N.C. Gen. Stat. § 153A-187

The board of commissioners may establish schedules of exemptions from assessments for water or sewer projects for corner lots when water or sewer lines are installed along both sides of the lots. A schedule of exemptions shall be based on categories of land use (residential, commercial, industrial, and agricultural) and shall be uniform for each category. A schedule may not allow exemption of more than seventy-five percent (75%) of the frontage of any side of a corner lot, or 150 feet, whichever is greater.