Members
Future Students:
I am always seeking curious, motivated graduate and undergraduate students with an interest in environmental fate and transport of contaminants to join our group. A list of ongoing and past projects is available under the Research page of this website.
Students in our group gain skills related to environmental sampling and analysis through a mix of lab and field experiences that rely upon collaborative teamwork.
MS/PhD students and some undergraduate students (Undergraduate Research Opportunity) gain written communication skills through the development of a research proposal in an area of mutual interest and oral communication skills through public presentations and regional, national, and international conferences.
Funding for graduate students in my lab has come from a mix of state, federal and local resource management agencies as well as Teaching Assistant positions and internal U of MN fellowships.
Applications for graduate studies in the Water Resources Science graduate program and the UMD Civil Engineering graduate program are typically submitted before mid-December each year and reviewed during the early spring.
Students interested in joining our group as an undergraduate researcher should submit a letter of interest and resume directly to me, or contact me about an application to the U of MN's UROP program.
Nathan W. Johnson Professor & Director of Graduate Studies
Department of Civil Engineering
University of Minnesota Duluth
Primary Zoom Office:
https://umn.zoom.us/j/5519796584
221 Swenson Civil Engineering
Duluth, MN 55812
ofc: 218-726-6435
BS Princeton University, 2003
MS/PhD University of Texas at Austin, 2005 & 2009
Current Students/Staff:
Britta Larson (MS Candidate, Water Resources Science, coadvised with Chan Lan Chun; BS Biology, UW Superior, 2022)
Britta's research is helping to understand the feasibility of amending unhealthy wild rice sediment with an innoculum of microbial communities from healthy, reproducing environments.
Anna Peterson (MS Candidate, Water Resources Science, coadvised with Afton Clarke-Sather; BS Biology, UMD, 2022)
Anna's research is helping to understand whether practices and governance structures of lake associations are systematically associated with improved lake water quality.
Marissa Castro (MS Candidate, Water Resources Science; BS Biology, San Francisco State, 2017)
Marissa is working to understand and describe the spatial distribution of MeHg and what it can tell us about MeHg sources to freshwater wetlands.
Kylie Pesik (BS Candidate, Mathematics and Statistics)
Kylie counted and weighed and ground a bazillion wild rice seeds to measure the quantity of metals and starch to help infer the nutritional quality of the rice grain.
Chase Boyer (BS Candidate, Chemical Engineering)
Chase is the mastermind behind what we anticipate being a successful wild rice growing season in the wild rice mesocosms at the UMD Research farm.
Past Students/Staff (updated Spring 2024):
Graduate Student & Researchers alumni
Nick Eshleman (BS Chemical Engineering, UMD, 2021) Nick was the mastermind behind efforts to sequester sulfur in iron materials following biological sulfate treatment of industrial wastewater. And he kept the lab running smoothly.
Jeremy Laurich (MS Water Resources Science, 2023; Water Resources Science; BS Biology, Bemidji State, 2021; currently at MN DNR)
Jeremy's research sought to understand the variability of nutritional properties of wild rice seeds in the context of their growth environment.
Kelsey Hogan (MS Civil Engineering, 2022; BS Mathematics and Chemistry, Carthage College, 2016; currently at Met Council, Twin Cities, MN)
Kelsey's research involved combining an understanding of the mechanisms involved in mercury removal with an evaluation of the efficacy of common municipal wastewater treatment approaches in removing particles (and mercury).
Amanda Brennen (PhD, Water Resources Science, 2021; MS Zoology, Southern Illinois University 2008, currently at EPA Research Triangle Park, NC)
Amanda's PhD involved developing a framework for incorporating the bioavailability of sediment contaminants into risk assessment.
Geordee Spilkia (MS, Water Resources Science, 2021; BS Environmental Science, Temple University, 2016; currently at Integral Consulting, Portland, OR)
Geordee studied the ways in which mercury binds to different organic and inorganic ligands in wastewater to help inform guidance to wastewater treatment plants.
Sophie LaFond-Hudson (with John Pastor; PhD, Water Resources Science, 2020; MS, Water Resources Science, UMN, 2016; BA Chemistry and Environmental Studies, St. Olaf College, 2014; currently Postdoc at Oak Ridge National Lab) Sophie's PhD dissertation covered the interaction among iron and sulfur in the near-root area of wild rice sediment.
Amber White (MS, Water Resources Science, 2020; BS Biology and Environmental Science, Loyola University Chicago, 2016, currently PhD student at UW Madison ) Amber's MS research involved the bioavailability of mercury in the St. Louis River Estuary, especially the sulfur and iron chemistry affecting mercury methylation and partitioning.
Jake Daire (with Chanlan Chun; MS, Civil Engineering, 2019; BSCE, UMD, 2017; currently with Barr Engineering, Duluth, MN); Jake worked on a project seeking to characterize mining waste materials in terms of their ability to release iron for the purposes of capturing sulfide in water treatment. He was also awarded a UROP project that involves quantifying the residence time and chloride balance of a local lake (Pike Lake).
Logan Bailey (MS, Water Resources Science, 2015; currently with MA Dept of Health, Boston, MA)
Logan did his MS research in the context of the DNR's MWRAP study investigating methyl mercury production and transport in sulfate-impacted lakes and wetlands.
Will DeRocher (MS, Civil Engineering, 2014; currently with TKDA, Duluth, MN)
Will did his MS research in the context of the MPCA wild rice sulfate standard study, specifically on the temperature dependency of sulfate diffusion and reaction in sediment.
Brian Beck (MS, Water Resources Science, 2013; currently with Minnehaha Creek Watershed District, Minneapolis, MN)
Brian completed his MS thesis on a project which investigated the influence of sulfate and carbon on methyl mercury in St. Louis River estuary sediment.
Dan Fraser (Junior Scientist, Civil Engineering; BS Biology, University of Wisconsin Superior, 2013, currently with MN Power, Duluth, MN)
Dan worked in our group as a full-time researcher from 2013 - 2017. He spent significant time on the Corps of Engineers-State of MN Bioavailability and the MPCA Hi 5 mercury projects and helping to manage the lab.
Ben Zhu (Postdoctoral Scholar, 2011-2013)
Ben worked on the Pumped Hydro project, was involved in the design of the Dredged Fines/Biosolids projects, and prelimninary work on the St Louis Bioavailability study. He also developed several stormwater-related research ideas.
Undergraduate alumni
Luke Hillman (BS, Civil Engineering, 2024) Luke helped to maintain mesocosms at the UMD farm, has helped extract sulfur from the lab and has softened hundreds of gallons of water to remove Ca for our water treatment system.
Isaac Martin (BS, Civil Engineering, 2023) Isaac helped to shuttle rice seed and water samples through analytical process for understanding how the nutritional quality of wild rice relates to water and sediment chemistry.
Brian Peters (BS, Civil Engineering, 2023) Brian helped maintain mesocosms investigating the fate of sediment mercury in surface waters and food webs in the context of activated carbon amendments. He also extracted sulfur from a bazillion sediment and wastewater samples.
Addie Johnson (BS, Environmental Science, 2022) Addie was the mastermind behind a successful wild rice growing season in the wild rice mesocosms at the UMD Research farm.
Mitch Jans (BS, Civil Engineering, 2022; currently PhD candidate, Princeton University) Mitch worked on research to understand the adsorption of mercury and methyl mercury to activated carbon in mesocosm studies.
Joey Pesik (BS, Civil Engineering, 2022) Joey has developed and maintained several analytical methods aimed at quantifying sulfur and iron in solid and liquid phases of environmental samples. He has also counted a bajillion wild rice seeds.
Victoria Neumann (BS Candidate, Chemistry) Victoria measured the speciation of sulfur in support of various projects and assisting with extracting dissolved organic matter from wastewater.
Leah Higgins (BS, Chemical Engineering, 2022) Leah helped to support the mesocosm and field efforts to understand how sulfur and sediment geochemistry/microbiology impact wild rice growth, reproduction, and nutrition.
Afton Douville (BS, Civil Engineering, UMD; 2020) Afton helped to get our wastewater Hg project off the ground and provided general lab assistance to other ongoing efforts.
Rene Nelson (Undergraduate, Chemistry) Rene worked to support analytical measurements and field sample collection for ongoing mercury and wild rice research.
Sam Fink (Undergraduate, Civil Engineering, 2018) Sam supported work on mercury in estuary water and sediment and helped with other projects in the lab.
Matt McDermott (Undergraduate, Civil Engineering) Matt worked on data analysis for wild rice and contaminated estuary sediment.
Jared Nash (Undergraduate, Civil Engineering, 2017) Jared worked on quantifying iron and sulfur in acid extractions for sediment and plant roots.
Nick Osmundson (Undergraduate, Civil Engineering, 2016) Nick started by helping to organize a lab cleanup project, but later was plugged into research related to the capacity for iron in sediments to remove sulfide. He pursued a method to quantify the "sulfide absorption capacity" of iron in sediments.
Anna Jefferson (Undergraduate, Civil Engineering, 2015)
Anna helped with bioaccumulation and SPME pore water analysis of PAHs in sediments. She also became the institutional knowledge for the group for microelectrodes to quantify fine-scale chemical gradients in the proximity of the sediment water interface, especially in the context of the Lake Superior seiche's effect on St. Louis Estuary sediments.
Joe Sternberg (Undergraduate, Civil Engineering, 2015)
Joe worked on measuring sulfide, iron, and pH in wild rice sediment with equilibrium "peeper" pore water samplers. He took the lead in data entry and validation.
Aaron Mika (Undergraduate, Civil Engineering, 2014)
Aaron led the the dredged material - biosolids leaching project. He also helped with various sampling initiatives and metals analysis on ICP-MS. He began an effort to quantify the capacity of iron in sediments to absorb sulfide.
Kyle Morberg (Undergraduate, Civil Engineering, 2014)
Kyle helped primarily with the mercury study in the St Louis River Estuary and several other ongiong projects. He also worked in the lab on quantifying water chemistry samples for several analytes.
Ryan Armstrong (Undergraduate, Civil Engineering, 2014)
Ryan assisted with the temperature dependent sulfate project as well as mesocosm and field porewater measurements. He assisted the biology department in quantifying fine-scale chemical gradients near the surface of corroding steel.
Yer Lee (Undergraduate, Civil Engineering, 2013)
Yer helped fabricate lab equipment and with analysis of sediment samples for the Corps of Engineers - State of MN Bioavailability study. She also helped with field sampling and analysis for the 2013 MPCA wild rice Project.
Alex Dickhaus (Undergraduate, Civil Engineering, 2013)
Alex spearheaded the massive effort to deploy peepers in mesocosms and field sites for the MPCA Wild Rice project in 2013 and subsequently helped Amanda with SPME analysis of PAHs in sediments.
Nathan Geiske (Undergraduate, Civil Engineering, 2012)
Nathan worked on a short UROP project that used Solid Phase Microextraction (SPME) fibers to measure Polycyclic Aromatic Hydrocarbons (PAH). He later assisted with various projects.
Max Elfelt (Undergraduate, Environmental Science, 2012)
Max worked on a UROP project that used mushrooms to degrade Polycyclic Aromatic Hydrocarbon (PAHs) contaminants in aquatic sediment.
Paul Kimpling (Undergraduate, Environmental Science, 2011)
Paul worked on the Pumped Hydro project but focused on the environmental impacts associated with mining. Following graduation in Spring 2011, he took a job at a local architectural firm and is considering graduate school in the future.
Abdiqadar Mohamud (Undergraduate, Chemical Engineering, 2011)
Abdi worked on the Pumped Hydro project and focused on reviewing and synthesizing the environmental impacts associated with hydroelectric power.
Summer visiting scholars (REU, STEM, etc.)
Michelle Anderson (Leech Lake Community College, NSF-REU, 2021)
Jackie Holman (University of Minnesota Morris, NSF-REU, 2021)
Sydney Crockett (Beloit College, NSF-REU, 2020)
Hope Calogero (Fond du Lac Tribal and Community College, NSF-REU, 2020)
Matthew McCormack (Red Rocks Community College, NSF-REU, 2019)
Gage Clark (Oklahoma State University, NSF-REU, 2019)
Victoria Thrash (University of Iowa, NSF-REU, 2019)
Arianna Northbird (Fond du Lac Tribal and Community College, NSF-REU, 2019)
LeAnn Zuniga (University of Puerto Rico, NSF-REU, 2018)
Myrna Girald-Perez (Cal State LA, NSF-REU, 2018)
Bruce Liscomb (cal poly san luis obispo, NSF-REU, 2018)
Brittany Trejo (University of New Mexico, NSF-REU, 2017)
Kevin Murphy (Carleton College, NSF-REU, 2017)
Kathleen Lugo (Florida International University, NSF-REU, 2017)
Alishia Orloff (University of Washington, NSF-REU, 2017)
Cynthia-Janette Mancilla (UC-Berkeley, NSF-REU, 2016)
Karina Redding (UC-Berkeley, NSF-REU, 2016)
Marissa Castro (San Francisco State University, NSF-REU, 2016)
LeAnn Charwood (Leech Lake Technical College, NSF-REU, 2016)
Marissa Samuelson (STEM/MnDRIVE, 2015)
Anjelica Johnson (UM-Morris, NSF-REU, 2015)
Megan Forcia (NSF-REU, 2015)