EPA captures (or "freezes") aggregated state data yearly. These frozen data sets are used in several places on EPA's website, including portions of the Enforcement and Compliance History Online (ECHO) website. Frozen data are used in the Comparative Maps and State Dashboards.

Several states have indicated that at the time the data were frozen, that errors existed. States that identified problems with the data were asked to send either a data file with corrected information, or a link to a state website that explained data errors or corrections.

State comments on frozen data are available through the links below, organized by the submission year. Additional data quality information which is not specific to the frozen data is available through the known data problems and State Review Framework Recommendations Tracker.