A Bozeman senator's bill would require drilling companies make public what chemicals they use to unleash natural gas trapped thousands of feet underground, tapping into a national debate over the controversial process of "fracking" and the effect it has on groundwater.

Proponents of http://laws.leg.mt.gov/laws11/LAW0203W$BSRV.ActionQuery?P_BLTP_BILL_TYP_CD=SB&P_BILL_NO=86&P_BILL_DFT_NO=&P_CHPT_NO=&Z_ACTION=Find&P_SBJ_DESCR=&P_SBJT_SBJ_CD=&P_LST_NM1=Wittich%2C+Art+&P_ENTY_ID_SEQ=8060"> Senate Bill 86, introduced by Sen. Bob Hawks, say the bill would shed much needed light onto hydraulic fracturing, which involves the injection of water, sand and chemicals at high pressure into the ground in order to extract natural gas.

As it stands now, state and federal law does not require energy companies to disclose the recipes, and fracking is exempt from the federal Clean Water Act.

However, a growing number of public health advocates and regulators across the country say the public should have more oversight and say into what is being injected deep into the Earth.

Hawks, a retired optometrist, said he was particularly concerned with getting the information to doctors in case the chemicals make people sick.

"I'm not requiring they divulge any proprietary information about how they combine these chemicals," said Hawks, a Democrat. "I'm only requiring them to notify surrounding landowners that they are going to drill, they are going to use fracturing chemicals. And they need to work out some kind of coordination with the medical community for getting access to that information very quickly."

In the past, energy companies have been reluctant to disclose exactly what chemicals they use in the process, saying their secret recipes are trade secrets worth millions of dollars. But a spokesman for Devon Energy, an oil and gas company with wells in Montana, said the industry is not opposed to disclosing chemicals but "the process needs to be timely so it doesn't impede the progress of completing the well and bringing on production."

Chip Minty also disputed the idea that fracking can contaminate groundwater, arguing that the fractures occur thousands of feet below aquifers and that more than 99 percent of fracking fluid is made up of water and sand. A http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/wells_coalbedmethanestudy.cfm"> 2004 study by the Environmental Protection Agency also found that fracking should not affect groundwater.

But not everyone agrees with that assessment.

An http://www.propublica.org/series/buried-secrets-gas-drillings-environmental-threat"> independent investigation by ProPublica has found water is more likely to be contaminated near drill sights. Much of the investigation centered on Pavillion, Wyo., where extensive gas drilling was followed by a federal government warning for residents to not drink the water there (the EPA did not blame drilling on the water contamination.)

The Environmental Protection Agency http://water.epa.gov/type/groundwater/uic/class2/hydraulicfracturing/"> is studying the chemicals that drilling companies use, and the U.S. Department of Interior is considering its own rules to require drilling companies disclose what chemicals they are using on public lands.

The latter action drew rebuke from the 32 members of Congress who comprise the Natural Gas Caucus, of which Rep. Denny Rehberg, R-Mont., is a member.

"The vast majority of scientific evidence shows hydraulic fracturing to be safe, less resource-intensive for the environment than traditional methods, and properly managed and regulated at the state level," the lawmakers wrote in a letter to Interior Secretary Ken Salazar. "Consequently, hastily proposed regulatory burdens on natural gas will increase energy costs for consumers, suppress job creation in a promising energy sector, and hinder our nation's ability to become more energy independent."

However, Montana's neighbor to the south has already made companies disclose. Wyoming enacted the rule in September after years of speculation by landowners that fracking was contaminating their groundwater.

Among those whose are expected to testify in favor of Hawks' bill Friday is his brother, Paul Hawks, who ranches near Melville.

Paul Hawks said he has leased mineral rights to a drilling company and thinks he has a right to know what chemicals they use if they go ahead with drilling.

"It's a matter of establishing a good business relationship with drilling companies," Paul Hawks said.

Sen. Hawks' bill will be heard in the http://leg.mt.gov/css/Committees/Session/Minutes/11minwrittenaudio.asp?Chamber=Senate#NAS"> Senate Natural Resources Committee on Friday.

Daniel Person can be reached at dperson@dailychronicle.com or 582-2665.