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
Water quality of Corydon Reservoir before implementation of agricultural best-management practices in the basin, Wayne County, Iowa, September 1990 to September 1991
Atrazine degradation in a small stream in Iowa
Brine contamination of ground water and streams in the Baxterville oil field area, Lamar and Marion Counties, Mississippi
Herbicide and nitrate variation in alluvium underlying a cornfield at a site in Iowa County, Iowa
Time of travel and dispersion in a selected reach of Roberts Creek, Clayton County, Iowa
Hydrologic data for the Big Spring basin, Clayton County, Iowa, water year 1990
Hydrologic data for the Big Spring basin, Clayton County, Iowa; water year 1989
Quality of water and bottom material of streams that drain potential lignite mining areas in the outcrop area of the Wilcox Group in Mississippi
Hydrologic data for the Big Spring basin, Clayton County, Iowa, water year 1988
Geohydrology and simulated effects of withdrawals on the Miocene aquifer system in the Mississippi Gulf Coast area
Background hydrologic information in potential lignite mining areas in north-central Mississippi, August 1985
Brine contamination of shallow ground water and streams in the Brookhaven Oil Field, Lincoln County, Mississippi
Science and Products
- Science
- Data
- Publications
Filter Total Items: 71
Water quality of Corydon Reservoir before implementation of agricultural best-management practices in the basin, Wayne County, Iowa, September 1990 to September 1991
A hydrologic investigation to define the water quality of Corydon Reservoir before implementation of agricultural best-management practices in the basin was conducted from September 1990 to September 1991. Runoff from the 1,680-acre basin is the primary source of water to the 58-acre reservoir. Current water quality of the reservoir is affected substantially by runoff from the agricultural basin.AuthorsS. J. KalkhoffAtrazine degradation in a small stream in Iowa
A study was conducted during 1990 through an 11.2-km reach of Roberts Creek in northeastern Iowa to determine the fate of atrazine in a surface water environment Water samples were collected at ~1-month intervals from April through November during stable low to medium flow conditions and analyzed for atrazine and two of its initial biotic degradation products, desethylatrazine and deisopropylatrazAuthorsD.W. Kolpin, S. J. KalkhoffBrine contamination of ground water and streams in the Baxterville oil field area, Lamar and Marion Counties, Mississippi
A hydrologic investigation to define the extent of brine contamination in ground water and streams in the Baxterville oil field area was conducted from October 1984 through November 1985. The 260-square-mile study area includes the Baxterville oil field (approximately 12.5 square miles) in southwestern Lamar and southeastern Marion Counties, Mississippi. Since 1944, disposal of more thanAuthorsStephen J. KalkhoffHerbicide and nitrate variation in alluvium underlying a cornfield at a site in Iowa County, Iowa
A hydrologic investigation to determine vertical and seasonal variation of atrazine, alachlor, cyanazine, and nitrate at one location and to relate the variation to ground-water movement in the Iowa River alluvium was conducted in Iowa County, Iowa, from March 1986 to December 1987. Water samples were collected at discrete intervals through the alluvial sequence from the soil zone to the base of tAuthorsS. J. Kalkhoff, M.G. Detroy, K. Cherryholmes, R.L. KuzniarTime of travel and dispersion in a selected reach of Roberts Creek, Clayton County, Iowa
Time of travel and dispersion were determined in a 9.4-river-mile reach of Roberts Creek in northwestern Clayton County, Iowa, in the spring of 1990. Time of travel was determined so that a discrete parcel of water could be sampled through the study area during medium to low streamflow conditions. Dispersion characteristics were determined to identify solute-transport differences under two streamfAuthorsD.W. Kolpin, S. J. KalkhoffHydrologic data for the Big Spring basin, Clayton County, Iowa, water year 1990
Hydrologic data were collected in the Big Spring basin located in Clayton County, Iowa, during the 1990 water year. The data were collected by the U.S. Geological Survey in cooperation with the Iowa Department of Natural Resources, Geological Survey Bureau, to provide information on variation and movement of agricultural chemicals in the hydrologic cycle in the basin. Precipitation, surface-water,AuthorsStephen J. Kalkhoff, R.L. Kuzniar, D. Kolpin, C.A. HarveyHydrologic data for the Big Spring basin, Clayton County, Iowa; water year 1989
Hydrologic data were collected in the Big Spring Basin located in Clayton County, Iowa, during the 1989 water year. The data were collected in cooperation with the Iowa Department of Natural Resources, Geological Survey Bureau, to provide information on variation and movement of agricultural chemicals in the hydrologic cycle in the Big Spring Basin. Precipitation, stream, and ground-water data werAuthorsS. J. Kalkhoff, R.L. KuzniarQuality of water and bottom material of streams that drain potential lignite mining areas in the outcrop area of the Wilcox Group in Mississippi
No abstract available.AuthorsS. J. KalkhoffHydrologic data for the Big Spring basin, Clayton County, Iowa, water year 1988
Hydrologic data was collected during the 1988 water year in cooperation with the Iowa Department of Natural Resources Geological Survey Bureau in the Big Spring ground-water basin located in Clayton County, Iowa. Information on precipitation, streams, and ground water was collected in the basin. Total rainfall at Big Spring was 24.08 inches. The greatest monthly rainfall was in September. CalciumAuthorsStephen J. KalkhoffGeohydrology and simulated effects of withdrawals on the Miocene aquifer system in the Mississippi Gulf Coast area
Intense development of the Miocene aquifer system for water supplies along the Mississippi Gulf Coast has resulted in large water level declines that have altered the groundwater flow pattern in the area. Water levels in some Miocene aquifers have declined about 2 ft/year since 1940; declines exceed 100 ft (80 ft sea level) in large areas along the coast. Water levels in the surficial aquifer systAuthorsD. M. Sumner, B. E. Wasson, S. J. KalkhoffBackground hydrologic information in potential lignite mining areas in north-central Mississippi, August 1985
The U.S. Geological Survey, in cooperation with the Mississippi Department of Natural Resources, Bureau of Geology, is conducting a hydrologic data collection program in potential lignite-producing areas in the outcrops of the Wilcox Group in Mississippi. During August 1985, hydrologic data were collected at a total of 15 stream sites in Benton, Lafayette, Marshall, and Union Counties. Main channeAuthorsS. J. KalkhoffBrine contamination of shallow ground water and streams in the Brookhaven Oil Field, Lincoln County, Mississippi
A hydrologic investigation to define areas of brine contamination in shallow freshwater aquifers commonly used for streams that drain the Brookhaven Oil Field, was conducted from October 1983 to September 1984. The Brookhaven Oil Field covers approximately 15 sq mi in northwestern Lincoln County, Mississippi. Since 1943, disposal of approximately 544.2 million barrels of brine pumped from the oilAuthorsS. J. Kalkhoff