IMPACTS ON NUTRIENTS AND ORGANIC CONTENT ON WATER QUALITY INDEX OF THE HEADWATER SYSTEM FEEDING THE LOCK HAVEN PUBLIC DRINKING WATER SUPPLY, CLINTON COUNTY, PA

Surface water within the McElhattan Creek watershed in central Pennsylvania serves as the source of drinking water for approximately 19,590 subscribers of the Central Clinton County Water Filtration Plant. The purpose of this study was to determine the water quality index for the source water within the system. Grab samples of water were collected at 5 locations on a monthly basis from April to September, 2017. HACH field and laboratory equipment were used to collect, process, and analyze data to evaluate baseline water quality. Data collected throughout 2016 served as a background dataset for understanding seasonal trends throughout the summer months, and provided insights into the changes in the system from one year to another. The primary objective of this study was to determine nutrient concentrations, due to their importance for the final outcome of the treatment process. Field parameters included temperature, pH, conductance, TDS, and DO. Additional lab analysis yielded results for COD, BOD, NH₃-N, NO₃-N, NO₂-N, and total phosphorous. Water Quality Index (WQI) was calculated following the methods developed by Vicente et al. (2009). The WQI values were found to be excellent. The WQI values were relatively similar between each of the 5 study locations through the duration of the study period. Throughout the course of the study period, none of the parameters tested had values that warranted alarm when compared to the US EPA’s primary drinking water standards. In general, nutrient concentrations measured in 2017 were higher than those measured in 2016. This increase led to concentrations which exceeded natural background concentrations during the summer months, but still were orders of magnitude less than the EPA’s maximum contaminant levels (MCLs). On average, the values of nutrients, such as NH₃-N and NO₃-N, were below or equivalent to the natural background levels suggested by the USGS literature (U.S. Geological Survey, 1999).