Publications

Municipalities in the lower Fox River Valley in northeastern Wisconsin obtain their water supply from a series of permeable sandstones and carbonates of Cambrian to Ordovician age. Withdrawals from this "sandstone aquifer" have resulted in water levels declining at a rate of more than 2 feet per year. The U.S. Geological Survey, in cooperation with the major water utilities in the Fox...

Estimates of the average ground-water component of streamflow for 195 streams in the United States part of the Great Lakes Basin range from 25 to 97 percent. Among the selected streams, the average ground-water component of streamflow was 67.3 percent. Estimates of the ground-water component of streamflow are based on hydrograph separation of 5,735 years of daily streamflow data...

The forms and partitioning of aqueous mercury species in the canals and marshes of the Northern Florida Everglades exhibit strong spatial and temporal variability. In canals feeding Water Conservation Area (WCA) 2A, unfiltered total Hg (HgT(U)) is less than 3 ng L-1 and relatively constant. In contrast, methyl mercury (MeHg) exhibited a strong seasonal pattern, with highest levels...

Calcareous fens in Minnesota are spring-seepage peatlands with adistinctive flora of rare calciphilic species. Peat characteristics andgroundwater geochemistry were determined for six calcareous fens in theMinnesota River Basin to better understand the physical structure andchemical processes associated with stands of rare vegetation. Onset of peataccumulation in three of the fens ranged...

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...

Spatial and temporal distribution of polychlorinated biphenyls (PCBs) in common carp (Cyprinus carpio) and walleye (Stizostedion vitreum) fillets from rivers in the Upper Mississippi River Basin upstream of the outlet of Lake Pepin are summarized. PCB concentrations in common carp and walleye fillets collected from rivers in the UMIS during 1975-95 by the Minnesota Fish Contaminant...

Saturated hydraulic conductivity of aquifer sediments at a crude-oil spill research site near Bemidji, Minnesota were examined using pneumatically-induced head-difference tests and packer/vacuum system tests. Results from slug tests on 58 wells show that hydraulic conductivity varies both horizontally and vertically in the range from about 10-7 to 10-4 meters per second (m/s), with a...

There are spatial differences in methyl mercury (MeHg) concentrations in biota in Water Conservation Areas 2 and 3 in the Everglades, with higher concentrations generally found in the southern areas. Fish and hemipterans had the most MeHg on a wet weight basis, with levels exceeding 30 ng g-1. The magnitude of MeHg accumulation in biota varies seasonally and does not always appear to be...

Six calcareous fens in the Minnesota River Basin, USA are in regional hydrogeologic settings with large discharges of calcareous ground water. These settings juxtapose topographically high areas of ground-water recharge with fens in lower areas of discharge, thus creating steep upward hydraulic gradients at the fens. Coarse glacial deposits with high permeability connect recharge areas...

Wetlands cannot exist without water, but wetland hydrology is difficult to characterize. As a result, compensatory wetland mitigation often only assumes the proper hydrology has been created. In this study, water sources and mass transfer processes in a natural and constructed wetland complex were investigated using isotopes of water and strontium. Water isotope profiles in the saturated...

In 1996, the U.S. Geological Survey (USGS), in cooperation with the Michigan Department of Environmental Quality (MDEQ) and nine southeast Michigan counties, began a study of the factors controlling arsenic concentrations in drinking water. The early results of this study raised broader concerns in Oakland County about the quality of groundwater in general and drinking water in...

Lac Vieux Desert, a 6.6 square-mile lake on the Michigan-Wisconsin border, is the headwaters of the Wisconsin River. The Lac Vieux Desert Band of Lake Superior Chippewa Indians have a number of homes and tribal property on the Lake's north shore. Most drinking water is obtained from wells drilled in unconsolidated glacial deposits. A gravel layer at or near the bedrock surface is the...