(a) All sets of plans, which include plans for sanitary sewers, shall include the current Township Sanitary Sewer Detail Sheets, which shall be considered an inseparable part of the plans when said plans are approved. Plans must be designed in accordance with the current detail sheets and standards noted herein.
(b) For every sanitary sewer project, there shall be indicated on the profile view (near the downstream end of the sewer) a manhole with a 12-inch deep manhole sump to be used for testing for infiltration. No sanitary sewer section having an infiltration rate, or an exfiltration rate, of more than 250 gallons per inch of pipe diameter per mile of pipe per 24-hour period, shall be approved for connection to the Township sanitary sewer system.
(c) The minimum allowable size for public sanitary sewers shall be ten inches in diameter. The minimum size of a building service sewer (wastewater) shall be six inches in diameter, except that a single mobile home dwelling unit may have a four-inch building service sewer (wastewater). However, a minimum of one eight-inch building service sewer shall be provided for a building containing from one to 12 dwelling units (or equivalent); and a minimum of two eight-inch building service sewers shall be provided for a building containing from 13 to 100 dwelling units (or equivalent). The minimum industrial building service sewer shall be eight inches with an inspection manhole or clean-out as required.
(d) The following table of acceptable slopes for sanitary sewers shall be adhered to:
Sewer Size (in.)
| Minimum Slope (%)
| Maximum Slope (%)
|
Sewer Size (in.)
| Minimum Slope (%)
| Maximum Slope (%)
|
4 | 1.00 | — |
6 | 1.00 | — |
8 | 0.50 | — |
10 | 0.30 | 4.00 |
12 | 0.22 | 3.00 |
15 | 0.15 | 2.00 |
18 | 0.12 | 1.50 |
21 | 0.10 | 1.30 |
24 | 0.08 | 1.20 |
(e) Sanitary sewage force mains shall be designed for a minimum velocity of two feet per second and maximum velocity of 12 feet per second, unless otherwise approved. Force mains shall be shown in a profile view with grades and elevations indicated thereon. An air relief and clean-out assembly manhole shall be provided at high points. Access (clean-out assembly) manholes shall be provided along the force main at least every 600 feet.
(f) A building service sewer shall be indicated on the plans for each building and for each premises in a single building in the project, unless otherwise approved by the Water and Sewers Department Superintendent. Where sanitary sewers are planned along roadways, the building service sewers shall be extended across the roadways (to the right-of-way line) prior to paving, whenever possible. Tracer wire shall be installed on the sewer lead piping with an approvable termination/testing box.
(g) Manholes shall be provided along all sanitary sewers (eight inches and larger) at:
(1) Points of horizontal deflection;
(2) Points where the size of the sewer is changed;
(3) Points where the slope of the sewer is changed;
(4) At junctions with other sewer lines;
(5) At the upstream terminus of a sewer run; and
(6) Along the sanitary sewer at other locations such that the maximum spacing between manholes shall not exceed 500 feet.
(h) At manholes where the size of the sewer changes, 0.8 diameter elevation points of the inlet and outlet sewer shall be matched. At horizontal deflections in the sanitary sewer greater than 45 degrees, a minimum of 0.10 feet additional adjustment in grade elevation shall be provided to allow for loss of head. When the invert of any inlet sewer is more than 18 inches above the outlet sewer at a manhole, a drop assembly shall be provided.
(i) In general, sanitary sewers shall be located within a public street right of way. Sanitary sewers shall not be located within rear lot line easements, except in extremely unusual circumstances, as determined by the Township Engineer. Where public sanitary sewers are located outside of public streets, they shall be placed in a recorded public utility easement that provides for unlimited access to the sanitary sewer for repairs, connections and maintenance.
(j) The sanitary sewers shall be designed to have a minimum depth from the finish grade elevation to the top of the sewer eight and one-half feet at local control points, or nine feet at locations where the sewer grade is parallel to the road grade. The sewer shall be designed to be deep enough to serve a standard depth basement for the type of building for which the land is zoned, except in specific locations where the existing receiving sewer limits the available depth. The sewer lead invert shall be at the crown elevation of the public sewer pipe with a minimal slope of 1.0% to the proposed building location.
(k) Each wye or terminus of a building service sewer shall be plugged with an infiltration-proof plug having a joint similar to those of the main sewer.
(l) The type of pipe and joints for sanitary sewers shall be in accordance with current Township standards.
(m) All facilities furnishing food services, including by illustration but not limitation, restaurants, clubs, senior facilities, schools, and other businesses furnishing for consumption to the public cooked food products within the Charter Township of Clinton shall comply with this chapter as follows:
(1) Any such facility furnishing cooked food services shall install an adequately sized grease trap. External grease traps are required unless the facility owner provides an alternate design with calculations and approval by the Department. These facilities shall be installed when the building is constructed with plumbing sleeved for each unit.
(2) Any existing facility remodeling to accommodate an expansion of the facility or any alteration as defined in the Michigan Building Code shall timely install an external grease trap in order to maintain an occupancy permit.
(3) Any facility which undergoes a change of use or increases the occupancy capacity of the facility shall install an external grease trap. Alternate designs with supporting calculations may be approved by the Department.
(4) Facilities which demonstrate within a calendar year difficulty in achieving compliance such that two or more sanitary sewer cleanout and/or inspections are required which presently does not have a grease trap, shall timely install a grease trap in order to maintain an occupancy permit.
(5) Where a grease trap is required, such grease trap shall be adequately sized in accordance with the current United States Environmental Protection Agency Design Manual or an approved equal as determined by the Township Engineer. Any current applicable Township standards including any adopted codes or rules issued by the Department of Public Services also apply to compliance of this ordinance.
(6) A signed and recorded covenant for grease interceptor maintenance shall be required and be on-file with the Township, If an agreement is not on file the Township, the property owner shall be required to submit one for review and approval, prior to being recorded and returned back to the Township.
(7) As a cumulative remedy, costs, including attorney fees for compliance shall be imposed and revocation of an occupancy permit must occur.
(Ord. 281. Passed 10-2-89; Ord. 439. Passed 12-18-17; Ord. 481. Passed 10-24-22.)