Section 2: Regulating Chemical Releases to Water

DMR Data for Facilities that Report to TRI

While the data collected by TRI and DMRs differ in important ways, using both TRI and DMR data provides a more complete understanding of pollutants being discharged into surface waters. As shown in the pie chart, 6% of the facilities that submit DMRs also report to TRI. The bar graph focuses on this subset of facilities that report to TRI and submit DMRs. Through their DMRs, these facilities provide information on many other parameters that may impact water quality, such as the temperature, or biochemical or chemical oxygen demand (i.e., organic enrichment) of their water discharges.

There are several considerations to keep in mind when comparing TRI and DMR data:

• Reporting facilities: Permitting authorities, such as the states, are not required to report DMR measurements for smaller, non-major, facilities. In addition, facilities may be exempt from reporting to TRI if they are not in a covered industry sector or do not meet the threshold number of employees.
• Regulated chemicals: In the DMR data, facilities only report discharges of pollutants that the NPDES permit requires them to monitor. The pollutants with monitoring requirements in a facility’s NPDES permit are at the discretion of the permitting authority. Other pollutants may be discharged but are not reported on DMRs. TRI facilities only report chemicals on the TRI list, and may be exempt from reporting releases of chemicals if they do not meet activity thresholds.

DMR and TRI data can be explored together using the DMR Pollutant Loading Tool. This tool provides information on which facilities are discharging pollutants to surface water, what pollutants and how much of each they are discharging, and where these discharges occur. Explore the tool to learn more about discharges of pollutants to surface waters in your community.

Jump to a DMR Loading Tool Search
Data Explorer	EZ Search
Advanced Search	TRI Search
Facility Search	Top Industrial Dischargers