Reconstruction of Pittsburghs Recent Industrial History Using Lake Core Sediments
Images from Panther Hollow
Pittsburghs industrial history has been mapped out through many venues, and this project seeks to add another. It has the potential to provide a record of the areas industrial development by serving as a catchment for fly ash. Through analyses of core sediments, the concentrations of metals and fly-ash particulates that were released from the high temperature fossil fuel combustion that took place during the citys steel boom earlier this century should be pinpointed.
Pittsburgh is at the hub of three major converging watersheds, the Lower Allegheny, the Lower Monogahela, and the Upper Ohio. The streams, ponds, lake, and wetlands of Pittsburghs Schenley Park fall into four subwatersheds. Phipps Run and Panther Hollow both drain into Panther Hollow Lake, a 96-year-old manmade reservoir, which then eventually contributes to the Monongahela River. Schenley Park has many bridges, bridle and pedestrian trails, and roads throughout. This increasing impervious surface area has increased the magnitude and frequency of the parks runoff into this small basin. This has also permitted erosion along the already steep topography. The pond is nearly stagnant with high organics and low visibility. It also exhibits prolonged renewal time due to the little flushing the concrete border allows the lake.
A 45.5 cm core was recovered from Panther Hollow Lake over the winter of 2002-2003. The core was extruded in the field at a 0.5 cm interval and the sediments analyzed for a suite of metals using an ICP-AES. Results show initially high values for lead, arsenic, chromium, nickel, and copper but each element shows a marked decreasing trend. Fly-ash typically includes aluminum, magnesium, potassium, sodium, calcium, iron, and barium, which are also being examined in this ongoing research. The magnetic susceptibility of these sediments is up into the 400 SI range, indicating the presence of heavy ferrimagnetic materials.