The Public Service Commission of Utah heard competing technical testimony on how Enbridge Gas Utah assigns distribution costs and sets large-customer (TSL/GS) rates in Docket 25-057-06. Intervenors proposed replacing parts of the company's allocator with measures tied to winter or excess peak demand; commissioners asked how those changes would affect customer classes.

Dr. Lance Darshana Kaufman, testifying for Nucor Steel Utah, recommended replacing "the annual throughput component of the F-2-30 allocator with winter throughput," arguing Enbridge sizes mains and stations to meet a design day defined as an average winter temperature of minus 5 degrees Fahrenheit and that winter throughput better aligns costs with design-day demand. Kaufman also proposed a low-pressure surcharge for a small subset of TSL customers, changes to TSL block volumetric rates to reflect economies of scale, moving the TSL basic service fee to the company's estimated cost, and increasing the TSL demand charge to better reflect allocated demand costs. Kaufman said, "No witnesses in this case dispute the accuracy of my cost analysis on this issue," and urged the commission to implement the changes without delay.

Bruce Richard Oliver, for the American Natural Gas Council, urged the commission to scrutinize Enbridge's classifications and allocation factors, arguing some are "unrelated to the manner in which costs in a specific account are either classified or allocated." Oliver called for clearer, printed rate-design exhibits rather than buried spreadsheets and recommended focusing a working group on how to restructure the dominant GS class so the commission can target reforms.

Matthew Paul Smith, for the Federal Executive Agencies, said the company's current peak-and-average allocator "results in a double counting of demand" for large-diameter mains and offered an "excess design-day demand and throughput allocator" that replaces the peak component with the difference between peak and average. Under cross-examination, Smith agreed that applying his allocator as shown in rebuttal charts would, approximately, realign about $14 million of cost to the GS class compared with Enbridge's filed approach; he emphasized the change corrects allocations to align with cost causation rather than being a simple dollar-for-dollar shift.

Commissioners pressed witnesses on trade-offs. Commissioner Harvey used a dump-truck analogy to probe who should pay for capacity and pressed witnesses on whether and how gradualism or policy choices should moderate cost-causation results to avoid rate shock. Witnesses agreed that allocation changes can create sizable class impacts and suggested mitigation could be handled in the revenue-spread and rate-design phase if the commission adopts new allocators.

Procedurally, the commission admitted the witnesses' prefiled direct, rebuttal and surrebuttal testimony and exhibits for Kaufman, Oliver and Smith without objection and declined to require post-hearing briefs, saying the record was sufficient. The commission asked for an issues matrix from the company by the end of the week and from interveners/respondents the following Wednesday and noted it expects to issue an order by December 27.

The case centers on technical allocation methodology and the commission's balancing of cost causation, rate continuity, and customer impacts; any change to allocators or TSL-specific charges could materially alter which customer classes bear distribution costs.