17. (1) The Commission sits in plenary session, in public hearing, in session or in practice. The quorum of the Commission is:
(a) in plenary session, twelve members, including the president and two other judges, one of whom is a vice-president;
(b) in public hearing, three members, including one judge;
(c) in session, three members, including one judge;
(d) in practice, one judge.
(2) In public hearing or in session, every question of law is decided by the presiding judge or, if there are three judges, by the majority.
(3) Notwithstanding subparagraph c of subsection 1, one member of the Commission may render alone a decision on a matter in which there is no opposition or intervention. In such case, such decision may be reviewed by the Commission sitting in public hearing on a written motion giving the reasons on which it is based and filed within fifteen days of the publication of such decision or a summary thereof in the Gazette officielle du Québec. Where, on a motion, the practice division orders the review of such a decision, that order shall suspend execution of the decision, unless the division orders provisional execution of the decision in cases of exceptional urgency.
(4) Notwithstanding subparagraphs b and c of subsection 1, the permits mentioned in section 38 may be issued in public hearing or in session by two members, one of whom is a judge.
(5) The Commission may sit simultaneously in several divisions in the same locality or in different localities.
(6) If the president or a member of the Commission is unable to act by reason of absence or illness, the Government may appoint another person to replace him temporarily and fix his salary.
(7) During his vacation, the president is replaced by a vice-president designated by the Government; such designation shall not entail any additional salary.