90. The operation of a trench landfill is also subject to the following conditions :
(1) in order to minimize the release of odours, the spread of fires, the proliferation of animals or insects, and blowing litter, the residual materials deposited in the trenches must, at least once a week from May to October, be covered with a layer of soil or other material referred to in paragraph 4, or be covered in another manner if the above purposes are accomplished. The weekly cover requirement does not apply to a landfill reserved exclusively for the use of an industrial, commercial or other establishment if the residual materials received are not likely to generate the nuisances referred to above;
(2) residual materials containing asbestos, sludge and animal carcasses or animal parts must be covered with other materials as soon as they are deposited. That requirement does not apply if the residual materials deposited are covered in another manner as provided for in paragraph 1. The words “containing asbestos” have the same meaning as in the fourth paragraph of section 41;
(3) the soil used to cover the residual materials may contain contaminants in a concentration equal to or lower than the limit values set out in Schedule I to the Land Protection and Rehabilitation Regulation (chapter Q-2, r. 37) for volatile organic compounds and in Schedule II to that Regulation for other contaminants. Those limit values do not apply to contaminants that do not originate from human activity. The thickness of the cover layer consisting of such contaminated soil may not exceed 60 cm;
(4) other material may be used to cover the residual materials deposited in trenches if the other material does not contain any substance that is not accepted in a trench landfill and is capable of accomplishing the purposes referred to in paragraph 1.