An energy boom is touching off sharp debates over the increased emergence of natural gas companies and their 14-story drilling rigs, which are going up in communities around the country, sometimes in the middle of neighborhoods.

Much of the debate is about the volatile issue of hydraulic fracturing. That's a form of gas drilling.

There is a new online registry of chemicals used in the process called “fracking.” The website fracfocus.org is a venture of the Ground Water Protection Council and the Interstate Oil and Gas Compact Commission.