A. Notwithstanding any other provision of the Signal Hill Municipal Code, walls of the diked area shall be of concrete, solid masonry or earth designed and maintained to be liquid-tight and to withstand a full hydrostatic head, except that within one year from the effective date of the ordinance codified in this title, all walls of diked areas in residential zones shall be solid masonry or poured in place concrete.
B. Except where permitted by the NFPA, the walls of the diked area shall not exceed six feet above the interior grade of the diked area. All dikes over thirty-six inches in height shall be engineered and constructed in accordance with Title 15 of this code to withstand a full hydrostatic head. Except as provided herein, all dikes comply with minimum yard setback requirements contained in Title 20 of this code. Notwithstanding the foregoing, where any storage tank or related facility approved prior to the effective date of the ordinance codified in this title is located in such required setback area, such tank or facility shall be diked in accordance with this chapter, provided that such dike wall does not extend into a public right-of-way.
C. All masonry dikes shall be solid grouted. Exterior walls shall be painted or color coated subject to the approval of the planning director.
D. Where two or more tanks within a common diked area may cause mutual exposure from spills, spill dividers shall be provided between tanks of ten thousand barrels or greater individual capacity. Groups of tanks of less than ten thousand barrels individual capacity and not in excess of fifteen thousand barrels aggregate capacity may be enclosed within a single spill dike.
E. All catchment basins shall be of concrete, designed to be liquid-tight, except that fiberglass or steel basins may be used if designed to meet the design requirements for hazardous materials when approved by the department.
(Ord. 90-08-1074 § 4 (part))