Watershed Conservation Plan - Destination Erie

Figure 5.16. Sulfate and nitrate deposition south of the lower Great Lakes since 1994 (from Lynch
et al. 2005a).
intervals from 1973–1993 in Elk, Walnut, and Sixteenmile Creeks (Figure 5.17) indicate little change in Elk
and Walnut Creeks, but increasing concentrations over time in Sixteenmile Creek. It is unknown whether the
increasing levels observed in this stream were due to atmospheric loads or increases from other sources of
nitrate within the watershed (e.g., nitrogen fertilizer use or discharges from the Welch