Measuring the Impact of Source Reduction
From 1991 to 2023, more than 24,000 industrial facilities reported implementing 480,000 unique source reduction activities to TRI. During this time, TRI chemical releases declined steadily. EPA looked closer at the data to find out how facilities achieved this reduction in releases and how much of the decrease could be attributed to source reduction.
To quantify the contribution of source reduction projects to reduced chemical releases, EPA conducted an analysis that accounted for other factors that could have influenced releases. For example, releases can decrease due to changes in the types and quantities of goods produced, outsourcing of manufacturing, and passage of pollution regulations. Results of the analysis show that the average source reduction project caused a 16% decrease in chemical releases in the year the project is implemented, with reductions continuing in subsequent years. To learn more about the methodology and results of this analysis, see the TRI Measuring the Impact of Source Reduction page.
Looking more closely at the five source reduction categories reported to TRI shows that the effects of a project vary based on the type of source reduction implemented. The source reduction categories resulting in the largest first-year decreases in releases were:
- Material Substitutions and Modifications with declines of 19%.
- Product Modifications with declines of 13%.
The analysis also estimated the total impact of these source reduction projects on the overall quantity of chemical releases reported to TRI. The graph below shows this cumulative effect of source reduction. The solid green line shows actual releases reported to TRI, and the dashed blue line shows an estimate of what releases would have been if no facilities implemented source reduction. EPA estimates that TRI source reduction activities eliminated 23 billion pounds of chemical releases between 1991 and 2023.
Although these estimates have important limitations, they indicate that source reduction has been an effective tool for reducing chemical releases at industrial facilities that report to the TRI Program.
This page was published in August 2025 and uses the 2023 TRI National Analysis dataset made public in TRI Explorer in October 2024.