Water quality was assessed at series of sites in the Little Sewickley Creek, a state listed high quality stream that directly feeds the Ohio River. The goal of the study is to determine the impact of large scale disturbance in the watershed (golf course construction) on water quality parameters and the abudnance of an important riparian indicator species, the Louisiana Waterthrush (Parkesia motacilla). Water samples were collected approximately bi-weekly beginning in late April 2016 and continuing throughout the subsequent 18 months. A 100 mL subsample aliquot of well-mixed sample was filtered through a weighted standard glass-fiber and the residue retained on the filter was dried to a constant weight at 103 to 105˚C. The increase in weight of the filter represents the total suspended solids using the following equation (Eaton and Franson, 2005). An additional 50 mL subsample was filtered through 0.45 µm membrane filter for elemental analysis using an ICP spectrometer as well as dissolved phosphate and nitrate using a colorimetric assay.
Results/Conclusions
Overall, total suspended solids were relatively low in the main channel, averaging approximately 3 mg/L TSS. Tributaries and springs entering the creek carried slightly higher suspended solids, averaging 42.1 mg/L TSS. Total Suspended Solid load was significantly correlated with the amount of precipitation in the previous 48 hours within the watershed. Dissolved phosphate concentrations averages less than 20 ug/L across all sampling dates. Total dissolved Ca averaged 28 ppm and total dissolved Mg averaged 7 ppm. Overall water quality for this high quality stream remains exemplary. Results throughout the watershed will be analyzed.