Companion bills were introduced yesterday in both the U.S. House and Senate to repeal the exemption for hydraulic fracturing in the Safe Drinking Water Act and to require the disclosure of chemical constituents used in frac fluids (the "FRAC ACT" - Fracturing Responsibility and Awareness of Chemicals Act). More information can be found here. Copies of the legislation can be found here (Senate - S. 1215) and here (House - H.R. 2766).
[Update: For more, see here (article from WSJ, subscription required); and here (from the Wayne Independent).]