Confidence: Verified.
The Plains Midstream Canada Sarnia NGL fractionator is the principal Eastern Canadian propane source. Supply continuity from Sarnia is the single most important variable in Ontario propane availability.
Operator: Plains Midstream Canada.
Function: Fractionates natural gas liquids into propane, butane, and other NGLs for distribution across Ontario, Quebec, and the Maritimes.
Distribution modes: Rail (63% of Canadian propane volume nationally; ~85% of Quebec supply) and truck.
Truck-deliverable footprint from Sarnia. Southwestern Ontario — including the Boucher & Jones service area in Norfolk, Oxford, Brant, Haldimand, Elgin, Wellington, Waterloo, Perth, Huron, and Middlesex counties — is within practical tanker reach of the Sarnia fractionator. This is the structural reason a local distributor with truck pickup at Sarnia can maintain supply when rail is disrupted. Quebec's near-total rail dependence is geometric: tanker round-trips from Sarnia to Montreal are not viable at the volumes required.
Disruption history. The 8-day November 2019 CN rail strike (see op-2019-cn-rail-strike-propane-disruption) caused multi-hour tanker lineups at the Sarnia terminal and forced provincial rationing across Quebec and Eastern Ontario. Truck capacity could not replace rail capacity at scale.
Sources: Canada Energy Regulator, Provincial and Territorial Energy Profiles — Ontario; Canadian Propane Association industry materials; CBC News coverage of November 2019 strike.