As part of the construction of development improvement, all
water mains shall be tested as described in this article. The Director
of Public Services and City Engineer shall be notified of the time
of the test a minimum of 24 hours prior to the test. All tests shall
be performed in the presence of the Director of Public Services and/or
City Engineer.
All new water mains and service lines shall be subjected to
a hydrostatic pressure of not less than 150 pounds per square inch.
Hold the test pressure for a duration of one hour without pressure
loss or further pressure application. Before applying the specified
test pressure, all air shall be expelled from the pipe. All visible
leaks shall be repaired until tight. The leakage in any section of
pipe shall not exceed 11.65 gallons per twenty-four-hour day per inch
diameter per mile of pipe. Any cracked or defective pipes, fittings,
valves, or hydrants discovered in consequence of this pressure test
shall be removed and replaced and the test repeated until satisfactory
results are obtained.
Prior to chlorination, the main shall be flushed as thoroughly
as possible with the water pressure and outlets available. Flushing
shall be done after the pressure test is made. It shall be understood
that such flushing removes only the lighter solids and cannot be relied
upon to remove heavy material allowed to get into the main during
laying. Hydrants shall be installed at the end of the main and shall
be flowed until the water runs clear.
A.Â
After the water main and appurtenance items, including other contract
items necessary to complete the water main ready for chlorination
and services have been pressure-tested and flushed, they shall be
disinfected in accordance with the requirements of the Michigan Department
of Health and AWWA Specifications C651-92.
B.Â
All piping shall be chlorinated with up to 50 parts per million or
more of liquid chlorine and the chlorinated water allowed to stand
in the main for 24 hours, at the end of which period the chlorinated
water at all parts of mains shall show a free available chlorine residual
of not less than 10 parts per million or the procedure will be repeated.
The recommended chlorine bearing compound shall be high-test calcium
hypochlorite (65% to 70% available chlorine).
C.Â
The point of chlorine application shall be at the beginning of the
water main construction, through a corporations cock on the downstream
side of the valve controlling the flow of water into the main. The
rate of chlorine application shall be in such proportion to the rate
of water flow entering the main that all the chlorine dose applied
shall produce 50 parts per million (420 pounds per million gallons)
chlorine concentration in the water within the main. The chlorine
concentration shall be checked at the corporation cock located at
the opposite end or ends of the section being tested from the point
of application.
D.Â
The chlorinated water shall then be removed form the main and the
main left full of water. When the water in the treated main shall
have been proven comparable to that of the source, water samples shall
be collected at each sampling tap, previously determined by the inspector,
and submitted to a laboratory for testing. Two consecutive safe bacteriological
samples shall be taken 24 hours apart before placing the water line
into service. Samples shall be collected for every 1,200 feet of new
main, plus samples for each branch and the end of the line. The chlorination
procedures shall be repeated if unsatisfactory results are obtained.
All chlorination expenses such as sampling taps, labor and laboratory
testing shall be the responsibility of the developer. The developer
shall be responsible for disposing of the chlorinated water in areas
which will not drain directly to any surface watercourse.
