When required by the public works director, the owner of any property served by a building sewer carrying industrial wastes shall install a suitable control manhole in the building sewer to facilitate observation, sampling and measurement of the wastes. Such manhole, when required, shall be accessible and safely located, and shall be constructed in accordance with the plans approved by the public works director and said manhole shall be installed by the owner at his expense, and shall be maintained by him so as to be safe and accessible to the city at all times. (Ord. 576, 2008).