Minnesota Water Resources Conference – Poster Presentations

Jasper Tao, University of Minnesota Department of Plant Pathology
Agricultural Water Issues

Potatoes are grown on approximately 43,000 acres in Minnesota, with most production relying on irrigation to meet water demands. Water availability and soilborne diseases are limiting factors in potato production, as inadequate irrigation can reduce yields and induce tuber deformities, while excess moisture can exacerbate disease pressure and nutrient leaching. This study evaluated varying irrigation regimes on Dakota Russet potato yields, soilborne disease incidence, and tuber quality at the Sand Plains Research Farm in Becker, MN. Three irrigation treatments, I1 (100% of full irrigation), I2 (80%), and I3 (60%), were applied using variable rate irrigation. Soil moisture was monitored at varying depths while yield and soilborne cosmetic disease incidence (common scab, black dot, soft rots) were evaluated at the end of the season. Results indicated that common scab was the most prevalent disease (disease incidence = 83%, SD = 23.5), particularly under low irrigation (I3). Hollow heart, an abiotic disorder, was impacted by irrigation rate (p = 0.05) and most frequently occurred under high irrigation. On average, I1 yielded more tubers below 4 oz (19% compared to 16% for treatments I2 and I3), though differences were not significant. Crop water use efficiency was highest under I3, suggesting reduced irrigation may optimize water use under certain conditions. Above-average rainfall (21.66 inches total) likely minimized water stress differences between treatments. This study found that reduced irrigation treatments on Dakota Russett did not result in lower yields or increase disease incidence, suggesting that full irrigation is not always necessary in order to maximize profits. These findings highlight the complex interplay between irrigation, disease, and yield, emphasizing the need for further research under typical weather conditions to refine irrigation strategies for Dakota Russet potato production.

Zixuan Chen, University of Minnesota
Agricultural Water Issues, Climate Change/Resiliency, Hydrology

The spread of nitrate in agricultural landscapes threatens the quality of surface water and groundwater. In surface water, excess nitrate can lead to oxygen depletion (hypoxia), impacting aquatic ecosystems. In groundwater, high nitrate levels pose serious human health risks for communities relying on drinking water wells. To mitigate these risks, understanding the fate and transport of nitrate is essential. Some previous studies have indicated that in addition to land use, future climate change can also increase nitrate contamination in groundwater. However, it remains uncertain how land-use and climate change can have a combined impact on groundwater nitrate. Our understanding is further complicated in karst groundwater systems, where groundwater flows through interconnected networks of fractures and conduits. The diverse flow pathways lead to variations in travel time and transport processes, introducing uncertainties in nitrate reactions and thus making it hard to quantify and predict in such systems. To address this knowledge gap, I focused on unsaturated zone leaching of nitrate by applying a reactive transport watershed model, BioRt-Flux-PIHM, in an agricultural karst springshed in southeastern Minnesota. Many wells in this region already exceed the federal maximum contaminant level for nitrate, highlighting the importance and immediate needs of our research. This model provides robust simulations of surface and near-surface processes and can thus predict the transport of nitrate to groundwater under different scenarios of expanded fertilizer application and climate change.

Robert Fowler, University of Minnesota Department of Soil, Water and Climate
Agricultural Water Issues, Groundwater, Nutrients

To build cover crop policies addressing specific resource concerns, there is a need for research on how cover crop (CC) planting rates and species alter environmental outcomes. To evaluate the ecosystem services of different biomass production levels in fall and spring, we planted cover crops at different seeding rates at three sites across southern Minnesota. Rye plantings at 10, 20, 40 and 80 lbs/acre are compared to a fallow control and oat/radish plantings at 10, 20, 40 and 60 lbs/acre oat and 1, 2, 4 and 6 lbs/acre of radish. Plots are organized in a randomized block design with 4 replicates in St. Paul, Waseca and Lamberton. Because reducing soil nitrate leaching to groundwater is a primary goal of CCs in the Upper Mississippi river basin, we have installed lysimeters in St. Paul and Waseca to analyze NO3- and NH4- concentration in soil  porewater. Cover crop root and aboveground biomass will be tested for N content to further evaluate the relationship between CC species, planting density, biomass and N leaching. Other objectives of this project include using mesh erosion mats to evaluate the effect of the CCs on water-borne sediment movement at the soil surface. We also anticipate assessing effects on physical and biological soil health, including a mycorrhizal assay, bulk density, potentially mineralizable C or N, or microbial C and N pools. For this poster, data presented will include CC biomass, water-borne sediment from erosion mats and soil porewater NO3-N taken from porous cup lysimeters.

Mason Hoffman, University of Minnesota, Water Resource Science Program
Aquatic Biota, Innovative Technologies, Invasive Species

This project developed a metabarcoding assay for the detection of aquatic invasive plants from eDNA using the MinION nanopore sequencing platform. The assay focuses on invasive plants in the Upper Mississippi River Watershed and surrounding regions, with an emphasis on making methods applicable to current early detection and rapid response efforts. Control of invasive plants relies heavily on early detection, as established populations become much more difficult to extirpate. Tissue samples were collected from 85 invasive and native species of interest through field sampling and collaboration with herbariums. DNA was extracted from all samples in order to build a reference database of sequences to compare to eDNA results. A primer mix was created that amplified all species for at least one of three DNA barcode regions. Primers were chosen for the rbcl, matK, and ITS regions of plant genomes.

In the summer 2025 field season, our primers, sampling protocols, and MinION sequencing were tested in the field. Results from this project will contribute to improving the accessibility of eDNA monitoring to conservation organizations and communities. The MinION could be a cheaper alternative to traditional sequencing methods. Our sampling methods will allow for simultaneous practice of eDNA and vegetation interception survey methods. Our reference database and recommended primer mix will help to reduce barriers to entry for groups with limited DNA experience. The details of the project outlined in this abstract will be completed by November 2025.

Jeremiah Shrovnal, UMN Minnesota Aquatic Invasive Species Research Center
Aquatic Biota, Invasive Species, Monitoring

Aquatic invasive species pose a serious threat to aquatic ecosystems in the Upper Mississippi River Basin (UMRB), affecting water quality, ecosystem functioning and services, and economic and recreational value. However, identifying at-risk waterbodies is a difficult task given the multitude of potential invaders and the wide variety of characteristics exhibited by waterbodies in the region. This problem becomes more complicated when considering suites of predictive variables that may appear different based on the scope of the underlying entitation. Here, we show the potential of model stacking to capture this varying covariate specification process through simulation using a machine learning model (boosted regression trees). We then demonstrate this approach to predict the potential occurrence of zebra mussels (Dreissena polymorpha) across the UMRB. We constructed models at two scales: one with global context (including species’ native range), and one with regional context in the UMRB (with more specific covariates). To do this we synthesized species records from the Global Biodiversity Information Facility with publicly available covariate data including hydrology, climate, land use / land cover, anthropogenic impacts, and water quality. Together, these two models integrate global information with regional high-resolution datasets only available within the UMRB in order to provide informed predictions that can be used to identify waterbodies at high, medium, and low risk of invasion. Additionally, we identified the primary environmental characteristics of these waterbodies that increased (or decreased) their susceptibility to invasion. With our model predictions identifying risk across the region for multiple aquatic invasive species, managers will be better able to prioritize where they direct their prevention and early detection and rapid response efforts.

Austin Konrath, University of Minnesota Duluth
Best Management Practices (BMPs), Green Infrastructure, Stormwater

Green stormwater infrastructure, such as bio-infiltration basins, is becoming increasingly popular for managing the growing volumes of stormwater runoff generated by a warming climate and a rapidly expanding urban sprawl. By leveraging natural processes to capture and filter runoff, bio-infiltration basins offer a sustainable solution to manage stormwater and alleviate the impact by reducing runoff volume and contaminant load. However, while bio-infiltration basins are known to be effective in reducing common pollutant loads such as sediments and nutrients from runoff, their impact on reducing runoff water temperature and buffering the temperature change in receiving waters, benefiting trout habitats, has not been well understood. In addition, the optimal designs of bio-infiltration, e.g., media composition and inlet and underdrain designs, for thermal reduction have not been well studied. To address these gaps, this study utilized HYDRUS-2D, a numerical modeling software supporting the analysis of water flow in variably saturated porous media, to evaluate the thermal reduction of an existing bio-infiltration basin on the University of Minnesota Duluth’s campus. We calibrated and validated the model’s hydrologic and heat transfer parameterizations based on field measurements. We further ran a series of modeling experiments to analyze the thermal reduction performance of bio-infiltration basins in front of various storm events and explore the impact of practice designs such as soil hydraulic conductivity, basin geometry, and inlet and underdrain designs on thermal reduction. From our investigation, we aim to improve our understanding of the thermal impact of green stormwater infrastructure and provide insights for better practice designs, potentially enhancing sensitive aquatic ecosystem protections.

Claire Bass, University of Minnesota
Climate Change/Resiliency, Contaminants of Emerging Concern, Monitoring

Excessive chloride concentrations threaten the ecology and biogeochemical function of urban aquatic systems. While road salt is a well known driver of chloride levels, other factors moderate the persistence and impact of chloride in surface waters but are much less well understood. This study aimed to discern and predict which urban surface waters are most affected by chloride during the summer, considering impacts of hydrology, land use, and winter inputs across diverse surface waters in the Twin Cities Metropolitan Area (TCMA), Minnesota. Upwards of fifty springs, streams, ponds, and lakes in the TCMA were sampled over two years for chloride and biogeochemical tracers to infer water sources. Tracer and hydrologic connectivity metrics were used to examine how variation in water sources from surface runoff or groundwater affected relationships between land cover and chloride in common surface water types. Land cover variables, including road density and percentage of a watershed developed, were used to understand connections between urbanization and surface water salinization. Preliminary results show relationships between percentage of watershed developed and road density with chloride concentrations, as well as a positive relationship between groundwater contributions to stream flow and chloride concentration.

These results demonstrate the year-round presence of elevated chloride in some settings, with persistent chloride from winter road salt applications throughout the entire year. Further, preliminary results show a strong influence of seasonal precipitation on summer chloride as indicated by consistent decreases in chloride concentrations from 2023 (dry summer) to 2024 (wet summer). Novel in finding that climate variably influences surface water chloride based on climate, land use, and hydrology, this study promotes consideration of site-specific strategies for minimizing the impacts of chloride in urban surface waters facing rapid anthropogenic change.

Chloe Mellgren, University of Minnesota Duluth
Contaminants of Emerging Concern

The recent discovery of 6PPD-quinone in urban runoff has caused growing concern due to its acute toxicity to various fish species. 6PPD-quinone and other toxic compounds can leach from tire wear particles (TWPs) and contaminate urban waterbodies. TWPs are ubiquitous in urban aquatic environments, yet the environmental fate of TWPs and TWP-derived contaminants is largely unknown. The project aims to improve the understanding of the abundance of TWP and derived contaminants in urban waterbodies, along with TWP weathering processes that lead to contaminant release. We will combine laboratory experiments evaluating TWP leaching and photochemical weathering behavior with field studies evaluating the abundance of TWPs and derived contaminants in Minnesota streams. Leaching experiments have been performed with a variety of representative TWPs to screen for various TWP-leachable contaminants (Objective 1). Ongoing work is focused on photochemical weathering experiments to evaluate the effects of natural organic matter (NOM) on the weathering of TWPs and the release/degradation of leachable contaminants (Objective 2). During the 2025 field season, water grab samples and passively collected suspended sediment samples will be gathered from Minnesota streams and samples will be screened for the presence of TWPs and TWP-derived contaminants (Objective 3). These efforts will be conducted in tandem with a separate ongoing effort to determine time-weighted concentrations of dissolved contaminants at the same locations using passive samplers, revealing a comprehensive picture of total contaminant loads in Minnesota streams. Preliminary results from Objectives 1 and 2 show that an abundance of contaminants are present in tire samples, and that leaching behavior is affected by photochemical weathering. Our findings can inform decision-making processes and position watershed managers to better protect local water quality and fish populations.

Wyatt Baude, Natural Resources Research Institute
Contaminants of Emerging Concern

Per- and Polyfluoroalkyl substances (PFAS) are environmental contaminants that are persistent due to their structural resistance to degradation. As a part of the Great Lakes Sediment Surveillance Program (GLSSP) survey funded by the US EPA, the concentration of 40 PFAS in surface sediments from 42 locations in Lake Erie will be investigated. Surface sediment is used to assess current spatial trends, and results will be compared to existing data for Lake Superior and Lake Huron. Surface sediments were collected from Lake Erie with a box corer on board the RV Lake Guardian during summer 2024. Sediment samples will be extracted using a method adapted from US EPA Method 1633 and analyzed by Liquid Chromatography-Quadropole Time of Flight-Mass Spectrometry (LC-QTOF-MS). It is hypothesized that total PFAS concentrations will be higher in Lake Erie than Lake Superior and Lake Huron due to the presence of large urban areas on the southern side of the lake, as urban areas may release substantial PFAS loads from wastewater, landfills, and industrial activity.

Nathaniel LaFond, University of Minnesota Duluth
Contaminants of Emerging Concern, Drinking Water/Water Supply, Monitoring

PFAS are a family of chemicals known as forever chemicals due to their slow environmental breakdown. They are a growing concern due to their resistance to degradation and association with adverse health effects. PFAS concentrations in drinking water can vary widely by location, rising as high as 4900 ppt in areas near contamination sources to undetectable amounts in more remote areas or areas where treatment is taking place. The EPA will enforce new regulations for municipalities’ PFAS water quality monitoring in 2027 and treatment in 2029. These regulations set new Maximum Contaminant Levels (MCLs) as low as 4 ppt for certain PFAS (e.g., PFOS and PFOA), requiring increased capacity for monitoring these PFAS at very low concentrations.

This research offers an efficient and convenient method for concentrating PFAS from a municipal water source followed by a colorimetric method for detecting levels of PFAS in the water. The colorimetric method uses methylene blue indicator, a common cationic dye that binds with anionic PFAS polar head groups. The ion pair is subsequently extracted into a nonpolar solvent, tributyl phosphate. Accuracy of the colorimetric measurements will be compared with samples tested by LC MS-MS.

We will demonstrate a small adsorbent column that can connect to typical household faucets and isolate PFAS present in the water stream. We will show the different results from various adsorbents and different water flow rates. Preliminary results using PFOA suggest that colorimetric detection will be possible in the 50 to 5000 ppb range. The adsorbent column will be responsible for concentrating the PFAS chemicals in the water stream three to four orders of magnitude to reach this range. This is a robust method that municipalities or organizations could use to make repeatable measurements that estimate a useful approximation of the concentration.

Abimbola Ige, University of Minnesota Duluth
Contaminants of Emerging Concern, Education and Citizen Involvement, Engineering Solutions and Applications

Widespread microplastic pollution necessitates building a network of scientists for monitoring the impact of this emerging contaminant on Minnesota waters. This project investigates the integration of citizen science into microplastic monitoring by developing a fluorescence-based detection protocol and evaluating its application in the field. The objectives are to optimize dye-based microplastic detection methods and assess the reliability of data collected by citizen scientists compared to research experts. The preliminary phase tested fluorescent dyes on various plastics to characterize the response of varying surface hydrophobicities fluorescent response. Nile red, Coumarin 6, Acridine Orange, and DAPI were tested on polypropylene, polyethylene, polylactic acid, and polyethylene terephthalate. We determined dyes at 0.05 mg/mL dissolved in ethanol produced the optimal staining conditions and that the signals produced with different stain times (between 0-60 min) were consistent. Sequential staining (i.e., staining with two different stains) was pursued as a potential avenue to differentiate polymers from each other and natural particles. Results yielded greater signal intensities compared to single staining and varying the stains showed differing spectral features depending on the dye combination and polymer material used, which is promising that different plastics will respond differently to the sequential stains. Moving forward, students from Minnesota high schools will sample lake water using simplified kits and their results will be compared to samples collected by trained microplastic researchers. Microplastic counts and QA/QC results will be completed showcasing a scalable model for integrating citizen science with research methods for microplastics detection.

Bella Callery, University of Minnesota
Contaminants of Emerging Concern, Emerging Issues

Chronic Wasting Disease (CWD) is a fatal neurodegenerative disease affecting cervids, which include deer, moose, and elk. Affected cervids are found in both farmed and wild populations across the United States. CWD is caused by infectious prions, highly stable misfolded proteins. Cervids can shed prions into soils and surface waters through urine, saliva, feces, and other methods. These environmental prions bind to particulates, such as soils and aquatic sediments,  and remain infectious for years, creating a possible long-term infection risk. The Real Time Quaking-Induced Conversion assay (RT-QuIC), a protein amplification assay, was developed to test for presence of prion protein in animal tissue through the binding of fluorescent dye Thioflavin-T to aggregates formed by infectious prions. Dye binding causes the sample to fluoresce, indicating the presence of prions.  Environmental samples, such as soil, water, and sediment can also be tested using RT-QuIC, though these matrices are more complex than animal tissue. Organic compounds in environmental samples may interact with Thioflavin-T to create fluorescence regardless of infectious prion presence, producing false positives. To refine the methodology of environmental soil and water testing, DOM Samples were taken from representative locations around the state and tested using RT-QuIC and Excitation Emission Matrix spectrography (EEMS). The resulting spectrograph provides insight into possible fluorescent interference with the positive range of RT-QuIC.

Alicia Erickson, University of St. Thomas
Contaminants of Emerging Concern, Stormwater, Watershed Management

Minnesota has a robust statewide water quality assessment and reporting program, but condition monitoring and Total Maximum Daily Loads (TMDLs) cannot always sufficiently identify or explain causes of biological impairments. The project was conducted in Spring Valley Creek, MN, stream where routine monitoring & assessment approaches could not identify stressors associated with observed fish and invertebrate impairments. To determine whether chemicals could be contributing to the biological impairment we collected water samples during low and high flow runoff events at eight locations throughout the watershed including wastewater treatment effluent (WWTP) and stormwater. Samples were analyzed for circa 90+ chemicals including industrial, wastewater and pesticide derived chemicals. As a part of this study exposure activity ratios (EAR; similar to hazard quotients) were calculated to identify exceedances of the aquatic-life benchmarks for pesticides. Aquatic Life Benchmarks codeveloped by US EPA and USGS are estimates of the concentrations below which pesticides are not expected to represent a risk of concern for aquatic life. Fish, invertebrates, vascular and non-vascular plant benchmarks were used. Assessment of 24-hour exposure to solid-phase extracts of stream waters on larval mortality and behavior was completed. Three toxicity evaluation methods, EAR-based predictions of toxicity, direct in vitro (data not shown), and direct in vivo assessments showed that WWTP and stormwater were important contributors of CECs in this system and that they may be able to initiate adverse biological responses. EAR-based assessment indicated that copper and clothianidin occur at most of the sampled sites at concentrations that exceed benchmarks, and that their quantity varies with hydrological conditions. Additional sampling is underway to develop additional benchmarks relevant to this site and to advance understanding of seasonal variations in chemistry and associated hazard.

Maya Winters, Natural Resources Research Institute
Contamination/Remediation, Contaminants of Emerging Concern, Stormwater

Conventional stormwater filtration systems aren't designed to remove poly- and perfluoroalkyl substances (PFASs), which are often called “forever chemicals” because they do not degrade in the environment. While adsorbent-amended stormwater filtration systems filters have demonstrated effective removal of various organic contaminants in urban runoff like pesticides, systems receiving PFAS-contaminated runoff may accumulate the “forever chemicals” over time, causing concerns surrounding the eventual need to dispose of the spent filtration media. This study aims to assess the effectiveness of passive treatment systems that use adsorbent-based replaceable filter cartridges to remove PFAS from stormwater. We hypothesize that systems containing either regenerated activated carbon (RAC), or biochar/sand mixtures in series with ion exchange resins, will demonstrate effective PFAS removal from stormwater in passive filtration systems. Long-term laboratory scale column experiments (43 storm events) are being conducted to simulate high rainfall events (20 cm hr−1) simulating 1.5 years of precipitation under unsaturated conditions. The study assesses two treatment conditions to provide insights into the fate and transport of PFAS in aqueous film-forming foams (AFFF)-impacted stormwater treatment systems. The first condition looks at the influence of dissolved organic carbon (DOC), specifically, leaf litter versus straw derived DOC on PFAS sorption dynamics and competitive sorption in RAC columns. The second condition examines the comparative performance of two ion exchange resin (IER) media, Purolite A520E and CalRes 2301, in PFAS removal following pre-treatment via biochar filtration. These results will provide critical insights into the effectiveness of these treatment approaches for mitigating AFFF-impacted stormwater.

Frieda von Qualen, Minnesota Department of Health
Drinking Water/Water Supply, Equity and Environmental Justice, Policy and Standards

Safe drinking water is essential to healthy families and communities. What do we need to do now to make sure drinking water is safe for everyone, everywhere in Minnesota in 2034? While Minnesota has an outstanding record of compliance with the Safe Drinking Water Act, not everyone in Minnesota has safe and sufficient drinking water. Minnesota developed the first ever Minnesota Drinking Water Action Plan, a 10-year plan to ensure that everyone in Minnesota has equitable access to safe and sufficient drinking water.

Minnesota Department of Health collaborated with the University of Minnesota Water Resources Center, Freshwater, and Clean River Partners to gather input and feedback from water professionals, state and local government, and people who drink water about how well drinking water is governed in Minnesota and what people’s concerns and priorities are for drinking water. We gathered input through community meetings, surveys, and meetings with agencies and organizations.

The poster will provide an overview of the resulting action plan, including what we heard. The poster will also highlight key strengths for Minnesota and areas where more focus is needed to ensure equitable access to safe and sufficient drinking water.

Nathan Lund, University of Minnesota
Emerging Issues, Invasive Species

Forests across North America are being invaded by exotic earthworms. Formerly glaciated landscapes, where the last glacial activities wiped out native earthworms, have been dramatically altered by the introduction of European earthworm species. Today, in many cases, such as in Minnesota, European earthworms are pervasive, and earthworm-free forests are rare. However, these forests also face a second wave of invasion from exotic Asian jumping worms. During invasion, jumping worms further alter the hydrology and biogeochemistry of the forest-soil system. Owing to the high frequency and magnitude of their activity at soil surface, jumping worms create novel soil conditions with poorly understood erosion potential. This project attempts to fill this gap by characterizing erosion rates in jumping worm-infested forests using two techniques: fallout radionuclides (Cs-137 and Pb-210) and erosion pins. These techniques will be applied to both European and jumping worm-infested forested hillslopes in central Minnesota. Erosion pins provide erosion rates on week- to year-timescales and allow for the quantification of local erosion and deposition. They are a relatively simple method that requires minimal post-processing for analysis. Fallout radionuclides provide erosion rates on decade- to century-timescales and give information on soil redistribution on a transect scale. Gamma spectroscopy will be used to quantify Cs-137 and Pb-210 activity, which can be further used to estimate erosion. Both methods will be implemented throughout the summer of 2025 at six sites across the Minnesota Landscape Arboretum and Lake Rebecca Park Reserve.

Jasper Goldstein, University of Minnesota Twin Cities
Invasive Species

Zebra mussels are invasive species that pose a serious threat to infrastructure and aquatic ecosystems in the Upper Mississippi River basin and across North America as they continue to spread. Much research has focused on how physiochemical characteristics such as calcium, pH, salinity, temperature, and dissolved oxygen can negatively affect mussels. However, understanding the relationships between hydrodynamic processes  (current, wave action, turbulence) and biologic processes (external fertilization, larval transport and settling, and suspension feeding) provides an  opportunity to identify water bodies and habitats resistant to mussel establishment. We will investigate the effect of hydrodynamic forces as potential controls for establishing invasive mussels through laboratory experiments (which will be done in the summer) on larval mortality and settling and adult mussel suspension feeding. The data and relationships developed in the laboratory experiments will be verified at the field scale by comparing them to existing data and hydraulic model results. The results of this study can be used to i) identify resistant areas in water bodies and watersheds where mussels struggle to establish, ii) inform management activities to create habitats that are more resistant to mussel growth, and iii) design new control strategies that rely on managing flow and corresponding fluid and hydrologic conditions. ecosystems. We are committed to actively eliminating the detrimental effects of invasive zebra mussels on aquatic ecosystems, restoring their vitality and ensuring their protection for the future.

Camila de Sousa Queiroz Almeida, University of Minnesota; BioTechnology Institute, Federal University of Jequitinhonha and Mucuri Valleys
Invasive Species

Early detection of aquatic invasive species (AIS) is essential to properly manage water resources. Compared to traditional AIS detection methods, environmental DNA (eDNA)-based quantitative PCR (qPCR) detection stands out for its high sensitivity, specificity, and ability to detect species at low abundances. This project aims to develop and validate qPCR assays to detect Minnesota’s 20 high-priority AIS for high-throughput applications. We selected 20 high-priority AIS based on the survey responses from AIS professionals in Minnesota. The list includes 7 fish, 7 invertebrates, 2 viruses, and 4 plant species, which ranged from 19.7% to 74.8% interest rates among all 127 survey responses. We obtained 17 probe-based qPCR assays from the literature or through our collaboration network. We developed new qPCR assays for curly-leaf pondweed (Potamogeton crispus), faucet snail (Bithynia tentaculata), and the Eurasian watermilfoil (Myriophyllum spicatum). For assay development, we retrieved representative sequences from GenBank and aligned them using MEGA 12 software to identify the conserved regions within the target species. Primers and probes were designed on the conserved regions using Primer-BLAST or Primer Express 3.0. We analyzed the hairpin, self-dimer, and heterodimer formation of the primers/probes by using the OligoAnalyzer Tool. We tested for in silico amplification probability (AP) of target and unintended target species with the eDNAssay tool. The three newly designed assays showed AP = 0.84 for our targets and AP < 0.65 for unintended species, demonstrating that our assays should be able to identify these species in eDNA samples correctly. We are currently experimentally validating the specificity and sensitivity of the qPCR assays with AIS tissue samples and DNA gBlocks solutions. Once these assays are validated and optimized, we plan to run these assays on a high-throughput qPCR platform to simultaneously detect all 20 AIS.

Becky Forgrave, University of Minnesota
Lakes, Monitoring

Public swimming beaches on lakes are a key feature of the twin cities metropolitan area where ecosystem and human health overlap, and one of the major ways people interact with and benefit from lakes. However, the water quality at these beaches are not always safe enough for swimming. To address this, regional management organizations monitor public swimming beaches for E. coli and, increasingly, cyanotoxin concentrations and indicators, and close the beaches for use if they are above public health thresholds. We synthesized beach monitoring data for 53 beaches across the metropolitan area to create a dataset spanning 40 years. This synthesis dataset reveals an increasing frequency of beach closures since 2007, relationships with climate conditions that lead to many beach closures in a given year, as well as spatial hotspots of beaches more vulnerable to E coli- or cyanobacteria-related closures.  This comparative data is useful for understanding drivers of swimming beach safety for urban lakes, guiding prediction of beach closures, and improving public communication of water quality and safety.

Andrew Toay, SRF Consulting Group

Clean Lakes Alliance commissioned this first-of-its-kind study of the Yahara Chain of Lakes in partnership with SRF Consulting Group, the University of Wisconsin-Madison, and the University of Wisconsin-Whitewater. The study revealed how lakes and their conditions impact tourism, real estate, and quality-of-life factors.

Janet Sanchez Sanchez, Department of Soil, Water, and Climate BioTechnology Institute
Watershed Management

Access to clean and safe water is a fundamental prerequisite for protecting public health. Microbial Source Tracking (MST) is a strategy that combines molecular and microbiological tools to identify the origin of fecal contamination in environmental waters, which is essential for effective watershed management. In Minnesota, many watersheds fail to meet water quality standards due to elevated levels of fecal indicator bacteria, notably Escherichia coli (E. coli).

This study investigates the spatiotemporal dynamics of fecal contamination across six watersheds, representing agricultural, urban, and forested areas in Minnesota. From May to October 2024, water samples were collected from multiple tributaries in each watershed. E. coli and total coliform concentrations were measured alongside water quality parameters, including total phosphorus, chemical oxygen demand (COD), total suspended solids, and total nitrogen.

Elevated levels of E. coli were observed during the summer months, likely influenced by increased runoff and higher temperatures conducive to bacterial growth. Watersheds with predominantly agricultural land use exhibited some of the highest E. coli concentrations, suggesting potential localized sources of contamination. Distinct patterns in nutrient and organic matter concentrations were observed among the six watersheds. Some exhibited high total nitrogen and phosphorus concentrations, likely elevated due to greater agricultural influence. Others experienced occasional increases in COD during the summer, which may reflect higher loads of organic material entering the tributaries, creating conditions for E. coli growth.

Ongoing high-throughput quantitative PCR-based MST and pathogen detection will further clarify contamination sources and associated health risks. Land-use patterns, precipitation, and physicochemical data will be analyzed using statistical tests and models to explain the occurrence of E. coli and pathogens in the future.

Meijun Cai, Natural Resources Research Institute
Contamination/Remediation, Wastewater

The Natural Resources Research Institute (NRRI) developed a barite precipitation technology to reduce sulfate in municipal and industrial wastewater to protect manoomin (wild rice). Pilot tests at five sites demonstrated its adaptability to sulfate concentrations ranging from 25 to 400 mg/L, with most sulfate removed within five minutes when using barium chloride. The process is fast and requires minimal infrastructure but generates significant sludge and cannot reliably reduce sulfate below 10 mg/L without risking toxic barium levels. To address this limitation, a combined approach is recommended: lowering sulfate to about 30 mg/L with barite precipitation, then using ion exchange to reach the 10 mg/L standard. This hybrid method both prevents barium overdose and extends resin life, and a generic plant design is now under development.

Andrew Bantz, University of Minnesota 
Engineering Solutions and Applications, Operation and Maintenance of BMPs, Stormwater

The performance of stormwater treatment practices such as detention ponds, infiltration basins, and wetlands is highly dependent on the infiltration rates of soil media, where the saturated hydraulic conductivity (Ks) is considered an important soil property. Direct Ks determination can be done in the field using infiltrometers or in the laboratory using permeameters. Indirect methods, including mathematical functions (pedotransfer functions) use commonly available soil information to estimate Ks. In this study, field measurements were made at three different forested soils in Duluth, MN, using the Modified Philip-Dunne Infiltrometer (MPD) and the Cornell Sprinkle Infiltrometer (CSI). In addition, soil samples were collected to determine soil properties (bulk density, porosity, texture, and organic matter) and to measure the Ks in the lab using a constant head permeameter. MPD determined a higher value of Ks when compared to the CSI. The Ks values estimated using the pedotransfer function presented consistency when compared with Ks measured in the field.

Imran Md. Azizul Islam, University of Minnesota Duluth
Groundwater, Hydrology, Stormwater

Urban water balances are significantly influenced by the complex interplay between infiltrated stormwater, subsurface soil, and buried infrastructures, yet these interactions are often overlooked. To elucidate these interactions, we developed an integrated hydrologic model using HYDRUS-2D to quantify the impacts of infrastructure-related fluxes such as inflow and infiltration (I&I) and exfiltration under varying conditions including different soil types, groundwater table depths, and pipe defect sizes, as well as variations in trench backfill materials.

Findings reveal that the rainwater partitioning and the resulting water balances exhibited notable variations across different native soil types and groundwater table depths. Finer-textured native soils caused more surface runoff and evapotranspiration, less subsurface groundwater fluxes, and minimal impact on I&I. Shallower groundwater tables caused greater I&I and subsurface groundwater fluxes but minimal impact on surface runoff and evapotranspiration. Infrastructure fluxes showed a positive correlation with pipe defect sizes; On average, I&I accounted for ~38% of total water budget under shallow groundwater conditions, and exfiltration accounted for ~10% of total water budget under deep groundwater conditions. We also performed a feature importance statistical analysis among different factors to further quantify the relative importance of these factors.

Additionally, our experiments on trench setup revealed that using native soil for trench backfilling minimally impacted hydrologic processes, with a slight reduction in I&I and exfiltration and an increase in surface runoff and evapotranspiration compared to using highly draining granular materials. This study emphasizes the importance of understanding the hydrologic context of subsurface flow dynamics and integrating all subsurface processes into urban hydrologic models to improve the sustainability and effectiveness of urban infrastructure design.

Mohsen Tahmasebi Nasab, AECOM
Hydrology

Rainfall temporal distributions influence hydrologic modeling and water resource infrastructure design. Selecting appropriate temporal distributions, such as NOAA Atlas 14 patterns, NRCS type storms, or other region-specific rainfall distributions, is essential for estimating runoff volumes and peak discharge. These temporal distributions vary in the timing of peak intensity, storm duration, and rainfall patterns, all of which can impact stormwater infrastructure performance and resilience. Selecting an unsuitable temporal distribution may lead to underestimation of runoff, increasing flood risks and causing infrastructure failure. On the other hand, an overly conservative approach can result in excessive costs due to over-designed infrastructure and unnecessary resource consumption.

This study evaluates the theoretical basis and practical applications of widely adopted storm temporal distributions across the United States. It highlights the significance of these distributions on hydrologic modeling and infrastructure design processes. Additionally, it emphasizes the need for a thorough understanding of regional rainfall characteristics that help engineers make informed decisions that effectively balance design safety, infrastructure resilience, and economic efficiency.

Anthony Chukwubueze Okoboshi, University of Minnesota, Duluth
Climate Change/Resiliency, Lakes, Nutrients

Rapid climate change is causing manifold changes to lakes, including changes in trophic status, water temperature, and ice cover duration. Understanding how primary productivity responds to these changes is crucial for predicting the future of aquatic ecosystems. This study examines primary production within the nutrient-color paradigm, focusing on six Minnesota and Wisconsin lakes of different trophic status. Using a 13C-based approach, we measured planktonic productivity in both open water conditions (summer) and under ice and snow (winter). 13C enriched bottles were incubated in situ at varying depths for 24 hours, and sensors continuously recorded incident light and ambient temperature during the experiment. We observed large differences in production between lakes and seasons, related to trophic status and light availability. While under-ice production rates were generally lower than open water rates, some lakes supported high production rates when sufficient light penetrated through the snow and ice. Our results show that winter-time production can make a significant contribution to the productivity of some lakes. We also show that winter conditions interact with lake trophic status, and changes to ice duration, snow conditions, and trophic status will have important consequences for temperate lakes.

Key words: Lake trophic status, Primary production, Seasonality, Under-ice limnology.

Devin Edge, Natural Resources Research Institute
Contaminants of Emerging Concern, Lakes

Persistent bioaccumulative toxic contaminants (PBTs) are pervasive throughout the environment, resistant to environmental degradation, and toxic to aquatic organisms. The objective of this interdisciplinary project is to advance understanding of the complex and interdependent relationships between environmental distributions of PBTs, biogeochemical cycling in sediments, and overall ecosystem health in the Great Lakes, as part of the US EPA Great Lakes Sediment Surveillance Program.

This presentation will focus on spatial and temporal trends for legacy and emerging organic contaminants in Lake Superior and Lake Huron. In particular, polyhalogenated carbazoles (PHCZs) have caused increasing concern due to their dioxin-like toxicity and increasingly documented widespread occurrence. While several industries unintentionally produce and emit PHCZs, sediment records have suggested that some PHCZs are generated naturally in the environment. In this presentation we will highlight new findings of PHCZs in surface sediments and sediment cores from Lake Superior, building on previous reports of PHCZs in sediments from the other Great Lakes. Temporal and spatial trends for PHCZs in sediments will be compared to new data for other classes of legacy and emerging contaminants (e.g, polychlorinated biphenyls, novel halogenated flame retardants, and organochlorine pesticides) to infer PHCZ origin as well as fate and transport processes. Preliminary data has shown that some PHCSs are present in Lake Superior sediments deposited prior to the development of modern industry, suggesting that they were generated naturally in the environment.

Overall, these results will provide new knowledge regarding the inputs of legacy and emerging contaminants into the Great Lakes, including new insights into the environmental conditions that lead to the generation of naturally occurring PHCZs.

Vikas Tandon, Foth Infrastructure & Environment, LLC
Groundwater, Mining, Water Resource Sustainability

Modeling predicts water system behavior, aiding planners in decision-making, risk management, and resource optimization. It provides insights for water management, infrastructure sizing, and environmental impact analysis, enhancing cost efficiency and sustainability. Modeling is essential for effective water resources management.

Water resources models have inherent uncertainties due to the complexity and variability of natural systems. Practical and cost limitations introduce uncertainty into predictions. Managing these uncertainties is vital for effective risk management. Proper management enhances prediction accuracy, identifies risks, aids in mitigation, and leads to informed choices. Efficient resource use avoids over- or under-designing infrastructure, while transparent handling builds stakeholder trust.

This presentation will showcase approaches, examples, and tools used in modeling and managing uncertainties in water resources for Northern Minnesota mining projects. Project application approaches will demonstrate conceptual models developed for mining projects, tested throughout site assessment and preliminary numerical modeling processes, allowing for checking assumptions and qualifying data gap significance towards uncertainties in numerical model projections in a scientific, progressive manner. The presentation will illustrate how emphasis is placed on uncertainties with material consequences to decision-making, while those with limited impact are given lower priority.

The audience will learn approaches to addressing uncertainties, identifying risks, developing mitigation strategies, and building stakeholder trust. Insights will be relevant to various water resources projects, covering both data-based uncertainties (measurement errors, variability, data gaps) and conceptual uncertainties (model structure, parameterization, simplifications, assumptions). Managing these uncertainties improves model reliability, decision-making, and risk management.