EPA carefully considered the issue of state delegation, particularly in light of the leadership and experience of several states in developing greenhouse gas (GHG) reporting and reduction programs, and also in the context of the pressing need for a nationwide reporting program and the strong emphasis placed in the vast majority of the rule comments for EPA to ensure that data collection begins on January 1, 2010 and that data are reported early in 2011. We determined that developing a program to delegate to states would take additional time and would not be available for 2010 reporting, and we also determined that a significant number of states would likely not request delegation, which would increase the complexity of assembling a consistent national data set. For these reasons, we determined that the most effective way to achieve nationwide GHG reporting of 2010 data was for reporters to submit data directly to EPA, as proposed. While EPA is not formally delegating rule implementation and enforcement to states, we are committed to working in partnership with states to address the issues related to the interaction between state and federal reporting programs.