![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Data Quality Information
Attribute Accuracy
Data element edits prevent invalid data from being entered into CERCLIS. Recent data are verified via various reports so that at the end of the month there is a high degree of confidence that the data are transferred correctly. Overall, the data are probably 95% accurately transferred.
Logical Consistency Report
Cross element edits prevent invalid combinations of data from being transferred from CERCLIS into Envirofacts. The only data that are found in more than one file are in the record keys which are not updatable.
Completeness Report
Only certain core data are required to be entered into CERCLIS. Edits at data entry time ensure that these data are entered. Other data, such as actual completion dates, are not entered when the record is first built because the data cannot be known.
Positional Accuracy
The National Priority List (NPL) sites do have latitude and longitude data accurate to within 30 meters and, in some cases, in the sub-meter range.
The latitude and longitude for other sites is the centroid of the ZIP code area for the ZIP code of the site's address.
Lineage
After Congress passed the Superfund Amendments and Reauthorization Act (SARA) in 1986, OERR began to develop a single, definitive data base system for information about abandoned/inactive hazardous waste sites. The result, CERCLIS II, contains data from CERCLIS I as well as databases that were tracking the Removal, Preremedial, and Enforcement programs.