Publications

Water-quality investigations in six interconnected lakes that comprise most of the surface area of Voyageurs National Park in northern Minnesota revealed substantial differences in water-quality. Three large lakes; Sand Point, Namakan, and Rainy, near the eastern and northern boundaries of the Park; are oligotrophic to mesotrophic, having low dissolved solids and alkalinity, and dimictic circulati

Taconite tailings, a waste product from processing of iron ore, have been deposited in a 2.5-square-mile containment basin near Keewatin, Minnesota, The basin, which is bounded by earthen dikes of compacted drift and clayey bouldery till, contains saturated tailings consisting of chert and other silica-rich particles that range from clay to coarse-sand size. Runoff from the tailings is slight and

In 1991 , the U.S. Geological Survey (USGS) began to implement a full -scale National Water-Quality Assessment (NA WQA) program. The long-term goal of the NA WQA program are to desc ribe the tatus and trends in the quality of a large, representative part of the Nation's urface- and ground-water resources and to provide a sound , scientific understanding of the primary natural and human factor affe

The Prairie du Chien-Jordan aquifer, which consists of the dolomitic Prairie du Chien Group and the underlying Jordan Sandstone, extends over southeastern Minnesota (fig. 1). Water quality in the aquifer fluctuates areally and with depth throughout the aquifer. Differences in chemical constituent concentrations are a result of both natural hydrogeologic conditions and human activities.

Wright-Patterson Air Force Base, in southwestern Ohio, overlies a buried-valley aquifer. The U.S. Geological Survey installed 35 observation wells at 13 sites on the base from fall 1988 through spring 1990. Fourteen of the wells were completed in bedrock; the remaining wells were completed in unconsolidated sediments. Split-spoon and bedrock cores were collected from all of the bedrock wells. Shel

The chromatic and leuco forms of malachite green and crystal violet were readily separated and detected by a sensitive and selective high-performance liquid chromatographic procedure. The chromatic and leuco forms of the dyes were separated within 11 min on a C18 column with a mobile phase of 0.05 M sodium acetate and 0.05 M acetic acid in water (19%) and methanol (81%). A reaction chamber, contai

The objectives of this study are to provide continuous discharge records for selected rivers at specific sites to supply the needs for regulation, analytical studies, definition of statistical properties, trends analysis, determination of the occurrence, and distribution of water in streams for planning. The project is also designed to determine lake levels and to provide discharge for floods, low

A new system was developed for maintaining suspensions of inorganic solids during laboratory studies on early life stages of fish. Microfine bentonite was successfully held in suspension in specially constructed units during a 21-d fishless test, a 28-d experiment with juvenile green sunfish (lepomis cyanellus), and four shorter experiments (5-9 d) with four species of larval fishes, white sucker

National Water Summary 1988-89 - Hydrologic Events and Floods and Droughts documents the occurrence in the United States, Puerto Rico, and the U.S. Virgin Islands of two types of extreme hydrologic events floods and droughts on the basis of analysis of stream-discharge data. This report details, for the first time, the areal extent of the most notable floods and droughts in each State, portrays th

In the late 1950's, intense demands for water and growing concerns about declines in the quality of water generated the need for more water-resources data. About thirty Federal agencies, hundreds of State, county and local agencies, and many private organizations had been collecting water data. However, because of differences in procedures and equipment, many of the data bases were incompatible. I

Water resources data for the 1990 water year for Michigan consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and water levels and water temperature of ground water. This report contains discharge records for 146 streamflow-gaging stations; stage only records for 1 river-gaging station and 13 lake-gaging stations; stage and contents fo

Lakes Clara and Vandercook are 33- and 43-hectare lakes, respectively, located in predominantly sandy outwash in north-central Wisconsin. Annual precipitation at National Weather Service stations during the 1951-80 calendar years averaged 794 millimeters near Lake Clara and 834 millimeters near Vandercook Lake. During the 1981 water year, annual precipitation measured at the lakes as part of this