Neb. Rev. Stat. § 14-1710: Neb. Rev. Stat. § 14-1710

All purchases and all contracts relating to the construction, maintenance, improvement, or extension of the authority's facilities, except contracts relating to the acquiring of real property or some interest in such real property or contracts of employment or some specialized service, involving the expenditure of two thousand dollars or more, shall be let to the lowest responsible bidder after not less than twenty days' public notice of request for bids.