Stephen Kalkhoff
Stephen Kalkhoff is currently a hydrologist with the U.S. Geological Survey, Central Midwest Water Science Center located in Iowa City, Iowa.
Biography
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.
Education
Graduate courses, Natural Resources, University of Minnesota,1979
B.S. Aquatic Biology--Bemidji State University, Bemidji, MN,1978
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
1980-1982 Hydrologist – collected water samples and prepared reports for waste assimilation studies in Mississippi
Science and Products
Assessment of Groundwater and Quality - Cedar River Project
ASSESSMENT OF GROUND-WATER AND QUALITY: Cedar River Alluvium, Cedar Rapids, Iowa
PERIOD OF PROJECT: Since 1992
PROJECT CHIEF: Steve Kalkhoff
STUDY AREA: Linn County
COOPERATING AGENCY: City of Cedar Rapids (...
Nutrient concentrations, loads, and yields in the Middle Iowa River Basin, Iowa
Concentrations, loads, and yields of nitrate plus nitrite, total nitrogen, and total phosphorus were assessed in the Iowa River upstream from the Coralville Reservoir in east-central Iowa. The results of this study describe baseline nutrient transport during two historical reference periods, 1980–96 and 2006–10, that can be used to evaluate the...
Garrett, Jessica D.; Kalkhoff, Stephen J.
Water-quality trends of urban streams in Independence, Missouri, 2005–18
The U.S. Geological Survey and the city of Independence, Missouri, Water Pollution Control Department has studied the water quality and ecological condition of urban streams within Independence since 2005. Selected physical properties, nutrients, chloride, fecal indicator bacteria (Escherichia coli and total coliform), total dissolved solids, and...
Barr, Miya N.; Kalkhoff, Stephen J.
Transport of nitrogen and phosphorus in the Cedar River Basin, Iowa and Minnesota, 2000–15
Nitrate concentrations in the Cedar River in Iowa and Minnesota have increased from an average of less than 1.0 milligram per liter in the early 1900s to more than 5.0 milligrams per liter in the 2000s and have resulted in periodic water-quality impairment of the river. Spatial differences and temporal changes in nitrogen and phosphorus transport...
Kalkhoff, Stephen J.
The effect of restored and native oxbows on hydraulic loads of nutrients and stream water quality
The use of oxbow wetlands has been identified as a potential strategy to reduce nutrient transport from agricultural drainage tiles to streams in Iowa. In 2013 and 2014, a study was conducted in north-central Iowa in a native oxbow in the Lyons Creek watershed and two restored oxbow wetlands in the Prairie Creek watershed (Smeltzer west and...
Kalkhoff, Stephen J.; Hubbard, Laura E.; Joseph P.Schubauer-Berigan
Phosphorus in sediment in the Kent Park Lake watershed, Johnson County, Iowa, 2014–15
Phosphorus data were collected from the Kent Park Lake watershed in Johnson County, Iowa, in 2014 and 2015 to obtain information to assist in the management of the water quality in the lake. Phosphorus concentrations were measured for sediment from several ponds in the watershed and sediment deposited in the lake. The first set of samples was...
Kalkhoff, Stephen J. Effect of variable annual precipitation and nutrient input on nitrogen and phosphorus transport from two Midwestern agricultural watersheds
Precipitation patterns and nutrient inputs affect transport of nitrate (NO3-N) and phosphorus (TP) from Midwest watersheds. Nutrient concentrations and yields from two subsurface-drained watersheds, the Little Cobb River (LCR) in southern Minnesota and the South Fork Iowa River (SFIR) in northern Iowa, were evaluated during 1996–2007 to...
Kalkhoff, Stephen J.; Hubbard, Laura E.; Tomer, Mark D.; James, D.E. Decadal surface water quality trends under variable climate, land use, and hydrogeochemical setting in Iowa, USA
Understanding how nitrogen fluxes respond to changes in agriculture and climate is important for improving water quality. In the midwestern United States, expansion of corn cropping for ethanol production led to increasing N application rates in the 2000s during a period of extreme variability of annual precipitation. To examine the effects of...
Green, Christopher T.; Bekins, Barbara A.; Kalkhoff, Stephen J.; Hirsch, Robert M.; Liao, Lixia; Barnes, Kimberlee K.
Occurrence and transport of nutrients in the Missouri River Basin, April through September 2011: Chapter G in 2011 floods of the central United States
Heavy snow and early spring rainfall generated substantial amounts of runoff and flooding in the upper part of the Missouri River Basin in 2011. Spring runoff in the upper and middle parts of the basin exceeded the storage capacity of the Missouri River reservoirs and unprecedented amounts of water were released into the lower parts of the basin...
Kalkhoff, Stephen J. Eleven-year trend in acetanilide pesticide degradates in the Iowa River, Iowa
Trends in concentration and loads of acetochlor, alachlor, and metolachlor and their ethanasulfonic (ESA) and oxanilic (OXA) acid degradates were studied from 1996 through 2006 in the main stem of the Iowa River, Iowa and in the South Fork Iowa River, a small tributary near the headwaters of the Iowa River. Concentration trends were determined...
Kalkhoff, Stephen J.; Vecchia, Aldo V.; Capel, Paul D.; Meyer, Michael T. Fate and transport of glyphosate and aminomethylphosphonic acid in surface waters of agricultural basins
BACKGROUND: Glyphosate [N-(phosphonomethyl)glycine] is a herbicide used widely throughout the world in the production of many crops and is heavily used on soybeans, corn and cotton. Glyphosate is used in almost all agricultural areas of the United States, and the agricultural use of glyphosate has increased from less than 10 000 Mg in 1992 to more...
Coupe, Richard H.; Kalkhoff, Stephen J.; Capel, Paul D.; Gregoire, Caroline
Environmental settings of the South Fork Iowa River basin, Iowa, and the Bogue Phalia basin, Mississippi, 2006-10
Studies of the transport and fate of agricultural chemicals in different environmental settings were conducted by the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program's Agricultural Chemicals Team (ACT) at seven sites across the Nation, including the South Fork Iowa River basin in central Iowa and the Bogue Phalia...
McCarthy, Kathleen A.; Rose, Claire E.; Kalkhoff, Stephen J. Fate and transport of glyphosate and aminomethylphosphonic acid in surface waters of agricultural basins
BACKGROUND: Glyphosate [N-(phosphonomethyl)glycine] is a herbicide used widely throughout the world in the production of many crops and is heavily used on soybeans, corn and cotton. Glyphosate is used in almost all agricultural areas of the United States, and the agricultural use of glyphosate has increased from less than 10 000 Mg in 1992 to more...
Coupe, Richard H.; Kalkhoff, Stephen J.; Capel, Paul D.; Gregoire, Caroline