Most efforts to quantify aquatic and terrestrial ecosystem damage from sulfur (S) and nitrogen (N) air pollution in the Adirondack Mountains and to examine more recent ecosystem recovery in response to emissions control have focused on lakewater chemistry.

E&S developed model applications to evaluate effects (and cross-cutting linkages) of multiple stressors on base cation supply

The critical load (CL) is the level of sustained atmospheric deposition of S, N, or acidity below which significant harm to sensitive ecosystems does not occur according to current scientific understanding. For the sensitive receptor stream water, the most commonly selected chemical indicator is acid neutralizing capacity (ANC).

The U.S. Forest Service is concerned about the current and future health of terrestrial and aquatic resources within the Blue Ridge Province of the Southern Appalachian Mountains in western North Carolina, eastern Tennessee, and South Carolina.