POINT-SOURCE CONTRIBUTION OF WASTEWATER TREATMENT PLANTS IN INCREASING THE NUTRIENT PROFILES OF THE WATERWAYS IN THE LOWER GENESEE RIVER WATERSHED AS FUNCTION OF SEASONALITY

A major concern in the Great Lakes Regions is the potential eutrophication of water bodies due to elevated nutrients, phosphorus and nitrogen, which are carried by streams and rivers. Higher concentrations of phosphorus and nitrogen come from both non-point sources like fertilizer runoff and point-sources such as wastewater treatment plants (WWTPs), which together contribute enormously to the rise of the trophic levels of waterways. The present long-term field-study investigated the relative nutrient concentrations of several upstream and downstream locations of two WWTPs in the lower Genesee River Watershed as a function of seasonality. The first WWTP (WWTP#1) is located along the bank of the Genesee River and discharges its effluents directly into the river; the second WWTP (WWTP#2) discharges its effluents to a feedwater stream, which meets with Black Creek, a tributary of the Genesee River. Both factors, i) sites (upstream vs downstream of WWTPs) and ii) seasons (summer and fall 2016; winter, spring, and summer 2017) showed significant variations in nitrate (p<0.001) and total phosphorus (TP) (p<0.05) profiles. Both WWTPs significantly increased the nitrate levels downstream in all five seasons; however, between the two, WWTP#2 (p<0.0001) showed a more pronounced effect than WWTP#1 (p<0.02). Ammonium and nitrite were also measured to determine the other N-species; the nitrite concentrations were below the detection limit and the ammonium concentrations remained well below the USEPA permissible limit (2 mg/L) at most locations. Interestingly, the TP levels in all sampling locations were many times higher than the USEPA permissible level of 0.02 mg/L in freshwater bodies, indicating substantial contribution of non-point sources along with these respected point-sources. However, both WWTPs significantly (p<0.0001 in WWTP#2 and p<0.1 in WWTP#1) increased the TP levels even further, establishing the need of an additional N and P removal process from the WWTP effluents. Our group is presently investigating the potential of a sustainable, zero-waste N and P removal system using waste by products from a local drinking water treatment facility and native plant species of Western New York.