They're saying that, you know, on average, it's at least going to be two cents per gallon and, in some instances, it's going to be as much as nine cents because they estimate that it will cost $10 billion dollars to do the upgrades that they will need for that.

JUDY WOODRUFF:And, Juliet Eilperin, it is my understanding also the administration is saying that this will save money in terms of public health costs.

JULIET EILPERIN:Absolutely.

When you do the math, what they are saying is because these tailpipe emissions, nitrogen oxide, soot, things like that, volatile organic compounds, those can contribute both to smog and in the case of soot also to heart and lung disease.

So overall they're saying that, by 2030, the benefits will be between $8 billion and $23 billion dollars, outweighing the cost of compliance.

JUDY WOODRUFF:And just to clarify, Juliet, the argument here is that it's not that the sulfur itself in gasoline is the problem; it's what it does to the catalytic converter, the emissions device.

JULIET EILPERIN:Right. That's what is very interesting.

Basically, the more sulfur you have, the less effective the catalytic converter is. So, as a result, you have greater tailpipe emissions. And it is these emission, the volatile organic compounds, the nitrogen oxide, the carbon monoxide and the soot, that are what actually affects the air that we breathe and what it does to our heart and lungs.

JUDY WOODRUFF:Now, let's broaden this out, because at the same time the administration issued these proposals today, meanwhile, everybody is out there waiting for two other sets of, I guess, regulations or proposals from the administration.

One has to do with of course the Keystone oil pipeline.

JULIET EILPERIN:Right.

JUDY WOODRUFF:The other one are the greenhouse gas emissions for power plants.

JULIET EILPERIN:Right.

JUDY WOODRUFF:How does this factor in to those sets of regulations which are—we're waiting to hear now?

JULIET EILPERIN:Right.

I think it's all part of the broader Obama second-term agenda. And so what they are obviously saying is, they are moving ahead with this, this one. They have made it more cost-effective and they're saying it is a huge public benefit. At the same time, the environmentalists are looking at all these other fronts. And they're saying, for example, on the Keystone pipeline, that they are saying that, you know, yes, this will supply oil from Canada, but it's basically a referendum on what Obama will do on climate.

So that is a very difficult decision that he will be making this summer. It is unclear what he is going to do, whether he is going to disappoint the community. And what also looking at is whether they will regulate both greenhouse gas emissions from new power plants. That's something that should be finalized soon, but may not be. Or are they going to regulate existing power plants in the future?

JUDY WOODRUFF:So how do you see the calculus here in announcing this while these others are pending?

JULIET EILPERIN:Well, certainly, this is something that was broadly welcomed by the environmental community.

And it's really going—it's going to be, with one possible exception, one of the most significant air policy rules that the Obama administration does. But it's not going to make up for, for example, if they decide to allow the Keystone pipeline to go through. That and regulating existing power plants, those are the two biggest litmus tests for the Obama administration this term.

JUDY WOODRUFF:And just quickly, these are proposals, but is it expected that they will take effect?

JULIET EILPERIN:Yes. While they haven't outlined the timeline—for example, the rules that were unveiled today could take a few months.

These are proposed rules, but there is an expectation that, since they have already done some negotiations, the final rule that will be adopted in a matter of months will be very similar to what we are seeing today.

JUDY WOODRUFF:Juliet Eilperin, the Washington Post, thank you very much.

JULIET EILPERIN:Thank you so much.