26.An engineered landfill which under this Regulation must have a double liner system must also have, in addition to the leachate collection system to be installed pursuant to section 25 over the upper geomembrane, a secondary leachate collection system placed between the 2 geomembranes and that consists of
(1) a system that incorporates the components prescribed by subparagraphs 1 and 2 of the first paragraph of section 25, except that
— the minimum thickness of the drainage layer must be 30 cm;
— the minimum diameter of the pipes must be 100 mm; or
(2) any other system if the system is at least as effective as the system referred to in subparagraph 1.
The secondary collection system must be designed to be monitored independently from the other collection systems on the site.