William G. Crumpton


Research: Ecosystem Ecology, Environmental Systems Modeling, Biogeochemistry, Aquatic and Wetland Ecology


Teaching: Environmental Systems Analysis and Modeling;

Microbial Ecology; Water Resources


Training: B.S., Univ. of West Florida (1975)

M.S. Univ. of West Florida (1979)

Ph.D., Michigan State Univ. (1980)

post-doc, UC Davis (1980-1982)


Positions: Chair, Environmental Science Graduate Program (2003-2009)

Chair, Environmental Science UG program (1996-present)

Chair, Environmental Studies UG Program (1994-present)

Environmental Programs Coordinator (1994-present)

Chair, Water Resources Graduate Program (1990-1994)

Assoc. Prof., Botany/EEOB, ISU (1991-present)

Asst. Prof., Botany, ISU (1982-1988)


Academic programs: I have been actively involved in interdisciplinary academic programs for as long as I have been at ISU, and have served as chair or interim chair for four separate majors including two undergraduate majors, Environmental Studies and Environmental Science, and two graduate majors, Water Resources (now Environmental Science) and Ecology and Evolutionary Biology.


Research program: Much of my current research focuses on wetland processes and functions, including the dynamics of energy flow and nutrient transformation in wetlands, the fate and effects of contaminants in wetlands, and the role wetlands in watershed hydrology and water quality. Our work combines experimental studies in wetland mesocosms, field studies in natural and restored wetlands, and dynamic simulation modeling in an effort to understand critical processes and predict wetland performance. Much of my personal effort is directed toward the development and application of performance forecast models for siting, design and assessment of wetland restorations in agricultural watersheds. We have developed and field validated a general model for nitrate loss in wetlands receiving non-point source loads, and have integrated this model in a watershed scale framework for performance forecast modeling of alternative wetland restoration scenarios. This work provided the research foundation for the Iowa Conservation Reservation Enhancement Program, a ten-year, $89 million program using targeted wetland restorations to reduce nitrate loads from tile-drained agricultural watersheds.


Selected publications

Dale, V.H., C. Kling , J .L. Meyer, J. Sanders, H. Stallworth, T. Armitage, D. Wangsness, T.S. Bianchi, A. Blumberg, W. Boynton, D.J. Conley, W. Crumpton, M.B. David, D. Gilbert, R .W. Howarth, R. Lowrance , K. Mankin, J. Opaluch, H. Paerl, K. Reckhow, A.N. Sharpley, T .W. Simpson, C. Snyder, D. Wright. 2010. Hypoxia in the Northern Gulf of Mexico. Springer, New York, 284 pages.

Miller, B. A., W.G. Crumpton, and A. van der Valk. 2009. Spatial distribution of historical wetland classes on the Des Moines Lobe of Iowa. Wetlands, 29:1146-1152.

Christensen , J.R., W.G. Crumpton, and A.G. van der Valk, 2009.Estimating the breakdown and accumulation of emergent macrophyte litter: a mass balance approach. Wetlands , 29:204-214.

Miller, B. A., L. Burras, and W.G. Crumpton. 2008. Using soil surveys to map quaternary parent materials and landforms across the Des Moines Lobe of Iowa and Minnesota. Soil Survey Horizons, 49:83-86.

Iovanna, R., S. Hyberg, and W. Crumpton. 2008. Treatment wetlands: Cost-effective practice for intercepting nitrate before it reaches and adversely impacts surface waters. Journal of Soil and Water Conservation, 63 (1): 14A-15A.

Crumpton, W.G., Kovacic, D., Hey, D., and Kostel, J., 2008. Potential of wetlands to reduce agricultural nutrient export to water resources in the Corn Belt. pp. 29-42 in Gulf Hypoxia and Local Water Quality Concerns Workshop , ASABE Pub #913C0308.

Parker, A., N. Andrews, M. Clark, C. Craft, W. Crumpton, I. Davis, N. Detenbeck, P. McCormick, K. Pintado, S. Potts, T. Rasmussen, R. Reddy, R. Stevenson, and A. van der Valk. 2007. Nutrient Criteria Technical Guidance Manual: Wetlands. Office of Water, U. S. Environmental Protection Agency, Washington, DC. EPA-822-R-07-004. 185 p.

Rose, C. and W.G. Crumpton. 2006. Spatial patterns in dissolved oxygen and methane concentrations in a prairie pothole wetland in Iowa, USA. Wetlands, 26:1020-1025.

Crumpton, W.G. 2005. Water quality benefits of wetland restoration: a performance based approach. pp. 183-190 in The Conservation Reserve Program-Planting for the future: Proceedings of a National Conference, ( Fort Collins, Colorado, June 6-9, 2004), eds. A.W. Allen and M.W. Vandever. U.S. Geological Survey Scientific Investigations Report 2005-5145, 248p.

Baker, J.L., S.W. Melvin, D.W. Lemke, P.A. Lawlor, W.G. Crumpton, and M.J. Helmers.  2004.  Subsurface drainage in Iowa and the water quality benefits and problem. pp. 39-50 in Proceedings of the Eighth International Drainage Symposium, ( Sacramento, California, USA), ed. Richard Cooke. ASAE Pub #701P0304.

Crumpton, W.G. 2001. Using wetlands for water quality improvement in agricultural watersheds: the importance of a watershed scale perspective. Water Science and Technology. 44: 559-564.

Lemly, A.D., G.R. Best, W.G. Crumpton, M.G. Henry, D.D. Hook, G.L. Linder, P.H. Masscheleyan, H.G. Peterson, T. Salt, and R.G. Stahl, Jr. 1999. Contaminant fate and effects in freshwater wetlands. pp. 69-151 in M.A. Lewis, F.L. Mayer, R.L. Powell, M.K. Nelson, S.J. Klaine, M.G. Henry, and G.W. Dickson (Eds) Ecotoxicology and Risk Assessment for Wetlands. SETAC Pellston Workshop on Ecotoxicology and Risk Assessment for Wetlands. Society of Environmental Toxicology and Chemistry, Pensacola, FL 375 p.

Goldsborough, L.G. and W.G. Crumpton. 1998. Distribution and environmental fate of pesticides in prairie wetlands. Great Plains Research, 8:73-95.

Crumpton, W.G. and L.G. Goldsborough. 1998. Nitrogen transformation and fate in prairie wetlands. Great Plains Research, 8:57-72.


Selected presentations

Potential Impact of Targeted Wetland Restoration on Nitrate Loads to Mississippi River Subbasins: Performance Forecast Modeling of Loads and Load Reductions. Poster presentation at Soil and Water Conservation Society Meetings, Des Moines, IA, Dec 2009.

Water quality performance of wetlands receiving nonpoint source loads: wetland nitrate removal efficiency and potential load reductions using targeted wetland restorations. Invited presentation at Society of Wetland Scientists Annual Meeting, Madison, WI, June 2009.

Integrated Drainage and Wetland Systems.Invited presentation at the Leopold Center Conference on ”Hypoxia in the Gulf of Mexico: Implications and Strategies for Iowa.” Iowa State University, October 2008.

Predicting Water Quality Perfomance of Wetlands Receiving Nonpoint Source Loads: Nitrate Removal Efficiency and Mass Load Reduction by Emergent Marshes.Invited presentation at STAC Special Session on Quantifying the Role of Wetlands in Achieving Nutrient and Sediment Reductions in Chesapeake Bay, the10th Symposium on Biogeochemistry of Wetlands, Annapolis, MD, April 2007.

Water Quality Functions of Restored Wetlands.Invited presentation at annual meeting of the Soil Science Society of America, special symposium on Soil and Water Quality Functions of Midwestern Wetlands, Indianapolis, IN, November 2006.

Geographic and Landscape Scale Considerations for Wetlands and Water Quality Trading.Invited presentation at “USEPA Research Planning Conference on the Role of Wetlands in Water Quality Trading”, Chicago, Il, February 2006.

Reducing Nutrient Loading in the Mississippi River: Scale and Targeting of Wetland Restoration in the Upper Basin.Invited presentation at Sand County Foundation’s North South Basin Summit II, New Orleans, La, February 2006.

Targeted Wetland Restoration for Water Quality Improvement: Potential Impacts on Nitrate Loads to Mississippi River Subbasins.Invited presentation at annual meeting of the American Society of Ecological Engineering, Ohio State University, Columbus May 2005.

Water Quality: Nutrient Processing by Wetlands in Agicultural Watersheds . Invited presentation at annual meeting of the American Society of Limnology & Oceanography. Savannah, Ga. June, 2004.

Water Quality Benefits of Wetland Restoration: A performance Based Approach.Invited presentation at FSA/USGS national conference “CRP: Planting for the Future”, Fort Collins, Co, June 2004.

Restoring Wetlands as N Sinks in Agricultural Watersheds: Siting, Design, and Performance Considerations.Invited presentation at the Columbus Workshop on Restoration of the Mississippi River Basin, Ohio State University, October 2003.

Effects of Vegetation Patterns on Biogeochemical Processes in Prairie Pothole Wetlands.Invited presentation at the7th Symposium on Biogeochemistry of Wetlands, Duke University, June 2001.

Using Wetlands for Water Quality Improvement in Agricultural Watersheds; the Importance of a Watershed Scale Approach.Invited presentation at 7th International Conference on Wetland Systems for Water Pollution Control, Lake Buena Vista, FL, November 2000.

Dynamics of Nitrate Loss in Emergent Wetlands: Wetlands as Sinks for Non-Point Source Nitrate Loads.Invited presentation as part of the Duke University Wetland Center’s Distinguished Speaker Series, Duke University, December 3, 1999.

Use of Performance Forecast Models in Siting and Design of Wetlands for Nonpoint Source Water Quality Remediation . Invited presentation at annual meeting of the Soil Science Society of America, special symposium on Use of Natural Resource Information in Wetland Creation and Restoration, October 20, 1998. Baltimore, Maryland.

Nutrient assimilation in Great Plains/Prairie wetlands . Invited presentation at Society of Wetland Scientists Annual Meeting, Bozeman, MT, June 1997.


Selected recent research projects (last 5 years, projects over $50,000)

(T echnical reports available for completed projects)


USEPA Targeted Watershed Project: Integrated Drainage-Wetland Systems for Reducing Nitrate Loads from Des Moines Lobe Watersheds . USEPA subgrant through Iowa Department of Agriculture and Land Stewardship; W. Crumpton & Matt Helmers Co-PIs.

January 1, 2005-September 30, 2012. $1,501,098

Water and Nutrient Research: In-field and Offsite Strategies. IA Dept. of Ag. and Land Stewardship; M. Helmers & W. Crumpton Co-PIs. Multi year project with annual allocations for studies of in-field management practices and performance of nitrate removal wetlands.

January 2010-December 2014. Projected 5 yr total is shown. $2,123,188

Assessment of Environmental Services of CREP Wetlands in Iowa and the Midwestern Corn Belt. USDA; D. Otis and W. Crumpton Co-PIs.

Sep 1, 2007 –December 31, 2009 $112,577

Water Quality Performance of Iowa Wetlands. IA Dept. of Natural Resources, W. Crumpton PI. Multi year project addressing phosphorous removal in wetlands receiving agricultural drainage.

July 2005-December 2009. $861,907

Water and Nutrient Research: In-field and Offsite Strategies. IA Dept. of Ag. and Land Stewardship; M. Helmers & W. Crumpton Co-PIs. Multi year project with annual allocations for studies of in-field management practices and performance of nitrate removal wetlands.

January 2005-December 2009. 5 yr total is shown. $1,506,158

Potential Benefits of Wetland Filters for Tile Drainage Systems: Impacts on Nitrate Loads to Mississippi River Subbasins. USDA; W. Crumpton PI (M.Helmers,J. Baker & S.Melvin Co-PIs) .

May 2004-September 30, 2005 $100,000

Quantification of Nutrient Inputs into the Iowa Great Lakes. USEPA; A.G. van der Valk PI & W.G. Crumpton Co-PIs.

October 2002 – September 2005 $99,641