Each such tank shall be located at least twenty feet (20') from any building, and shall be constructed of 12-gauge steel, monolithic concrete, or of brick or concrete blocks adequately coated inside so as to be impervious to water. Baffle shall be located from six inches (6") to nine inches (9") away from the inlet and outlet and must extend twelve inches (12") beneath the sewer level in the tank. Each tank must be equipped with a manhole or similar suitably covered opening to permit inspection or cleaning. (1968 Code, sec. 53-103)