Jan. 20: This post has been corrected.

Congress isn’t going to regulate hydraulic fracturing any time soon. But the Department of Interior might. For starters, Interior is mulling whether it should require drilling companies to disclose the chemicals they use to frack wells drilled on public lands, and already the suggestion has earned Interior Secretary Ken Salazar an earful.

On January 5, a bipartisan group of 32 members of Congress, who belong to the Natural Gas Caucus, sent Salazar a letter imploring him to resist a hasty decision because more regulations would “increase energy costs for consumers, suppress job creation in a promising energy sector, and hinder our nation’s ability to become more energy independent.”

A week later, 46 House Democrats followed up by signing a letter to Salazar urging him to at least adopt the disclosure requirement because, as Rep. Maurice Hinchey, D-N.Y., said, “communities across America have seen their water contaminated by the chemicals used in the hydraulic fracturing process.”

"The public has a right to know what toxins might be going into the ground near their communities, and what might be leaking into their drinking water," said the letter, which was sent by the three initial sponsors of now-stalled legislation to regulate fracturing, Hinchey, Rep. Jared Polis, D-Colo., and Rep. Diana DeGette, D-Colo.

In the context of today’s roiling political and energy debates, it’s not at all clear who will win. But if money is an indicator, the anti-regulatory group has the upper hand.

A back-of-the-envelope analysis of campaign finance dollars contributed to the members of Congress who are speaking out on the issue shows that the Natural Gas Caucus received 19 times more money from the oil and gas industry between 2009 and 2010 than the group who signed Rep. Hinchey’s letter. According to data from Open Secrets, the 32 members against disclosure received $1,742,572. The average contribution from the oil and gas sector to individuals from that group was $54,455. Oklahoma Democrat Dan Boren, who co-chairs the caucus, personally received more than $202,000, including almost $15,000 from Chesapeake Energy, one of the largest natural gas producers in the United States.

By comparison, the Hinchey-DeGette-Polis group—which has 14 more people than the Natural Gas Caucus—received $91,212 from the industry. The average contribution to those members was $1,982, 1/27th the amount donated to members of the Natural Gas Caucus.

Requiring disclosure of the chemicals used to drill on federal lands would affect only a small proportion of gas wells drilled in the country each year—roughly 11 percent, by the Department of Interior’s estimates. In 2009, 19,000 new gas wells were drilled, adding to the 493,000 gas wells already producing in the United States. According to Hinchey’s office, disclosure on federal lands would set an important precedent, because that information would become part of the public record and, when combined with state-based disclosure rules, “would provide a great deal of useful information for those concerned with the risks these chemicals may pose.”

Traditionally, the exact recipes of chemicals used in the fracturing process have been kept secret by the companies to protect their competitive advantage, and the fracturing process itself is exempt from federal regulation under the Safe Drinking Water Act. The disclosure issue has become a rallying point against natural gas development in the United States because scientists have repeatedly said that they can’t thoroughly examine water contamination cases for links to drilling because they don’t know what to test for.

At least four states have already mandated some degree of disclosure of fracking chemicals: Wyoming, New York, Pennsylvania and Colorado. If federal lands are added to those states, then public disclosure of fracking chemicals would be required on roughly 40 percent of the gas wells in the United States. (It’s difficult to pinpoint the exact percentage because federal statistics don’t distinguish between oil and gas wells.)

The resistance to disclosure mandates on federal lands contradicts the public position of many of the oil and gas companies involved. Chesapeake Energy, the company that contributed so heavily to Rep. Boren, has repeatedly stated that it supports more transparency and believes the chemicals used in fracturing should be disclosed.

Nicholas Kusnetz contributed to this report.

Correction (Jan. 14): The original version of this story represented a statement made by Rep. Maurice Hinchey about the letter he sent to the Department of Interior as a quotation from the letter itself. The story has been revised to make the distinction between his statement, and the letter. Also, in the data table below, the contribution amounts for Rep. Boren and Rep. Murphy had been switched.

Campaign contributions from the oil and gas industry, 2009-2010

Source: Open Secrets

To the: Natural Gas Caucus

Campaign contributions from the oil and gas industry, 2009-2010

Source: Open Secrets

To the: Hinchey-DeGette-Polis group

Correction (Jan. 20): This story originally listed Rep. Donna Edwards as a democrat from Texas. She is, in fact, from Maryland.