All manholes shall be vacuum tested. Manholes that fail the test shall be corrected as required and retested. Vacuum test procedures and requirements shall be as follows:
(A) After completion of the manhole barrels but prior to backfilling, sealing of PVC liner seams and installing grade rings, all openings in the manholes shall be sealed with plugs and a rubber ring “donut” type plug inserted inside the opening of the cone.
(B) A small vacuum pump shall be attached to a hose connected to the plug, and 4 psi (8 inHg) of vacuum applied.
(C) The vacuum shall be permitted to stabilize at 3.5 psi (7 inHg) for one minute before the test begins.
(D) The manhole must maintain vacuum such that no greater than 0.5 psi (1 inHg) of vacuum is lost during the specified test period. The specified test period is as follows:
Manhole Depth (Feet) | Test Period (Minutes) |
0 - 5 | 4.5 |
5 - 10 | 5.5 |
10 - 15 | 6.0 |
Greater than 15 | 6.5 |
(E) A vacuum regulator shall be provided on the vacuum pump such that no greater than 10 psi (20 inHg) can be applied to the manhole during the test.
(F) All manholes that do not meet the leakage test, or are unsatisfactory from visual inspection, shall be repaired to the satisfaction of the engineer.
(Ord. 2019-02, passed 4-25-2019)