(1) Except in the case of an external leader, after a section of drainage system or a venting system has been roughed in, and before any fixture is installed or piping is covered, a water or an air test shall be conducted.
(2) Where a chief building official requires a final test, it shall be carried out after every fixture is installed and before any part of the drainage system or venting system is placed in operation.
(3) Where a prefabricated system is assembled off the building site in such a manner that it cannot be inspected and tested on site, off-site inspections and tests shall be conducted.
(4) Where a prefabricated system is installed as part of a drainage system and venting system, all other plumbing work shall be tested and inspected and a final test shall be carried out on the complete system.
(5) A ball test shall be carried out on a sanitary building drain, sanitary building sewer, storm building drain and a storm building sewer buried underground.
(6) A sewer lateral extension need not be tested and inspected if the sewer lateral extension was constructed, tested and inspected at the time of the installation of the public sewer.