The lessee may apply for the renewal of a mining contract, except placer mining contracts issued pursuant to RCW
79.14.310, to the department within ninety days before the expiration of the contract. Upon receipt of the application, the department shall make the necessary investigation to determine whether the terms of the contract have been complied with, and if the department finds they have been complied with in good faith, the department shall renew the contract. The terms and conditions of the renewal contract shall remain the same except for royalty rates, which shall be determined by reference to then existing law.