This proceeding involved special and unique circumstances and the issues examined were complex and technically difficult. In addition, Calgary was the sole intervener who participated in this proceeding, and without its participation, the Commission would not have conducted an oral public hearing to consider the issues in this proceeding. ###>difficiles du point de vue technique. De plus, Calgary est la seule intervenante à avoir participé à l'instance et, sans elle, le Conseil n'aurait pas dirigé une audience publique en vue d'examiner