Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 13 of 13

Full-Text Articles in Fresh Water Studies

Swine Slurry Characteristics As Affected By Selected Additives And Disinfectants, Jon Duerschner, Shannon L. Bartelt-Hunt, Kent Eskridge, John E. Gilley, Xu Li, Amy M. Schmidt, Daniel D. Snow Jan 2020

Swine Slurry Characteristics As Affected By Selected Additives And Disinfectants, Jon Duerschner, Shannon L. Bartelt-Hunt, Kent Eskridge, John E. Gilley, Xu Li, Amy M. Schmidt, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Current swine industry practice is to house animals in confinement facilities which capture and store feces and urine as slurry in pits below the production area. Additives and disinfectants may be introduced into the manure pits. This study was conducted to measure the effects of additives and disinfectants on temporal changes in swine slurry characteristics. Slurry from a commercial swine production facility in southeast Nebraska, USA was collected and transferred to 57 L reactors located within a greenhouse. Selected additives and disinfectants were added to the reactors and physical properties, chemical characteristics, and antibiotic concentrations were monitored for 40 days. …


Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson Aug 2016

Trend Analysis Of Water Quality In Northwest Arkansas Streams Reflects Changes In The Watershed, Zachary Paul Simpson

Graduate Theses and Dissertations

Watershed export of nutrients, sediments, and chemicals impacts receiving waters. Changes within the watershed (e.g., anthropogenic or climatic) can alter the transport of constituents in streams. Stream monitoring is crucial for understanding these effects. This study developed a potential improvement to flow-adjusting constituent concentrations in streams, an important step of analyzing monitoring data in lotic systems for trends. The method incorporates a K-fold cross-validation procedure to optimize a model explaining the relationship between the concentration and streamflow, thus providing a valuable tool to researchers in water quality. Additionally, two case studies were conducted on watersheds located in northwest Arkansas using …


Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar Dec 2015

Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar

Graduate Theses and Dissertations

Energy security through increased biofuel production is one of the components of the Energy Independence and Security Act (EISA) 2007. As per EISA 2007 mandate, appropriate independent research institutes are required to assess concerns to natural biodiversity due to biofuel production and report it to the Congress through the Environment Protection Agency (EPA). Planners, researchers, and agencies concerned with environmental regulations, ideally, would like to have location-specific information about the impacts for developing appropriate management interventions. This study examines long-term impacts on water quality in response to targeted (i.e. marginal lands) production of biofuel crops by setting up two SWAT …


A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh Dec 2012

A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh

Graduate Theses and Dissertations

This study compares a novel simulation approach to the conventional Soil and Water Assessment Tool (SWAT) modeler's approach for targeting biofuel crop production on marginal lands. In conventional SWAT modeling approach, non-spatial definition of hydrological response units (HRUs) results in the simulation of biofuel crops on both marginal and non-marginal land. This study provides an alternative approach in which a marginal-land raster was integrated into the land use and land cover (LULC) raster in such a way that the land uses were divided into marginal and non-marginal components. This modified LULC was used for model setup which resulted in marginal …


Identification Of Tire Leachate Toxicants And A Risk Assessment Of Water Quality Effects Using Tire Reefs In Canals, S. M. Nelson, G. Mueller, D. C. Hemphill, U.S. Bureau Of Reclamation Jan 1994

Identification Of Tire Leachate Toxicants And A Risk Assessment Of Water Quality Effects Using Tire Reefs In Canals, S. M. Nelson, G. Mueller, D. C. Hemphill, U.S. Bureau Of Reclamation

Publications (WR)

Cover is an important component of aquatic habitat and fisheries management. Fisheries biologists often try to improve habitats through the addition of natural and artificial material to improve cover diversity and complexity. Habitat-improvement programs range from submerging used Christmas trees to more complex programs using sophisticated artificial habitat modules. Used automobile tires have been employed in the large scale construction of reefs and fish attractors in marine environments and to a lesser extent in freshwater and have been recognized as a durable, inexpensive and long-lasting material which benefits fishery communities.

Recent studies by the U.S. Bureau of Reclamation have quantified …


The Effects Of Limited Food Availability On The Striped Bass Fishery In Lake Mead, John R. Baker, Larry J. Paulson Jan 1983

The Effects Of Limited Food Availability On The Striped Bass Fishery In Lake Mead, John R. Baker, Larry J. Paulson

Publications (WR)

The original range of striped bass (Morone saxatilis) was along the Atlantic Coast. They were introduced into the lower Sacramento River in 1879 and are now also found along the Pacific Coast. A landlocked striped bass fishery was established in Santee-Cooper Reservoir, South Carolina, in 1954, and they have since been introduced into numerous other reservoirs, including Lake Havasu, Lake Mead and Lake Powell on the Colorado River. Striped bass were introduced into Lake Mead in 1969 in response to declines in the largemouth bass (Micropterus salmoides) fishery that occurred during the 1960s and in order to further utilize the …


Federal Water Pollution Control Act Section "404" Evaluation For Dickey-Lincoln School Lakes, New England Division, United States Army Engineer Division, United States Army Corps Of Engineers Jan 1980

Federal Water Pollution Control Act Section "404" Evaluation For Dickey-Lincoln School Lakes, New England Division, United States Army Engineer Division, United States Army Corps Of Engineers

Dickey-Lincoln School Lakes Project

The purpose of this report is to relate various aspects of the proposed Dickey-Lincoln School Lakes Hydroelectric Project to appropriate considerations defined by Section 404 of the Federal Water Pollution Control Act of 1972.


Lake Mead And Lake Powell Salinity Reports, Cathy Lee, Steve Gazafy Feb 1979

Lake Mead And Lake Powell Salinity Reports, Cathy Lee, Steve Gazafy

Publications (WR)

The enclosed reports were compiled for the Colorado River Water Quality Office based on salinity data for Lake Mead and Lake Powell. According to the regional director of the office, the reports are not considered "polished" documents for public distribution. However, he considers them to be "interesting, rough appraisals of general trends that may be very important In our understanding the hydro-salinity system in the Colorado River."


Dickey-Lincoln School Lakes Project Environmental Impact Statement: Appendix E: Aquatic Ecosystem And Fisheries Studies (Supplement), Christoipher J. Schmitt, Dennis R. Sasseville, Normandeau Associates, Inc., New England Division, United States Army Engineer Division Jan 1978

Dickey-Lincoln School Lakes Project Environmental Impact Statement: Appendix E: Aquatic Ecosystem And Fisheries Studies (Supplement), Christoipher J. Schmitt, Dennis R. Sasseville, Normandeau Associates, Inc., New England Division, United States Army Engineer Division

Dickey-Lincoln School Lakes Project

Sediment mercury concentrations higher than levels normall y considered trace or background were encountered up to 80 cm belo w the sediment-water interface in samples obtained from four oligotrophi c lakes in northern Maine . These lakes are in three different watershed s and are as far as 65 km apart . The values reported are far lower than levels reported elsewhere from contaminated sites . The distributio n and magnitude of the sediment concentrations encountered suggest long-ter m diffuse mercury inputs to the lakes from the watersheds . In addition , concentrations up to twice as high in near-surface …


Dickey-Lincoln School Lakes Hydroelectric Project : Summary Of Water Quality Factors, New England Division, U.S. Army Corps Of Engineers Jan 1977

Dickey-Lincoln School Lakes Hydroelectric Project : Summary Of Water Quality Factors, New England Division, U.S. Army Corps Of Engineers

Dickey-Lincoln School Lakes Project

The prediction of future water quality conditions in and downstream from a proposed impoundment is dependent upon a myriad of physical, chemical and biological phenomena. It is known from limnology (science of lakes) that all physicochemical and biological functions are greatly controlled or influenced by lake hydro-dynamics, lake thermodynamics, and the quality of inflowing water.


Dickey-Lincoln School Lakes, Maine, U.S.A. And Quebec, Canada: Design Memorandum No. 5: Water Quality, New England Division, United States Army Corps Of Engineers Jan 1977

Dickey-Lincoln School Lakes, Maine, U.S.A. And Quebec, Canada: Design Memorandum No. 5: Water Quality, New England Division, United States Army Corps Of Engineers

Dickey-Lincoln School Lakes Project

This design memorandum presents the results of several studies undertaken to provide an understanding of present and potential future water quality conditions within and downstream from Dickey and Lincoln School Lakes in accordance with the requirements of ETL 1110-2-1402, dated 12 November 1976. Included are an examination of baseline water quality conditions and the findings of qualitative and quantitative predictive analyses performed to evaluate water quality conditions during all phases of the project's lifetime. This document will also serve as a reference for the water quality portions of the project Environmental Impact Statement.


Automation Of The Continuous Coagulation Monitor, Dee Mitchell, James J. Oskowis Jan 1974

Automation Of The Continuous Coagulation Monitor, Dee Mitchell, James J. Oskowis

Technical Reports

The development of automation in the past 50 years has paralleled the accelerating growth of today’s vast technological society. Automatic control systems are indispensable extensions of man's brain that enable him to monitor and regulate his complex environment. The principles of automatic control have a wide range of applications and interests in virtually every scientific field. The need for automatic control systems in vital applications of environmental engineering is both real and urgent. Extensive pollution has resulted in unavoidable water re-use and in the inevitable establishment of stringent effluent standards. Both water and wastewater treatment processes have necessarily become more …


Water Quality Study Of Lake Mead, Dale A. Hoffman, Paul R. Tramutt, Frank C. Heller, Bureau Of Reclamation Nov 1967

Water Quality Study Of Lake Mead, Dale A. Hoffman, Paul R. Tramutt, Frank C. Heller, Bureau Of Reclamation

Publications (WR)

This report presents Lake Mead Water quality data obtained from 1964 to 1966. The effect of filling Lake Powell on the water quality of Lake Mead is evaluated. General limnological principles and the present limnology of Lake Mead are discussed. Lake Mead has a warm monomictic annual temperature cycle characterized by summer stratification, fall overturn leading into a continuous circulation throughout the winter; temperatures never fall below 39 deg F (4 deg C). During stratification, lower dissolved oxygen values were recorded in the thermocline than in the epilimnion and hypolimnion. Mineral content increases from the upper to the lower end …