Enbridge outlines progress, costs and scheduling risks for Utah pipeline replacement tracker

Enbridge Gas told the Utah Public Service Commission at a technical conference in docket 23-080-5718 that the company has replaced about 45% of the feeder-line footage listed on its tracker and has roughly 308 miles remaining, and described project timing, material choices and cost drivers for the 2024 annual plan.

The disclosure matters because the tracker — known in the testimony as the IRA or tracker — is the cost-recovery mechanism that moves specific capital investment between general rate cases into a surcharge on customer bills and because ongoing replacements affect safety, city coordination and environmental handling. "The IRA for short, or we oftentimes call it a tracker, is a cost recovery mechanism and attracts specific capital costs, from rate case to rate case," said Jordan Stevenson, with Enbridge Gas's regulatory group.

Enbridge representatives summarized program history and reporting requirements and gave project-level updates. Company witnesses said the tracker was approved by the commission in 2010 and later expanded in the 2013 general rate case to include belt-line replacement. The company said it files an annual budget and quarterly cost reports under the tracker and that, when investments roll into a general rate case, the tracker surcharge is reset to zero. Jordan Stevenson said the company updates a master list of pipeline footages each year and expected to file the 2025 master list the week of the conference.

On program progress and scope, Enbridge said it has replaced 45% of the footage identified on master lists (including pre-2013 work) and reported an average replacement pace of about 16.6 miles per year; the company said about 308 miles remain on the current list. "We have replaced 45% of all of those footages that have been identified and reported on on these master lists," Stevenson said. Company witnesses emphasized the lists change as the company learns more about the system.

Speakers described differences in materials, up-sizing practices and project costs. Enbridge staff said belt lines larger than 8 inches are typically steel (16-inch examples were discussed) while replacements up to 8 inches commonly use high-density polyethylene (HDPE). Company engineers said upsizing occurs when hydraulic and growth analyses indicate higher capacity is prudent; they described system modeling and local region engineers' role in sizing decisions rather than an ad hoc judgment. Enbridge cited a depreciation example with an approximate useful life on new mains around 70 years.

Project examples discussed include BeltLine 7 Phase 3 on South Temple (8-inch installation in two phases), Belt Line 27 (16-inch work near North Temple), and larger high-pressure replacements including a 24-inch project running from 30th to the county line and other feeder-line segments. Enbridge said some projects were delayed or had higher costs because of COVID-era shutdowns, easement negotiations and long borings under waterways; the company identified a roughly $3,000,000 variance on one belt-line project and attributed the increase to pandemic interruptions, an easement issue in a Salt Lake City park and a bore under the Gordon River.

Environmental and construction constraints also affected schedule and cost. Enbridge said crews encountered contamination at a site near a designated EPA Superfund area, requiring additional sampling, handling plans and training; the company described a "6 plus figure" increase for HAZWOPER training and other contamination handling costs tied to that alignment. The company said it incorporated those remediation and handling costs into its 2025 budget. Enbridge also described coordination with UDOT and municipalities — timing limits for night work, moratoriums and resurfacing plans — as factors that can push projects into subsequent years to reduce community disruption.

Company witnesses described directional drilling practices for long bores, the use of back-reamers and drilling fluids, and engineering controls to reduce the risk that drilling fluids migrate to the surface in sandy or cobbled alluvial soils. They also discussed operations to test, clean and odorize new mains before placing them in service.

The conference included no formal votes or commission decisions on the record; presenters paused the public stream before one confidential slide and noted they would not display confidential material on the live feed. The company and commission staff left the session with the stated next steps of filing the updated 2025 master list and continuing the regular reporting required by the tracker tariff.

Less critical details: attendees asked about material lifespans, the feasibility of large-diameter plastic pipe and the operational reasons behind upsizing; Enbridge said 16-inch installations are generally steel and that moving between plastic and steel introduces additional costs and construction complexity. Commission and division staff asked technical and prudence questions throughout the session.