Unless otherwise provided herein, any notice required to be given by the Director of Public Works under <cite data-path="|25">this article</cite> shall be in writing and served in person or by registered or certified mail, except when immediate action is required to prevent or minimize damage to life, safety, the POTW, or the environment. If served by mail, the notice shall be sent to the user’s last address known to the Director. Where the address is unknown, notice may be made upon the owner of record of the property involved. Notice shall be deemed to have been given at the time of its deposit, postage prepaid in a facility regularly serviced by the United States Postal Service. City Code, 1976/83, art. 25, §11(a)(1)(2nd - 4th sens.) Ord. 91-775