439. It is forbidden to drill at a distance of less than:(1) 150 mm (5.9 in) from the bottoms of drill holes that have been loaded and blasted;
(2) 1.5 m (4.9 ft) from a hole containing explosives following a misfire;
(3) 15 m (4.9 ft) from blasted rock that might conceal a misfire;
(4) 5 m (16.4 ft) from any loaded hole or any place where explosives are loaded; however, if the drilling and the loading are carried out alternately, the drilling of a drill hole may be carried out at a distance of less than 5 m (16.4 ft) if the specific conditions of an open-pit mine require it and the following conditions are met:(a) only cartridged explosives may be used;
(b) drill holes may be drilled only in parallel and their alignment shall be checked so that the margin of error does not exceed 3°;
(c) the minimum distance shall be 1.2 m (3.9 ft) from any hole loaded with explosives or 20% of the depth of the holes, whichever is greater; no hole may be drilled to a depth of more than 12 m (39.4 ft), or more than 15 m (49.2 ft) for holes with a diameter of 102 mm (4 in) or more, except where an engineer certifies, before drilling begins, that deeper holes may be drilled without any danger; the engineer’s certification shall be sent to the Commission des normes, de l’équité, de la santé et de la sécurité du travail;
(c.1) if the holes have a depth of 6 m (19.7 ft) or more, the first drilling rod shall be replaced by a guide tube;
(d) loaded holes shall be marked by stakes that are red or carry a red ribbon;
(5) the distance stipulated, in the case of a frozen cut, in any of the following situations:(a) 300 mm (12 in) from the frozen cut, where it is 460 mm (18 in) deep or less;
(b) a distance equal to the depth of the frozen cut, where it is more than 460 mm (18 in) but less than 915 mm (36 in) deep;
(c) 915 mm (36 in) from the frozen cut, where it is more than 915 mm (36 in) deep.
For the purposes of subparagraphs a, b and c of subparagraph 5 of the first paragraph, the prescribed minimum distance for drilling holes shall be measured from a circle marking the outside edge of the frozen cut and the holes shall be drilled parallel to the cut. In the cases of subparagraphs b and c of subparagraph 5, the drill holes shall not be deeper than the frozen cut.
For the purposes of subparagraph 5 of the first paragraph, “frozen cut” means the first holes blasted in a round that did not break the rock as expected but rather fractured and compacted it and where explosives are not detected.
O.C. 213-93, s. 439; O.C. 1236-98, s. 25; O.C. 460-2000, s. 31; 945-2020O.C. 945-2020, s. 41.