Browsing by Author "Geological Survey (U.S.)"
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- 1937 Blacksburg, VA, Topographical MapGeological Survey (U.S.) (Geological Survey (U.S.), 2011-08-11)
- 1965 Blacksburg Topographical Map, 1983 revisionGeological Survey (U.S.) (Geological Survey (U.S.), 2011-08-11)Topographic map of a portion of Virginia from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24,000
- The 1986 amendments to the Safe Drinking Water Act : impacts on Virginia's water supply industryCox, William E.; Sherrard, Joseph H.; Gaw, Christopher D. (Virginia Water Resources Research Center, Virginia Polytechnic Institute and State University, 1991-10)
- Agricultural use of sewage sludge : a literature reviewKelley, W. D.; Martens, David C.; Reneau, Raymond B.; Simpson, Thomas W. (Virginia Water Resources Research Center, Virginia Polytechnic Institute and State University, 1984-12)Stricter regulations on discharge of sewage into waters, higher costs of alternate disposal procedures, and higher prices of chemical fertilizers have increased interest in the use of sewage sludge in crop production. This review addresses the benefits and risks of agricultural use of sewage sludge. Topics evaluated in this study are the biological, chemical, and physical aspects of sewage sludge relating to trace elements, pathogens, nitrogen, and phosphorus and also the economic aspects of land application of sewage sludge. For each topic, additional research needs are identified.
- Evaluation of the performance of five aerated package treatment systemsKellam, J. Lee; Boardman, Gregory D.; Hagedorn, Charles III; Reneau, Raymond B. (Virginia Water Resources Research Center, Virginia Polytechnic Institute and State University, 1993)
- Fate and transport of pesticides in a Virginia Coastal Plain soilHeatwole, Conrad D.; Zacharias, Sebastian; Mostaghimi, Saied; Dillaha, Theo A. III; Young, Roderick W. (Virginia Water Resources Research Center, Virginia Polytechnic Institute and State University, 1992)The fate and transport of atrazine, metolachlor, and bromide as a tracer, were characterized through surface runoff monitoring and soil core sampling on no-till and conventionally tilled field plots planted with corn. A rainfall simulator was used to generate a surface runoff event within 48 hours of pesticide application. In comparison with the conventional-tillage plot, the no-till plot yielded 32% of the runoff volume, 8% of the sediment, and 50% of the pesticide mass. Total losses of atrazine and metolachlor in surface runoff were 0.5-1 .5% of the amount applied, with the greatest losses associated with conventional tillage. Significant precipitation in the early stages of the study resulted in rapid leaching of the chemicals in both plots. Statistical tests show that chemicals moved deeper in the no-till plot, as compared to the conventional-tillage plot, in the first two weeks after application. However, statistical analysis of the remaining period shows no consistent differences in pesticide concentrations in the soil profile based on tillage practice. Atrazine dissipation was higher in the no-till plot, and there was a significant carryover of the pesticide in both plots at the end of the 157-day period.
- Interactions between surface water and groundwater in a Virginia coastal plain watershedEshleman, Keith N.; Pollard, John S.; Kuebler, Anne (Virginia Water Resources Research Center, Virginia Polytechnic Institute and State University, 1992-04)