Utilities that have acquired a gas or liquid energy conversion facility site or gas or liquid transmission line route in accordance with this chapter may proceed to construct or improve such site or route for the intended purposes at any time, subject to subsections 2 and 3 of section 49-22.1-13; provided, that if the construction and improvement commences more than four years after a certificate or permit for the site or route has been issued, the utility must certify to the commission that the site or route continues to meet the conditions upon which the certificate of site compatibility or gas or liquid transmission facility construction permit was issued.