Publications

Nitrate concentrations in excess of national drinking-water standards (10 mg/1 as N) are present in certain sand-plain aquifers in central Minnesota. To investigate nitrate sources in the aquifers, nitrogen-isotope values of nitrate (δ15NNO3No3) were measured in shallow ground water from 51 wells in five land-use settings. The land-use settings and corresponding average nitrate...

Water resources data for the 1992 water year for Michigan consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and ground water levels. This report contains discharge records for 145 streamflow-gaging stations; stage only records for 1 river-gaging station and 8 lake-gaging stations; stage and contents for 4 lakes and...

Oxygen-isotope compositions of authigenic-layer silicates (

The northern cornbelt sand-plains Management Systems Evaluation Area (MSEA) program is a multiagency, multistate initiative to evaluate the effects of modified and prevailing farming systems on water quality in a sand-plain area in Minnesota and at satellite areas in North and South Dakota, and Wisconsin. The primary objective of Minnesota MSEA is to evaluate the effects of ridge-tillage...

Hydrologic and precipitation data and water-quality samples were collected by the U.S. Geological Survey from rivers in the East River basin in northeastern Wisconsin during 1985-86. The Fox Valley Water Quality Planning Agency suspected that agricultural and urban nonpoint-source discharges were contributing significantly to the degradation of water quality in the basin. Two continuous...

An investigation of the effects of hypothetical residential development in the Graber Pond watershed was done by the U.S. Geological Survey in cooperation with the city of Middleton. The investigation entailed evaluation of the existing (1989) water budget and water-level conditions for the pond and the water-level conditions expected to result from the hypothetical development that may...

This report presents the annual results of the U.S. Geological Survey's (USGS) watershed-management evaluation monitoring program in Wisconsin. The overall objective of each individual project in the program is to determine if the water chemistry in the receiving stream has changed as a result of the implementation of land-management practices in the watershed. This is accomplished...

Rates of water movement through the unsaturated zone greatly affect the amount and concentrations of agricultural chemicals that may reach the water table. For example, recharge can flush to the water table chemicals that have accumulated In the unsaturated zone during dry periods. A better understanding of how topography influences recharge and the movement of agricultural chemicals is...

Accurate delineation of recharge areas for wells is an important requisite to protecting ground-water quality. Zones of transport and zones of contribution are two types of recharge areas that can be delineated. Analytical-calculation, numerical-modeling, and hydrogeologic-mapping methods were used to delineate recharge areas for two high-capacity wells (greater than about 200 gallons...

Changes in the distribution of inorganic solutes in a shallow ground water contaminated by crude oil document a series of geochemical reactions initiated by biodegradation of the oil. Upgradient of an oil body floating on the water table, oxidation of oil to carbonic acid dissolves carbonate minerals in the aquifer matrix. In this oxidized zone pH is depressed ∼1 pH unit, and the...

Selected basin characteristics and water-quality dam for the Minnesota River Basin are presented in this report as 71 maps, 22 graphs, and 8 tables. The data were compiled as part of a four-year study to identify non-point sources of pollution and the effect of this pollution on water quality. The maps were prepared from geographic information system data bases. Federal, State, and local...

INTRODUCTION As part of the National Water-Use Information Program, the U.S. Geological Survey (USGS) stores water-use data in standardized format for different categories of water use. The data base (Site Specific Water Use Data System) is updated annually or as more current water-use information becomes available. Information about amounts of water withdrawn, sources of water, how the...