Pesticides Improved analytical capability developed in USGS laboratories detects pesticides at concentrations much lower than regulatory limits and allows the USGS to observe the transport and fate of pesticides after they are applied. Herbicides were detected most frequently in streams draining watersheds with significant agricultural use, and insecticides were detected most frequently in streams draining watersheds that are urbanized or that contain extensive areas of vineyards or orchards. Concentrations of most pesticides detected were low, generally not exceeding 0.1 part per billion. Continuing work is examining pesticide occurrence in some of the Finger Lakes, in the sole source aquifer system on Long Island, in public water-supply sources, and in ground water. 67KB Figure 2.
Sediment accumulation obstructs New York Harbor and causes economic losses.
Some of the sediment is contaminated with heavy metals, PCB's, and other organic compounds, and the contamination makes the disposal of dredged material a concern. Planning for the safe disposal of the contaminated, dredged material requires identification of which sediments deposited within the harbor are contaminated and evaluations of disposal sites. The USGS is studying this region to identify sediments on the sea floor, map the distribution of contaminants in the sediment, and develop a predictive capability for the long-term transport and fate of sediments and contaminants. A regional understanding of the sea floor geology, topography, and dynamics of these coastal sediments is needed for management and use of the nearshore environment and to plan further studies. Previous work by the USGS has shown that Hudson River tributaries supply differing amounts of sediment depending on flow conditions and on land use in their basins.