When the advertising device control section determines that an advertising device is in violation of any section of Chapter 5516. of the Revised Code or any rule contained in Chapter 5501:2-2 of the Administrative Code, or an advertising device is being maintained without a validly issued permit, it shall send a letter of warning to the sign owner, if known, that such device is illegal. If the sign owner is not known or can not be located, such letter shall be sent to the owner or lessee of the land and shall be posted on the advertising device for thirty days. The letter shall indicate that the advertising device is illegal pursuant to the specific statute or rule which it violates, and shall request that the sign owner or land owner or lessee voluntarily remove the device or take specific remedial action as outlined in the letter within a specified period of time, if remedial action is appropriate. Only one equal extension of time to take remedial action will be granted. If voluntary removal or remedial action is not taken within the specified time or its extension, the matter will be submitted to the director for the issuance of a removal order pursuant to section 5516.04 of the Revised Code.