WHAT FLOWS THROUGH IT? MONITORING, IDENTIFYING AND TRACKING THE GEOCHEMICAL CHARACTERISTICS OF DEEP CREEK LAKE, WESTERN MARYLAND

Deep Creek Lake (DCL) is the largest purpose built inland body of water in the state of Maryland covering circa 6 miles² (16 km²) with 69 miles (111 km) of shoreline. DCL was constructed in 1920 by Youghiogheny Hydroelectric as a component of a hydroelectric project. The state of Maryland took charge of lake recreation activities in 1980, and purchased the land underlying the lake and buffer zone in 2000. DCL supports a diverse ecology and is extensively utilized for a wide variety of recreational activities and lake health is an integral component of a prosperous tourism economy located within rural Central Appalachia.

In 2018, a 12-month monitoring program was initiated to both characterize the general water quality of DCL and interpret the pattern of annual chemical and sediment flux into and out of the system. A land-use survey of the surrounding lake catchment recorded a range of anthropogenic activities, with great potential to significantly impact water quality and ecosystem health. These include an expanding housing and commercial presence, transport infrastructure, and recreational facilities footprints that increase runoff into the lake. The regional legacy of mining operations discharges acid mine drainage (AMD) and associated toxic minerals, metals, and metalloids. This study monitored fluxes in suspended and dissolved load with turbidity and electrical conductivity meters, and physical parameters of pH, Oxidation Reduction Potential (ORP), and temperature were also recorded. Nitrate (NO₃) and sulfate (SO₄) concentrations were analyzed to assess anthropogenic inputs into lake chemistry. Initial results have elucidated areas of significant runoff and chemical input from the surrounding watersheds. This study will generate baseline data to develop an understanding of geochemical thresholds that allow the DCL ecosystem to function, and if surpassed may lead to severe environmental and economic consequences.