D. ACCESSORIES:
1. All accessories shall be installed in accordance with manufacturer's instructions.
2. Stubs shall be set accurately to the dimensions indicated on the drawings. Stubs shall be
sealed with suitable watertight plugs.
3.02 LEAKAGE TESTS FOR SEWER MANHOLES:
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 (Seconds)
0-12 30 39 49
12-16 40 52 67
1620 50 65 81
90-24 59 78 97
26-30 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 FOR SEWER MANHOLES:
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.
2022 Sewer Replacement Project Precast Manholes and Catch Basins
Nashua, NH 02631-7
