New Hampshire Code of Administrative Rules
Puc - Public Utilities Commission
Chapter Puc 800 - UNDERGROUND UTILITY DAMAGE PREVENTION PROGRAM
Part Puc 805 - DUTIES OF AN EXCAVATOR
Section Puc 805.02 - Excavation That Affects the Tolerance Zone

(a) Any person conducting excavation activity that affects the tolerance zone surrounding an underground facility shall exercise at all times such reasonable care as is necessary to protect the underground facility from damage.

(b) Except as provided in (c) below, in order to locate and identify an underground facility, the excavator shall excavate by methods limited to:

(c) For bituminous pavement and concrete travel surface removal an excavator shall not be limited to hand digging and the other non-invasive methods cited in (b) above.

(d) For parallel type excavations, such as excavation along an existing underground facility at an approximately equal distance when measured periodically, the excavator shall expose the existing underground facility at intervals as often as necessary to avoid damage.

(e) For perpendicular type excavations in which the markings are completed in accordance with 806.01 (a) (2), the excavator shall expose the existing underground facility using methods listed in (b) above within the defined tolerance zone.

(f) In the event the excavator exposes what appears to be the underground facility that is offset from the centerline:

(g) For trenchless excavations, such as horizontal drilling, boring, pneumatic jacking, tunneling, and pavement reclamation, reasonable care for purposes of Puc 805.02(a) shall include determining the exact depth of the underground facility and clearances required by the operator and incorporating location details into the trenchless excavation procedure so as to avoid any potential damage of the underground facility.