Physical Sciences and Mathematics Commons^™

Flow Through Well Screens As A Function Of Pump Intake Location, Kristjan F. Bekker

Theses and Dissertations

Greater well efficiency and lower production costs may result from a knowledge of water flow through well screens. Current practice generally locates the intake of a pump in the cased section of the well above the screen. This work shows that placing the pump within the screen will increase well efficiency and therefore lower energy cost. This work also shows a correlation of increased well efficiency with respect to larger sand size, larger screen slot size, and lower flow rates.

A semicircular model based on the radial symmetry of a well and screen was used to simulate water flow from …

Laboratory Denitrification Using Sediments From The Elk Valley Aquifer, Alison E. Kammer

Theses and Dissertations

An experiment was conducted to determine if a decrease in the content of sulfides related to denitrification could be measured in the laboratory using sediments of the Elk Valley Aquifer in eastern North Dakota. The experiment entailed analyzing sediments for sulfides and solid organic carbon and isolating them in sample containers with a nitrate solution to determine if a measurable decrease in these components could be observed.

Previous denitrification studies in the Elk Valley Aquifer showed an increase in sulfate in conjunction with a decrease in the concentration of nitrate. Sulfate is a by product of autotrophic denitrification where sulfide …

Lithospheric Flexure Of The Devils Lake Basin, North Dakota, Erica M. Peterson

Theses and Dissertations

Devils Lake is the largest lake in a chain of approximately 20 interconnected lakes in east central North Dakota. The Devils Lake drainage basin of approximately 8,600 km2, lies in a bowl sculpted by glaciation; thus it is closed and receives and loses water only through precipitation and evapotranspiration. Since 1940, the lake level has risen 14.4 m due to increased precipitation. Geological data show that in the past 10,000 years the lake has alternately dried up and filled due to climate fluctuations (Murphy et al., 1997). During this time it has reached its spill elevation of 444. 7 m …