49 CFR 196.103
What must an excavator do to protect underground pipelines from excavation-related damage?
Prior to and during excavation activity, the excavator must:#
(a)Use an available one-call system before excavating to notify operators of underground pipeline facilities of the timing and location of the intended excavation;#
(b)If underground pipelines exist in the area, wait for the pipeline operator to arrive at the excavation site and establish and mark the location of its underground pipeline facilities before excavating;#
(c)Excavate with proper regard for the marked location of pipelines an operator has established by taking all practicable steps to prevent excavation damage to the pipeline;#
(d)Make additional use of one-call as necessary to obtain locating and marking before excavating to ensure that underground pipelines are not damaged by excavation.#