Water-quality assessment of part of the upper Mississippi River basin, Minnesota and Wisconsin — Design and implementation of water-quality studies, 1995-98

From 1995 through 1998, water-quality and aquatic-biological samples were collected, processed, and analyzed for the U.S. Geological Survey's National Water-Quality Assessment Program in the Upper Mississippi River Basin in Minnesota and Wisconsin. Sites were selected and samples collected for integrated studies designed to provide a comprehensive description of water-quality conditions, to identify trends, and to determine the factors that affect existing conditions.

This report describes the design, site-selection, and implementation of the study. Methods used to collect, process, and analyze samples; characterize sites; and assess habitat are described. A comprehensive list of sample sites is provided. Sample analyses for water-quality studies included chlorophyll a, major inorganic constituents, nutrients, trace elements, tritium, radon, environmental isotopes, organic carbon, pesticides, volatile organic compounds, and other synthetic and naturallyoccurring organic compounds. Aquatic-biological samples included fish, benthic macroinvertebrates, and algal enumeration and identification, as well as synthetic-organic compounds and trace elements in fish tissue.