President-elect Donald Trump says he plans to nominate Oklahoma's Attorney General Scott Pruitt to lead the Environmental Protection Agency as its administrator.

Pruitt has been a critic of the EPA. And Trump has positioned himself as no friend of regulation. He campaigned on the idea of scrapping regulations across the economy. That includes rules that many say have constituted a "war on coal" as a fuel for electric power generation.

All of this lends fodder for speculation. But first, some background.

Scott Pruitt, EPA Administrator-designate.Most of the air and water emission rules affecting power plants stem from the Clean Air Act and the Clean Water Act. Both were passed by Congress decades ago. Both have been subjected to lots of litigation over the years with rulings handed down from as high up as the Supreme Court.

In short, many of the rules have been written, debated, modified, litigated, revised again, and set in place so that they are firmly entrenched pieces of regulation. What's more, billions of dollars worth of emission control equipment has been installed at power plants to comply with the rules.

True enough, some administrations have been more aggressive than others in writing rules and enforcing existing regulations.

The George W. Bush EPA was seen by some as taking a less active role in writing rules. Environmental groups were only to happy to sue. In some instances, court orders that stemmed from Bush-era lawsuits compelled the Obama EPA to write rules.

The EPA, first under Lisa Jackson and now under Gina McCarthy, may have been aggressive in what they proposed and ultimately put in place. But in many instances, court orders compelled the agency to get out its paper and pen and write some rules.

For many, then, the Obama administration's "war on coal" is the fruit (rotten or otherwise) of lawsuits brought during the Bush years. And if anything is true about the EPA, it is a lightning rod for lawsuits. If an environmental group isn't suing, then an industry group (and even the Oklahoma Attorney General himself!) is in court.

Enough background. Let's speculate.

1. As EPA administrator, what do you roll back or repeal? Because most of the rules stem from the Clean Air Act and the Clean Water Act, an act of Congress (literally) might be the only way to make deep and lasting changes. How tough would it be to amend or rewrite either Act? Very.

Not only that, but citizen lawsuits are likely to meet every change that is proposed. Groups like the Environmental Defense Fund are not going away. These groups already are frequent litigants against EPA and likely will remain so. The next four years could see existing rules remaining in place while a tsunami of lawsuits make their way through the courts.

2. What about natural gas? Fracking has made low-cost natural gas widely available in the U.S. Not so long ago, natural gas prices were wildly volatile, making the fuel an unreliable choice for baseload power generation. Love it or hate it, fracking has made huge reserves of domestic U.S. natural gas economically viable.

Then too, natural gas presents a smaller environmental footprint compared to coal (although it still is a fossil fuel and a source of carbon emissions). And technology advances mean that gas-fired generation is a reliable and competitive fuel for power generation.

So roll back environmental rules that impact coal generation if you want to. Natural gas remains an economically viable fuel. Market forces may have the upper hand on this one.

3. Let's fact it, most utilities long ago committed to the idea of championing clean air and water. Most embrace energy efficiency (light bulbs, insulation) as a fifth generating fuel in addition to coal, nuclear, natural gas, and renewables.

What's more, upstarts like Elon Musk's SolarCity have brought solar rooftop technology to homes across the country. In doing so, Musk and others are challenging the traditional utility business model. Few, if any, utilities have any intention of willfully shutting off their emission control equipment and returning to the days of billowing black smoke.

Utilities have invested heavily in clean air and water, not to mention renewables and energy efficiency programs. That isn't going to change.

Robynn Andracsek, P.E., an environmental engineer and air quality specialist with Burns & McDonnell, points out that a lot of inertia exists in the system. That inertia is likely sufficient to keep environmental rules and enforcement largely as they are.

But Obama's Clean Power Plan? Dead. Further work on greenhouse gas emission rules? Doubtful. Continued defense of legal challenges to existing and pending EPA rules? Shelved.

And what about new rules to squeeze, say, that extra tenth of a percent of clean air?

Well, as they say in New York: fuhgeddaboudit.