Executive Summary: Key Legal and Evidentiary Issues

• Scope of the Ontario Energy Board’s discretion to control its own process, including whether intervenors have any right to file evidence or demand a technical conference.
• Proper interpretation of s. 15(1) of the Statutory Powers Procedure Act and whether “relevance” obliges the OEB to admit all relevant intervenor evidence.
• Alleged denial of procedural fairness to Environmental Defence Canada Inc. (EDC) when the OEB refused its proposed expert and survey evidence and declined to hold a technical conference.
• Weight to be given to survey evidence about future customer connections and competing technologies (electric heat pumps) in assessing the economic viability and public-interest merits of natural gas expansion projects.
• Application of the Baker factors and Vavilov/Larocque line of authority to determine the content of procedural fairness owed to an intervenor, whose own legal rights are not being directly determined.
• Extent to which concerns about delay, cost, and regulatory efficiency can legitimately justify excluding intervenor evidence and declining additional oral discovery in energy regulatory proceedings.

Background and regulatory setting

Environmental Defence Canada Inc. v. Ontario Energy Board, 2026 ONSC 1002, arose from four Ontario Energy Board (OEB) “leave to construct” applications by Enbridge Gas Inc. to build natural gas pipelines to serve previously unserved communities: Bobcaygeon, Sandford, Neustadt and Eganville. The projects formed part of Ontario’s Natural Gas Expansion Program (NGEP), designed to extend natural gas service to rural and northern communities with high energy costs and no existing pipeline infrastructure. The NGEP is enabled by the Access to Natural Gas Act, 2018 and related regulations, which identify specific projects that can receive subsidies funded by natural gas ratepayers to make otherwise uneconomic projects viable. Enbridge applied under s. 90 of the Ontario Energy Board Act, 1998 for leave to construct, and the OEB was required under s. 96 to determine whether the proposed construction was “in the public interest.” In this NGEP context, the government’s legislative and regulatory selection of projects meant that the “need” for these projects and the choice of natural gas as the energy source were treated as effectively fixed. The OEB focused instead on issues such as economic feasibility, forecast customer connections, and protection of existing gas customers over a 40-year period.

The parties and their interests

Enbridge Gas Inc. was the applicant in all four proceedings, seeking approval to build and expand gas distribution infrastructure to the designated communities. Its burden was to satisfy the OEB that the pipelines met the public-interest test, including long-term economic feasibility for ratepayers. Environmental Defence Canada Inc. (EDC), a broad-based environmental advocacy group opposed to fossil fuel expansion and subsidization, was granted intervenor status in all four cases. EDC regularly appears before the OEB and represents environmental and ratepayer interests seeking clean and affordable energy systems. Other intervenors included Pollution Probe, the Federation of Rental-housing Providers of Ontario (in Bobcaygeon), and a local resident in Sandford. The OEB is a quasi-judicial administrative tribunal with exclusive jurisdiction to regulate the electricity and natural gas sectors in Ontario. It has power to grant intervenor status, set procedural steps, and decide whether to allow intervenors to file evidence or to convene technical conferences (a form of oral discovery) after written interrogatories.

The NGEP projects and economic feasibility concerns

The four Enbridge projects at issue were among 28 selected by the Ontario government from 210 proposed community expansion projects to receive NGEP funding. The regulation caps the subsidy available for each project, and standard OEB leave-to-construct approvals are still required. Local municipalities and communities strongly supported the projects, as shown by resolutions and letters, reflecting concerns about high energy bills and the desire for access to more affordable home heating options comparable to southern and urban Ontario. In NGEP leave-to-construct hearings, the OEB treats project “need” as established through the legislative and regulatory scheme. It does not reassess alternatives such as electric heating; instead, it concentrates on whether enough customers will connect and stay connected over 40 years so that pipeline costs will be recovered and projects will be financially feasible. Enbridge had to demonstrate sufficient forecast customer attachments to justify the investment, especially given the initial subsidies.

EDC’s substantive objections to the projects

EDC argued that the pipelines were not in the public interest for three broad reasons. First, it said the projects were not economically feasible and would financially harm existing gas customers, who ultimately fund subsidies and may be exposed to additional revenue shortfalls if forecasts proved wrong. Second, it claimed newly connected customers would face needlessly high energy bills because electric heat pumps were allegedly cheaper in these communities. EDC also asserted that Enbridge’s customer surveys were flawed and that customers were misled or not properly informed about comparative costs. Third, EDC stressed climate concerns, arguing that extending gas infrastructure would lock in increased fossil fuel consumption for decades at a time when national and international climate targets require rapid reductions in fossil fuel use over the next 25 years. In EDC’s view, these economic and environmental risks required a much more robust evidentiary record and procedural process than the OEB allowed.

Intervenor participation and EDC’s procedural requests

Intervenors before the OEB have no automatic right to file evidence. They must seek permission, and the OEB has explicit discretion, both under its Rules of Practice and Procedure and under the Statutory Powers Procedure Act, to control what evidence is received and whether to hold a technical conference. In the four NGEP proceedings, EDC participated extensively in written discovery: it submitted hundreds of interrogatories, and Enbridge produced hundreds of pages of responses. Through this process, EDC obtained evidence on non-gas alternatives such as electric heat pumps, comparative cost-effectiveness analysis sourced in part from a Guidehouse Inc. report, and underlying customer survey data from Forum Research used by Enbridge to project connection rates. After interrogatories, EDC asked the OEB for three key procedural steps: permission to file expert evidence on the cost-effectiveness of heat pumps versus natural gas; permission to retain a public opinion research firm to conduct its own community surveys on likely connections; and an order convening a technical conference to question Enbridge’s witnesses. EDC argued that its survey evidence would show Enbridge’s surveys were deficient (for example, by not informing customers of potential heat pump savings), and that customers might connect at lower rates or disconnect earlier than forecast, yielding revenue shortfalls that existing ratepayers would have to cover beyond the regulated subsidy.

The OEB’s evidence and procedural rulings

In February 2024, the OEB issued evidence decisions in each case, rejecting EDC’s requests. It held that the proposed heat pump evidence was not required because, in NGEP projects, the legal question was whether the Enbridge projects were in the public interest, not whether heat pumps should be chosen instead of natural gas. The regulatory framework had already selected natural gas expansion as the policy tool, so a comparative “heat pump versus gas” choice was outside the core of the leave-to-construct test. On the proposed survey evidence, the OEB emphasized several points. It accepted that there was a risk that customers might opt for heat pumps, but said it was already aware of that risk and did not require further survey evidence to appreciate it. It noted that consumer energy decisions are driven by a mix of financial and non-financial factors, limiting the probative value of another survey. It also warned that any additional survey could spark lengthy disputes about methodology, timeliness and reliability, causing delay and cost in proceedings funded ultimately by ratepayers. Most significantly, the OEB pointed to the ten-year “rate stability period” built into the regulatory framework. During this period, Enbridge is responsible for any revenue shortfalls relative to its revenue requirement, meaning existing customers are protected for at least ten years even if connection forecasts are not met. The OEB described a “clear and reasonable expectation” that customers would not be required to provide further subsidies for post-rate-stability-period shortfalls. Against this background, it saw the incremental value of EDC’s survey as limited. The OEB further refused to convene a technical conference, concluding that interrogatories had already given intervenors substantial discovery and that a technical conference or oral hearing would have only limited additional probative value while delaying service to customers and increasing costs.

Final OEB decisions on the projects

In May and June 2024, after receiving written submissions, the OEB granted leave to construct all four projects. Its final decisions reiterated that, even if actual customer attachments fell short of Enbridge’s forecasts, the rate stability period placed responsibility for revenue shortfalls on Enbridge, thereby protecting existing customers in the key early years. It also recognized the inherent limitations of survey evidence in forecasting long-term customer behavior in a rapidly changing energy environment with evolving technologies, policies and prices. The OEB accepted that there were risks from customer take-up of electric heat pumps, but concluded that the built-in protections, combined with the legislative framework and the community support, meant the projects remained in the public interest.

The review motion before the OEB

EDC then brought a Motion to Review and Vary the final decisions, raising largely the same complaints it later advanced in court: that the OEB had applied the wrong legal test for admitting evidence, had unduly emphasized efficiency and delay, had misconceived its proposed evidence, and had underappreciated the risks of revenue shortfall and climate impact. In April 2025, the OEB dismissed the review motion. It confirmed its earlier view that the process was fair and that EDC had not shown errors warranting reconsideration. The Board also stressed again that it had considered the potential advantages of heat pumps and the risk they posed to project viability, but concluded that its original decisions appropriately balanced these risks with statutory objectives and procedural efficiency.

The appeal to the Divisional Court

EDC appealed to the Ontario Divisional Court under s. 33 of the Ontario Energy Board Act, which allows appeals on questions of law or jurisdiction. It argued two “main legal errors,” both grounded in procedural fairness. First, it said the OEB applied the wrong legal test to the admissibility of evidence by effectively asking whether EDC’s proposed evidence could decisively prove the projects uneconomic or contrary to the public interest, instead of simply applying a relevance test. Second, EDC argued that the combined refusal to admit its evidence and to hold a technical conference breached the duty of procedural fairness owed to it as a full “party” intervenor. The court noted that on a statutory appeal, questions of law, including procedural fairness, are reviewed on a correctness standard. It relied on leading authorities such as Housen v. Nikolaisen (standard of review), Abrametz (procedural fairness as a question of law on appeal), and Université du Québec à Trois-Rivières v. Larocque, which holds that a tribunal’s refusal to receive evidence only violates natural justice if it has a significant impact on the fairness of the proceeding. The court also invoked Council of Canadians with Disabilities v. VIA Rail, emphasizing that tribunals with authority to control their processes enjoy considerable deference in procedural rulings, especially where their statutes contemplate flexible procedures and require them to balance fairness with efficiency.

The court’s analysis of the evidence-admissibility standard

On the first issue, the Divisional Court rejected the argument that the OEB had misstated or misapplied the legal test for admitting evidence. It held that s. 15(1) of the Statutory Powers Procedure Act is permissive: tribunals “may” admit anything relevant; they are not required to admit all relevant evidence. Relevance is a threshold, but not an absolute right of entry. The court found that Larocque had already rejected the idea that administrative tribunals must admit all relevant evidence, and that the same principle applied beyond the labour context. It further observed that the OEB’s reasons, read as a whole, showed a careful weighing of probative value against fairness, efficiency, and statutory purpose. When the OEB stated that EDC’s proposed survey was “not likely to provide information that could support a definitive conclusion” that the projects were uneconomic or contrary to the public interest, this was not the governing legal test but a contextual remark following a broader analysis. The Board had considered relevance, materiality, comparative value of the evidence, the existence of the rate stability period, and the risk of delay and complexity, and had concluded that admitting the evidence was not warranted. The court held that evidentiary decisions of this nature lie squarely within the OEB’s discretion and that its approach did not amount to a “reckless” exercise of that discretion or a misdirection on the law.

The court’s assessment of procedural fairness

Turning to the second issue—whether EDC was denied procedural fairness—the court first accepted that some duty of fairness was owed. However, it emphasized that the content of this duty is “eminently variable” and depends heavily on context, guided by the Baker factors: the nature of the decision and process, the statutory scheme, the importance of the decision to affected interests, any legitimate expectations, and the tribunal’s own procedural choices. Applying these factors, the court placed EDC’s procedural rights at the lower end of the spectrum. It stressed that the OEB’s leave-to-construct hearings were not adjudicating EDC’s own legal rights; Enbridge alone bore the burden of proof and was seeking approvals that would not compel any individual to take gas service. The economic risk of early revenue shortfalls lay primarily on Enbridge for at least ten years, and future impacts on customers were cushioned by the regulatory framework and Board expectations. The court also found that EDC had no legitimate expectation of being allowed to file its own evidence in every case. Historically, EDC had sometimes been allowed and sometimes refused, and the OEB’s rules expressly made such permissions discretionary. The OEB’s rules and past practice contemplated that intervenors might participate through interrogatories and submissions without necessarily filing their own evidence or having oral discovery.

Treatment of intervenors and comparative fairness

EDC argued that, as an intervenor with “party” status under the OEB Rules and as a representative of environmental and ratepayer interests, it should be afforded the same opportunities as Enbridge to adduce evidence. It pointed to case law suggesting that both sides in an adjudicative proceeding should be able to call relevant evidence. The court distinguished those authorities, noting that many arose in contexts like professional discipline or court-like hearings directly affecting livelihoods or legal rights, where procedural protections are stronger. By contrast, leave-to-construct applications are polycentric, involve multiple public-interest considerations, and do not determine EDC’s own rights. The court also referred to leading commentary on administrative procedure, which recognizes that the extent of an intervenor’s participation is determined by the tribunal, taking into account how much that participation will assist in fulfilling its mandate.

Reasonableness of refusing a technical conference and additional survey evidence

The Divisional Court upheld the OEB’s refusal to order a technical conference, finding that the Board reasonably concluded that written interrogatories had already provided adequate discovery and that additional oral discovery would add limited value compared with the delay and cost it would introduce. The court also rejected several additional alleged errors. It held that it was legitimate for the OEB to consider regulatory efficiency and the resource burden on ratepayers when deciding whether to admit further survey evidence that would require complex adjudication over methodology. Likewise, it was not improper to consider the legislative design of the NGEP and prior OEB decisions when assessing whether EDC’s proposed evidence was necessary. The court dismissed the suggestion that the OEB improperly “assumed” the merits in Enbridge’s favour when it observed that the company, as a regulated utility, could be expected to have carefully considered potential shortfalls. That remark was read as a contextual observation rather than a legal presumption about the merits.

Outcome and monetary award

In the result, the Divisional Court concluded that EDC had not shown that the OEB’s refusal to receive its proposed evidence or to hold a technical conference had a significant impact on the fairness of the proceedings amounting to a denial of natural justice. The court held that the OEB applied the correct legal principles on evidence and permissibly balanced probative value against efficiency, delay and its statutory mandate. The appeal was therefore dismissed, and the OEB’s approvals of the four NGEP gas expansion projects were left undisturbed. Enbridge Gas Inc. and the Ontario Energy Board emerged as the successful parties, with the court ordering Environmental Defence Canada Inc. to pay costs to Enbridge in the all-inclusive amount of $2,500; no other damages or monetary awards were made beyond this modest costs order.