Part V, "Small Underground Wastewater Disposal Systems", of the code of waste disposal regulations, adopted by the Utah division of health and Utah state committee on water pollution in May, 1965, as revised by action of the board June 2, 1967 and June 21, 1967, and issued and published as a code in book form, three (3) copies of which have been filed for use and examination by the public in the office of the recorder, is adopted by the city as the small underground wastewater disposal systems code within the city, except as it may be altered or modified by the provision of this or the preceding chapter. Occupancies in existing building may be continued as provided in section 104(g) of the uniform building code, except as to those structures which are found to be substandard as defined in the housing code. (Prior code § 9-620)