Estimation of PCB Loads from the Black River Basin to Lake Ontario, NY

Science Center Objects

Problem - There is a stated need to provide information on loading of persistent toxic pollutants to Lake Ontario from New York tributaries. The information is specifically required for the Lake Ontario Mass Balance Model, which is an integral part of the long-term Great Lakes research. The project described here is designed to demonstrate a cost-effective approach for estimation of loads of...

 

Problem - There is a stated need to provide information on loading of persistent toxic pollutants to Lake Ontario from New York tributaries. The information is specifically required for the Lake Ontario Mass Balance Model, which is an integral part of the long-term Great Lakes research. The project described here is designed to demonstrate a cost-effective approach for estimation of loads of polychlorinated-biphenyls (PCBs) through use of a relatively small number of large-volume whole-water samples for PCB analysis. The Black River basin was selected to demonstrate the feasibility of the approach because it is the largest New York contributor of PCBs to Lake Ontario.

Objectives - The objective of this project is to conduct a demonstration project to evaluate the feasibility of estimating loads of polychlorinated-biphenyls from a New York tributary to Lake Ontario using surrogate constituents that are much less expensive to analyze -- specifically, suspended sediment (SS), total particulate nitrogen (TPN), dissolved organic carbon (DOC), and particulate organic carbon (POC).

Approach - The study will be conducted on the Black River at Watertown, NY (USGS gage #04260500, drainage area 1864 mi2). USGS will obtain 50 samples for the surrogate constituents (SS, TPN, DOC, POC) at a range of flows throughout water year 2005. In addition, ten 60-liter samples will be selectively collected for PCB analysis under varying flow conditions, and each sample will be collected concurrently with a sample for the surrogate constituents. The solid-phase PCB components will be Soxlet-extracted from particulate filters, and the liquid-phase (filtered) components will be extracted through XAD-resin cartridges. Analysis of the solid- and liquid-phase PCB extracts will be done by gas chromatography and high-resolution mass spectrometry (GC/HRMS) according to EPA method 1668A. The method 1668A analyses through AXYS Analytical Services will provide congener-specific results for PCBs, with congener detection limits that range from 0.04 to 26 pg/L (part per 1015) for a 60-L sample. A load-estimation model for the carbon and sediment (surrogate) data (n=50 samples) will be developed and coupled to load estimations for PCBs through correlations of the surrogate concentrations to suspended and dissolved PCB concentrations for the subset of split samples (n=10).

Relevance and Impact - This project will determine the feasibility of estimating tributary loads of PCBs using relatively inexpensive surrogate constituents (SS, DOC, POC). Direct monitoring of the PCBs is prohibitively expensive, because of their low concentrations and specialized analytical requirements. A successful outcome of this project will produce load estimates for PCBs that are more reliable than those currently available. The loading data will provide necessary input to the Lake Ontario Mass Balance Model, and enhance its utility as a tool to guide remedial efforts for Lake Ontario as part of the Lake Ontario LaMP within the Great Lakes Program. Ultimately, it should contribute to better understanding of the Lake Ontario ecosystem, particularly for toxic pollutants that restrict fish consumption. A successful demonstration may also show the feasibility of the approach to other tributary rivers to the Great Lakes. Although this project focuses on the feasibility of using surrogate constituents to evaluate tributary loads of PCB congeners, it may ultimately be applied as well to other priority pollutants -- such as dieldrin, DDT, and mirex. 

Project
Location by County

Lewis County, NY, Jefferson County, NY, Oneida County, NY, Herkimer County, NY, Hamilton County, NY