2026 Poster Presentations

Minnesota has prioritized reducing excess nutrient loading to protect downstream waters, but agricultural land, which relies on commercial fertilizers, remains a major source. In addition to their downstream effects, fertilizers face significant lifecycle challenges across their production and use, emphasizing the need for nutrient reduction and recovery. Current nutrient management strategies focus on reduction rather than recovery, and most recovery technologies are designed for concentrated waste streams rather than diffuse, low-strength agricultural runoff. While reduction efforts help limit downstream loading, expanding nutrient recovery to these overlooked dilute sources would address inefficiencies across the imbalanced fertilizer lifecycle. Our research aims to develop an integrated treatment system for the selective recovery of nitrogen, phosphorus, and sulfur from agricultural runoff through a combination of a bioelectrochemical system (BES), sorption, and chemical precipitation. Technologies such as sorption/ion-exchange, struvite precipitation, and BES recover nutrients effectively in high-strength waste streams, but their effectiveness declines in low-strength waste streams, where integrated treatment configurations may enhance their performance. To identify the optimal treatment configuration, we have systematically conducted sorption isotherm experiments and electrolysis-assisted microcosms across a matrix of geomedia compositions, electrode materials, and influent compositions. Geomedia selection and microcosm design target nutrient-recovered products, including biochar materials containing struvite, iron phosphate, elemental sulfur, and zeolite-ammonia, which will be characterized for nutrient contents and release rates. Results from these bench-scale experiments will inform the design of the integrated treatment system to maximize nutrient recovery from dilute and variable agricultural water compositions.

The central region of Minnesota is dominated by sandy soils which require irrigation to grow crops like corn and soybeans. These soils drain rapidly, which can reduce resident times for nitrate rich water leading to a reduction in soil denitrification and larger leaching losses. Cover crops and alternative tillage practices, like no till, have the potential to help reduce nitrate leaching while also improving soil health, but these practices have not been fully studied in sandy conditions. The objective of this study is to determine crop yields, nitrate leaching, soil moisture dynamics, and soil health metrics under combinations of rye cover crop usage and tillage practice under different moisture regimes simulated by irrigation at two locations in Minnesota’s central sandy region. Preliminary results have shown that no-till can significantly reduce crop yield in corn production, but not soybeans, while cover crops have no significant impact of crop yield for either corn or soybeans. Early results do not show any differences in nitrate concentration, volumetric water content or nitrate leaching losses by tillage or cover crop treatments. 

While ideally all fertilizer nitrogen (N) is utilized by crops, much is lost to the environment as nitrate (NO3), nitrous oxide (N2O), or ammonia (NH3). Best management practices can improve agronomic systems and reduce environmental N losses. Here, 15N enriched urea was applied to continuous corn (CC) and corn–soybean (CSb) rotations at 250 or 200 kg N ha -1, respectively, versus an unfertilized control, with select cover crops (no cover, winter rye, kura clover) to assess practices that optimize fertilizer N utilization. Rye and no cover crop treatments showed greater yield compared to both fertilized and unfertilized kura clover treatments, suggesting kura clover competes with corn for N availability. The loss of N2O and NH3 was even across rate and cover crop treatments, though these losses only accounted for a small fraction of total N applied. Greater NO3 leaching was shown with increased N rates for no cover crop and rye treatments, though this was not the case for kura clover, likely due to the continuous deposition of kura biomass. Analysis of 15N dispersion showed no difference in the loss of fertilizer derived NO3, N2O or NH3 between cover crop treatments. In total only 10 and 6  kg N ha -1 of 15N was lost from the soil in CC and CSb rotations respectively while 183 and 156  kg N ha -1 was recovered in plant tissues across three years, suggesting an idealized nutrient management system. Further isotopic analysis of soil N pools will help determine where fertilizer derived N disperses in a given growing season.

Agricultural runoff enriched with nutrients contributes to the persistent hypoxic zone in the Gulf of Mexico. Despite decades of conservation efforts in the U.S. Midwest, nitrogen loading to the Gulf has not decreased. On November 4, 2008, Minnesota voters approved the Clean Water, Land & Legacy Amendment to protect, enhance, and restore lakes, rivers, streams, and groundwater by increasing the sales and use tax rate by 3/8%. After 15 years of statewide initiatives, has water quality in Minnesota rivers improved? We analyzed annual flow-weighted mean concentrations of TSS, TKN, NOx-N, TP, and PO4-P at 102 water quality monitoring stations in Minnesota to evaluate Sen’s slope trends for each of the parameters available for HUC-8 level watersheds. Additionally, we analyzed the relationship between conservation expenditure and water quality through regression models to determine if there were any meaningful relationships. The findings of this study will provide knowledge on how Minnesota water quality has progressed over the last 15 years and what may be done to continue improving it. 

This project highlights statewide data resources on practice adoption and water erosion from 2016-2025 in Minnesota. Ground-truth photos collected from 5,732 locations were used to calibrate satellite remote sensing algorithms to estimate crop residue cover (%) and cover crop emergence at the 30 m resolution. To estimate soil erosion and water runoff based on topography, soil, crop, and precipitation, as well as the crop residue cover and cover crop data described above, we ran a daily model across 197k hillslopes statewide (The Daily Erosion Project).

Annual results from this project have been summarized at spatial scales commonly used in Minnesota (statewide, County, agroecoregion, major and minor watersheds) and made publicly available via the Minnesota Office for Soil Health (MOSH): https://mosh.umn.edu/statewide-data-residue-cover-crops-and-erosion. Users can now identify temporal patterns, track trends, and quantify all three project outputs. The poster will demonstrate uses for the dashboards and report statewide trends in residue cover, fall cover crop emergence (avg. 3% of row crop acres), cover crop acreage (an increase from 180K to 440K acres), and water erosion (avg. 0.6 to 1 t/ac). Regional variations will also be illustrated. The project team will keep annually updating these user-friendly dashboards as well as adding newer project outputs, such as wind erosion, lateral redistribution of soil organic carbon by erosion, and erosion on forested land.

The Pineland Sands region of north-central Minnesota features cold-water streams and outwash aquifers that allow anthropogenic solute transport between terrestrial and aquatic systems. As part of a larger Pinelands study, this work examines the biogeochemical impact of land cover in groundwater, lakes, streams, stream beds, riparian zones, and natural springs. Field parameters and major cation-anion data were collected from 2023 to 2025 and integrated with 2023 land cover spatial data to identify primary drivers of water quality.

Redundancy Analysis (RDA) and correlation matrices revealed an absolute positive correlation between agricultural land-use intensity and concentrations of nitrate-nitrogen, sulfate, and other pollutants. Notably, this chemical signature was consistent across the hydrologic gradient, with significantly elevated nutrient concentrations observed in deep upland wells, the shallow riparian groundwater discharging into local streams, and at the streambed. The pinelands soils derived from outwash have limited nutrient attenuation capacity in the A and B horizons due to limited organic matter. Dry land farming will have nutrient leaching, but the addition of irrigation water exasperates the transport of nutrients to the aquifer.

The tight coupling between agricultural land management and nutrient concentrations suggests that sandy soil with limited organic matter allows for minimal attenuation of agriculture-derived surface inputs. These findings highlight the unique vulnerability of the region and emphasize the need for holistic management that addresses irrigated agricultural management and the fate and transport of chemicals into the groundwater and the resurgence surface-water discharge.

Soil water storage and hydrologic behavior influence field-scale runoff, drainage, and watershed streamflow response. Hydrologic models rely on parameters which may not capture management-induced changes in soil function, especially in scaling up from core, to field, to watershed. This leads to the question: how do different management systems affect soil hydrologic functions and impact watershed outcomes? We will explore novel approaches for assessing pedon-scale water dynamics to identify indicators that can be used in hydrologic models to more accurately simulate streamflow effects of management systems. To do this, we selected fields that represent a gradient of management systems: conventional cropland, soil health cropland, and grazed pasture. Field data will be collected from representative catenas in South Central Minnesota, spanning well-drained upland soils to poorly drained Hydrologic Soil Group C/D soils. Dye tracer experiments will be conducted twice during the growing season at the summit position of the catena, on the Clarion soil series (Typic Hapludolls), to assess water movement and preferential flow pathways. Samples will be collected from all horizons to characterize physical and hydrologic properties of these soils. The dataset will inform us of the potential soil water storage capacity across different management systems. We will identify parameters that differentiate them and that hydrological models are sensitive to. We will use SWAT+ and GSSHA models to simulate portions of the High Island Creek watershed at two spatial scales. Model parameters will be adjusted to represent the field-measured properties, based on their magnitude of change between practices, to quantify the impact on soil water storage and streamflow. This work will help inform hydrologic models and management decisions by linking soil health practices to measurable changes in soil water function and watershed water quantity.

Irrigated agriculture in Central Minnesota faces increasing pressure to improve water use efficiency while maintaining crop productivity under spatially variable soils and changing precipitation patterns. For growers, irrigation managers, Extension professionals, and water resource decision-makers, a key challenge is determining whether variable rate irrigation (VRI) improves crop performance beyond the effects of inherent soil and topographic variability. This study evaluated how irrigation strategy and soil-topographic conditions influenced corn yield across three center-pivot-irrigated fields in Central Minnesota. The study compared static VRI, dynamic VRI, and uniform irrigation treatments. High-resolution yield monitor data were integrated with proximal soil electrical conductivity measurements and terrain attributes derived from digital elevation models, including elevation, slope, aspect, and curvature. Linear mixed-effects models, correlation analysis, and regression approaches were used to separate irrigation treatment effects from soil and landscape controls while accounting for spatial variability within fields. Results indicate that soil electrical conductivity, elevation, and slope were consistent predictors of corn yield, while irrigation treatment effects were generally not significant after accounting for soil and topographic differences. These findings suggest that soil-driven water availability and landscape position may exert stronger control on yield variability than irrigation prescription alone. The results highlight the need for soil-informed irrigation planning, careful evaluation of VRI zones, and integration of terrain and soil data into irrigation decision support. For practice, VRI adoption should be paired with field-specific soil mapping, yield analysis, and adaptive management to ensure that irrigation prescriptions address actual water-limiting conditions rather than spatial variability unrelated to irrigation needs.

The Root River watershed of southeastern Minnesota is characterized by steep blufflands, rolling agricultural terrain, and an extensive network of cold-water streams. Much of the watershed is underlain by karst-dominated Paleozoic bedrock with minimal glacial till cover. While this unique geology defines the watershed’s character, it also heightens vulnerability for public health and ecosystem integrity. In this setting, rapid infiltration allows contaminants to move quickly into drinking-water aquifers. Groundwater then flows through a complex network of fractures within stacked aquifers, aquitards, and aquitardifers, producing an anisotropic flow regime that restricts vertical movement while promoting lateral flow, spring discharge and stream baseflow. As a result, groundwater residence time varies widely from hours to millennia depending on geographic location and hydrostratigraphic position.

To better characterize these dynamics a 3D hydrogeologic model was developed for the Root River watershed to illustrate the distribution of hydrogeologic units and residence time.  An extensive groundwater chemistry database compiled by the Minnesota Geological Survey and partner organizations was analyzed using multiple tracers, including nitrate, tritium, chloride and chloride/bromide ratios to determine residence time. Groundwater was classified as recent or vintage using established thresholds: tritium > 0.8 TU, nitrate > 1 mg/L, chloride > 2 mg/L and/or Cl/Br ≥ 300 indicate recent. Residence time was mapped using the elevation of the bottom of recent water using an interpolated probability GIS approach. Results provide an integrated framework for understanding groundwater vulnerability in karst terrain and support effective management of water quality and ecosystem health in the Root River watershed.

Approximately 20% of Minnesotans use private wells for drinking water. While community water supplies are monitored and regulated for contaminants, private well users are solely responsible for ensuring their tap water is safe. The Minnesota Department of Health estimates that 10% of private wells have arsenic concentrations exceeding the safe drinking water standard of 10 ppb, though growing research indicates that long-term exposure, even at low levels, can cause serious health problems. When dissolved into groundwater, arsenic can impact the safety of drinking water. This may increase the risk of cancer and other health concerns such as cardiovascular and respiratory disease, neurodevelopmental effects in children, and result in skin problems, thereby representing a significant public health concern for rural populations.

Funded by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR), Freshwater and Mayo Clinic are partnering to test private drinking water wells for arsenic in eight southern Minnesota counties (Rice, Steele, Freeborn, Waseca, Faribault, Blue Earth, Watonwan, and Martin). Using a three-pronged approach, we are increasing access to private well testing by: 1) partnering with physicians to educate and encourage residents to test their wells, 2) implementing a mixed-media marketing campaign that increases awareness of the need to test and the availability of free testing, and 3) hosting community-based clinics. Through this project we aim to conduct 8,000 arsenic tests for private well users through free, convenient testing opportunities and will help determine effective outreach methods for rural audiences, evaluate regional partnership models, and inform policy recommendations that support lasting well testing programs throughout Minnesota. 

Safe drinking water is essential to healthy families and communities. Yet, over one million Minnesotans have fewer safeguards in place to ensure safe drinking water because they rely on a private well. Unlike their peers on public water systems, private well users are essentially their own water operators and are responsible for making sure their drinking water is safe for everyone in their household. As water resource professionals, we can play a role in supporting private well users. This poster will help tell the story of private well users in Minnesota through maps and data visualizations, identify ways we can support private well users, and facilitate discussion about how Minnesota Department of Health (MDH) can help provide data to inform local private well efforts.

Over the last several years, MDH leveraged funding from the Centers for Disease Control to build county-level and census-tract level estimates and maps of private well indicators in Minnesota. We built these indicators and maps as a tool for partners to better understand how many private well households they may have in their jurisdiction and water quality risks that private well users may be facing in their community.

This poster will provide some examples of the maps and ways to interact with the updated Minnesota Data Portal. We are still refining the data displays and determining upcoming indicators. We would use the poster session as an opportunity to engage people in thinking about private well users, gather feedback on the current and proposed maps and indicators, and to help MDH better understand and serve water resource professionals’ interests and data needs as they relate to private wells.

Contaminants of emerging concern (CECs), including contaminants from personal care products, pharmaceuticals, and PFAS, pose a threat to the cultural, subsistence, and recreational uses of Tribal lands and waters in Minnesota. Tribes in Minnesota are nationally-recognized leaders in documenting the extent of contamination in waters and wildlife and advocating for environmental standards that protect the health of tribal communities and culturally important foods and waterways. This poster presents recent findings of an ongoing environmental monitoring project within the 1854 Ceded Territory and the Grand Portage Band of Lake Superior Chippewa reservation. Monitoring efforts focus on CECs, including PFAS, personal care products, pharmaceuticals using passive water sampling (POCIS) and tissue analysis of wildlife and plants, with a particular focus on culturally important species.

This project is a collaboration between the Grand Portage Band of Lake Superior Chippewa, and Red Lake Nation, and the University of Minnesota. Its goals are to establish baseline contamination levels, identify potential sources, advance water quality and fish sampling protocols for CEC monitoring, and inform strategies to reduce future pollution. By integrating environmental monitoring with policy analysis, this work addresses both contamination and tribal environmental governance. The project aims to support Tribal authority in water regulation by equipping tribes with the biophysical data needed to better understand contamination prevalence and exposure risk.

In 2025, 50 randomly selected river and stream locations were sampled across Minnesota for pharmaceuticals, illicit drugs, hormones, anti-corrosive chemical, flame retardants, and detergents. Every river included in the study had at least one contaminant.  A total of 53 different chemicals were detected, with an average of 6.4 chemicals per location. The 15 most frequently detected chemicals comprised 78% of the total detections. Ten antibiotics and three anti-depressants were detected at least once. Cotinine, a metabolite of nicotine, was the most frequently detected, found at 76% of the locations at a maximum of 5 ng/L.  Theophylline, a bronchodilator,  was detected in 66% of the samples up to 165 ng/L, while metformin, a drug used in the treatment of type II diabetes, was detected at a frequency of 62% at a maximum of 235 ng/L.  Seven orthophosphate esters were also frequently detected, with TDCPP the most frequently detected in 54% of the rivers. Other detected chemicals included benzotirazoles and their derivatives, illicit drugs, Bisphenol F, Bisphenol A, and the insecticide DEET.  Together, the results show a very widespread presence of these contaminants across Minnesota’s surface water. 

Rivers serve as both sinks and transport pathways, carrying microplastics downstream to lakes and oceans. Previous research on riverine microplastic pollution has highlighted the importance of watershed-scale anthropogenic characteristics as key drivers of microplastic abundance and spatial variability; however, the extent of their influence remains unclear, limiting guidance for watershed managers and water quality agencies.

This study examined the spatial distribution of microplastics in major Minnesota rivers. It assessed how river discharge, land use, population density, and wastewater variables affect microplastic concentrations at the catchment scale. Surface water and sediment samples were collected from 22 sites across seven major Minnesota rivers using a 100 μm Manta net and a Ponar grab, respectively.

Surface water concentrations ranged from 0.000465 to 0.0275 microplastics/L (mean ± SD: 0.00735 ± 0.00807). Sediment concentrations ranged from 0 to 91.7 microplastics/kg dry weight (mean ± SD: 33.2 ± 29.7). Surface water and sediment concentrations were not correlated.

Population density and developed land use correlated positively with surface water microplastic concentrations. Sediment concentrations showed no relationship with local catchment anthropogenic factors but correlated negatively with river discharge, suggesting low flow promotes settling and retention of plastic particles.

These results show that catchment urbanization is linked to higher microplastic concentrations in surface water, while sediment accumulation depends more on local hydrologic conditions than on catchment characteristics. Water quality managers should prioritize microplastic monitoring in urbanized catchments for surface water and target low-flow depositional zones for sediment sampling and remediation.

Monitoring surface water sources can help to identify common surface water quality contaminants based on watershed characteristics, climate, and seasonality. Urban contaminants included PFAS, chloride, nitrate-N, imidacloprid, caffeine, and cotinine. In rural communities’ higher concentrations of human-use pharmaceuticals (e.g., caffeine, carbamazepine, codeine), were also found in surface waters, likely a result of an older wastewater (e.g., septic systems). An agricultural stream showed the highest concentrations of antibiotics used to treat livestock (e.g., lincomycin, sulfonamide) as well as atrazine. When these contaminants enter drinking water sources, they have the potential to degrade or interact with disinfection methods, potentially creating micropollutants and unregulated disinfection byproducts with unknown toxicological effects. Constructed wetlands are a best management practice that has been used for non-point sources and during wastewater treatment to mitigate environmental pollution, particularly for nitrogen (N) treatment. Yet, the implications of other contaminants on N removal remain relatively unknown. Therefore, the goal of the study was to quantify the removal of common water quality contaminants and determine their effect on N removal processes. Two types of constructed wetlands, floating treatment wetlands (FTW), and free water surface wetlands (FWS), were tested. The constructed wetlands were an effective treatment option; however, contaminant mixtures inhibited N removal rates while FTWs increased plant uptake of all contaminants. By understanding the impact that different types of contaminants have on N removal, treatment wetlands can be specifically designed for the expected water quality characteristics of the site that vary by land use and season. Furthermore, the integration of source watershed precursors into the source water protection and/or upgrading drinking water treatment systems are critical for protecting public health.

When firefighters extinguish a structural fire, the water used can mobilize toxic chemicals formed as building materials, especially plastics, transform under extreme heat. In urban areas, this runoff typically enters stormwater infrastructure and discharges untreated to nearby rivers, lakes, and ponds. Airborne fire emissions and firefighter exposure are well studied, but the chemical composition of firefighting wastewater runoff remains poorly characterized. With 6,479 structure fires reported statewide in 2024, this is a recurring water-quality concern relevant to stormwater managers, fire service agencies, and policymakers.

Partnering with the Saint Paul and Minneapolis Fire Departments, we collect grab samples from structural fire responses and timed samples during controlled burns. Samples are analyzed by high-resolution GC/MS and standard EPA methods for persistent organic pollutants (PAHs, PCBs, PBDEs, dioxins and furans), PFAS, and heavy metals such as lead. Using municipal stormwater models and literature-based degradation and partitioning data, we will model contaminant fate and transport to estimate chemical loads delivered to receiving waters.

Anticipated outcomes include the first empirical characterization of contaminant types and concentrations in fire wastewater and a spreadsheet tool that estimates pollutant loads reaching surface waters. These findings can inform fire suppression and runoff containment practices, stormwater management, and monitoring priorities, helping agencies reduce contaminant loading to urban watersheds and protect aquatic ecosystems and public health.

Per- and polyfluoroalkyl substances are persistent water contaminants whose strong carbon–fluorine bonds make them difficult to destroy using conventional treatment technologies. Many current approaches, including adsorption, ion exchange, and membrane filtration, primarily concentrate PFAS into secondary waste streams, while destructive technologies often require high temperature, high pressure, or chemical-intensive conditions. Our group has collaborated with Plasma Blue to successfully develop and demonstrate a continuous-flow in-liquid cold plasma reactor for destructive treatment of PFAS-contaminated water and complex waste streams.

The reactor generates controlled plasma discharge directly within the liquid stream using a regular AC power source, enabling simultaneous formation of highly reactive reductive and oxidative species. These species attack C–F and C–C bonds, promoting PFAS defluorination, chain shortening, and molecular destruction. Previous testing demonstrated strong removal of highly concentrated PFOA, including 91.0% removal within 30 minutes and 93.4% removal within 60 minutes under optimized conditions, with approximately 87.75% fluorine removal and limited short-chain byproduct formation. We further expand the application space from model PFOA solutions to field-relevant samples, including PFOS/PFHxS-contaminated water and raw landfill leachate. Third-party-audited testing showed PFOS and PFHxS reductions to below detection or regulatory limits, while raw leachate trials demonstrated substantial removal of regulated PFAS, including PFBS, PFHxS, PFOA, PFOS, and PFNA, after plasma treatment.

These results indicate that continuous-flow in-liquid plasma can move beyond lab model PFAS deconstruction toward on-site PFAS destruction in real water, wastewater, landfill leachate, and concentrated treatment residuals. 

Historic and systemic inequities, climate change, and other factors shape and exacerbate unequal access to safe, accessible, and affordable water across the seven-county Twin Cities region. The Metropolitan Council's Water Policy Plan names water equity as a core objective, yet planners, utility managers, and policymakers currently lack a shared tool to identify where water-related burdens and social vulnerability overlap. This work is intended for water resource planners, municipal staff, and policymakers engaged in equity-focused water planning.

We present an early-stage, exploratory Water Vulnerability Index combining water-related stressors (affordability, quality, access, infrastructure, climate) with social vulnerability indicators (physiological risk, economic precarity, housing conditions), alongside planning context layers for historical disparities, actionability, and cultural relevance. This tool remains in development in part because composite indices carry real equity risks: fixed indicators, weights, and boundaries can flatten lived experience, encode the biases of whoever selects the data, and produce "official" maps that exclude or misrepresent communities, compounding rather than repairing past harm.

Next steps may include community workshops to gather feedback, prioritize and validate variables, and surface missing context. Development of a story map component to pair quantitative scores with community-submitted narratives and lived experience of water are also in development. Anticipated outcomes are not a finalized index but a framework for discussion to be used in tandem with other inputs from community in decision-making. 

Starry stonewort (Nitellopsis obtusa) is an invasive freshwater macroalgae that is of growing concern to lake managers due to its ecological and economic impacts. Management options are limited and have varying success, therefore early detection and rapid response is necessary. Early detection presents a challenge for lake managers as starry stonewort appears visually similar to native charophytes, making traditional monitoring methods difficult. Environmental DNA (eDNA) monitoring could reduce the need for time-intensive visual monitoring, however positive results require visual verification, therefore additional resources are needed to allow lake managers to confidently monitor for starry stonewort using eDNA.

This poster will provide a midpoint update on a collaboration between Ramsey County staff and the University of Minnesota Waterhouse Lab, with funding provided by the Minnesota Aquatic Invasive Species Research Center (MAISRC) and the State of Minnesota. This project seeks to increase capacity for starry stonewort detection by providing lake managers with new tools to assess macroalgae populations. During the 2026 summer field season, County staff will collect and identify approximately 10-12 macroalgae species, including starry stonewort, from Minnesota lakes. The Waterhouse Lab will use these samples to develop a curated reference metabarcoding database for macroalgae. This database will improve eDNA-based macroalgae identification and provide infrastructure for lake managers to assess native macroalgae, facilitating more informed monitoring of starry stonewort. With support from the Minnesota Department of Natural Resources, County staff will develop a visual identification guide for macroalgae species, which will allow managers to confidently assess their native macroalgae populations and confirm non-native species presence. This poster will provide takeaways from sample collection, identification, and progress toward the visual identification guide.

Rising chloride concentrations in Minnesota lakes via road salt has become an increasingly important issue, especially as increasing salinity can compound the impacts of climate change on freshwater systems. Zooplankton are the middlemen of energy transfer from primary producers to consumers; therefore, declines in abundance, food quality, and feeding efficiency caused by increasing salinity can negatively impact fish biomass, lake diversity, and overall lake health. Additionally, climate-driven changes to water temperature, water hardness, and cyanobacterial abundance impact zooplankton’s responses to chloride conditions requiring a multi-faceted approach to understand the interactive effects of increasing salinity on zooplankton under future climate scenarios. In this study, we investigated 16 Minnesota lakes with a concentration gradient of 0 to 1500mg/L of Cl-, to uncover changes in zooplankton diversity and abundance, as well as lake parameters that could alter zooplankton response to these changes. Whole water column zooplankton communities were collected monthly between June and October in 2023 and 2024 and individuals were identified to the lowest possible taxonomic resolution. Preliminary work shows that zooplankton communities exhibit greater variability throughout the growing season than across salinity gradients, suggesting that zooplankton are resilient to salinity shifts within 0-1500 mg Cl-/L. Lake biogeochemical and physical parameters, including nutrient concentrations, chlorophyll-a, water column temperatures and dissolved oxygen, and lake mixing regime, will also be examined across chloride concentrations to better characterize the interactions between lake physiochemistry, salinity, and zooplankton. The results of this work will enhance our understanding of the impacts freshwater salinization has on food web structure and can inform best management practices for healthy fisheries and water quality improvements.

Urban lakes are managed to meet water quality standards based on water quality measurements such as total phosphorus, transparency, and chlorophyll. However, these metrics do not always align with public perception of water quality, which can be influenced by factors such as vegetation or trash. To gain a better understanding of how visual conditions affect visitor perception of lake water quality, we collected and analyzed photos as well as corresponding visitor perception surveys and water quality from 17 urban lake sites in the Twin Cities region of Minnesota throughout the summer months of 2025. Survey participants rated their perceived water quality of the lakes while photos were collected weekly for each site’s water surface. These photos were analyzed for color metrics. Red, green, and blue (RGB) values were extracted from each photo and normalized to reduce the influence of glare and shadows. Vegetation indices were created using the RBG values to classify lakes into three visual condition categories: clear water, macrophyte dominant (floating vegetation ie. algae), and turbid. A training data set was created by manually selecting 10-15 photos that most clearly represented each category, allowing for additional photos to be classified by category. We observed wide variation of visual surface quality across lakes, and seasonal variation within some. Results indicated that vegetation patterns influenced perceived water quality, with some lakes receiving lower ratings despite meeting traditional water quality standards. These findings suggest that standardized metrics alone do not fully capture public perceptions of lake quality and highlight the importance of visual conditions in shaping visitor experience.  

Improving and maintaining the water quality of lakes is important to cities, watershed management organizations, and other local government units in Minnesota. The monitoring of standard water quality variables (including trophic state indicators) is an important tool for achieving the goal of high water quality in lakes. Yet little is known about how the general public perceives the water quality of lakes, or how monitoring data are understood by lake visitors. Using a voluntary survey that was taken via text, we are studying how lake visitors perceive the water quality of lakes and why they perceive it that way. Preliminary results indicate that the presence of algae, the presence of trash, water clarity, and the odor of the lake are important variables when shaping water quality perceptions. Most lake visitors appear to make judgments about water quality based on immediate observations of the lake. While not used as frequently as directly assessing the lake, the history of the lake and observing whether other people are recreating in or on the lake are also considered. Importantly, it appears that local government unit communication is not a major source of water quality perceptions for the general public. With greater familiarity on how people perceive water quality and how they obtain their assessments, water resource managers can disseminate information in ways that are understandable and valuable to the general public.

Early Detection and Rapid Response (EDRR) is for preventing the establishment of new invasive aquatic macrophytes and their spread in freshwater systems. Traditional methods, such as dive-and-rake-toss surveys, can fail to detect invasive aquatic macrophytes early in the growing season and when species are present at low abundance. Environmental DNA (eDNA) methods may provide a cost-effective solution for improving detection of invasive macrophytes, but the dynamics of aquatic biomaterial collection remain poorly understood. Additionally, environmental conditions in lentic systems pose challenges to the efficient capture of macrophyte eDNA. This study aims to optimize processes involved in field eDNA sample collection targeting aquatic plants. 

Shoreline properties across Minnesota and Wisconsin inland lakes and along western Lake Superior face multiple complex issues including variable water levels, shoreline erosion, aquatic invasive species, fisheries habitat loss, and increased development pressures. Real estate professionals serve as important information pathways for property buyers regarding environmental regulations, shoreline zoning, and best management practices for water resources.

To better understand and capitalize on educational opportunities surrounding shoreline property transfers, a regional survey is being launched in summer 2026 focused on licensed Realtors across northeast Minnesota and northwest Wisconsin. The survey assesses Realtor knowledge of and attitudes towards water quality and shoreline issues, the top environmental questions asked by clients, and preferred modalities for receiving professional development and resources on priority topics.

This poster shares preliminary results from the survey, highlighting priority Realtor and client learning needs and actionable recommendations for extension educators, watershed managers, and those providing technical assistance to property owners. These insights will guide future outreach and targeted professional development programs to empower realtors as informed conduits of information at point of sale and beyond regarding  sustainable shoreline stewardship. 

Shallow prairie lakes in southern Minnesota are increasingly affected by shoreline development and agricultural land use, contributing to nutrient enrichment and declining ecological condition. Although many of these lakes occur within the same ecoregion and are generally eutrophic, they often differ in water quality. This variation suggests that local-scale characteristics, particularly shoreline condition, may influence ecological processes beyond broader regional factors. While the effects of eutrophication on aquatic communities are well documented, less is known about how shoreline-related differences in water quality influence multiple biological communities within the same lake ecosystem. This study investigates relationships among shoreline condition, water quality, fish assemblages, and bird richness across 15 lakes in the Western Corn Belt Plains ecoregion. During summer 2026, water-quality variables, including nutrients, turbidity, chlorophyll a, dissolved oxygen, temperature, and water clarity, will be measured. Fish assemblages will be sampled using beach seining and gill netting, while bird communities will be surveyed using point count method. Shoreline development will be quantified using GIS-based assessments. Principal component analysis and generalized linear mixed models will be used to evaluate relationships among shoreline condition, water quality, and biological responses. We anticipate that lakes with highly developed shorelines will exhibit poorer water quality, and this will be associated with altered fish assemblage structure and bird species richness. We will also evaluate whether fish and birds respond similarly to water-quality gradients. Coordinated responses would suggest that water quality is a common driver of ecological condition across taxa, providing information that can guide shoreline management, habitat conservation, and lake restoration efforts in prairie lakes.

Lakes and rivers provide critical benefits that support human lives; clean water to drink, safe fish to eat, enrichment through cultural activities. Aquatic invasive species (AIS) infestations can compromise fundamental ecosystem processes, ultimately diminishing ecosystem benefits. Managing AIS is a key challenge in Minnesota, USA, which has abundant lakes and rivers, an engaged population that relies on them, and several established populations of priority AIS. Managing AIS requires navigating substantial demand with limited resources in a spatially and temporally variable AIS risk context. Prioritization decisions may be informed by site values, such as economic, social, or public health importance (e.g., fisheries or drinking water sources). However, these values often remain implicit and applied selectively. By integrating ecosystem services into established decision support tools, we aim to formalize and ease the application of ecosystem services in AIS management decisions. To scope the breadth of freshwater ecosystem services, we conducted a standardized literature review of the benefits delivered by surface freshwaters in Upper Mississippi River Basin by searching Web of Science, Water Resources Abstracts, CAB Abstracts, and state and federal databases. Preliminary screening suggests ~300 articles will be included in the review, evidencing how services are valued and considered for water resources research and management. The highest priority services, identified through key stakeholder elicitation for AIS impacts and management decisions, will be applied using eco-epidemiological models to predict AIS impacts under simulated scenarios. The results will be incorporated into the AIS Explorer decision support tool, www.aisexplorer.umn.edu, through interactive user-defined prioritization and relative statewide distributions, integrating consequence risk into the existing invasion risk frameworks that include propagule pressure and habitat suitability. 

Sulfate in freshwater ecosystems is an environmental concern due, in part, to its potential role in formation of neurotoxic methylmercury and the elevation of toxic sulfides in sediments. While treatment technologies exist for high-strength sulfate wastestreams, options capable of reducing medium-range sulfate concentrations to freshwater levels (commonly 3-30 mg/L) are limited. One promising technology is phytoremediation using fast-growing hybrid poplar trees (Populus spp.). Poplar systems have previously demonstrated efficacy in remediating various inorganic and organic contaminants along with nutrients, but little research has examined hybrid poplars for sulfate phytoremediation. We hypothesize that moderate sulfate loading will have minimal effects on tree growth and physiology, supporting their suitability for sulfate remediation.

To test hybrid poplars for sulfate remediation, we established a field study in Aurora, Minnesota that examines tree growth and physiology. The site is located near a mine pit lake containing ~400 mg/L sulfate. The field experiment, established in 2025, includes four hybrid poplar clones (‘99007115’, ‘9732-31’, ‘DN34’, ‘InnovaTree’) belonging to the Populus deltoides Bartr. ex Marsh × P. nigra L. ‘DN’ genomic group, and two treatments (irrigation with the lake water and biochar amendment) across 144 trees. In the 2026 growing season, sulfate treatments will begin. Half of the trees will be irrigated with lake water. During the growing season, soil samples will be collected monthly for sulfur analysis, along with measurements of tree diameter and chlorophyll content. Leaf water potential and light- and dark-adapted chlorophyll fluorescence will be measured in August. Findings from this study will support the implementation of poplar-based phytoremediation as an efficient, environmentally sound, and cost-effective strategy for reducing sulfate loading to natural aquatic systems.

Over 700 lakes in Minnesota are listed as impaired due to excess nutrients, chloride, or emerging contaminants such as perfluorooctanesulfonic acid (PFOS). Managing water quality is challenging as these contaminants vary in their source distributions, in transformation and retention along flowpaths, and in their persistence in lakes. Relationships between watershed inputs and lake water quality in urban areas are further complicated by highly altered watershed runoff pathways and management history. We seek to answer: (1) What are the major lake and watershed drivers of concentrations of phosphorus, nitrogen, chloride, and PFOS in urban lakes? and (2) what physical characteristics of lakes, their watersheds, or regional management results in deviations from these relationships? We examined these questions by relating detailed lake and watershed information to lake water quality datasets for a large set of well studied urban lakes. Using 171 lakes from the DNR Lakesheds project, we calculated landscape metrics hypothesized to represent urban impact for each lake watershed, including impervious surface cover, road density, population density, land use, land cover, and average building age. These watershed metrics were compared to lake water quality, as measured by mean concentrations of water column total phosphorus, total Kjeldal nitrogen, and chloride, as well as mean PFOS in fish tissue. Preliminary relationships show that chloride and PFOS concentrations respond linearly to increased impervious surfaces and road density, and both commercial and industrial land use, while total phosphorus concentrations show no relationship with any watershed metrics, suggesting that internal cycling and management actions potentially have a stronger effect on in-lake concentrations than watershed inputs. Together, these results indicate contaminant-specific relationships between watershed structure and lake concentration or bioaccumulation. 

Rapid shifts in climate are increasing wildfire activity, producing larger and more intense burns with far‑reaching ecological consequences. As the threat posed by wildfire increases, it is essential to understand how water resources are impacted by wildfire events.Although wildfire effects on lake ecosystems have been studied, findings remain inconsistent due to the complex interplay of watershed characteristics, burn severity, hydrology, and post‑fire material transport. These contradictions highlight critical knowledge gaps in understanding how wildfire disturbances influence microbial processes that regulate mercury fate.  Lake sediments provide habitat within which mercury can be methylated into methylmercury (MeHg), a dangerous neurotoxin known to bioaccumulate and negatively impact organisms at higher trophic levels including fish, birds, and mammals. Mercury methylation and demethylation are largely regulated by microbiomes, the complex communities of microorganisms present in all environments.

This study aims to understand biogeochemical responses from the 2021 Greenwood wildfire, particularly in regards to mercury biotransformation. Taxonomic composition and functional traits of microbial bacterial communities within lake sediments impacted by wildfire will be characterized and compared to nearby control lakes. To achieve these objectives, 16S sequencing, amplicon sequencing, metagenomics, and metatranscriptomics will be utilized to determine mercury methylation rates within lake sediments impacted by wildfire. These genetic data will be paired with environmental measurements and watershed level data. Findings from this study will advance the understanding of how wildfire reshapes sediment microbiomes to potentially enhance methylmercury production in inland lakes, with implications for water quality, ecosystem health, and mercury exposure risk in a changing climate.

Harmful algal blooms (HAB) have increasingly become more common in the naturally chilly, but quickly warming, inland waterbodies of Minnesota. While they are a natural phenomena, they can pose challenges for human use and can go against our definition of a “healthy” lake ecosystem. Current methods for controlling and remediating HABs in freshwater consist of efforts to monitor and mitigate nutrient build up in water systems, as well as chemical and physical treatments; phage therapies are beginning to be explored as a control method. Phage viruses have highly specific hosts, so are considered a more targeted approach to an infection. I aim to isolate novel cyanobacteria and cyanophages from environmental HABs and to gain an understanding of the role that phage predation has in modulating the community dynamics of cyanobacterial blooms. Candidates will be selected based on their ability to induce high microbial mortality in ecosystems where anthropogenic activity and climate change have increased bloom frequency. My objective is to explore how naturally occurring phages contribute to the inherent resilience of aquatic ecosystems and how they might be harnessed to mitigate algal blooms. In order to create a library of native cyanobacteria and cyanophages, I will sample from a wide range of waters to 1) characterize the diversity and distribution of freshwater cyanobacteria and cyanophages and how they coevolve across freshwater ecosystems, 2) investigate the role of cyanophages in regulating cyanobacterial population dynamics, and 3) examine cyanobacteria-cyanophage host-range relationships and patterns of host resistance and phage infectivity.

As anthropogenic climate change and excess nutrient inputs accelerate, cyanobacteria harmful algal blooms (cHABs) are projected to intensify. These blooms pose significant threats to public health, ecosystem welfare, freshwater resources, and local economies through production of excessive biomass and sometimes toxins. Current methods of detecting cHAB toxins often struggle with generating timely results for management purposes and lack standardized monitoring protocols. Such drawbacks make decisions on beach closures, water treatment needs, and other mitigation practices more difficult, as people can be exposed to toxins before warnings are posted. This project aims to improve forecasting of cyanotoxin levels and develop a toolbox for local water resource management groups to use, allowing them to better communicate risks of cHABs with the public. Working in collaboration with project partners, samples will be collected from across Minnesota lakes and analyzed for cyanotoxin concentrations, toxin-encoding genes, and water quality parameters. Encoding genes are of particular interest, as the gene codes have experimentally acted as an indicator for future toxin concentrations. From these data, correlations between toxin presence and bloom formation will be analyzed to develop a predictive test for cyanotoxins before they are present in water bodies.  These analyzed results will be used in developing a field-deployable cyanobacteria testing kit. The kit will comprise of portable laboratory tools, which use molecular biology methods, allowing for genomics and microbial testing in the field. Kits will be tested and evaluated by researchers initially to ensure effectiveness for beta-testing with partners. To further engage water resource managers, workshops will be conducted to demonstrate the kit and obtain feedback on its practicality and limitations. This project will provide improved data on early-detection of cyanotoxins, thereby creating a proactive strategy for cHAB mitigation to protect public and environmental health. 

Mni Owe Sni (Coldwater Spring) is a ~60 gallon per minute spring complex emanating from the Platteville limestone, along the Mississippi River bluff about a mile northwest of Fort Snelling, Minnesota. The spring is considered sacred by the Dakota and other tribes, and is managed by the National Park Service (NPS) in partnership with Tribal communities. Water quality in the spring is known to be affected by road salt, nitrate, and emerging contaminants. Minnesota state law prohibits any actions that would reduce flow to the spring. 
A cooperative project between the U.S. Geological Survey (USGS) and NPS seeks to better delineate the groundwater contributing area (springshed) to Mni Owe Sni using groundwater flow modeling. A MODFLOW 6 model is being constructed to simulate groundwater flow to the spring from potential sources including areal recharge and leakage from surface water features. The model extends east from Lake Harriet to the Mississippi River, south from Lake Hiawatha to encompass most of the Minneapolis-St. Paul International Airport, and vertically down to the base of the Jordan Sandstone, allowing for consideration of competing sinks including other springs along the Mississippi and Minnesota River Bluffs, and discharge to the Mississippi River. The model structure is based on bedrock surfaces from the Hennepin County Geologic Atlas and Quaternary lithologic texture data provided by the Minnesota Geological Survey. Uncertainty in the model inputs and structure is considered by creating an ensemble of plausible model configurations that are fit to observed groundwater levels and spring flows using the PEST++ Iterative Ensemble Smoother. A probabilistic springshed map produced by the study will inform where potential management actions could improve water quality and protect spring flow.

The Minnesota Pollution Control Agency established a long-term biological monitoring program in 2013 with the primary purpose of understanding the impacts of climate change on aquatic life in flowing waters. Effectively implementing Minnesota’s ‘watershed approach’, from assessments to strategy development, requires a firm understanding of climate-associated disturbances, such as altered flow and temperature regimes, and their impact on aquatic life. Fish and aquatic macroinvertebrates, along with a suite of other parameters, are being routinely monitored at 67 locations throughout the state, many of which are paired with stream gages. Increasing resiliency of the watershed approach relies on the development of novel biological metrics that are sensitive to climate-associated disturbances as well as elucidation of broad-scale temporal trends related to riverine ecosystems. Identifying aquatic life impairments that have a strong ‘climate signal’ will allow limited resources for restoration to be focused elsewhere on watersheds where outcomes have the greatest potential for success. A summary of various collaborations as well as preliminary results from the first decade of this program will be presented.

Pupil shape plays a pivotal role in visual ecology.  In taxa such as mammalian herbivores, anurans (frogs), and snakes, previous research has established linkages between pupil shape and ecological niche. However, systematic assessment of pupil shape diversity and their association with niches in freshwater fish is limited. This study investigates interspecific variation in pupil shape and its niche relationship of freshwater stream fishes, encompassing over 500 species, and approximately 1500 photographic records of individual fish specimens. This study surveyed image-based records from online platforms (e.g., iNaturalist, Joel Sartore’s Photo Ark, state and federal agency sites), and primary literature. In addition, niche group assignments were made using the open source FishTraits Database. For each species, a minimum of three and a maximum of five individual images were assessed. Species-level pupil shape was assigned using a majority rule, whereby a shape was recorded if at least two of three individuals shared the same form. A total of six pupil shapes were identified such as circular, anteriorly elliptical (oval & almond shape), dorso-ventrally elliptical, antero-posteriorly elliptical, etc., with the oval shape occurring at the highest frequency. Species exhibiting egg-guarding behavior predominantly had almond-shaped pupils. Pearson’s Chi-square test confirmed significant associations between pupil shape and trophic ecology, habitat preference, and reproductive ecology. Additionally, Multiple Correspondence Analysis indicated that specific pupil shapes clustered with particular ecological niches. Notably, pupils with vertices in the anterior position (almond shape) tended to be associated with fast current stream predators. This study shows that the pupil shape categories provide a useful framework for characterizing ecological niches in freshwater fish. Results suggest that pupil shape is functionally associated with habitat preference and trophic ecology.

Spatial models of rivers benefit from explicitly considering the network structure of upstream and downstream connections in the river system. Properly processed spatial datasets (available at national scale from US Geological Survey) can enable spatial stream network models (SSNMs) that can improve predictions of parameters like stream temperature, nutrient loads, pollutant levels, and aquatic species distributions. However, the automated processing and national scale of available stream network datasets preclude sound application for some (perhaps many) river systems in Minnesota. Thus, we are processing the National Stream Internet dataset (built on US Geological Survey hydrography) to correct errors for Minnesota's 80 HUC8 watersheds using the statewide hydrography dataset from the Minnesota Department of Natural Resources (MN DNR). We aim to produce a networked, spatially explicit streams dataset that can be used with SSNMs. With this poster, we present our methodology and examples of the completed components of the processing. Our goal is for this dataset to serve as a foundation upon which statewide or watershed-scale models can be built to predict physical, chemical, or biological characteristics of streams in Minnesota.

The Upper Mississippi River System (UMRS) provides critical transportation, economic, and ecological services across the United States. Cumulative impacts of water withdrawals along the river navigation system have the potential to negatively impact these services, yet this issue remains understudied. This study reported on here develops a sensitivity analysis framework to evaluate how increasing consumptive water use affects streamflow at navigation infrastructure along the Mississippi River channel corridor within Minnesota. Using the Water Balance Model (WBM) 2.0.0, we simulate daily discharge at lock-and-dam locations along Minnesota sections of reaches of the Mississippi River under two scenarios: a baseline simulation excluding anthropogenic water withdrawals, and comparative simulations incorporating irrigation, livestock, domestic, and industrial water withdrawal. Sensitivity is assessed by quantifying changes in simulated inflow at each lock-and-dam location relative to the baseline. Results will characterize the relative contribution of each withdrawal sector to streamflow reduction and identify locations and periods of greatest hydrological vulnerability. This work represents an initial component of a broader, multi-sector water availability assessment for Minnesota, with implications for navigation planning and water resource management under future demand scenarios.

Diatoms are single-celled photosynthetic algae found in most bodies of water globally. Diatom species, similar to fish and macroinvertebrates, have specific tolerances to water quality variables such as temperature, pH, or salinity. Samples were collected from the Le Sueur and Watonwan Rivers, MN from summer 2025 - spring 2026. Samples were analyzed using a scanning electron microscope (SEM) to visualize and identify individual specimens. Samples had excess organic material burned away and were sputter-coated with gold before using the SEM. Twenty-four distinct species were identified by their shape and specific structures. Early results indicate presence of species common in shallow, nutrient-rich waters, such as Stephanocyclus meneghinianus. Project next steps involve evaluating the distribution and abundance of diatom species across a sample of northern and southern MN lakes. A more universal understanding of diatom communities, their seasonality, and ecosystem functions could provide valuable insight into aquatic ecosystem health.

The Morrison County Historical Society owns the Charles A. Weyerhaeuser Museum, located on the west bank of the Mississippi River in Little Falls. The streambank at this location is 30-ft high, relatively steep and began failing in 2015. Morrison Soil and Water Conservation District was asked to assist with technical assistance in stabilizing and repairing the erosion.  By 2022 the failing streambank was 12-ft horizontal to the foundation of the museum and a significant source of sediment being discharged to the river, a Special Resource Water. Ulteig was then retained to find solutions to restore the streambank and associated habitat. Braun Intertec provided geotechnical engineering services. First an alternatives analysis was completed that led to the selection of streambank restoration with a reinforced soil slope at the museum and grading the bank to a stable slope in adjacent areas. To protect the water quality of the Mississippi River and to provide new habitat, instream wood, live root stock, revegetation with native species, and fish habitat structures were incorporated into the project. Since that time environmental review, permitting, design, bidding and construction phases of the project have been completed. Extensive cultural resources surveys were completed to ensure culturally significant resources were recovered. The project was funded by MCHS, a grant from the Clean Water Legacy Fund, by local funding, and from direct state legislative appropriation. This poster will describe project details from planning phases through completion of construction and is targeted to people interested in restoration of water resources.

Predicting the onset and subsequent erosion rates of muddy, clay-rich sediment is a persistent challenge in our understanding of sediment transport processes in lakes and rivers. With many nutrients and pollutants sorbed to these sediments, accurate transport predictions are crucial for effective modern lacustrine and fluvial management practices. Here, we develop a computational fluid dynamics model that incorporates the Darcy-Brinkman-Biot framework to model the incipient erosion of a muddy sediment bed and the development of cohesive sediment gravity flows, illustrating the utility of this framework for modeling sediment transport processes in both fluvial and lacustrine systems. We validate our model with recently performed flume experiments from the Yang Group at the St. Anthony Falls Laboratory and literature reported experiments. Additionally, we demonstrate the relevance of numerous sediment properties (rheology, density, and concentration) in influencing erosion thresholds and sediment flow speeds. This work encourages the adoption of computational fluid dynamics (CFD) in sediment transport engineering practices through demonstrating the unique ability of CFD to improve our understanding of these complex sediments through enhanced data visualization capabilities, efficient parametric evaluations, and as a complement to existing erosion experimental data.  

Stochastic storm transposition (SST) provides a framework for using observed storms to estimate flood potential beyond the limits of short streamflow records. However, SST results are influenced by how storms are identified, how representative they are of the watershed, and where they are allowed to be transposed. This study evaluated these decisions for the Minnesota River Basin HUC-4 subregion (HUC 0702) to support rainfall development for hydrologic and hydraulic modeling.

Candidate transposition domains were evaluated using PRISM 30-year climate normals for precipitation and dewpoint, together with elevation. A three-tier screening process was applied to assess area ratio, meteorological consistency, and climatological similarity between each candidate domain and the watershed. The selected domain matched at least two of the three climate variables across approximately 97 percent of its area and all three variables across approximately 63 percent. Kolmogorov-Smirnov and other descriptive statistics were used to compare climate-variable distributions between the watershed and selected domain. The results showed that the selected domain was spatially consistent and distributionally similar.

A storm catalog was developed for the selected domain using hourly AORC precipitation data. Sensitivity testing showed that storm-identification settings affected the number of selected storms, event magnitudes, timing, and location of maximum precipitation. Coarser temporal settings generally produced fewer and smaller storms and shifted the temporal structure of selected events. These results show that storm catalog construction is not simply a preprocessing step, but a modeling decision that can influence SST-based rainfall inputs and downstream H&H modeling results.

Spanning over 2,000 miles and bordering ten U.S. states, the Mississippi River is a cultural landmark, a drinking water source for millions of residents, and a recreational and ecological resource. Understanding how river visitors engage with and perceive the Mississippi is essential for its management, but data on existing uses of water bodies are often missing or incomplete. Collecting data on river visitors along the entire corridor is challenging, given the length of the river, the remoteness of many access sites, and the plethora of organizations managing those sites. In 2023, researchers from the University of Minnesota and the University of Washington deployed a novel survey method using SMS chatbots to connect with river visitors as part of a broader project focused on understanding people’s values and uses of the Mississippi River. At 184 places along the river, local partners installed signs with a unique phone number for each site that invite river visitors to send a photo of the river. Participants were then asked to rate the quality of the water for swimming, fishing, and other uses, describe perceived threats to the river, and their motivations for visiting. Over 4,300 visitors responded to the survey. Overall, perceptions of water quality decline from north to south. In addition, visitor responses indicate respect and even reverence for the river, with high value placed on leisure and recreational uses. Results suggest enduring cultural and social values for the river despite varying perceptions of present water quality and recognition of threats to water quality in the future. These findings provide important insights for interstate water pollution control policy by assessing previously largely unknown visitor preferences and values for the Mississippi River.

Ella Graham is a second-year graduate student in the Science, Technology, and Environmental Policy program at the Humphrey School of Public Affairs and a National Science Foundation Circularity Impact Research Trainee

Peatlands are widespread in Minnesota, comprising more than a tenth of the land area. Most peatlands lie in the northern half of the state where glacial depressions have filled with organic matter over thousands of years. The water-logged, oxygen-poor conditions mean that dead organic matter decays slower than it accumulates, creating dense layers of organic, carbon-rich soils that build up over time. Peatlands are important for Minnesota water resources and provide ecosystem services as they support unique wetland habitats, buffer storm runoff, supply streamflow, and sequester a disproportionate amount of carbon for their small size. Changing precipitation patterns accompanied by warming trends of 0.5°C/decade in Northern Minnesota have led to questions about peatland productivity under a winter shift from snow to rain and hotter, prolonged growing seasons. We use a calibrated and validated land surface model called CLM-Hillslope to simulate surface, subsurface, and vegetative water fluxes in a 9.5 ha peatland watershed at the Marcell Experimental Forest (MEF) in Northern Minnesota and compare peatland hydrologic responses under current climatology and future trends. We find that a snow to rain transition lengthens the spring melt season and increases soil ice formation due to reduced snow insulation. Warmer growing seasons see longer and more frequent drought conditions from increased evapotranspiration. The consequent impact to storage of water and carbon in peatlands is still uncertain, but recent experiments at MEF point to increased desiccation and a transition from mosses to shrubs. Taken together, these changes have the potential to decrease peatland water retention, thus reducing summer baseflows and flood buffering capacity.

Issues regarding water and climate can be an overwhelming, divisive, and disheartening topic. However it is one that we cannot ignore. The Minnesota Marine Art Museum is exploring ways in which we can engage and educate our visitors with environmental issues while also structuring ourselves to be a resource that helps build community resilience. Being a marine art museum, most of our art and what we do is related to water in some way. This presents us with the unique opportunity to build off of the themes present within our museum and relate it to the clean water and climate issues we face today.

MMAM is examining various ways to connect our community with the climate conversation through exhibits, operations, and outreach. For exhibits, we have found that including an interactive display that builds off the water theme present has been an approachable and engaging way to get visitors curious about the issues. Operationally, the museum has taken steps that center the physical space around sustainability such as installing solar panels, reusing exhibition materials, and minimizing waste. Reaching out and partnering with local and statewide clean water and climate organizations has allowed for us to host various conversations highlighting critical climate topics, while also bringing to light the significance of art within the climate conversation. Overall the work done so far has been effective in highlighting the value of cultural institutions as a place that helps bridge the gap between climate information and the human experience.

Elevated in-stream chloride levels in the Coon Creek Watershed District (CCWD) during periods of baseflow indicate groundwater as a likely source of chloride. Spatial patterns and temporal history of chloride loading within the CCWD is needed for input to a MODFLOW 6 groundwater model to estimate when changes in road-salting practices might lead to improvements in water quality. A GIS analysis including land cover, road lane miles, winter road maintenance jurisdiction, stormwater infrastructure, and measured salt application rates is being used to determine the annual quantities and locations of salt application. We will compare our local method to a national methodology developed by the U.S. Geological Survey to see what insights can be gleaned at a smaller scale. Community engagement through the watershed district has yielded detailed salting information from municipal, county, and state agencies tasked with winter road maintenance. This highlights the importance of cooperation between various local governmental units to solve common problems related to water quality. Data practice lessons learned will be shared to assist these entities in sharing the data of their operations with water resource professionals. Process assumptions, data challenges, and other considerations will be discussed.

Chloride pollution from winter de-icing chemicals is one of Minnesota’s most persistent and challenging water quality issues. Unlike many pollutants, chloride does not break down in the environment and accumulates over time in lakes, streams, wetlands, and groundwater. Recent research indicates that approximately 70–78% of de-icing salt applied in the Twin Cities ultimately remains in local water resources or infiltrates groundwater, contributing to a growing number of impaired waters statewide. The Minnesota Clean Water Council has developed a policy statement with recommendations to address this challenge without compromising public safety.

The policy recommendations include establishing a granular salt fee to create market incentives for reduction, expanding funding for the Minnesota Pollution Control Agency’s Chloride Reduction Program, investing in research and remediation, incorporating low-salt design standards into site development, requiring Smart Salting practices for state facilities and contracts, and establishing professional licensing standards for winter maintenance applicators. The recommendations recognize that no practical large-scale alternative to chloride-based de-icers currently exists and therefore emphasize reducing unnecessary salt use without compromising safety through improved design, training, accountability, and behavior change.

The poster will provide an overview of the environmental impacts of chloride pollution, discuss barriers to implementation, and highlight opportunities for statewide policy action. Water resource professionals will gain insight into emerging approaches that combine regulation, incentives, education, and professional standards to achieve measurable chloride reductions while protecting public safety and supporting long-term water quality goals. Further, people will have an opportunity to share feedback and propose next steps to advance recommendations.

Chloride pollution from winter de-icing practices continues to impair lakes, streams, wetlands, and groundwater across Minnesota. While public agencies have made significant progress in reducing salt use through training, equipment improvements, and MS4 permit-driven requirements, a substantial portion of winter salt application occurs on privately managed commercial and industrial properties in urban areas. Municipalities have few practical tools to engage these properties beyond voluntary outreach, limiting the effectiveness of local chloride reduction efforts.

This poster presents a concept framework for a Commercial Winter Maintenance Licensure Ordinance that emphasizes training, accountability, and technical assistance rather than regulating snow and ice management practices directly. Under the proposed framework, commercial and industrial property owners would submit a simple licensure application every three years identifying responsible personnel, winter maintenance contractors, Smart Salting certification, and salt storage information.

The poster will describe the policy rationale, implementation framework, anticipated staffing requirements, and legal and administrative precedents that support the concept. Key features include leveraging existing training programs, engaging property managers alongside contractors, creating a community-wide network of trained winter maintenance professionals, and providing local governments with a practical mechanism to address chronic oversalting without prescribing operational methods.

The concept offers a scalable model for communities seeking measurable chloride reductions while maintaining public safety, minimizing administrative burden, and building long-term accountability among private-sector winter maintenance practitioners. Introducing this concept to water resources professionals will help to advance the conversation around chloride pollution reduction initiatives at the local government level.

In August of 2025, the South Washington Watershed District (SWWD) began a pilot project to harvest cattails from a large wetland complex in Oakdale, MN. The goal was to learn if that effort could be scaled up to meaningfully and cost-effectively improve water quality in Armstrong Lake. With guidance provided by Barr Engineering Co., SWWD staff led the project with field labor provided by the Washington Conservation District.

This poster will summarize work completed, lab analysis conducted, and resulting data, including some interesting local results related to phosphorus and chloride content in cattail biomass. Additional field work and lab analyses from the winter of 2026 are included for seasonal comparisons. The poster will share SWWD's experiences, explore concepts related to management of the harvested cattail material, and extrapolate cost-benefit relationships for this work in an effort to continue dialogue on this emerging topic.

A 2023 Municipal Separate Storm Sewer System (MS4) Phase I permit from the Minnesota Pollution Control Agency required the City of Minneapolis (City) to develop a commercial, industrial, and institutional (CII) stormwater program within 36 months. CII facilities can be a significant source of stormwater pollutants, and an effective program is essential to improving water quality and achieving long-term regulatory compliance. In response, the City undertook a structured, multi-year effort to design a comprehensive and defensible CII stormwater program tailored to local water resource priorities and its organizational capacity.

The first phase of program development was a nationwide benchmarking study, which included research and interviews with peer MS4 communities to identify best practices, common challenges, and innovative approaches. These insights informed a framework that balances regulatory rigor with practical implementation considerations.

The resulting CII program, currently in development as part of phase two, will integrate core components such as risk-based CII facility prioritization and inspection protocols; educational materials to build awareness and understanding; guidance on best management practices (BMPs); compliance enforcement procedures; protocols to prevent contaminants from entering the storm sewer system; a data management and mapping framework to organize and track CII facility information; and coordination with existing City inspection programs to maximize efficiency and reduce duplication.

In this poster, the City of Minneapolis and Young Environmental Consulting Group will highlight key insights, challenges, and lessons learned from the benchmarking phase. This presentation will be especially valuable for other MS4 communities and organizations in the early stages of program development that are considering incorporating benchmarking into their approach.

Phosphorus is the limiting nutrient in freshwater bodies. When phosphorus is added to a water body it will cause algae blooms, resulting in blue green algae which can release toxic chemicals. Roughly 40% of the lakes across the US are impaired due to excess phosphorus and the resulting eutrophication. We discovered in 2016 that stormwater ponds are not well-mixed, but are stratified due to the high level of sheltering from the wind. The result is that many ponds have low dissolved oxygen levels near the bottom, with internal phosphorus loading from the sediments. We are now working on remediation technologies for ponds that have high internal phosphorus loading to avoid phosphorus export to receiving water bodies.

• What is the most effective means of reducing phosphorus export from stormwater ponds?
• Which is the most cost-effective remediation method?
• What recommendations can we make?

We found that eliminating trees around ponds, installing and operating intelligent water level control and lining ponds did not have a substantial effect upon phosphorus export from stormwater ponds. Iron filings placement on pond sediments is effective for about five years, but alum treatments are effective for more than five years. Both remediation technologies are cost-effective. An intense street sweeping program, designed to reduce inflow to ponds by 25%, is the most cost-effective means of reducing phosphorus export.  The combination of alum treatment and intensive street sweeping will be a powerful combination designed to reduce phosphorus export from stormwater ponds. We are currently investigating aeration/mixing techniques as a viable remediation technique for pond phosphorus export.

The Pond Assessment Tool was developed for stormwater practitioners to conduct assessment of many ponds in an efficient and cost-effective manner, with results intended to inform monitoring or maintenance strategies for pond phosphorus management. Early versions of the Tool have been well-received by potential users, consisting of department of transportation staff as well as city, county, and consulting staff scientists and engineers. The Tool was developed to be easily updated and expanded to realize its potential as a robust and useful screening and assessment method for identifying stormwater ponds in need of further study, maintenance, or other management, especially for phosphorus, with the ultimate goal of improving or restoring functionality of at-risk ponds. Future versions of the Tool could be adapted to incorporate new information and predictive relationships and address hydrologic functions, other pollutants in stormwater, and impacts of retrofits or design practices (e.g., weir skimmers, sand filter benches). 

Ponds are ubiquitous in urban landscapes in much of the world, and a potentially vital but under-studied aspect of water quality in urban watersheds.  Stormwater management has focused mainly on the role of ponds for storage and attenuation of high flows; water quality benefits (e.g., phosphorus reduction) are assumed to arise from settling of particulates, with relatively little consideration to interactions between hydrological and biogeochemical processes. To inform improved management of ponds for phosphorus (P) retention, we studied three urban detention ponds in the Twin Cities, MN, USA to quantify a complete annual budget of water and P fluxes in the ponds. We continuously monitored inflows, outflows, and water quality (nutrients, dissolved oxygen), along with temperature profile time series. Across the ponds, annual retention of total P was high (>50%) despite expecting them to be net sources of P due to old age, high outflow P concentrations, and frequently-observed hypolimnetic hypoxia that could cause soluble P release from sediments. Event-scale analyses suggested strong hydrologic controls on P: retention of P increased roughly with antecedent pond storage capacity, and soluble P in outflow tended to decrease as inflow-induced mixing depth increased, suggesting an influence of anoxic vs. oxic sediment exposure. By contrast, wind-mixing events were rare due to high sheltering by trees. Together these results suggest that understanding hydrologic and wind-sheltering effects are crucial to improving pond performance for meeting downstream water quality goals. 

In 2026, the Minnesota Stormwater Research Council and the Water Resources Center hosted a first-of-its-kind symposium that brought together 185 urban stormwater pond practitioners, professionals, policy leaders, and researchers from public and private sectors to 1) Summarize the state of the science and implementation of ponds as a stormwater management practice, 2) Present past and current pond research, 3) Share, exchange and catalog ideas between practitioners, professionals, owners and operators, 4) Showcase pond demonstration, retrofit, and management projects highlighting approaches, successes, challenges and opportunities, 5) Refine and identify pond research priorities, resource and guidance needs, and 6) Identify future potential research and demonstration project collaborations.

The symposium utilized presentations, panel discussions, small group workshops, and interactive polling to foster an exchange between researchers and practitioners. More than twenty-five presenters and panelists provided content over the course of the two days.

This poster will showcase the symposium, offering a few highlights of the content and the unique presentation methods. It will also highlight a few of the outcomes and outputs. Examples include:

• Over 75% of participants gained actionable job knowledge, with 100% learning foundational pond hydrology.
• 100% of the evaluation respondents indicated that they learned the foundational information on pond hydrology and pollutants.
• 51% of the respondents indicated that they connected with another participant that they expect to collaborate with in the future. 

Facilitated small group discussions identified research and resource needs that are being used to inform the next stormwater research RFP in late 2027. 

Documented education and resource needs and solutions to unique management challenges generated in the field by practitioners.

Stormwater runoff significantly contributes to pollution in roadside environments. Biochar has emerged as a promising soil amendment for stormwater treatment because its high surface area and porous structure enhance water retention, pollutant adsorption, and support healthy plant growth. However, biochar properties vary depending on feedstock type and pyrolysis temperature. Additional guidance is needed regarding application specifications such as particle size and amendment ratios.

In Phase I, stormwater treatment was evaluated at laboratory-scale for biochar produced from black ash at a range of pyrolysis temperatures (300-975 °C ). The laboratory results from Phase I informed the selection of biochar types most suitable for field application. In Phase II, the focus is on developing the engineering design needed to optimize stormwater treatment. Our team evaluated the stormwater treatment efficiency of biochar produced at two different temperatures (500 °C and 700 °C ) and at three different particle sizes (finer than sand, sand, and coarser than sand) and in combination with various media (compost, topsoil and iron enhanced sand) at different ratios. Pots were filled with mixed media (by volume) and evaluated in a greenhouse to assess water retention capacity, pollutant (metals and nutrients) removal efficiency, and plant growth. Once analysis is completed, biochar at specified sizes, will be blended with selected materials and applied to a site at a parking lot for field evaluation. For each plot, on-site moisture sensors and stormwater collectors will be deployed to monitor hydrologic performance and contaminant removal. The findings from both phases will be used to establish specification criteria and recommendations for the use of biochar as a soil amendment in stormwater treatment. These recommendations will support biochar production and selection, media type(s), and implementation methods in coordination with the Minnesota Department of Transportation.

Urban growth and climate change are increasing stormwater runoff and pollutant loads across Minnesota, while existing stormwater practices remain limited in their ability to remove emerging organic contaminants and pathogens under cold, saline conditions. University of Minnesota and Geosyntec teamed to investigate the potential for fungal-enhanced biofiltration to improve stormwater treatment performance in cold-climate systems. Over 150 locally sourced fungal species were systematically screened for environmental tolerance and removal efficiency for contaminants such as E. coli, nutrients, PAHs, PFAS, and PCBs. Promising fungal species are being further evaluated using laboratory column experiments simulating stormwater biofilters to assess potential treatment effectiveness. The research aims to identify resilient fungal amendments that can be incorporated into existing biofiltration systems to create a sustainable, living treatment option that is capable of long-term contaminant removal. Outcomes include a curated fungal performance database, preliminary design recommendations, guidance for future field-scale implementation, and advancing a new biofiltration design for stormwater treatment. This presentation will focus on the bench screening of fungal species and preliminary results from the column studies.

Minnesota’s stormwater infrastructure was graded as a “C” in the 2026 ASCE infrastructure report card. Despite receiving an average grade, Minnesota is perceived as a national leader in stormwater management and works to advance innovative stormwater management solutions through the use of green infrastructure and water quality monitoring. However, this grade reflects how our infrastructure has been increasingly stressed by aging assets, intensifying rainfall and funding gaps. These challenges, amongst others, contribute to increased risk of flooding, deteriorating systems and escalating maintenance needs across the state. Continued progress depends on aligning funding, policy and design practices across the state.  

The ASCE report card committee issues a survey to infrastructure owners at the beginning of their data collection. Responses from stormwater infrastructure owners about the current condition of their systems and future outlook span from poor to exceptional. Additionally, publicly available data assessing stormwater infrastructure systems and not just resultant water quality or flooding is lacking. A major goal of the infrastructure report card is to foster conversation about the state of infrastructure and an emerging solution to raise the grade for stormwater is to implement needs assessments to understand the gap between funding and future needs.

This interactive poster will invite conference attendees to engage with the water resources community and share their experiences and opinions through interactive elements and open ended questions. Building on the presentation about the report card more generally, this poster aims to bring diverse professional insights together to help facilitate a deeper conversion about what steps need to be taken to improve Minnesota’s infrastructure. 

MPCA has added new materials to the Minnesota Stormwater Manual to help planners, designers, communities, and residents plan, design, and adopt green infrastructure practices.

The Green Infrastructure for Minnesota Communities booklet introduces green infrastructure principles, practices, and benefits by highlighting green infrastructure projects in and near Minnesota. This booklet can be used for education and outreach efforts to encourage green infrastructure adoption in yards, commercial spaces, and public projects.

Four new green infrastructure case studies were developed to help communities and planners understand how smaller green infrastructure practices have been envisioned and implemented. These include: Green Infrastructure Case Study: The Bee Line, Green Infrastructure Case Study: City of Rochester Public Works Transit and Operations Center, Green Infrastructure Case Study: 8th Street Stormwater Planters, and Green Infrastructure Case Study: Riverside Plaza

New or updated design details of green infrastructure practices were developed for engineers and builders including raingarden, permeable pavement, biofiltration planter, constructed wetland, and native plantings.

A contrast to typical research project-based posters, this poster will focus on educating the audience on new materials available for outreach, planning, and design of green infrastructure practices. The poster will include photos of green infrastructure projects from across Minnesota, submitted by the diverse advisory team, making a lighter and visually interesting poster. QR codes will be included for quick access to these new materials.

Joanne Boettcher and Paula Kalinosky of MPCA were Project Managers and editors. Kelly Barton of MPCA did graphic edits. Contractors at LimnoTech (list available) developed the draft content and layout, and over 20 technical team members (list available) contributed content, graphics, and editing.

Nitrification is an important step in biological wastewater treatment to satisfy permit requirements, avoid ammonia toxicity, and prevent eutrophication.  This biochemical process is carried out by ammonia-oxidizing microorganisms (AOM). Our understanding of AOM comes from a relatively small number of laboratory isolates of Nitrosomonas spp. that may not adequately represent the AOM in genuine wastewater bioreactors.  Samples were collected from 10 municipal wastewater facilities across Minnesota spanning diverse treatment designs (conventional activated sludge, membrane bioreactor, sequencing batch reactors, and anaerobic/oxic systems).  Samples were analyzed by proximity-ligation metagenomic sequence analysis, enabling the construction of communities of 50-100 metagenome-assembled genomes (MAGs) per sample.  Within these MAGs, numerous Nitrosomonas spp. were identified that primarily clustered phylogenetically with each other rather than the genome sequences of previously isolated Nitrosomonas spp.  Similarly, the sequences of the ammonia monooxygenase (amo) operons in our MAGs were similar to each other but divergent from previously published genomes and MAGs.   Because most previous research on nitrifying bacteria in wastewater treatment bioreactors has involved PCR, an in silico analysis of four commonly used PCR primer sets targeting amoA primers was also performed.  Each of these primer sets likely would have failed to amplify all of the amoA genes in each sample.  Our research demonstrates, therefore, that promixity-ligation metagenomic sequence analysis can detect more AOM than previous approaches.  This poster targets wastewater treatment plant operators, environmental engineers, and microbial ecologists seeking to better understand and manage nitrification.