(a) Manholes shall be installed at the end of each line, at all changes in grade, size or alignment, at all intersections of mains, and at distances not greater than 400 feet for sewers fifteen inches or less, and 500 feet for sewers eighteen inches or larger.
(b) A drop pipe should be provided for a sewer entering a manhole at an elevation of twenty-four inches or more above the manhole invert. Where the difference in elevation between the incoming sewer and the manhole invert is less than twenty-four inches the invert should be filled to prevent solids deposition.
(c) Manholes shall be precast reinforced concrete meeting ASTM designation C-478 except that circumferential reinforcement shall be not less than 0.18 in two per lineal foot. Minimum diameter of manholes shall be forty-eight inches. The manhole is a standard precast. The material shall conform to ASTM C-470. The “O” ring shall conform to ASTM C-443.
(d) Manhole frames and lids must be solid cast iron. Lids shall be of the Columbus Standard Type. Lid diameter shall be twenty-two and one-fourth inches, thickness shall be one inch. Sealed lids must be used in flood areas. Minimum combined weight of lid and frame shall be not less than 250 pounds.
(e) The flow channel through manholes shall be made to conform in shape and slope to that of sewers. Slope of concrete fill around channel shall be one to four from top of the pipe to the side of the manhole. All concrete for manhole bases and fill shall meet requirements for class "C" concrete as listed in the latest edition of Ohio Department of Highways Construction and Material Specifications.
(Ord. 12-2-74-A. Passed 1-20-75.)