4) The diameter of sewers proposed shall not exceed the diameter of the existing or proposed outlet whichever is applicable unless otherwise directed by the Director of Public Works.
(5) No public sewer shall be less than eight inches in diameter.
(6) All sewers shall be designed and constructed with hydraulic slopes sufficient to give mean velocities when flowing full or half-full of not less than two feet per second. The grades shown in the following table are based on Manning’s Formula and an “n” factor of 0.013 and shall be minimum acceptable slopes. Lesser “n” factors will be considered for special material where new “n” can be demonstrated.
Size of Pipe in Inches I.D. | Fall in Feet per 100 Feet of Sewer |
8 | 0.33 |
10 | 0.25 |
12 | 0.20 |
15 | 0.15 |
18 | 0.11 |
21 | 0.09 |
(7) Sewers shall be laid in straight alignment where possible with uniform grade between manholes. In those cases where horizontal curvature must be utilized to serve a particular area, the smallest radius of curvature shall be 100 feet and in all cases shall be in accordance within the particular manufacturer’s recommendations.
(8) Sanitary sewers shall be located within street or alley right-of-way unless topography dictates otherwise. When located in easements on private property, access shall be provided to all manholes.
(9) A minimum horizontal distance of nine feet shall be maintained between parallel water and sewer lines. At points where sewers cross water mains, the sewer shall be constructed of pressure type pipe with water-tight joints for a distance of ten feet in each direction.
(2012 Code, § 77-212)