(A) After the construction is completed and before final acceptance, all lines, manholes, catch basins and the like shall be thoroughly cleaned and tested. All sewers shall be lamped, mandrel tested, low pressure air tested and/or televised prior to acceptance in an approved manner as set forth by the engineer.
(B) After completing backfill of a section of wastewater line, the contractor shall, at his or her expense, conduct a line acceptance test using low pressure air. The test shall be performed according to stated procedures and under the supervision of the engineer.
(C) The manhole shall be visually evaluated for infiltration during a period of high groundwater table. Any visible infiltration shall be corrected before acceptance. ASTM C828 shall apply for low pressure air testing procedures. Time periods for testing shall be completed as described in the following paragraph. ASTM F1417-92 (or most current addition) shall apply for plastic pipe low pressure air testing of the sewer line.
(D) The section of sewer line to be tested shall have been trench backfilled and cleaned. Testing shall be done after lateral sewers are connected but before laterals are put in service. All Ys and laterals shall be tightly plugged. Pneumatic plugs, having a sealing length equal to or greater than the diameter of the pipe to be tested, shall be placed in both ends of the test section and inflated to 25 psi. Air shall be slowly added to the test section until the air pressure within the test section reaches a point 4.0 psi greater than the average back pressure due to the ground water table. This shall be accomplished by adding 0.43 psig to the initial pressures for each foot the groundwater table is above the center line of the pipe. Do not exceed ten psi total pressure in the line. All plugs shall be checked for leakage and the air shall be allowed to stabilize at least two minutes before the actual test begins. After the stabilization period, the pressure within the test section shall be decreased to 3.50 psig above the average groundwater back-pressure, and the time in seconds measured for the pressure to drop 1.0 psig to 2.5 psig above the average groundwater back-pressure.
(E) If the measured time is equal to or greater than the test time given in Table I below, the line shall be deemed free from significant defects and acceptable. If the measured time is less than the required ASTM duration, the source or sources of leakage shall be located and corrected. If, after all apparent sources of air leakage are corrected, and there is still difficulty in meeting the minimum specification time, an infiltration or exfiltration test shall be conducted to determine the acceptability of the line.
TABLE I AIR TEST TABLE Minimum Test Time for Various Pipe Sizes | |
Normal Pipe Size | T(time), min/100 feet (30.5m) |
TABLE I AIR TEST TABLE Minimum Test Time for Various Pipe Sizes | |
Normal Pipe Size | T(time), min/100 feet (30.5m) |
3 inches (75mm) | 0.2 |
4 inches (100mm) | 0.3 |
6 inches (150mm) | 0.7 |
8 inches (200mm) | 1.2 |
10 inches (250mm) | 1.5 |
12 inches (300mm) | 1.8 |
15 inches (380mm) | 2.1 |
18 inches (450mm) | 2.4 |
21 inches (535mm) | 3.0 |
24 inches (600mm) | 3.6 |
27 inches (675mm) | 4.2 |
30 inches (750mm) | 4.8 |
33 inches (825mm) | 5.4 |
36 inches (900mm) | 6.0 |