Section Env-Wq 704.17 - Manholes: Testing(a) Manholes shall be tested for leakage using a vacuum test in accordance with the ASTM C1244 standard in effect when the testing is performed, available as noted in Appendix D. A manhole may be backfilled prior to performing a vacuum test, but if the manhole fails the vacuum test, backfill shall be removed so repairs to the manhole can be made from the outside of the manhole prior to retesting.(b) The manhole vacuum test shall conform to the following:(1) The initial vacuum gauge test pressure shall be 10 inches Hg; and(2) The minimum acceptable test hold time for a 1-inch Hg pressure drop to 9 inches Hg shall be: a.Not less than 2 minutes for manholes less than 10 feet deep in depth;b.Not less than 2.5 minutes for manholes 10 to 15 feet deep; andc.Not less than 3 minutes for manholes more than 15 feet deep; (c) The manhole shall be repaired and retested if the test hold times fail to achieve the acceptance limits specified in (b), above.(d) Inverts and shelves shall not be installed until after successful testing is completed.(e) Immediately following completion of the leakage test, the frame and cover shall be placed on the top of the manhole or some other means used to prevent accidental entry by unauthorized persons, children, or animals, until the contractor is ready to make final adjustment to grade.N.H. Admin. Code § Env-Wq 704.17
Adopted byVolume XXXIV Number 46, Filed November 13, 2014, Proposed by #10693, Effective 10/15/2014, Expires10/15/2024.