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| TRI Comparative Analysis Tool - Water Data Sources |  |
This TRI Comparative Analysis tool allows users to compare records from the Toxics Release Inventory (TRI) with those from ICIS-National Pollutant Discharge Elimination System (ICIS-NPDES) data system; ICIS-NPDES is a modernized data system containing NPDES data for more than one half of the states. The TRI Comparative Analysis tool was originally developed to identify data quality problems in these data systems as well as potential compliance issues under the Clean Water Act (CWA) and the Emergency Planning and Community Right-to-Know Act programs.
For example, the CWA prohibits the discharge of "pollutants" from a "point source" into a "water of the United States" without a NPDES permit. Query 1 allows users to compare TRI facilities that report to TRI greater than zero pounds of releases of toxic chemicals to water with the facilities' corresponding NPDES permit information to see if there are potential inconsistencies between TRI reporting and NPDES permits as reflected in ICIS-NPDES. To identify potential noncompliance with TRI reporting requirements, Query 2 of this tool allows users to review facilities with NPDES permits against corresponding TRI records.
It is important to note that that the links between TRI and NPDES permitted facilities are based on name and address matching algorithms applied by EPA's Facility Registry System (FRS); there may be inaccuracies in linking facilities that are in these two data systems. Accordingly, users can verify the absence of corresponding records between TRI and ICIS-NDPES using the Facility Finder button 
. In those instances where a user finds a potential TRI-ICIS-NPDES match through Facility Finder that was not reflected in this tool's results report, the user is encouraged to use the "report error" feature on the relevant ECHO Detailed Facility Report to alert the Agency to the potential missing integration between the TRI and ICIS-NPDES databases.
You can also search through ICIS-NPDES facility, permit, discharge monitoring report, and pollutant loading data with the DMR Pollutant Loading Tool. This tool allows users to compare these data against matching TRI data. You can also start your search on TRI facility and pollutant loading data and then compare the results with ICIS-NPDES data. This tool is particularly helpful if you want to compare the annual estimates of a pollutant releases for a particular pollutant at a particular facility (one estimate based on ICIS-NPDES data and other based on TRI data).
The TRI Comparative Analysis tool is an ECHO partner site developed by the TRI Program in EPA's Office of Environmental Information. Questions and comments about this tool should be directed to ECHO Support.
ICIS-NPDES information for TRI facilities reporting >0 pounds of direct water discharges
TRI information associated with NPDES permits