WATER QUALITY MONITORING ALONG THE FOURMILE CREEK AND EIGHTMILE CREEK TRIBUTARIES TO LAKE ERIE, NORTHWESTERN PENNSYLVANIA

Fourmile Creek and Eightmile Creek are third-order streams located within the southeastern portion of the Lake Erie Watershed. Fourmile Creek flows through forested and urbanized areas and Eightmile Creek flows through forested and agricultural areas. Both watersheds are developed on a landscape controlled by the area’s late Pleistocene glacial history and by subsequent fluctuations in paleo-Lake Erie water levels. Growth in urbanization and agriculture in Erie County is likely causing changes in stream quality, detectable through monitoring of pH, temperature, conductivity, suspended sediments, total dissolved solids (TDS), and organic compounds.

The objectives of the research were to obtain baseline water-quality data from the trunk stream of each watershed and to identify the amounts and types of organic compounds present. To determine how these parameters varied seasonally, each stream had three equally-spaced sampling sites that were monitored on a weekly basis for salinity, conductivity, TDS, temperature, pH, flow velocity, and organic compounds.

From late summer to spring, the pH of Fourmile Creek ranged from 7.0-8.5 and the conductivity ranged from 274-747 µS. Salinity fluctuated from 130-360 ppm and TDS ranged from 180-500 ppm. Flow velocity fluctuated between 0.1 m/s and 0.88 m/s and stream temperature ranged from 24.5 to 9.9°C. The pH of Eightmile Creek ranged from 7.0-8.0 and the conductivity fluctuated from 88.6-658 µS. The salinity ranged from 40-310 ppm and TDS ranged from 50-420 ppm. Flow velocity varied from 0.02-1 m/s and stream temperature ranged from 23.5 to 10.5°C. Preliminary interpretation of the data showed that precipitation events in Erie County are accompanied by increased TDS, conductivity, salinity, and stream flow. Preliminary data also revealed that there was no correlation between precipitation and the amount of organic compounds at the mouths of the streams.