(a) Manholes shall be installed: at the end of each line; at all changes in grade, size, or alignment; at intersections; and at distances not greater than 400 feet for sewers 15 inches or less, and 500 feet for sewers 18 inches to 30 inches, except that distances up to 550 feet maximum may be approved in cases where adequate modern cleaning equipment for such spacing is provided. Cleanouts may be used only for special conditions and shall not be substituted for manholes nor installed at the end of laterals greater than 150 feet in length.
(b) Drop manholes shall be used whenever a sewer enters the manhole at an elevation of 24 inches or more above the manhole invert. When an invert difference occurs at an existing manhole, a drop connection shall be installed.
(c) The same energy gradient shall be maintained through a manhole whenever there is a change of pipe size.
(d) Whenever there is a change of direction in a sewer at a manhole in excess of 30 inches, an allowance of 1/10 foot in grade shall be made for loss of head through the manhole.
(e) The minimum inside diameter of all manholes shall be 48 inches.
(f) All manholes shall be precast concrete.
(g) Precast rings shall be placed over the top of the cone section of all manholes when they are within a road right-of-way.
(h) Manhole covers shall be set to proposed grades if in a road right-of-way and six inches above proposed grades in other locations. Proposed manhole cover grades shall be shown on plans. Manhole rings and covers shall be heavy duty and have external chimney seals attached thereto, as prescribed by the Engineer of the Village.
(i) Manhole joints shall be made with rubber gaskets conforming to ASTM C-443. All pipe connections to precast manholes shall be made with flexible rubber gaskets meeting ASTM C-443. All joints shall be watertight.
(Ord. 11-06. Passed 5-3-11.)