RALEIGH — The gas company that serves Vance, Granville and Franklin counties has asked state regulators to approve a rate increase it says will add about $4 a month to the monthly bill of an average residential customer.

Dominion Energy Inc. filed the request with the N.C. Utilities Commission on Thursday, the same day a moratorium on rate increases that dated from 2019 expired.

The Richmond, Virginia, company acquired its North Carolina gas business in 2019 via a merger, and had agreed to the two-year moratorium to secure the state’s approval of the deal.

It now notes that the rate increase would actually be the first since 2016 for the customers of what was once the Public Service Co. of North Carolina, PSNC for short.

A Utilities Commission decision that year allowed PSNC and its then-corporate-parent, South Carolina SCANA Corp., to earn a return on its equity of 7.53%. Over time, its actual return has dropped to 5.32%.

Dominion Energy is now asking the commission to let it get a return on equity of 10.25%, a level it argues is necessary to give investors reason to buy its stock.

Such an increase would translate into $53.1 million in additional annual revenue, with $32.9 million of that to come from residential customers.

Company officials say they’ve put money back into their network of natural-gas pipelines, which along with the greater Triangle also serves customers in a group of western North Carolina counties that run from the mountains to Gastonia, and in another, smaller group that includes communities in the Interstate 77 corridor like Statesville and Concord.

Locally, its investments include the so-called “T-30 pipeline,” which skirts the east side of Raleigh along a 38-mile run from Clayton in Wake County to Franklinton in Franklin County.

Opening the new transmission line allowed it to reduce the operating pressure of another, older one, which improved safety and reduced the company’s operating costs, Shaun Randall, general manager for gas operations, told the Utilities Commission in a statement Dominion filed in support of its rate-increase application.

Randall said the building the T-30 pipeline, which is 20 inches wide, was “necessary to support regional growth and improve system reliability.” The $170 million project also provides capacity to supply natural gas to an additional 50,000 or more homes in “the largest and fastest-growing area of PSNC’s territory.”

Another company official, Director for Regulation Bryon Hinson, told the Utilities Commission the rate increases on paper would nominally represent a 9.26% increase over current revenues, but they net out to 7.27% of planned rebates of savings from federal and state tax cuts.

Hinson attached to his statement tables showing that for residential customers, Dominion would implement the rate increase by raising what it charges for actual gas consumption. A $10 a month “facilities charge” would stay the same.

Contact Ray Gronberg at rgronberg@hendersondispatch.com or by phone at 252-436-2850.

Contact Ray Gronberg at rgronberg@hendersondispatch.com or by phone at 252-436-2850.