Lead and Cadmium Contamination in Surface Water Sediments of Lackawanna County, Pennsylvania
Authors: Black Shandon , Matchko Thomas , Dumancas Gerard 
Published: November 2024

The Little Roaring Brook, a tributary of Roaring Brook in Lackawanna County, Pennsylvania, flows through densely populated towns before joining the Lackawanna River, which eventually empties into Delaware Bay—a vital hub for the U.S. seafood industry. Waterways are instrumental in transporting and dispersing chemical compounds and other pollutants worldwide, including harmful substances generated by human and industrial activities. These pollutants travel from their sources to distant areas through processes like evaporation and rainfall, reaching regions where they were never directly used. In February 2024, a malfunction during the reconstruction of a dam in Lackawanna County caused a sediment release that accumulated 2 to 3 feet deep in downstream areas, including sections of Roaring Brook and the Lackawanna River. Built in 1886, the dam had accumulated sediment in its reservoir over many years, and the surrounding watershed includes major roadways that can release toxic pollutants. Additional significant pollution sources near these streams, such as an industrial and municipal waste landfill, an automotive salvage yard, and an artillery manufacturing plant, are rarely assessed by independent parties. This study seeks to quantify heavy metal contamination in sediments near these potential pollution sources. The primary sources of pollution examined include the landfill, the salvage yard, the sediment release from the dam reconstruction, the manufacturing plant, and road-related runoff. Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) was used to analyze sediment samples from Roaring Brook and Little Roaring Brook, revealing elevated levels of lead (Pb) and cadmium (Cd) at sites near these pollution sources. These levels were compared to the 2013 revision of the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZECC/ARMCANZ) Sediment Quality Guidelines. The sample immediately downstream from the landfill showed the highest concentration of Pb at 104.85 mg/kg, while the highest Cd concentration of 0.504 mg/kg was found just downstream of the automotive recycling center. Sediments from Roaring Brook, downstream of the sediment release, also showed elevated levels of Pb (80.34 mg/kg) and Cd (0.466 mg/kg), compared to the upstream concentrations of 64.46 mg/kg for Pb and 0.154 mg/kg for Cd. The lowest concentrations of Pb and Cd were found in the upstream samples from Little Roaring Brook, with 50.53 mg/kg of Pb and 0.146 mg/kg of Cd. According to the ANZECC/ARMCANZ Sediment Quality Guidelines, all Pb concentrations exceeded the 50 mg/kg threshold, above which further investigation is recommended. While Cd concentrations were all below the 1.5 mg/kg threshold, analysis of matrix-spiked samples indicated that the actual levels of Pb and Cd may be higher than initially determined due to the effects of sediment particle size. Roaring Brook and Little Roaring Brook are infrequently assessed for pollutants, underscoring the need for more research to establish a clearer understanding of the pollution sources in the area. This study provides an initial, independent assessment of heavy metal contamination in these streams, highlighting the need for further analysis of other potential pollutants and their ecological and public health impacts.