N.Y. General City Law § 51

§ 51. Notice of violation of rules. Whenever any inspector or other\nperson reports a violation of any such rules and regulations for\nplumbing and drainage, or a deviation from any officially approved plan\nor specification for plumbing and drainage filed with any board or\ndepartment, the appointing power shall first serve a notice of the\nviolation thereof upon the master plumber doing the work, if a\nregistered plumber.\n