The enhanced trickle-down model was applied to White Oak Run, a second-order stream, located in the Shenandoah National Park, Virginia, on the western slope of the Blue Ridge Mountains. Calibration of the model was performed using five years of field data collected at the site. Simulation results indicated that 30% of the incoming sulfate is being retained in the upper soil horizons and 15% is being retained in the unsaturated zone compartment. The alkalinity concentrations in the stream exhibited a seasonal variation with increased values during low flow and decreased values during high flow. Ion exchange processes in the upper soil neutralized 50% of the incoming acidity and weathering processes accounted for 20% of the neutralization in the unsaturated zone. Long term (100 year duration) simulations indicated the White Oak Run is a delayed response system primarily due to high sulfate sorption capacity. This has significant policy implications because reductions in deposition levels will not result in a quick recovery of the system.