If the precise location of an underground facility cannot be verified by the excavator after diligent search at a reasonable depth within the tolerance zone as staked, marked or otherwise designated by the operator, the excavator shall so notify such operator as soon as possible. The operator shall respond in accordance with section 753-4.10 of this Part.
N.Y. Comp. Codes R. & Regs. Tit. 16 §§ 753-3.7