N.Y.C. Admin. Code § 24-517: § 24-517 Injury to sewers.

It shall be unlawful for any person to injure, break or remove any portion of a receiving basin, covering, flag, manhole, vent, sewer, sewage disposal plant or drain, to obstruct the mouth of a sewer or drain, or to place or deposit any substance exceeding one ton in weight upon any wharf or bulkhead through which a sewer or drain has been laid or upon or over any sewer or drain where the same shall be within three feet of the surface of the street.