Upon the completion of water or sewer facilities pursuant to contract mentioned in the foregoing section, the governing body of any such municipality shall be authorized to approve their construction and accept the same as facilities of the municipality and to charge for their use such water or sewer rates as such municipality may be authorized by law to establish, and if any such water or sewer facilities are so approved and accepted, all further maintenance and operation costs of said water or sewer lines and facilities shall be borne by such municipality.