No business shall be transacted by the commission without the presence of a quorum of four (4) commissioners. The commission shall meet regularly at least once each calendar quarter and as many additional times as determined by the commission. A special meeting of the commission may be called in writing by the chairperson, by any three (3) commissioners, or by the board of trustees. Notice of at least forty eight (48) hours shall be given to all commissioners, and in compliance with the Illinois open meetings act, prior to any special meeting. All meetings shall be open to the public except when closed pursuant to the provisions of the open meetings act. (Ord. O2013-07, 3-19-2013)