Every operator of any well shall appoint an agent who resides in the state and is one upon whom all orders and notices provided in this title may be served in person or by registered or certified mail. Every operator so designating such agent shall within ten days of any change in the agent or the mailing address notify the Agency in writing of the changes, unless its operations within the city have been discontinued. Service in person or by registered or certified mail on the agent so designated constitutes completed service within the meaning of and for the purposes of this title.
(`78 Code, § 14.32.050.)