Publications

Steiner Branch basin in southwestern Wisconsin has rugged mature topography. Corn is planted in 30 percent of the basin on slopes ranging from 0 to 20 percent. Although contour stripcropping is a recommended practice for these easily eroded soil slopes, few conservation practices are followed to reduce soil losses. Because the stream drains into a manmade lake used for recreation, its...

An intensive study of nonpoint-source runoff was conducted in the Twin Cities metropolitan area in Minnesota during 1980. The purpose of the study was to determine the relationships between land use, watershed characteristics, and the quantity, quality, and timing of runoff. Discharge and water-quality data were collected at 19 sites located in 6 rural and 4 urban watersheds. Basin...

An investigation of flood flows from small drainage basins in Minnesota is being made to aid in the design of bridges, culverts and other highway drainage structures. Results of the investigation provide peak-flow data on streams generally with drainage areas less than 200 square miles, placing particular emphasis on those with drainage areas lees than 10 square miles. Basin parameters...

The high-performance liquid-chromatography (HPLC) procedure requires only minutes per sample, is specific, and is relatively sensitive (limit of detection 0.005 mg/L for both chemicals). A combined buffer (pH 4) and internal standard (3-chlorodiphenylamine) reagent is added to the water sample, which is injected through a Sep Pak C18 disposable cartridge. The cartridge adsorbs and...

No abstract available.

A preliminary quasi-three-dimensional finite-difference ground-water-flow model of the seven-county Twin Cities Metropolitan area was constructed and used to evaluate parameter sensitivity and adequacy of available data. Fourteen geologic units that underlie the study area were grouped into nine hydr,bgeologic units and were incorporated into a five-layer model. The layers in the...

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The influence of background polychlorinated biphenyl (PCB) residues in rainbow trout (Salmo gairdneri) on the susceptibility of the fish to nine chemicals routinely or occasionally used in fishery operations was evaluated. Rainbow trout fry were divided into three groups: one was exposed to 0.01 ppb and another to 0.1 ppb of the PCB Aroclor (R) 1254; the third (control) group was...

No abstract available.

Sulfate concentration and pH were determined in surface water, groundwater, and precipitation samples collected in the Filson Creek watershed to evaluate the sources of sulfate in Filson Creek. During and immediately after snowmelt, sulfate concentrations in Filson Creek increased from about 2 to 14 mg/l. Concurrently, H+ ion activity increased from an average of 10−6.6 to 10−5.5. These...