(1) a base shall underlie the containers which is free of cracks or gaps and is sufficiently impervious to contain leaks, spills, and accumulated precipitation until the collected material is detected and removed;

(2) the base shall be sloped or the containment system shall be otherwise designed and operated to drain and remove liquids resulting from leaks, spills, or precipitation, unless the containers are elevated or are otherwise protected from contact with accumulated liquids;

(3) the containment system shall have sufficient capacity to contain precipitation from at least a 24-hour, 25-year storm plus 10 % of the aggregate volume of all containers or the volume of the largest container, whichever is greater. Containers that do not contain free liquids need not be considered in this determination;

(4) run-on into the containment system shall be prevented unless the collection system has sufficient excess capacity in addition to that required in subsection (b)(3) of this section to contain any run-on which might enter the system; and

(5) spilled or leaked waste and accumulated precipitation shall be removed from the sump or collection area in as timely a manner as is necessary to prevent overflow of the collection system. If the collected material is a hazardous waste under chapter 11 of this division, it shall be managed as a hazardous waste in accordance with all applicable requirements of chapters 12 through 16 of this division. If the collected material is discharged through a point source to waters of the United States, it is subject to the requirements of section 402 of the Federal Clean Water Act, as amended (33 U.S.C. section 1342).

(1) The storage area is sloped or is otherwise designed and operated to collect and remove liquid resulting from precipitation, or

(2) The containers are elevated or are otherwise protected from contact with accumulated liquid.