Section 27-921. Testing of plumbing and gas piping systems

(a) New, altered,
  extended,  or repaired systems. Every new plumbing and gas piping system
  and every part of an existing system that has been altered  or  repaired
  except  for  minor  alterations and ordinary repairs, shall be tested as
  hereinafter prescribed to disclose leaks and defects.  However,  testing
  may be waived in the following cases:
    (1)  In  any  case  that  does not involve replacement, alteration, or
  relocation of any water supply, drainage, or vent piping.
    (2) In any case where plumbing equipment may be set up temporarily for
  exhibition purposes.
    (b) Representation at test.
    (1) Tests  required  by  section  27-922  of  this  article  shall  be
  conducted  in the presence of the commissioner or an authorized plumbing
  inspector of the department.
    (2) The commissioner may also authorize such test to be  witnessed  by
  architects,  engineers,  master  plumbers  or representatives of utility
  companies, each of whom must be acceptable to the commissioner.  Persons
  performing  this  function  shall  have  had  at  least  five  (5) years
  experience in inspection and testing of gas piping systems,  or  hold  a
  current master plumbers license. Such tests may be conducted without any
  verifying  inspection  or  tests  by members of the department, provided
  that verified statements and supporting inspectional  and  test  reports
  are filed with the department within one working day of such tests.
    (c)  Exposure  of  work.  If  any  plumbing  system or part thereof is
  enclosed  before  it  has  been  inspected,  tested,  and  accepted   as
  prescribed  in  this  subchapter,  such  system or part thereof shall be
  uncovered upon the direction of the commissioner.
    (d) Retesting. If, upon inspection and tests, any of the work fails to
  meet the test requirements, the  necessary  corrections  shall  be  made
  before any reinspections or retests are conducted.