A. The adequacy of the existing sanitary sewers to which the proposed development is to outlet into must first be determined by the developer. If the existing sewers are not adequate, it shall be the developer's responsibility to find an outlet for the sanitary sewers. This work shall be done in cooperation with the city engineer and the city wastewater superintendent.
B. All design calculations must be submitted to the city engineer for approval.
C. Where the subdivider can show by cost estimates that it is not economical to connect to public sewers (taking into account the cost of installing individual septic systems and their maintenance costs), he shall furnish percolation and other test results to indicate that the lots are of adequate size for proper sanitary waste disposal. This information shall be pre-pared by the registered professional engineer. The area used for seepage fields shall not be under any proposed driveways, parking areas, buildings, nor on public property for easements. No seepage field shall be connected to any storm drainage facility. See "Water Distribution" section of these standards for septic tank and well locations.
D. All permits required must be obtained by the developer (i.e., Environmental Protection Agency permit).
E. All sanitary sewer work shall be done in accordance with the current Standard Specifications for Water and Sewer Main Construction in Illinois and the Environmental Protection Agency of the state;except as follows:
1. Sanitary sewer mains shall be a minimum of eight inches diameter;
2. Maximum distance between manholes shall be three hundred fifty feet;
3. Manholes shall be constructed in accordance with the attached Standard Drawing No. 6, located at the end of this title;
4. All main sewer lines shall be terminated with a manhole;
5. Each lot shall be provided with a wye connection located near the center of the lot (with pancake plug; cemented in place). All service lines and wyes shall be constructed to a watertight, approved method; See Standard Drawing No. 6, located at the end of this title;
6. The invert of all service connections made at manholes must be at the top of the main line pipe;
7. Any service stub which is seven feet or greater from the finished surface shall be provided with a riser to bring the service within seven feet of the surface, all such service wyes shall be encased with six inches of concrete (with pancake plug);
8. Drop connections for services at manholes will not be allowed;
9. Back lot line sanitary sewer services shall be provided with manholes at all street crossings;
10. The top of all manhole rims shall be set two inches above the finished ground line;
11. Slope: All sewers shall be designed and constructed to give mean velocities, when flowing full, of not less than 2.0 feet per second, based on Kutter's formula using an "n" value of 0.013. The following minimum slopes shall be provided; however, slopes greater than these are desirable:
Minimum Slope
in Feet
Sewer Per Flow
Size 100 Feet (MGD)
in Feet
Sewer Per Flow
Size 100 Feet (MGD)
8-inch 0.40 0.45
10-inch 0.28 0.70
12-inch 0.22 1.02
14-inch 0.17 1.40
15-inch 0.15 1.57
16-inch 0.14 1.79
18-inch 0.12 2.30
12. Services shall have a minimum slope of:
4" diameter - 1/4" per foot
6" diameter - 1/8" per foot
13. The type of sewer pipe for mains and laterals shall be:
a. Extra strength clay pipe in accordance with ASTM designation: C-700 for up to eighteen-inch diameter,
b. For greater than eighteen-inch diameter sewer, the pipe shall be either concrete pipe (ASTM C-14) or reinforced concrete pipe (ASTM C-76);
14. All force main pipe shall be ductile iron pipe in conformance with AWWA C 151 and ANSI A 21.51;
15. Minimum cover shall be 3.5 feet from finished grade to top of pipe for gravity sewers or force mains. Special structural protection shall be provided for cases where there is less than the minimum cover;
16. The type of service pipe material from the wye connection or service stub, whichever comes first, shall be:
a. Extra strength clay pipe in accordance with ASTM designation: C-700 within the limits of the right-of-way,
b. Plastic pipe: In the areas beyond the right-of-way lines (not city property nor maintenance responsibility) the service pipe may be plastic,
(i) Polyvinyl Chloride Pipe: shall conform to ASTM D 1785, Schedule 40 or CS272, Type II, with wall thickness not less than 0.2 inch in the four-inch diameter and not less than 0.25 inch in the six-inch diameter,
(ii) Acrylonitrile-Butadiene-Styrene (ABS) Pipe: Conform to CS 270 or PS 18 with wall thickness not less than 0.2 inch in the four-inch diameter and not less than 0.25 inch in the six-inch diameter,
(iii) Fittings: Fittings shall be the same plastic material as the pipe.
(Ord. 81-10 § 11.1 (A), 1980).