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.
A.
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.
B.
The sewer shall be tested by exfiltration or low pressure air testing
method as selected by the City Engineer.
(1)
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.
(2)
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.
