N.D. Cent. Code § 61-35-48
Upon complying with this chapter, a district may defray the expense of any or all of the improvements by special assessments, including the construction of all or part of a water supply system or a sewerage system, or both, or any improvement, extension, or replacement of such systems, including the construction and erection of wells, intakes, pumping stations, settling basins, filtration plants, standpipes, water towers, reservoirs, water mains, sanitary and storm sewer mains and outlets, facilities for the treatment and disposal of sewage and other district, industrial, and domestic wastes, and all other appurtenances, contrivances, and structures used or useful for a complete water supply and sewerage system. In planning an improvement project, the board may include in the plans any and all items of work and materials which in its judgment are necessary or reasonably incidental to the completion of an improvement project of that type.
N.D.C.C. § 61-35-48