Stephen Kalkhoff
Stephen Kalkhoff is currently a hydrologist with the U.S. Geological Survey, Central Midwest Water Science Center located in Iowa City, Iowa.
Steve has more than 40 years experience with the USGS in Mississippi and Iowa. While in Mississippi, his work involved documenting contamination from oil production and coastal saltwater intrusion due to industrial pumping. Steve's work in Iowa involved study of the impact of agriculture on surface and ground water in karst areas, impact of agriculture on quality of water in public supply reservoirs, impact of large-scale animal production on water quality, and impact of increased corn production for use by the ethanol industry. His studies have documented the occurrence, transport and in some case trends in nutrients, pesticides, and sediment.
Professional Experience
2015-present Project Chief of a study of spatial and temporal variability of nutrients and pesticides in an alluvial aquifer that is the source of municipal supply
2012-2014 Documented the ability of oxbow wetlands to reduce transport of nutrients from agricultural drainage tiles as Project Chief of US EPA funded project
2011-2012 Documented transport of nutrients during the record 2011 flooding in the Missouri River
2008-2009 Member of team that documented nutrient and sediment transport during record 2008 floods in Eastern Iowa
2004-2008 Project Chief - Transport of nutrients and pesticides from Iowa to the Missouri and Mississippi River study Cooperative Iowa DNR /USGS project
2004-2005 Project Chief USGS, Central Region Integrated Science program (CRISP) Perchlorate reconnaissance of surface and ground water in the United States
2000-2002 Team Member – Heinz Center Report on the State of the Nation’s water resources
1994-2012 Chief of the Eastern Iowa Basins (EIWA) study unit USGS National Water-Quality Assessment program
1986-1994 Project Chief – Big Spring project (study impact of changing land use practices on water quality in an area of karst topography in Iowa) Cooperative Iowa DNR/USGS project
1982-1986 Project Chief – Brine contamination of surface and ground water in Mississippi Cooperative Mississippi DNR/ USGS project
1985 Hydrologist – collected water samples and mapped chloride concentration gradient along Mississippi Gulf Coast to document saltwater intrusion
Education and Certifications
Graduate courses, Natural Resources, University of Minnesota,1979
B.S. Aquatic Biology--Bemidji State University, Bemidji, MN,1978
1980-1982 Hydrologist – collected water samples and prepared reports for waste assimilation studies in Mississippi
Science and Products
Herbicides and transformation products in surface waters of the Midwestern United States
Herbicides and herbicide degradation products in upper midwest agricultural streams during august base-flow conditions
It's not just how high; it's how clean: Sampling the spring 2001 flood in the Upper Mississippi River Basin
Occurrence and distribution of pesticides in streams of the Eastern Iowa Basins, 1996-98
The occurrence of chloroacetanilide and triazine herbicide degradates in streams in eastern Iowa
Water quality in the eastern Iowa basins
Influence of natural factors on the quality of midwestern streams and rivers
Water-quality assessment of the eastern Iowa basins– Nitrogen, phosphorus, suspended sediment, and organic carbon in surface water, 1996–98
Summary of the major water-quality findings from the Eastern Iowa Basins study unit of the National Water-Quality Assessment Program
Major ground-water findings from the National Water-Quality Assessment Program (NAWQA) in Iowa
Water quality in the eastern Iowa basins, Iowa and Minnesota, 1996-98
Occurrence of acetochlor and acetochlor metabolites in alluvial aquifers in Iowa
Science and Products
- Science
- Data
- Publications
Filter Total Items: 71
Herbicides and transformation products in surface waters of the Midwestern United States
Most herbicides applied to crops are adsorbed by plants or transformed (degraded) in the soil, but small fractions are lost from fields and either move to streams in overland runoff, near surface flow, or subsurface drains, or they infiltrate slowly to ground water. Herbicide transformation products (TPs) can be more or less mobile and more or less toxic in the environment than their source herbicAuthorsW.A. Battaglin, E. M. Thurman, S. J. Kalkhoff, S. D. PorterHerbicides and herbicide degradation products in upper midwest agricultural streams during august base-flow conditions
Herbicide concentrations in streams of the U.S. Midwest have been shown to decrease through the growing season due to a variety of chemical and physical factors. The occurrence of herbicide degradation products at the end of the growing season is not well known. This study was conducted to document the occurrence of commonly used herbicides and their degradation products in Illinois, Iowa, and MinAuthorsS. J. Kalkhoff, K. E. Lee, S. D. Porter, P. J. Terrio, E. M. ThurmanIt's not just how high; it's how clean: Sampling the spring 2001 flood in the Upper Mississippi River Basin
Floods can cause water-quality problems because of the large amounts of contaminants (sediment, nutrients, pesticides, and bacteria) that can be transported by floodwaters. during the flood on the Upper Mississippi River in 2001, water-quality and water-quality data were collected during near-record streamflow. This is the first time that samples for determining organic wastewater contaminants (phAuthorsGlenn Patterson, Dana W. Kolpin, Stephen J. Kalkhoff, Kathy Lee, Douglas J. Schnoebelen, Kimberlee K. Barnes, Richard H. CoupeOccurrence and distribution of pesticides in streams of the Eastern Iowa Basins, 1996-98
The U.S. Geological Survey began collection of water samples in streams of the Eastern Iowa Basins in 1996 for the analysis of pesticides and pesticide degradates as part of the National Water Quality Assessment Program (NAWQA). This study provides some of the first large scale monitoring data on pesticides and pesticide degradates in Eastern Iowa. Three hundred and forty-four samples were collectAuthorsDouglas J. Schnoebelen, Stephen J. Kalkhoff, Kent BecherThe occurrence of chloroacetanilide and triazine herbicide degradates in streams in eastern Iowa
No abstract available.AuthorsStephen J. Kalkhoff, Douglas J. Schnoebelen, Earl Michael ThurmanWater quality in the eastern Iowa basins
This article summarizes major findings about nutrients in surface and groundwater in the eastern Iowa basins (see map) between 1996 and 1998. The data were collected as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA). Water quality is discussed in terms of local and regional issues and compared with conditions found in all 36 National NAWQA study areas aAuthorsStephen J. Kalkhoff, Kimberlee K. Barnes, Kent Becher, Mark E. Savoca, Douglas J. Schnoebelen, Eric M. Sadorf, Stephen D. Porter, Daniel J. Sullivan, John CreswellInfluence of natural factors on the quality of midwestern streams and rivers
Streams flowing through cropland in the Midwestern Corn Belt differ considerably in their chemical and ecological characteristics, even though agricultural land use is highly intensive throughout the entire region. These differences likely are attributable to differences in riparian vegetation, soil properties, and hydrology. This conclusion is based on results from a study of the upper Midwest reAuthorsStephen D. Porter, Mitchell A. Harris, Stephen J. KalkhoffWater-quality assessment of the eastern Iowa basins– Nitrogen, phosphorus, suspended sediment, and organic carbon in surface water, 1996–98
Twelve sites on streams and rivers in the Eastern Iowa Basins study unit were sampled monthly and during selected storm events from March 1996 through September 1998 to assess the occurrence, distribution, and transport of nitrogen, phosphorus, suspended sediment, and organic carbon as part of the U.S. Geological Survey’s National Water-Quality Assessment Program. One site was dropped from monthlyAuthorsKent Becher, Stephen J. Kalkhoff, Douglas J. Schnoebelen, Kimberlee K. Barnes, Von E. MillerSummary of the major water-quality findings from the Eastern Iowa Basins study unit of the National Water-Quality Assessment Program
An integrated assessment of the water quality in streams and aquifers in the Wapsipinicon, Iowa, Cedar, and Skunk River basins was conducted in 1996 through 1998 as part of the Eastern Iowa Basins (EIWA) study unit of the U.S. Geological Survey's National Water-Quality Assessment Program (NAWQA). The EIWA study unit is one of 59 study units across the Nation designed to assess the status and trendAuthorsStephen J. KalkhoffMajor ground-water findings from the National Water-Quality Assessment Program (NAWQA) in Iowa
No abstract available.AuthorsStephen J. KalkhoffWater quality in the eastern Iowa basins, Iowa and Minnesota, 1996-98
The water quality in rivers and streams and in selected aquifers in eastern Iowa and part of southern Minnesota is described and illustrated. Major ions, nitrogen and other nutrients, and pesticides and some of their breakdown compounds were analyzed in both surface and ground water. Biological communities that included fish, invertebrates, and algae, were described in relation to stream water quaAuthorsStephen J. Kalkhoff, Kimberlee K. Barnes, Kent Becher, Mark E. Savoca, Douglas J. Schnoebelen, Eric M. Sadorf, Stephen D. Porter, Daniel J. SullivanOccurrence of acetochlor and acetochlor metabolites in alluvial aquifers in Iowa
No abstract available.AuthorsStephen J. Kalkhoff, Mark E. Savoca, Eric M. Sadorf, Dana W. Kolpin, Earl M. Thurman