(a) Components of an alternative collection system must be tested for water tightness by one of the methods shown in the following table:
Attached Graphic
(b) Hydrostatic Head Test for Pipe. The total infiltration or exfiltration, as determined by the hydrostatic head test, must not exceed 10 gallons per inch diameter per mile of pipe per 24 hours at a minimum head of 2.0 feet. If the quantity of infiltration or exfiltration exceeds the maximum quantity specified, the owner shall take remedial action to reduce the infiltration or exfiltration to an amount below the specified maximum limits.
(c) Hydrostatic Head Test for Tanks. The test consists of filling the tank to the top and holding the water for 24 hours to determine whether the tank is leaking.
  (1) The hydrostatic head test must demonstrate that the tank is not leaking before the placement of backfill around a tank.
  (2) The hydrostatic head test for a tank constructed from flexible or semi-rigid material is required after placement and backfilling according to the tank manufacturer's recommendations.
(d) Low-Pressure Air Test. The low-pressure air test must conform to the requirements of §217.57 of this title (relating to Testing Requirements for Installation of Gravity Collection System Pipes).
(e) Pressure Pipe Test.
  (1) The test pressure must be a minimum of 25 pounds per square inch or 1.5 times the maximum pipe design pressure, whichever is larger. The maximum allowable leakage must be calculated using the following equation:
Attached Graphic
  (2) If the leakage exceeds the maximum amount calculated, the owner shall take remedial action to reduce the leakage to an amount within the allowable limit from paragraph (1) of this subsection.
(f) Vacuum Test for a Tank.
  (1) The test may begin only after establishing an initial stable vacuum of 4.0 inches of mercury.
  (2) The total vacuum loss during a vacuum test must not exceed 1.0 inch loss of mercury vacuum after five minutes.
  (3) A tank constructed of flexible or semi-rigid material must not allow more than a 3% change in tank dimensions in any direction while under vacuum.
  (4) If the quantity of vacuum loss or if tank deformation equals or exceeds the maximum quantity specified in paragraph (2) of this subsection, then the owner shall take remedial action to reduce the amount of vacuum loss or amount of deformation to comply with this subsection.

Source Note: The provisions of this §217.99 adopted to be effective August 28, 2008, 33 TexReg 6843; amended to be effective December 4, 2015, 40 TexReg 8254