N.J. Stat. § 27:16-23
The board of chosen freeholders, or any county board or commission, owning or having control of a road, parkway or other highway, may grant permission to any municipality to lay water mains, sewers and proper house connections in such road, parkway or other highway, upon application being made to such board or body for that purpose by any municipality in which such road, parkway or other highway is situate.
Permission shall not be granted until the municipality applying therefor shall enter into a written agreement with such board or body regarding inspection and the restoration of the surface of the road, parkway, or other highway to the same condition in which it was before being opened for such purpose.
The agreement shall provide that on failure of the municipality so to restore the surface for a period of ninety days after notice from the board or body requiring such restoration, such board or body may itself undertake the work and recover the expense of restoration from the municipality by an action at law in any court of competent jurisdiction.
N.J.S. § 27:16-23