SECT-44_TESTING_OF_GRAVITY_SANITARY_SEWERS.docx

SECTION 44 - TESTING OF GRAVITY SANITARY SEWERS

Item No. Title

44.1 TESTING

44.1.1 GENERAL

All projects shall be tested upon completion of installation in the presence of the CITY ENGINEER or designee, representative(s) of the contractor, and/or other authorized agencies with a minimum forty-eight (48) hours advance notice (not including weekends or holidays). Testing shall conform with UNI-BELL recommended practice, UNI-B-5-78 and UNI-B-6-79, and the following requirements. All equipment for performing tests and making measurements shall be furnished by the contractor at his own expense, unless specified and agreed to otherwise in writing with the CITY ENGINEER or designee. Sections of sewer which fail to pass the required tests shall have the defects located and repaired or replaced and be retested until within the specified allowance at the contractor's own expense. Confirmation as to the type(s) and method(s) of testing required will be made at the pre-construction conference by the CITY ENGINEER or designee upon approval of the CITY ENGINEER or designee.

44.1.2 CLEANING

Prior to any tests, all sewer lines shall be cleaned and inspected for major defects. Pre-cleaning by appropriately sized sewer cleaning ball or by high velocity jet or other method may be necessary.

44.1.3 VISUAL TEST

All sewer lines shall be inspected visually to verify accuracy of alignment and freedom from debris and obstructions. The full diameter of the pipe for straight alignments shall be visible when viewed between consecutive manholes. The method of test shall be photography or visually lamping with mirrors and lights, unless a specific method is required by the special provisions.

44.1.4 TELEVISION TEST

It shall be the responsibility of the CONTRACTOR that all sewer lines shall be inspected by closed circuit television. Test shall be from manhole to manhole. Test shall stop at all laterals and inspect connection and lateral. Test shall also stop and inspect any deformations or inconsistencies. A copy of the final VHS inspection tape shall be remitted to the City. All VHS tapes shall be of high quality and a minimum of “Gold” standard by Kodak, Fuji, Memorex or approved equal. The tape label shall, at a minimum, state the project name, date, contractor, and manholes between which the pipe on the tape has been inspected. [Service lateral pipes from main pipe to lateral pipe terminus (clean-out) assembly may be required per City Engineer or his designee.]

44.1.5 LEAKAGE TEST

Points for leakage measurement and the method of testing will be selected by the CITY ENGINEER or designee. Method of test is low-pressure air exfiltration. Explicit instructions for the following methods of test will be supplied by the CITY ENGINEER or designee. Plugs, caps, and branch connections must be secured against blow-off during leakage test. (Infiltration or exfiltration leakage tests are not acceptable test methods.)

Air testing shall be completed as specified by “Uni-Bell Plastic Pipe Association UNI-B-6-82, Low-Pressure Air Testing of Installed Sewer Pipe,” or latest version, or 7 psi for 7 minutes between manholes, including service laterals.

44.1.6 DEFLECTION TESTING

Unless specified and approved otherwise, the maximum allowable pipe deflection (reduction in vertical inside diameter) shall be 7 ½%. The CITY ENGINEER or designee reserves the right to require the contractor to perform random deflection tests of pipe before final acceptance at construction locations between successive manholes where the construction encountered unstable trench walls or bottoms, heavy rainfall, high ground water levels, deep lines, or difficulty in achieving compaction. Should random test locations be unsatisfactory, then the contractor shall deflection test the entire sewer system. All locations with excessive deflection shall be excavated, and repaired by re-bedding and/or replacement of the pipe. Other devices for testing include: properly sized mandrel, sewer ball, or deflectometer.