Confidence: Verified.

The Plains Midstream Canada Sarnia NGL fractionator is the principal Eastern Canadian propane source — and, with the Pembina salt-cavern storage complex at the same site, the price-formation point for Ontario propane. Supply continuity from Sarnia is the single most important variable in Ontario propane availability; Sarnia spot price is the dominant driver of Ontario propane invoice movement.

Operators. Plains Midstream Canada (fractionator). Pembina Pipeline (Sarnia salt-cavern storage). These are the two facilities OPIS names as comprising "Sarnia" in its NGL methodology.

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.

Supply origin into Sarnia

Three main physical routes feed Sarnia:

1. Enbridge Line 1/5 — mixed NGLs Edmonton → Superior, WI on Line 1, then Line 5 (645 miles, 540,000 bpd crude + NGL) Superior → Sarnia via Michigan's Upper Peninsula. Side-stream depropanization at Rapid River, MI; the remaining mixed NGL is fractionated at Sarnia. Enbridge discloses Line 5 serves "55% of statewide [Michigan] propane needs · 65% of Upper Peninsula propane needs." Line 5 status is a perennial Ontario tail risk.
2. Utopia East Pipeline — eastern remnant of the former Cochin pipeline (reversed 2014, repurposed by Kinder Morgan / Velocity Midstream in 2018, sold to Pembina in 2019). Delivers Marcellus/Utica NGL from Ohio into the Windsor-Sarnia corridor. Supplemented by the Plains Windsor-Sarnia Pipeline (50,000 bpd ethane + NGL).
3. Rail — CN and CPKC tank cars from Pembina's Redwater terminal in Alberta and from US Bakken/Marcellus producers. Pembina's Redwater facility is the only Canadian facility capable of amassing 105-car propane unit trains (Pembina PRNewswire release, November 24, 2019, during the Quebec fuel shortage).

Best public estimate of origin split: ~60–70% Canadian NGL origin (entering Sarnia as the propane fraction of Enbridge mainline NGL mix, plus rail from Redwater); ~30–40% Marcellus/Utica US origin via Utopia East / Plains pipeline / rail. The CER does not publish a clean Ontario-origin breakdown.

Producer concentration: Pembina Pipeline, Plains Midstream Canada, Keyera, and AltaGas dominate Canadian midstream aggregation. US Marcellus/Utica supply enters via Enterprise Products Partners and MPLX (Marathon). Per the CER / Competition Bureau Propane Market Review Final Report (2014, para. 3.3), 85–90% of Canadian propane is a gas-processing byproduct (Alberta 88%, BC 7%); the remaining 10–15% is a crude-refining byproduct.

Plains Fort Saskatchewan debottleneck (May 2025): Plains All American SEC Form 8-K (filed May 9, 2025) confirms the 30 Mb/d Fort Saskatchewan fractionation complex debottleneck project was placed into service. GlobeNewswire release May 8, 2025: "over $200 million investment" creating "over 350 jobs."

Price formation

The Sarnia rack price is the wholesale clearing price for HD-5 propane out of the Plains fractionator + Pembina storage. Trades typically in 7,500–10,000 bbl in-well parcels; OPIS uses smaller parcels for directional gauge. Settled after futures market close as a daily low/high/average assessment in US cents per gallon. Ontario marketers convert to CAD¢/L using daily FX.

Triangulating references:

• Mont Belvieu LDH propane (US Gulf Coast) — Sarnia historically within ±10–15 US¢/gal
• Conway, Kansas — mid-continent reference relevant to crop-drying season
• Edmonton propane (WCSB) — usually 10+ US¢/gal discount to Sarnia since the 2014 Cochin reversal removed pipeline arbitrage

Verified Sarnia rack reference points (CAD¢/L), 2025–26, from New Brunswick EUB Maximum Allowable Prices weekly schedule (OPIS-sourced — the cleanest public re-publication in Canadian-dollar units):

Typical 2025–26 trading range: 33–37 CAD¢/L. Winter premium over summer is typically 5–15 CAD¢/L. This is well above the unusual 2020 COVID-era low (16–21 CAD¢/L) and below the late-2013/early-2014 polar-vortex spike (80 CAD¢/L).

Who publishes it: OPIS (daily, the standard reference cited by Ontario marketers and Canadian regulators), Argus Media (North American NGL report), Bloomberg Oil Buyer's Guide (weekly contract rack average; used as regulatory benchmark by the Newfoundland & Labrador PUB and indirectly by the New Brunswick EUB). NRCan publishes retail propane only, not wholesale Sarnia.

What moves it: crude (WTI, correlated but not 1:1), Henry Hub natural gas (gas plants are the main producer), US LPG export demand (VLGC charter rates, ARA arb to NW Europe, Asian demand into Japan/Korea/India), Ontario/Quebec/Northeast heating degree-days, SW Ontario crop-drying demand, Enbridge Line 5 status, CN/CPKC rail strike risk.

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.

Related entries

• op-propane-price-decomposition-farm-bulk-2026 — the full nine-stage cost decomposition from Sarnia rack to farm gate; explains how the marketer's 25–35 CAD¢/L spread above Sarnia decomposes into logistics, last-mile, margin, and HST
• op-ag-propane-price-benchmark-2026-05 — current delivered-price benchmark for SW Ontario farm bulk
• op-2019-cn-rail-strike-propane-disruption — operational concept for rail-disruption response
• op-hd5-propane-spec-combustion-quality — purity specification of the HD-5 product loaded at Sarnia

Sources

• OPIS NGL methodology (Sarnia = Plains fractionator + Pembina caverns)
• New Brunswick Energy & Utilities Board Maximum Allowable Prices weekly schedule (OPIS-sourced)
• Canada Energy Regulator, Provincial and Territorial Energy Profiles — Ontario; CER/Competition Bureau Propane Market Review Final Report (2014)
• Enbridge "Propane, Michigan and Line 5" disclosure
• Plains All American SEC Form 8-K filed May 9, 2025; GlobeNewswire press release May 8, 2025
• Pembina Pipeline PRNewswire November 24, 2019
• Canadian Propane Association industry materials; CBC News coverage of November 2019 strike
• Conference Board of Canada, Canada's Propane Supply Chain: Reliability and Resilience (August 2021)