When it is inadvisable or impractical for the sanitary district to build a water supply, sewage system or part of either to serve an area within the sanitary district, a corporation or residents within the sanitary district may build and operate a system at its or their own expense. The system shall be constructed and operated under plans and specifications approved by the district board and by the Department. The system shall also be constructed and operated in accordance with applicable rules and statutes.
N.C. Gen. Stat. § 130A-58