Whenever the county board has ordered the installation of a sewerage disposal system and plant or plants or the improvement or extension of an existing system, the fact that such order was issued shall be recited in the official minutes of the county board. Upon approval of plans for such installation, improvement, or extension, the county board shall advertise for sealed bids for the construction of the system, improvement, or extension once a week for three weeks in a legal newspaper published in or of general circulation within the county, and the contract shall be awarded to the lowest responsible bidder.
Neb. Rev. Stat. §§ 23-3615