(1) Preparation for Testing for Leakage. The completed gravity sewer, including sewer laterals, shall be tested after installation of all underground utilities and compaction of backfill. Prior to testing, the developer shall be required to clean and flush all gravity sewer lines. This will be permitted prior to paving. The sewer shall then be tested by the low-pressure air test method and/or an infiltration test. In certain conditions an exfiltration test may be required by the district.

The first section of pipe not less than 300 feet in length installed by each crew shall be tested, in order to qualify the crew and/or the material. A successful installation of this first section shall be a prerequisite to further pipe installation by the crew. At the developer’s option, crew and/or material qualification testing may be performed at any time during the construction process after at least two feet of backfill has been placed over the pipe.

(2) CCTV Inspection. After the gravity sewer lines have been substantially completed, the developer shall perform a complete televised inspection of all main lines and laterals in accordance with current district sewer video requirements. The pipes shall be cleaned, flushed and manholes channeled, prior to the CCTV inspection being performed.

The developer shall perform a complete televised inspection of the sewer pipe and laterals and provide to the district an electronic file with a log of the television inspection. The camera shall be a pan and tilt type equipped with adequate light and focusing to allow inspection of sewer main, laterals and full circumference inspection of main line joints and fittings.

Immediately prior to the televised inspection, the developer shall run water through each sewer line for five to 10 minutes to provide water for detection of any adverse grade sections visible by the presence of ponded water. The camera shall be stopped periodically at the ponded areas and the depth of water shall be measured and recorded. During the inspection, all tees and other fittings shall be logged as to exact location within one percent maximum error in measurement, wherein accuracy is checked with various fittings and the terminating manhole.

The district shall be notified 48 hours prior to any television inspection and this work shall be performed on a schedule to allow the district to witness the inspection. Alternately, the developer may have the district perform the CCTV inspection and pay for the actual costs.

Any defects in material or installation identified by the television inspection shall be repaired as required by the district at the developer’s expense.

A final CCTV inspection may be performed on the main line, laterals, and side sewers by the district at the end of the developer extension two-year warranty period. If defects are found that need correction, the cost of the final CCTV inspection shall be the responsibility of the developer.

(3) Low Pressure Air Test. The developer shall furnish all facilities and personnel for conducting pressure tests. Methods other than low pressure air test shall be subject to the approval of the district. Pressure gauge to be oil filled with a zero to 30 psi read range. The sewer pipe shall be tested for leaks through the use of air (unless exfiltration test is approved) in the following manner:

Following the pipe cleaning, utility installation, and paving, the pipe installation shall be tested with low pressure air. Air shall be slowly supplied to the plugged pipe installation until the internal air pressure reaches four pounds per square inch greater than the average back pressure of any ground water that may submerge the pipe. Two-fifths (0.40) pounds per square inch is to be added per one foot of water table over the pipe to a maximum of six psi. At least two minutes shall be allowed for temperature stabilization before proceeding further.

The rate of air loss shall then be determined by measuring the time interval required for the internal pressure to decrease from 3.5 to 2.5 pounds per square inch while maintaining the stipulated pressure greater than the pipe section’s average adjacent groundwater back pressure.

The pipeline shall be considered acceptable if the total rate of air loss from any section tested in its entirety between manholes, cleanouts or pipe ends does not exceed the following table:

Test time in minutes and seconds. Minimum test period is five-minute duration.

Test times will be provided by the engineer for combinations other than eight-inch mains and six-inch laterals.

If the pipe installation fails to meet these requirements, the developer shall determine at his own expense the source or sources of leakage, and shall repair (if the extent and type of repairs proposed by the developer appear reasonable to the district) or replace all defective materials or workmanship. The completed pipe installation shall meet the requirements of this low-pressure air test or the alternative water exfiltration test before being considered for acceptance.

Plugs used to close the sewer pipe for the air test shall be securely braced to prevent the unintentional release of a plug. Gauges, air piping manifolds and valves shall be located at the top of the ground. No one shall be permitted to enter a manhole where a plugged pipe is under pressure. Air testing apparatus shall be equipped with a pressure release device such as a rupture disk or a pressure relief valve designed to relieve pressure on the pipe under test at six psi.

(4) Deflection Test. If required by the district after the CCTV inspection, deflection tests shall be performed on all ASTM D3034 PVC gravity sewer mains by pulling a mandrel through the pipe. Unless otherwise approved by the district, the allowable deflection test limit shall be five percent of the base inside diameter in accordance with APWA test procedures and the nominal mandrel size shown in the following table:

Deflection testing is not required for ductile iron or pipe diameters 15 inches and greater.

The sewer lines shall be thoroughly cleaned prior to the deflection test. [Res. 835 § 2 (Exh. 2), 2022; Res. 735 § 1, 2017.]