A COMPREHENSIVE ASSESSMENT OF THREE HIGH-QUALITY HEADWATER STREAMS IN THE CHESAPEAKE BAY WATERSHED

The development of unconventional oil and gas (UOG) resources from the Marcellus and Utica shales underlying much of central and western PA has proceeded rapidly in recent years. These headwaters are critical habitat for brook trout, among many other important species. However, little is known about the impact of UOG activity on the small streams within the headwaters of the Chesapeake Bay watershed. We have begun a detailed study of the baseline conditions of three high-quality streams in Tioga State Forest, Tioga County Pennsylvania, located near planned UOG leases, prior to drilling and infrastructure development. This study intends to characterize the baseline geochemistry of these streams and to determine the composition of their microbial communities, periphyton, benthic macroinvertebrates, and fish assemblages. Data sondes have been deployed to record pH, Specific Conductance, Total Suspended Solids, Temperature, Dissolved Oxygen, and Turbidity at 15 minute intervals to provide baseline physico-chemical characteristics of the streams. We collected quarterly samples for periphyton and benthic macroinvertebrates assemblages, along with annual collections of fish assemblages. Water and sediment samples were collected at 2 discrete time points to assess the trace organic and inorganic geochemistry and microbial community composition. These streams are characterized by low specific conductance (<100 µS/cm), with most trace elements in the low ppb range. Periphyton and benthic macroinvertebrates assemblages indicated all streams and reaches were of high-quality (i.e., a high number of sensitive taxa, high integrated benthic macroinvertebrate score). Fish surveys showed most reaches had native brook trout populations. Analysis of the microbial communities is ongoing, and will provide baseline data for the composition of these communities present prior to UOG development. These data will provide a robust, comprehensive assessment of the pre-development conditions present in a high-quality stream, and allow for the rapid determination of impacts from future UOG development.