Joshua Valder
Midcontinent Region Science Coordinator
Education and Certifications
Doctorate of Philosophy, Atmospheric and Environmental Sciences, 2010, South Dakota School of Mines and Technology, Rapid City,SD;
Masters of Science, Geology and Geological Engineering, South Dakota
Affiliations and Memberships*
Adjunct Professor, South Dakota School of Mines and Technology, Rapid City, SD
Science and Products
Filter Total Items: 28
Percent recoveries of anthropogenic organic compounds with and without the addition of ascorbic acid to preserve finished-water samples containing free chlorine, 2004-10
This report presents finished-water matrix-spike recoveries of 270 anthropogenic organic compounds with and without the addition of ascorbic acid to preserve water samples containing free chlorine. Percent recoveries were calculated using analytical results from a study conducted during 2004-10 for the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). The stud
Authors
Joshua F. Valder, Gregory C. Delzer, David A. Bender, Curtis V. Price
Multivariate analyses with end-member mixing to characterize groundwater flow: Wind Cave and associated aquifers
Principal component analysis (PCA) applied to hydrochemical data has been used with end-member mixing to characterize groundwater flow to a limited extent, but aspects of this approach are unresolved. Previous similar approaches typically have assumed that the extreme-value samples identified by PCA represent end members. The method presented herein is different from previous work in that (1) end
Authors
Andrew J. Long, Joshua F. Valder
Prioritization of high-production volume (HPV) chemicals for assessing water resources
PDF version of a presentation on assessing water resources given at the 2010 National Water-Quality Monitoring Conference.
Authors
James Pankow, John Zogorski, Joshua Valder, Wentai Luo
Study design and percent recoveries of anthropogenic organic compounds with and without the addition of ascorbic acid to preserve water samples containing free chlorine, 2004-06
The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) began implementing Source Water-Quality Assessments (SWQAs) in 2002 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems in the United States. As used for SWQA studies, source water is the raw (ambient) wat
Authors
Joshua F. Valder, Gregory C. Delzer, Curtis V. Price, Mark W. Sandstrom
Science and Products
Filter Total Items: 28
Percent recoveries of anthropogenic organic compounds with and without the addition of ascorbic acid to preserve finished-water samples containing free chlorine, 2004-10
This report presents finished-water matrix-spike recoveries of 270 anthropogenic organic compounds with and without the addition of ascorbic acid to preserve water samples containing free chlorine. Percent recoveries were calculated using analytical results from a study conducted during 2004-10 for the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). The stud
Authors
Joshua F. Valder, Gregory C. Delzer, David A. Bender, Curtis V. Price
Multivariate analyses with end-member mixing to characterize groundwater flow: Wind Cave and associated aquifers
Principal component analysis (PCA) applied to hydrochemical data has been used with end-member mixing to characterize groundwater flow to a limited extent, but aspects of this approach are unresolved. Previous similar approaches typically have assumed that the extreme-value samples identified by PCA represent end members. The method presented herein is different from previous work in that (1) end
Authors
Andrew J. Long, Joshua F. Valder
Prioritization of high-production volume (HPV) chemicals for assessing water resources
PDF version of a presentation on assessing water resources given at the 2010 National Water-Quality Monitoring Conference.
Authors
James Pankow, John Zogorski, Joshua Valder, Wentai Luo
Study design and percent recoveries of anthropogenic organic compounds with and without the addition of ascorbic acid to preserve water samples containing free chlorine, 2004-06
The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) began implementing Source Water-Quality Assessments (SWQAs) in 2002 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems in the United States. As used for SWQA studies, source water is the raw (ambient) wat
Authors
Joshua F. Valder, Gregory C. Delzer, Curtis V. Price, Mark W. Sandstrom
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government