ASSESSING THE RELATIONSHIP BETWEEN TOTAL PCBS, TOTAL SUSPENDED SOLIDS AND TURBIDITY SAMPLES COLLECTED DURING SURFACE WATER MONITORING OF THE HUDSON RIVER REMEDIAL DREDGING PROJECT, NEW YORK

Over a 30 year span, a significant mass of Polychlorinated Biphenyls (PCBs) were released into the Hudson River from General Electric’s capacitor manufacturing plants in Fort Edward and Hudson Falls, New York; leading to one of the largest environmental dredging cleanup projects in the North East. The United States EPA released its Record of Decision for this Federal Superfund site in 2002, seeking the removal of contaminated sediments from a 40-mile stretch from Fort Edward to Troy, NY. By completion in 2015, the dredging work done by GE removed a total of 2.75 million cubic yards of contaminated sediment from numerous sectors of the Hudson; meanwhile conducting a robust comprehensive monitoring program throughout. This research investigates the relationships between a subset of project monitoring constituents, including the number of Total Suspended Solids (TSS), daily average turbidity values and total PCB contaminant loads seen during high flows, average flows and below-average flows. Generally, an increased abundance of TSS and/or turbidity is often associated with higher concentrations of local pollutants. It was often inferred that sediment resuspension or substrate disturbance from the dredging would increase the amount of turbidity and TSS materials; likewise increasing the overall local abundance of total PCBs in the near field. Sampling was conducted under the Remedial Action Monitoring Plan (RAMP), employing both automated and manual samplers throughout the dredging period from 2009 to 2015. The automated samplers collected random aliquots on a 15-minute basis, with TPCBs analyzed in ng/L via one of two methods: EPA Method 508 or through use of the Modified Green Bay Method. Turbidity samples were also collected on a 15-minute basis using a nephelometer, with units measured in NTU. TSS samples were directed through a 1.50 µm particle retention filter and dried, with the remaining TSS material measured in mg/L. Data was analyzed through ACCESS and EXCEL software, and further investigated to examine the relationship between the three data sets in diverse flow circumstances. The analysis concluded that neither particulate resuspension nor increasing turbidities from dredging operations are sufficient indicators for total TPCB concentrations in both the near and/or far field.