Maximum allowable infiltration allowed under these development standards shall be in accordance with the current requirements of the Michigan Department of Environment, Great Lakes and Energy (EGLE). The joints shall be tight, and visible leakage in the joints, or leakage in excess of that specified above, shall be repaired at the contractor's expense by means approved by the City Engineer.
Upon completion of construction and prior to acceptance of this sewer system and again prior to expiration of the maintenance guarantee, an internal inspection of the sanitary sewers shall be made through the use of TV equipment. All services and appurtenances shall be cleaned prior to testing. The TV inspections shall be done by the contractor and witnessed by the City Engineer. All deficiencies noted during the TV inspection shall be repaired by the contractor at his expense by means approved by the City Engineer. A written report and a color, VHS-format videotape of the inspection shall be supplied to the City Engineer.
Prior to City approval of the sanitary sewer system and before any connections are made, the system shall have passed exfiltration or low pressure air tests conducted by the contractor and as selected by and witnessed by the City Engineer or Superintendent of Sewer.
The sewer shall be tested by exfiltration or low pressure air testing method as selected by the City Engineer.
Exfiltration. A test for water tightness shall be made by bulkheading the sewer at the manhole at the lower end of the section under test and filling the sewer with water 24 inches above the top of the sewer in the manhole at the upper end of the section. Leakage will then be the measured amount of water added to maintain the above described level.
Low-pressure air testing. Seal pipe openings with airtight plugs and braces. Whenever the sewer to be tested is submerged under groundwater, insert a pipe probe by boring or jetting into the backfill material adjacent to the center of the sewer to determine the groundwater hydrostatic pressure by forcing air to flow slowly through the probe pipe. Add air to the plugged sewer sections under test until internal air pressure reaches 4.0 psi greater than any groundwater hydrostatic pressure. Allow at least two minutes for air temperature to stabilize, and add air to maintain the initial test pressure. Shut off the air supply after stabilizing the air temperature and record the time in seconds using an approved stopwatch for the internal sewer pressure to drop from 3.0 psi to 2.5 psi greater than any groundwater hydrostatic pressure. Allowable limits: total rate of air loss not to exceed 0.0030 cubic feet of air per minute per square foot of internal pipe area. If the air test fails to meet these requirements, locate and repair, or remove and replace, any faulty sections of sewer in a manner approved by the City Engineer as necessary to meet the allowable limits upon retesting.
A mandrel shall be pulled through a minimum of 5% of all PVC pipe to test for deflection. The City Engineer shall select the sections to be tested. Deflection shall be limited to 5.0% of the base inside diameter of the pipe. Failed test sections shall be uncovered and the embedment and backfill properly recompacted prior to retesting.