After verifying the location of an underground facility, the excavator shall not employ powered or mechanical excavating equipment closer than four inches in any direction from the staked, marked or otherwise designated or known outside diameter or perimeter of such facility or its protective coating unless agreed to in writing by the operator of the affected underground facility. Any such written agreement shall be furnished to the excavator by the operator, upon request.
N.Y. Comp. Codes R. & Regs. Tit. 16 §§ 753-3.8