Data on polychlorinated biphenyls, dieldrin, lead, and cadmium in Wisconsin and Upper Michigan tributaries to Green Bay, July 1987 through April 1988

Abstract

A reconnaissance study was conducted of 22 streams tributary to Green Bay to determine whether any of the streams contribute toxic substances to the bay. This effort was part of a comprehensive investigation of Green Bay funded by the U.S. Environmental Protection Agency, Great Lakes National Program Office. The U.S. Geological Survey sampled the bottom sediments and water columns of 11 streams tributary to western Green Bay for polychlorinated biphenyls, lead, and cadmium. Four of these streams also were sampled for dieldrin, a pesticide previously used in the watershed. An additional 11 streams tributary to eastern Green Bay were sampled for dieldrin in the bottom sediment and storm runoff. Samples were collected from July 1987 through April 1988. Neither dieldrin nor cadmium was detected in any of the sampled tributaries. Detectable concentrations of polychlorinated biphenyls and lead were found at only three sites. Polychorinated biphenyls (0.10 microgram per gram) and lead (10 milligrams per kilogram) were found in the bottom sediment of Duck Creek, a western-shore tributary near the city of Green Bay. Lead (10 milligrams per kilogram) also was found in the bottom sediment of the Suamico River near the mouth, about 5 miles north of Duck Creek. Lead (4 micrograms per liter) was detected in a spring-runoff sample from the Fishdam River, a tributary from upper Michigan. INTRODUCTION Green Bay is an arm of Lake Michigan adjacent to Wisconsin and the Upper Penninsula of Michigan (fig. 1). During 1987, the U.S. Environmental Protection Agency (ERA) began a comprehensive study of polychlorinated biphenyls (PCBs), dieldrin, lead, and cadmium in Green Bay. It was necessary to identify all significant sources of these target contaminants to quantify loadings to the bay. A previous investigation by Marti (1984) indicated that all the primary tributaries to Green Bay transported PCBs into the bay. Marti found that the Fox, the Menominee, the Oconto, the Peshtigo, and the Escanaba Rivers contained detectable concentrations of PCBs in water, as follows: Fox River 97.3 ng/L (nanograms per liter) Menominee River 15.3 ng/L Oconto River 6.7 ng/L Peshtigo River 10.8 ng/L Escanaba River 17.1 ng/L During 1987 and 1988, the U.S. Geological Survey conducted a study of other important tributaries not investigated by Marti to determine whether they were significant sources of PCBs, dieldrin, lead, and cadmium. Laboratory analysis of samples was provided by the Wisconsin State Laboratory of Hygiene; funding was provided by the ERA. Purpose and Scope This report presents data collected by the U.S. Geological Survey during a water-sampling reconnaissance study of 22 tributaries to Green Bay (fig. 1). The ERA. will use these data to determine whether any of these tributaries will be monitored during the comprehensive Green Bay Mass Balance Study of PCBs (U.S. Environmental Protection Agency, 1988). Eleven of the tributaries studied are on the western shore of Green Bay and Michigan's Upper Penninsula; these were sampled for PCBs, lead, and