N.Y.C. Admin. Code § 27-910: § 27-910 Individual sewage systems.

Where public sewers are deemed not available according to subdivision (e) of section 27-901 of article one of this subchapter, an individual on site private sewage disposal system shall be installed in accordance with the requirements of this subchapter. When public sewers are made available, the individual on site private sewage disposal system shall be abandoned in a manner prescribed by the commissioner, and the building house sewer shall be connected to the available public sewer within six months of the date of notification that the sewer has been accepted to receive flow by the agency or agencies having jurisdiction.