3.02 LEAKAGE TESTS:
A. Leakage tests shall be made by the Contractor and observed by the Engineer on each
manhole. The test shall be by vacuum or by water exfiltration as described below:
B. VACUUM TEST:
1. The vacuum test shall be conducted in accordance with ASTM C1244. Test results will
be judged by the length of time it takes for the applied vacuum to drop from 10 inches
of mercury to 9 inches. If the time is less than that listed in Table 1 of ASTM C1244,
the manhole will have failed the test. Test times from Table 1 are excerpted below.
TABLE 1 Minimum Test Times for Various Manhole Diameters
Diameter (Inches)
Depth (Feet) 48 60 72
Times ( oeconds)
0-1 30 39 49
016 40 52 67
16-20 50 65 81
50.04 59 78 97
76-30 74 98 121
2. If the manhole fails the initial test, the Contractor shall locate the leaks and make
proper repairs. Leaks may be filled with a wet slurry of accepted quick setting
material. If the manhole should again fail the vacuum test, additional repairs shall be
made, and the manhole water tested as specified below.
C. WATER EXFILTRATION TEST:
1. After the manhole has been assembled in place, all lifting holes shall be filled and
pointed with an approved non-shrinking mortar. All pipes and other openings into the
manhole shall be suitably plugged and the plugs braced to prevent blow out. The test
shall be made prior to placing the shelf and invert. If the groundwater table has been
allowed to rise above the bottom of the manhole, it shall be lowered for the duration
of the test.
2. | The manhole shall be filled with water to the top of the cone section. If the
excavation has not been backfilled and observation indicates no visible leakage, that 1s,
no water visibly moving down the surface of the manhole, the manhole may be
considered to be satisfactorily water-tight. If the test, as described above, 1s
unsatisfactory as determined by the Engineer or 1f the manhole excavation has been
backfilled, the test shall be continued. A period of time may be permitted if the
Contractor so wishes, to allow for absorption by the manhole. At the end of this
period, the manhole shall be refilled to the top of the cone, if necessary, and a
measuring time of at least 8 hours begun. At the end of the test period, the manhole
shall be refilled to the top of the cone, measuring the volume of water added. This
amount shall be extrapolated to a 24-hour loss rate and the leakage determined on the
0263 1-7
