(A) A separate and independent building sewer (lead) shall be provided for every building; except where one building stands at the rear of another on an interior lot and no private sewer is available or can be constructed to the rear through an adjoining alley, court, yard or driveway, the building sewer from the front building may be extended to the rear building and the whole considered as one building sewer. Other exceptions will be allowed only by special permission granted by the Supervisor.
(B) All costs and expenses incident to the installation of the building sewer and the connection of same to the public sewer shall be borne by the property owner.
(C) All building sewers (leads) shall meet or exceed the requirements of the ordinances of the City of Williamston or the requirements of this chapter, whichever shall be most stringent.
(D) Building sewers hereinafter installed shall consist of pipes and fittings of the following types and sizes.
(1) Pipe must be of sufficient diameter to carry the estimated volume of discharge. Minimum pipe size permitted is four-inch ID.
(2) Pipe must be one of the following materials and cannot be mixed in the connection lines to include the fittings:
(a) Cast iron with rubber-type gaskets or leaded joint;
(b) Cast iron NH pipe with neoprene stainless couplings;
(c) Ductile iron with rubber-type gaskets, slip joint or mechanical joint;
(d) Vitrified clay tile with ASTM C425 joints;
(e) Reinforced concrete with ASTM C443 joints; and
(f) PVC plastic, Schedule 40 or better.
(3) No tees, double tees or crosses or double hub pipes shall be permitted.
(4) Old building sewers or portions thereof may be used in connection with new buildings only when they are found on examination and tested by the Inspector to meet all requirements of this chapter.
(5) All changes in grades of direction shall be made with appropriate fittings.
(E) Clean-outs shall be installed every 100 feet of straight run and at each 90-degree direction change and all clean-outs shall be plugged.
(F) All lines shall be laid at a minimum slope of one-eighth inch per foot grade and a maximum slope of one-half inch per foot grade for four-inch lines and at a minimum of one-eighth inch per foot grade and a maximum one-half inch per foot grade for six-inch lines.
(G) The method to be used in excavating, placing of pipe, jointing, testing and backfilling the trench shall conform to the requirements of the Plumbing Code Rules (Part 7) issued by the Michigan Department of Labor Construction Code Commission and the regulations of Williamstown Township where applicable.
(H) All joints and connections shall be gastight and shall conform to the requirements of the current building and plumbing codes.
(I) Whenever possible, the building sewer shall be brought to the building at an elevation below the basement floor. No building sewer shall be laid parallel to or within three feet of any bearing wall, which might thereby be weakened. The depth shall be sufficient to afford protection from frost. All excavations required for the installation of a building sewer shall be open trench work unless otherwise approved by the Inspector. Pipe laying and backfill shall be performed in accordance with current ASTM Specifications except that no backfill shall be placed until the work has been inspected by the Inspector or his or her representative.
(J) No building sewer shall be laid within three feet of any bearing wall. The depth shall be sufficient to afford protection from frost.
(K) In all buildings in which any building drain is too low to permit gravity flow to the public sewer, sanitary sewage carried by the drain shall be lifted by an approved pumping system and discharged to the building sewer.
(L) All excavations for building sewer installation and connection shall be adequately guarded by barricades and lighting so as to protect the public from hazards. Streets, sidewalks, alleys, parkways and other public property disturbed in the course of the installation and connection work shall be restored.
(M) The connection of the building sewer into the public sewer shall be made at the "Y" branch designated for that property, if the branch is available at a suitable location. Any connection not made at the designated "Y" branch in the main sewer shall be made only as directed by the Inspector and approved by the Supervisor.
(N) The applicant for the building sewer shall notify the Inspector when the building sewer is ready for inspection and connection to the public sewer. The connection shall be made under the supervision of the Inspector or his or her representative.
(Ord. 26, eff. 6-19-1982)