By: Martin Olszynski

Decision Commented On: Reference re Impact Assessment Act, 2023 SCC 23 (CanLII)

PDF Version: Triviality and Significance of Federal Environmental Effects after Reference re: Impact Assessment Act

This is the sixth ABlawg post regarding the Supreme Court of Canada’s recent opinion in Reference re Impact Assessment Act, 2023 SCC 23 (CanLII) (IAA Reference) (see the first five posts here). In this post, I address the thorny issue of thresholds, i.e., the level or point at which an effect becomes material or relevant under the Impact Assessment Act, SC 2019, c 28, s 1 (IAA). Since the opinion’s release last fall, I have read and heard concerns that the majority has imposed some kind of minimum threshold regarding the magnitude of effects required to trigger federal jurisdiction, or that the federal government could only refuse to deem such effects to be in the public interest if they are significant (see here for a thoughtful commentary on the practical problems with such an approach). As noted by Justices Andromache Karakatsanis and Mahmud Jamal in their dissent, however, it has actually long been an interpretive rule – since the Supreme Court of Canada’s environmental law decision in Ontario v Canadian Pacific Ltd, 1995 CanLII 112 (SCC), [1995] 2 SCR 1031 (Canadian Pacific) – that broadly worded environmental legislation is to be interpreted in a manner that does not capture trivial, or de minimis, impacts (IAA Reference at para 278). Importantly, however, and as I discussed almost a decade ago in “Ancient Maxim, Modern Problems: De Minimis, Cumulative Environmental Effects and Risk-Based Regulation”  (2015) 40-2 Queen’s Law Journal 705, 2015 CanLIIDocs 5272, (“Ancient Maxim, Modern Problems”), non-triviality is a very low bar; between trivial and significant lies a wide spectrum of impacts, which at the very least includes low and moderate impacts. Trivial or de minimis impacts are essentially only those impacts that a regulatory regime could systematically ignore while still obtaining its objectives – they are treated the same as no impacts whatsoever. Continue reading →