Water Quality Index Assessment of the Headwater System Feeding the Lock Haven Public Drinking Water Supply

Surface water within the McElhattan Creek watershed in central Pennsylvania serves as the source of drinking water for 19,590 subscribers of the Central Clinton County Water Filtration Plant in Pennsylvania. 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. The primary objective of this study was to determine total organic carbon concentration, due to its 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, PO4-P, Cl-, and SO4-2. 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. The highest observed NO3-N values were less than 1/10 the MCL for drinking water; other parameters showed results that were also below those suggested by the US EPA. 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). The toxicity levels, in terms of heavy metals, in sediment samples collected were also less than the probable effect levels published by the US EPA (Ingersoll et al., 2000)