AltaGas Reaches Positive FID on Dimsdale Phase II Gas Storage Expansion in Alberta
AltaGas has reached a positive final investment decision on the Phase II expansion of its Dimsdale gas storage facility in Alberta, advancing a 30-Bcf project backed by long-term contracts.
(P&GJ) — AltaGas Ltd. has reached a positive final investment decision (FID) on the Phase II expansion of its Dimsdale natural gas storage facility in Alberta, advancing a 30-Bcf project backed by long-term, take-or-pay contracts.
The Phase II expansion is supported by multi-year firm storage agreements, including incremental commitments from Tourmaline and Gunvor above their previously disclosed Phase I capacity, as well as four new customers. The project will add compression and dehydration facilities and include the drilling of five new storage wells. AltaGas estimates capital costs of about $165 million, with an in-service target of mid-2027.
With Phase II moving forward, AltaGas expects to deploy roughly $230 million over the next 18 months to expand gas storage capacity in the Alberta Montney, all under long-term take-or-pay contracts. The company said the investment reflects rising demand for storage to balance future Canadian LNG exports and underscores the strategic value of assets located near key supply hubs such as Dimsdale.
Beyond the Dimsdale decision, AltaGas also provided updates across its midstream portfolio.
Pipestone Phase II Reaches Commercial Operations
AltaGas said Pipestone Phase II has entered full commercial service following completion of construction in early November and successful commissioning. The facility achieved first gas in mid-December 2025 and was declared fully operational later that month. Pipestone I and II are now operating as a single, integrated complex with two processing trains.
Train II is operating at more than 90% of design capacity, with contracted volumes expected to continue increasing in coming months. Pipestone II is fully contracted under long-term take-or-pay agreements and provides gas processing and liquids handling capacity in the liquids-rich Alberta Montney.
MVP Southgate Receives FERC Approval
In the U.S., AltaGas said the Mountain Valley Pipeline (MVP) Southgate project continues to advance under a revised development plan. In late December, the U.S. Federal Energy Regulatory Commission unanimously approved a shortened route for the pipeline extension into North Carolina, following a positive environmental assessment issued in October.
AltaGas said the approvals support its decision to retain ownership in MVP, including MVP Boost and MVP Southgate, with the Southgate extension expected to generate attractive project-level returns.
CFO Transition
AltaGas also announced a leadership transition, with Executive Vice President and Chief Financial Officer James Harbilas set to retire April 1, 2026. Sean Brown has joined the company as incoming CFO and will assume the role effective immediately, while Harbilas will serve as strategic advisor through the transition.
“On behalf of the Board and the entire AltaGas team, I want to thank James for his strong contributions to AltaGas' success,” said Vern Yu, president and chief executive officer of AltaGas. “Over the past six years, AltaGas has de-leveraged its balance sheet, completed strategic acquisitions and divestitures and advanced a disciplined capital allocation framework across our two core businesses.”
“We are pleased to welcome Sean Brown as our next CFO,” Yu added. “Sean's proven leadership in strategy, capital allocation, risk management and investor relations will be instrumental as we continue to execute on our long-term strategic plan and deliver sustained value for our stakeholders.”