DENTON, Texas (AP) - Gov. Rick Perry says Texas continues to be the nation's oil and gas leader while protecting the environment.

Starting next summer, drillers must publicly disclose the chemicals they use when extracting oil and gas from dense rock formations.

Texas was the first state to pass such a law when Perry signed the bill last month.

On Friday he did a ceremonial signing of that bill and two others at Peterbilt Motors Co. in Denton, 40 miles northwest of Dallas.

One bill provides grants for companies to switch their heavy vehicles from diesel fuel to natural gas.

Another bill provides funding for additional air monitoring in the Barnett Shale. It's a 5,000-square-mile underground rock formation packed with natural gas spanning about two dozen North Texas counties.

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