Publications

No abstract available.

The persistence of rotenone was compared between a cement-lined pond (0.04 hectare) and an earthen-bottom pond (0.02 hectare) treated with 5 μL Noxfish/L (250 μg rotenone/L) during spring, summer, and fall. Water temperatures on the days of treatment in each season were 8, 22, and 15°C, respectively. Both ponds were filled with pond water from a common source 1 week before each of the...

No abstract available

No abstract available.

The presence of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in feral lake trout eggs (Salvelinus namaycush) may increase the risk of lake trout early life stage mortality in the Great Lakes. To assess the combined toxicity of PCDDs, PCDFs, and PCBs to lake trout early development, toxic potencies, relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin...

Predicting the steady state distribution of air pressure in the unsaturated zone resulting from a pneumatic test provides a method for determining air-phase permeability. This technique is analogous to the inverse problem of well hydraulics; however, air flow is more complicated than ground water flow because of air compressibility, the Klinkenberg effect, variations in air density and...

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.

This report presents selected physical and chemical data collected by the U.S. Geological Survey for the Minnesota River Assessment Project, a four-year interagency study coordinated by the Minnesota Pollution Control Agency. Water samples were collected at 12 sites on the Minnesota River and at the mouths of 10 major tributary streams located from the outlet of Lac qui Parle Reservoir...

The U.S. Army Corps of Engineers is planning to reduce aquatic growth and siltation in Sauk Lake in west-central Minnesota in order to improve recreation. A detailed water-quality survey of the lake and surrounding watershed was needed to plan remedial activities. Water-quality data were collected at 11 sites on Sauk Lake, at sites on 3 major tributaries to the lake, and at the outflow...

Water levels, locations, depths, and aquifers tapped are given for 108 observation wells. Tabulated data include a listing of ground-water reports in Michigan, extremes of water levels for calendar year 1989 and for the period of record, pumpage of most major ground-water users in the State, and water-quality data from selected wells. In 1989, the two largest municipal users of ground...

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 (greater than about 200 gallons per...

The quality of surface and ground water can be related to various physical factors such as land use, soil type, geology, and depth to water table. Land use in Dakota County, Minnesota, is changing: urbanization and industrialization in the north and increasing irrigation and application of agricultural chemicals in the central part of the county. The U.S. Geological Survey, in...