(a) Except as described in the transition requirements in section 360.4 of this Title, only a storage tank system may be used to store leachate. The aboveground and on-ground leachate storage tank system must be capable of containing a minimum of three consecutive months combined primary and secondary leachate flow based on calculations required by section 363-4.3(e) of this Part unless an alternate storage and transport system is approved by the department, and must have a secondary containment system capable of retaining leachate in the event of a leachate spill.

1. (1) The design volume for the secondary containment system must be at least 110 percent of the volume of either the largest tank within the containment system or the total volume of all interconnected tanks, whichever is greater.
2. (2) The secondary containment system must be constructed of a one-foot layer of compacted soil with a hydraulic conductivity of 1x10_-7 centimeters per second or less, a concrete pad of sufficient thickness to maintain integrity for the lifetime of the tank with a corrosion-resistant coating, or a geosynthetic liner of a minimum thickness equal to 60 mils. If a geomembrane is used, construction and certification must meet the requirements of section 363-6.8(b) and (c) of this Subpart, except for the electrical resistivity testing provisions of section 363-6.8(c)(3)(vii) of this Subpart.
3. (3) All aboveground and on-ground tanks must be equipped with an overfill prevention system.
4. (4) All uncovered tanks must maintain a minimum of two feet of freeboard.
5. (5) Appurtenances should be detailed illustrating the ability for filling and draining the containment system, including design details for draining uncontaminated precipitation from the secondary containment system.