Introduction

In 863880 Ontario Limited v. Canadian Pacific Railway Company, 2025 ONCA 755, the Ontario Court of Appeal delivered an important reminder about limitation periods in environmental contamination cases. The key takeaway for transactional lawyers: actual knowledge that property is contaminated starts the limitation clock ticking, even if your client doesn’t yet know the full scope of the problem.

Background

The appellant purchased contaminated property from CP Rail’s predecessor in 1990. Between 1990 and 1991, the purchaser received four environmental reports confirming soil contamination, though the extent remained uncertain. The purchaser, a property developer, decided not to address the contamination at that time, partly because excavation was planned as part of the intended development anyway.

Fast forward to 2002: excavation revealed the contamination was far more extensive than originally understood. The purchaser sued in January 2004, seeking damages for the contamination. CP Rail moved for summary judgment, arguing the claim was statute-barred.

The Motion Judge’s Decision

Justice Parghi granted summary judgment, finding that the six-year limitation period (applicable at the time) began running in April 1991 when the purchaser had actual knowledge of the contamination. By the time the action was commenced in 2004, the limitation period had long expired.

The Appeal

The appellant advanced two main arguments on appeal:

1. Context and Perspective: The appellant argued that while it knew about contamination in 1991, it considered it minor and unimportant. The contamination wasn’t deemed significant enough to affect development plans. The appellant maintained it only discovered it was “worse off” in 2002 when the true extent became apparent. The appellant challenged the motion judge’s findings, suggesting she made palpable and overriding errors in determining when actual knowledge arose.
2. Continuing Nuisance: The appellant argued its continuing nuisance claim should survive, based on allegations that contamination continued leaking onto the property until between 2010 and 2014.

The Court of Appeal’s Analysis

The Court of Appeal rejected both grounds, affirming the summary judgment dismissal.

Knowledge of Contamination vs. Knowledge of Full Extent

The Court’s most significant holding addresses a distinction transactional lawyers must understand: a plaintiff need not know the full extent of contamination for the limitation period to begin running. Citing Hamilton (City) v. Metcalfe & Mansfield Capital Corp., 2012 ONCA 156, the Court confirmed that actual knowledge of contamination, regardless of degree, is sufficient to trigger the limitation period.

The appellant knew in 1991 that the land was contaminated and consciously chose not to deal with it. That strategic decision proved fatal to the claim. The limitation period started then, not when later excavation revealed more extensive problems.

Standard of Review

The Court refused the appellant’s invitation to remake the motion judge’s factual findings. Absent palpable and overriding error, appellate courts defer to findings of fact. Here, the motion judge carefully reviewed four environmental reports, all indicating contamination. Her conclusion that the appellant had actual knowledge by April 1991 was well-supported and entitled to deference.

The Continuing Nuisance Argument

The Court also rejected the continuing nuisance argument, though on procedural grounds. The appellant had mentioned this theory only in passing, discussing it in only a single paragraph in its factum, without properly developing it before the summary judgment was entered.

The Court held that the appellant could not “hive off the continuing nuisance cause of action in the context of a claim so clearly time barred.” The motion had been argued on the basis that the appellant knew about contamination in 1991, albeit of uncertain extent. Having taken that position and lost, the appellant could not rely on this undeveloped theory to reverse the summary judgment.

Practical Implications for Transactional Lawyers

This decision carries several important lessons:

1. Early Knowledge Triggers Early Limitation Periods: Advise purchaser clients that discovering any contamination starts the limitation clock, even if the full scope remains unknown. Don’t wait to investigate further or to see if the problem is “really that bad.”
2. Document Decision-Making: If a client decides to proceed despite known contamination, document that decision carefully. The strategic choice not to pursue contamination issues can preclude later claims.
3. Environmental Due Diligence is Critical: Phase I and Phase II environmental assessments aren’t just box-checking exercises. Any indication of contamination in those reports has serious limitation period implications.
4. Preserve All Causes of Action: If environmental reports suggest continuing contamination sources, consider whether continuing nuisance or other ongoing causes of action should be specifically pleaded and preserved. Don’t rely on vague references. Develop these theories fully from the outset.

Conclusion

863880 Ontario Limited reinforces that knowledge is power, but also starts limitation periods running. Transactional lawyers advising on contaminated property purchases must ensure clients understand that even preliminary environmental concerns trigger time-sensitive legal rights. When in doubt, investigate immediately and document all decisions carefully.