Pipelines Water Quality (copy)

A "No Pipeline" sign is posted next to a property line marker only a few feet from the center line of the route of the Atlantic Coast Pipeline on June 6, 2017, in Bolar, Va. 

South Carolina’s next multibillion-dollar disaster could be just around the corner.

That’s especially concerning given that the state is still reeling from the $9 billion fallout from abandoning two nuclear reactors that were under construction at the V.C. Summer site. SCE&G and Santee Cooper customers could end up paying for that debacle for decades.

Dominion Energy, which has submitted several offers to buy SCE&G parent company SCANA, is building a natural gas pipeline from Pennsylvania to southeastern North Carolina. So far, that project is years behind schedule and at least $1.5 billion over budget.

Sounds familiar.

Dominion’s Atlantic Coast Pipeline won’t likely have much of anything to do with electric ratepayers in South Carolina — unless Dominion seals a deal to buy SCANA.

Even then, Dominion executives have said they’re not interested in expanding the Atlantic Coast Pipeline into South Carolina, where they already own hundreds of miles of gas lines. But it would become much easier for them to get regulatory approval to do so if they owned a power company in the state.

And as The Post and Courier’s Andrew Brown reported last week, South Carolina law doesn’t give the state Public Service Commission, which regulates for-profit utilities, any authority over new pipeline projects until they’re already built.

In other words, Dominion could extend the Atlantic Coast Pipeline into South Carolina at tremendous cost, and the PSC wouldn’t get to weigh in until Dominion asks to raise customer rates to pay for it all.

It could be the V.C. Summer disaster all over again.

Dominion’s most recent offer to buy SCANA is imperfect to say the least. The company is willing to give SCE&G ratepayers a small discount in exchange for their agreeing to continue paying off a portion of the nuclear debt for the foreseeable future.

It is unclear, however, that SCE&G customers wouldn’t be better off paying the rates they do now — a 15 percent cut over the peak nuclear-related rate — while the utility refinances its nuclear debt to lower its interest costs over the next several years.

Even if the Dominion deal falls through, the state Legislature must make it a top priority to give the PSC regulatory oversight over new pipelines before they get built. Other power utilities have expressed an interest in pipeline projects in South Carolina, so ratepayers are likely to need protection eventually.

Over the longer term, South Carolina lawmakers should enact reforms to make the state’s power utilities more competitive, with less monopoly power. Doing so would give customers a better deal with less need for heavy-handed regulation.

South Carolina regulators could announce as early as Friday whether they will let the Dominion deal move forward.

The only consideration should be the ratepayers’ best interest — both now and well into the future.