27. Construction standards: A seepage bed built with a gravity feed system must comply with the construction standards in subparagraphs a, d, e, f, g, g.1, g.2, g.3, h and h.1 of the first paragraph of section 21 and the following standards:
(a) perforated pipes must be not more than 1.2 m apart and be at a maximum distance of 60 cm from the limit of the disposal site;
(b) the bottom of the seepage bed must be at least 90 cm above bedrock, impermeable soil or low permeability soil or underground water if the effluent is from a primary treatment system, and at least 60 cm if the effluent is from a secondary treatment system;
(c) where infiltration chambers are used, they must be side by side or spaced not more than 1.2 m apart; in the latter case, they must be installed on a layer of gravel or crushed stone at least 15 cm thick in accordance with subparagraph f of the first paragraph of section 21.
A seepage bed built with a low pressure feed system must comply with subparagraphs a, b and c of the first paragraph, subparagraphs d, e, f, g, g.1 and g.2 of the first paragraph of section 21 and subparagraphs a and b of the second paragraph of that section.
R.R.Q., 1981, c. Q-2, r. 8, s. 27; O.C. 786-2000, s. 29.