Federal spill prevention control and countermeasure (SPCC) regulation has been at the forefront of recent U.S. EPA regulatory initiatives (see here, e.g.). The U.S. House Committee on Energy and Commerce is working on legislation that suggests we may see even more changes to the SPCC Rule in the near future. See here (linking to H.R. 5626, known as the "Blowout Prevention Act of 2010" and - as drafted today - which would apply to certain non-marginal onshore production wells).