Description: <div>Surface water chemistry is a direct indicator of the effects of acid rain on water bodies. Networks that monitor surface water chemistry over long time periods provide valuable information on aquatic ecosystem health and how water bodies respond to changes in acid-causing emissions. EPA oversees the Long-Term Monitoring (LTM) program, which tracks changes in surface water chemistry in response to changing air emissions and acid deposition.</div><div><br /></div><div>The goal of this long-term program is to track whether the Clean Air Act Amendments (CAAA) have been effective in reducing the acidity of surface waters in New England, the Adirondack Mountains, Appalachian Plateau, and the Central Appalachians and advance the science of air pollution impacts on water resources.</div><div><br /></div><div>This layer file lists the location of streams and lakes that are included in our annual trend analysis for our LTM program. </div><div><br /></div><div>LTM water quality data can be found at: <a href="https://doi.org/10.23719/1518546" target="_blank">https://doi.org/10.23719/1518546</a></div><div><br /></div><div>LTM website can be found at: <a href="https://www.epa.gov/airmarkets/monitoring-surface-water-chemistry" target="_blank">https://www.epa.gov/airmarkets/monitoring-surface-water-chemistry</a></div><div><br /></div>