(a) Licensing of Contractors. Before a contractor can commence sewerage line construction within the Village, he must first obtain a license as required under Section 1020.03
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(b) Preparation of Trenches. Except in rock, water-bearing earth or where granular fill or concrete is to be used, mechanical excavation of trenches shall be stopped above the final invert grade elevation so that the pipe may be laid on a firm undisturbed earth bed. The bottom portion of the trench shall then be hand excavated to conform to the shape of the pipe barrel, and bell holes dug so that after placement only the barrel of the pipe bears on the trench bottom. If over- digging occurs, all loose dirt must be removed and the trench bottom brought to grade with granular material.
A four-inch minimum foundation of granular material must be used in trenches where rock or water-bearing earth is encountered and may also be placed under the pipe in lieu of hand excavating for the pipe barrel and bell holes at the contractor's option. Trenches shall be dry when the trench bottom is prepared.
The width of trenches shall be such as to provide adequate space for workmen to place and join the pipe properly, but in every case the trench shall be kept to a minimum width.
The contractor shall be responsible for installing all necessary sheeting and bracing to support the walls of the trench and existing structures.
(c) Pipe Laying. Pipe shall be protected during handling against impact, shocks and free fall, and shall be kept clean at all times. All pipes are to be laid in accordance with lines and grades shown on the drawings and shall start at the low point with hub ends laid upgrade. Preparatory to making pipe joints, all surfaces of the portions of the pipe to be jointed or of the factory-made jointing material shall be clean and dry. Lubricants, primers, adhesives, etc., shall be used as recommended by the pipe or joint manufacturer's specifications. As soon as possible after the joint is made, sufficient backfill material shall be placed along each side of the pipe to hold it in place.
The contractor shall use a top line and plumb bob to insure proper alignment, and he shall maintain three batter boards at all times to check the grade of the sewer. At the end of each day's work a vitrified stopper shall be placed in the line.
(d) Laying Fittings. Branches of wyes shall be inclined at approximately forty-five degrees to the horizontal and the top and sides shall be covered with four inches of granular material. Ends of wye branches which are not to be immediately used will be sealed with vitrified clay stoppers tightly cemented in place, and marked with a two-inch by two-inch board extending from the wye branch to approximately one foot below ground surface. Bends and risers for drop manholes shall be encased in concrete.
(e) Backfilling. No backfilling over completed structures shall be done without permission of the Inspector. All trenches shall be backfilled as soon as possible after the pipe is laid, inspected, tested and approved by the Sewer and Plumbing Inspector.
Materials for backfilling shall be reasonable free from rubbish, muck, stones exceeding one cubic foot in volume and other unsuitable materials, and the contractor shall provide satisfactory filling material.
For a height of eighteen inches above the top of the pipe, the backfill shall be composed of fine material, free from stones and an excess of water, and shall be placed completely under the pipe haunches and thoroughly tamped with satisfactory tamping equipment. All trenches which lie in roadways or driveways shall be compacted in eight-inch layers (loose depth) or filled with suitable granular material for the full depth of the trench as required. Puddling of trenches shall not be allowed without permission of the Inspector.
(f) Manhole Construction. All manholes shall be thoroughly bonded to the barrel of the sewer. The upper portion of manholes over six feet in depth, beginning at a point five feet eight inches below the top, shall be tapered in evenly and equally on three sides to the proper diameter to receive the casting. The minimum inside diameter of manholes shall be forty-eight inches, except where manholes are less than five feet in depth.
Manhole walls shall be a minimum of eight inches thick, except for precast concrete. All brick manholes over twelve feet in depth shall have twelve-inch walls.
Interior joints of brick manholes shall be pointed and the exterior surface plastered with a one-inch coat of two to one cement mortar. Inverts shall be formed of grout and vitrified half- tile.
(g) Testing. If there is any doubt as to the quality of workmanship or the ability of a section of sewerage line to resist leakage, the Village shall have the authority to require the contractor to perform either an exfiltration or infiltration test, as determined by the Sewer and Plumbing Inspector. The test shall be performed in the presence of the Inspector. No sewerage line may show leakage exceeding 0.75 gallons per hour, per inch of pipe diameter, per 100 feet of pipe.
The test shall be made between two successive manholes, before any house connections are made, by closing the lower end of the sewer being tested and the inlet sewer of the upper manhole, and filling the pipe and manhole with water. Drop of the water level in the manhole will then be observed. If leakage in the line exceeds the allowable leakage specified above, the contractor shall be required to re-excavate and replace the line. Depending upon the grade of the sewer, the minimum head allowed in the downstream manhole will be four feet above the invert, and the maximum head for which an exfiltration test is required is ten feet above the invert of the lower manhole. The minimum depth of water in the upper manhole shall be one foot above the invert.
In areas where ground water exists above the top of the sewer, the section may be tested by an infiltration test. This test shall be conducted by sealing off the incoming tile in the upper manhole of the section being tested, along with all wye branches or other openings in the tile, and measuring the quantity of water which flows over a weir or other suitable measuring device in the lower manhole.
(h) Cleaning Up. All surplus excavated materials and materials for construction shall be removed as work progresses. All streets and driveways shall be rendered suitable, safe and convenient for traffic.
(Ord. 870. Passed 2-3-64.)