Whenever the distance from the end of the utility's existing distribution line to the boundary of the development is 100 feet or more, the 100 feet of new distribution line nearest to but outside the boundary shall be installed underground if practicable; and whenever the distance is less than 100 feet from the boundary, all of the new distribution line nearest to but outside the boundary shall be installed underground if practicable. The installation required by this section shall be provided by the utility, without cost to the applicant.
52 Pa. Code § 57.84
This section cited in 52 Pa. Code § 57.19 (relating to line extensions); 52 Pa. Code § 57.88 (relating to subdivisions); and 52 Pa. Code § 69.43 (relating to notice lead-time).