Concurrent Session I
Track I: Groundwater and Drinking Water Wells
Session ID: 1058 – Groundwater Conflict at the Edge the Minneapolis-St. Paul Metropolitan Area, Minnesota: When High-Volume Pumping Puts Private Well Owners Out of Water
Primary Author: Amanda Yourd, Minnesota Department of Natural Resources
In the summer of 2022, the Minnesota Department of Natural Resources (DNR) received well interference complaints (low water supply or out-of-water) at 50 private domestic wells in the City of Ham Lake, Minnesota. Ham Lake is on the northern edge of the Minneapolis-St. Paul Area and does not have a municipal water supply. Many communities near Ham Lake have groundwater municipal water systems, including the City of Blaine directly south of Ham Lake. Blaine has more than four times the population of Ham Lake and uses more than 15 wells for municipal supply.
DNR is directed to investigate domestic well interference complaints per Minnesota Statute 103G.261. The DNR investigation into the 50 complaints in Ham Lake consisted of interpreting area geology, analyzing groundwater level and water use data from nearby permitted high-capacity wells, and using predictive analytical modeling to determine if high-capacity pumping caused the domestic well interferences.
DNR found that pumping by the City of Blaine was the sole cause of water level decline in 45 complaints and was the main cause in two complaints. Other nearby high-capacity pumping by two golf courses also contributed to two of the complaints but were considered a minor contributor to the interference. Because there is a continued risk of well interference in the area, the DNR is currently working with the City of Blaine to protect domestic water supply in the future.
The results of this investigation highlight the potential for conflicts over water resources at the edge of metropolitan areas where adjacent communities have drastically different populations, water systems, and water needs. In these settings, state and local water managers must work together to ensure water supply for all residents in the future.
Topic Area(s): Drinking Water/Water Supply, Groundwater, Water Resource Sustainability
Session ID: 1048 – MDH Investigative Monitoring for Lithium and other Unregulated Contaminants in Drinking Water
Primary Author: Jane de Lambert, Minnesota Department of Health
Through the Unregulated Contaminant Monitoring Program (UCMP), the Minnesota Department of Health (MDH) tested drinking water across the state for unregulated contaminants and contaminants of emerging concern (CECs). While the project included a wide spectrum of CECs, only a fraction of them were detected in drinking water. Lithium, an inorganic metal, was detected in 100% of samples where it was tested.
Lithium is a geogenic, naturally occurring element present in the environment. Lithium also has many commercial applications including in lithium-ion batteries, electric vehicles, as a sanitizing agent, and as a pharmaceutical drug.
Adverse health effects from lithium exposure at therapeutic doses have been observed in humans, including both neurologic and kidney-related effects. There is limited information on health effects from exposure to lithium at lower doses, such as those present in drinking water (EPA Technical Fact Sheet, Lithium in Drinking Water).
MDH will provide a synopsis and discussion of the lithium results from previous testing, as well as an update on testing of other unregulated contaminants through the Drinking Water Ambient Monitoring Program (DWAMP).
Topic Area(s): Contaminants of Emerging Concern, Drinking Water/Water Supply, Emerging Issues
Session ID: 1057 – A Review of Private Well Sampling in Dakota County
Primary Author: Matthew Belanger, Dakota County
Dakota County, located in the Twin City Metropolitan Area, is two-thirds rural residential use and has close to 9,000 households dependent on groundwater from private drinking water wells with varying water quality. The county’s Community Focused Sampling Program was developed with the goal to provide every private well owner with an opportunity for a free well test. Participants collect samples from their outdoor faucets that will be analyzed for arsenic, nitrate, manganese, and chloride and their indoor faucets for nitrate, arsenic, manganese, and lead. Participants receive their water test results and water treatment recommendations, if warranted. Since the program began, free well testing has been offered to nearly 9, 000 private well owners. As of 2023, roughly 2,200 well owners have participated (~25% participation rate). This program has provided the county valuable data to assess groundwater conditions around Dakota County, educated well owners, and has guided targeted efforts to protect groundwater.
In 2023, the county completed a report summarizing the PFAS results from 97 wells that examined the relationship between results and distance to known sites where biosolids from water treatment plants have historically been applied. Microplastics were analyzed in five well samples; 84 microplastics were found in one of the 4 ml samples. In 2020, the Ambient Groundwater Quality Study 1999–2019 report of private well results found 62% exceeded one or more drinking water guidelines; including the discontinued herbicide, cyanazine. Providing water treatment is important and a pilot water treatment grant program was completed for low-income households with a drinking water guideline exceedance.
Topic Area(s): Drinking Water/Water Supply, Groundwater, Monitoring
Session ID: 1055 – Will We Have Safe Drinking Water in 2034? Minnesota’s Drinking Water Action Plan
Primary Author: Tannie Eshenaur, Minnesota Department of Health
Safe drinking water is essential to healthy families and communities. What do we need to do now to make sure drinking water is safe for everyone, everywhere in Minnesota in 2034? While Minnesota has an outstanding record of compliance with the Safe Drinking Water Act, not everyone in Minnesota has safe and sufficient drinking water. Minnesota has developed the Minnesota Drinking Water Action Plan, a 10-year plan to ensure that everyone in Minnesota has equitable access to safe and sufficient drinking water.
Minnesota Department of Health collaborated with the University of Minnesota Water Resources Center, Freshwater, and Clean River Partners to gather input and feedback from water professionals, state and local government, and people who drink water about how well drinking water is governed in Minnesota and what people’s concerns and priorities are for drinking water. We gathered input through community meetings, surveys, and meetings with agencies and organizations. We will share what we heard and describe Minnesota’s key strengths and issues when it comes to equitable access to safe and sufficient drinking water. Two issues of note are the need to invest in our water system infrastructure and workforce.
Finally, we will walk through the issues, goals, and strategies identified in the Plan that will help provide safe public drinking water and better protect Minnesotans who rely on private wells. This Plan serves as the State’s commitment to protect against existing and emerging threats to drinking water.
Topic Area(s): Drinking Water/Water Supply
Track II: Exploring User Perceptions of Local Water Management Practices
Session ID: 1025 – Bioretention Basins and Retired Residents: A Pilot Project
Primary Author: Lori Haak, City of Eden Prairie
The Stable Path neighborhood in Eden Prairie consists of 17 one-story single family homes and a large, highly visible bioretention basin. The City received numerous complaints about standing water and weeds as homes sold and mostly retirement-aged residents moved in. The City leveraged developer contributions, watershed district cost-share funds, and stormwater utility fees to launch a pilot project with three main goals: 1. Increase City expertise in guiding and inspecting installation, establishment, and management of bioretention basins (especially soils and vegetation); 2. Improve basin effectiveness by addressing soil and vegetation issues; and 3. Design an approach for building advocacy for green stormwater management through homeowner education and engagement. Neighborhood meetings, frequent communication with the association, and a neighborhood planting event increased neighborhood investment in the green infrastructure. Join us to learn if realized benefits persisted and to engage in the real and ongoing conversation about how to better balance requirements, aesthetics, and expectations.
Topic Area(s): Best Management Practices (BMPs), Education and Citizen Involvement, Stormwater
Session ID: 1063 – Patterns in Minnesota’s Lake User Perception, Eutrophication, and Lake Assessment Datasets: A 35-Year “Big Data” Retrospective
Primary Author: Allison Gamble, MPCA
Formal lake-user perception metrics were first developed in the USA in Vermont in the 1980’s and have been associated with the Minnesota Pollution Control Agency’s professional and volunteer lake monitoring programs since 1987. We present the first comprehensive, state-wide analysis of this lake user perception data. Specifically, we discuss our analysis of patterns in paired lake user perception survey data, eutrophication water quality datasets, and lake assessment results from 1987–2022. Underpinning our work is the substantial quality assurance and data screening evaluations that were necessary when working with these large datasets, which included decades of collected values from thousands of lakes across the state. Our work demonstrates that the subjective perception metrics were very consistent with the MPCA’s formal, science-based assessments of lake water quality that use measured water quality parameters (total phosphorus, chlorophyll a, and secchi depth).
Topic Area(s): Education and Citizen Involvement, Lakes, Monitoring
Session ID: 1110 – Investigating Resident Water-Related Concerns in Urban Lake Nokomis Area
Primary Author: Kerry Holmberg, University of Minnesota Bioproducts and Biosystems Engineering
During the wettest seven years on record in the Twin Cities (2013-2019), property owners in the Lake Nokomis area reported a myriad of water-related concerns. These included issues such as wet basements, sinkholes, saturated backyards and impacts on private sewer lines. The escalating precipitation trends in Minnesota over the decades have significantly heightened runoff, groundwater recharge, and infrastructure vulnerabilities.
In response to the community's voiced concerns and observations, a collaborative effort involving multiple agencies delved into investigating the various hypotheses regarding the underlying causes of these water-related challenges. The culmination of their investigations pointed towards a confluence of factors: historical land development on wetlands during the early 1900s, recent unprecedented precipitation levels, and the unique perching conditions attributed to the abundance of lacustrine soils in the area.
In 2022–2024, the U of MN completed an in-depth study aimed at elucidating the relationship between precipitation patterns and groundwater dynamics within both the Lake Nokomis vicinity and control areas. The objectives included a more precise quantification of meteorological, geological, and hydrogeological factors influencing groundwater elevations, focusing on perched conditions. Leveraging a community network, residents experiencing water-related issues volunteered to participate, allowing for the installation of monitoring wells on their properties. Detailed soil layer analyses were conducted, alongside repeated measurements of water levels and chemical composition. These datasets, in conjunction with other pertinent information, were utilized to develop lake water cycle and groundwater models. The overarching goal is to empower property owners with a deeper understanding of how these influencing factors impact their properties and to facilitate the formulation of more effective mitigation strategies for local municipalities.
Topic Area(s): Stakeholder & Community Engagement
Session ID: 1095 – Visitor Perception of Lake Water Quality in Highly-Managed Urban Lakes in the Twin Cities
Primary Author: Gaston Small, University of St. Thomas
Managing water quality in urban lakes is challenging and often requires large investments. While data on water quality are typically collected by management organizations, we know less about how these management activities affect user perception of lake water quality. We collected user perception data from two highly-visited urban lakes in Saint Paul, Minnesota, using an SMS-based chatbot. Signs posted at three high-traffic locations around each lake invited visitors to text a response to a “hook question”, which initiated the survey. We collected data from Como Lake, a 27-ha lake that has recently been the focus of an intensive phosphorus and macrophyte management effort, in 2022 and 2023. In 2023, we also collected data from Lake Phalen, an 80-ha lake with a less-urbanized watershed. Visitor perception of lake water quality showed seasonal patterns that generally tracked chlorophyll and water clarity. Respondents noted water turbidity, macrophytes, algal blooms, dead fish, trash, and odor in documenting their scores. Water quality perceptions in Como Lake also reflected a large inter-annual difference between late summer chlorophyll concentration of the two study years. However, a large difference in water clarity and chlorophyll between Lake Phalen and Como Lake was not reflected in water quality perception scores. Perceived changes in lake water quality over time reflect water quality conditions at the time of the response more than multiyear trends in chlorophyll or transparency. These results suggest that visitor perception of water quality is likely influenced by a variety of lake-specific factors, potentially including messaging from management organizations.
Topic Area(s): Lakes, Monitoring, Social Science/Human
Track III: PFAS Deposition, Concentration, and Treatment in Water Bodies
Session ID: 1113 – Removal of PFAS from Stormwater: Sorption to Biochars, Activated Carbons, and Ion Exchange Resins
Primary Author: Lekshmi Balakrishnan Nair, National Resources Research Institute
Conventional stormwater treatment systems are not designed for removal of poly- and perfluoroalkyl substances (PFASs). While biochar-amended filtration systems have shown promise for removal of degradable organic contaminants such as pesticide, these systems challenges associated with disposal of spent sand-based filtration media are anticipated for catchments containing substantial PFAS pollution. The objective of this study is to evaluate the feasibility of passive treatment systems with exchangeable filter cartridges for removal of PFAS from stormwater. We hypothesize that co-application of black carbon sorbents (BCs, e.g., biochar and granular activated carbon, GAC) and ion exchange resins (IERs) will be an effective approach, because initial removal of organic matter and long-chain PFAS by BCs will enhance the longevity of IERs. Batch screening tests were carried out to evaluate the sorption of PFAS to six BCs (two GACs and 4 biochars) and six IERs. Calgon F400 GAC showed the most effective performance among BCs, while Norit GAC830R regenerated activated carbon (RAC) was similarly effective. Biochar produced by Biochar Supreme via pyrolysis of wood waste at >1000°C showed the most effective performance among biochars, with LogKd values exceeding 5.5 L/kg for long-chain PFAS. Batch sorption experiments with IERs revealed that polystyrene-based resins demonstrated the most effective sorption of short-chain PFAS (LogKd > 4 L/kg). Current work is focused on evaluation of BCs and IERs in batch kinetic and isotherm tests with varying water chemistry conditions (i.e., salinity, presence of co-contaminants). Future work will involve evaluation of PFAS treatment performance in intermittently dosed column experiments, with an anticipated project end date in 2026.
Topic Area(s): Stormwater
Session ID: 1051 – A Deeper Dive into PFAS in Sediments of the Great Lakes: Lake Superior and Lake Huron
Primary Author: Quinn Whiting, Natural Resources Research Institute
Per- and polyfluorinated alkyl substances (PFAS) are a class of highly persistent organic pollutants that have been linked to adverse health effects in humans and aquatic organisms. Their ubiquitous detection in the environment is cause for concern. The objective of the US Environmental Protection Agency’s Great Lakes Sediment Surveillance Program (GLSSP) is to advance understanding of relationships between environmental distributions of persistent bioaccumulative toxic contaminants (PBTs, including PFAS) and overall ecosystem health in the Great Lakes. During 2021 and 2022, six sediment cores and over 60 surface sediments were collected from Lake Superior and Lake Huron, respectively. Lake Superior sediments have been extracted and analyzed for 37 PFAS, while analysis of Lake Huron sediments is ongoing. Despite being widely considered as the most pristine of the Great Lakes, PFAS were present at detectable levels in all Lake Superior Surface sediments, with concentrations of total PFAS ranging from 0.2 to 17.8 ng/g. Interestingly, these concentrations are higher relative to a 2011 survey (measured total PFAS concentrations ranged from undetectable up to 10 ng/g), though these differences may be due to advances in analytical methodologies over the last decade. Higher total concentrations and similar PFAS compositions (primarily perfluorocarboxylic acids) were observed at offshore surface sites, relative to nearshore sites with lower total concentrations and more varied compositions. Temporal trends from the downcore sites showed an increase in PFAS since the 1950s, which contrasts previous results suggesting downward migration of PFAS in sediments over time. Future work will focus on analysis of PFAS in sediments in all five of the Great Lakes, with an anticipated project end date in 2026.
Topic Area(s): Contaminants of Emerging Concern, Lakes
Session ID: 1053 – PFAS in Wet Deposition and Sediments from the Western Great Lakes Region: Insights into the Profile of Atmospherically Deposited PFAs
Primary Author: Samantha McClung, University of Minnesota Duluth
Per- and polyfluoroalkyl substances (PFAS) are a large family of persistent contaminants with diverse and poorly characterized sources. Our understanding of their environmental cycling is improving, but is still quite limited. The presence of PFAS in environmental media (e.g., sediments, surface water, ice) from remote areas emphasizes the significant gaps in our understanding of the sources, fate, and transport. In particular, the importance of atmospheric transport and transformation of PFAS as a pathway into surface hydrologic systems is poorly understood. To investigate the magnitude and profile (fingerprint) of PFAS characteristic of atmospheric deposition, wet deposition (rain and snow) samples were collected from a suite of National Atmospheric Deposition - National Trends Network (NADP-NTN) precipitation monitoring sites around the upper Great Lakes, and analyzed for 33 target PFAS. To further investigate the role of atmospheric deposition as a source of PFAS to terrestrial and aquatic ecosystems in the western Great Lakes region a sediment core from Loaine lake, a remote Minnesota lake with primarily atmospheric inputs (seepage lake), was age-dated and analyzed for 37 target PFAS. The lake sediment core and wet-deposition datasets are compared to sediment PFAS concentrations observed by the US Environmental Protection Agency Great Lakes Sediment Surveillance Program (US EPA GLSSP). This presentation will share initial results from the wet deposition samples, the seepage lake sediment core, and comparisons to Lake Superior sediments. These preliminary data sets are just one component of a larger effort to constrain PFAS wet deposition across the Great Lakes.
Topic Area(s): Contaminants of Emerging Concern, Lakes
Session ID: 1013 – Spatiotemporal Evaluation of PFAS Concentrations and Partitioning in Mississippi River
Primary Author: Alison Ling, University of St. Thomas
We investigated spatiotemporal concentration trends and partitioning behavior of per- and polyfluoroalkyl substances to fish and sediments both upstream and downstream of a major PFAS discharge. The study site encompasses the Mississippi River immediately upstream and downstream of 3M’s Cottage Grove facility, which has historically served as a diffuse source of PFAS through groundwater and a point source of PFAS through wastewater effluent. Bioaccumulation factors (BAF) and sediment partitioning coefficients (Kd) were calculated based on ratios of concentrations between the water phase and fish tissue or sediment phase, respectively. Spatially averaged concentrations for estimated fish ranges were developed using ArcGIS.
13 out of 46 PFAS analyzed were detected in at least 15% of river water samples. Water column concentrations ranged from 0.3 to 356 ng/L total PFAS (of 46 analyzed) in the main column of the river, with much higher concentrations averaging 2, 150 ng/L on the north bank near the contaminated site. Aqueous concentrations of most PFAS increased significantly along the north bank between 2001 and 2021.
865 fish samples were collected across 11 species with average PFOS concentrations of 33 ng/g. None had fish tissue concentrations lower than the state health standard of 0.37 ng PFOS/g fish tissue. Generally, higher BAF values were observed with long-chain and ultra-short chain PFAS, with no clear differences between trophic levels. PFAS partitioning to sediment was reflected by log-Kd values between 1.0 and 3.5, with higher values for both longer-chain PFAS and ultra-short chain PFAS. Additional work in the summer of 2024 will focus on more detailed temporal analysis of hot spots and partitioning behavior, with project completion anticipated in early 2025.
Topic Area(s): Aquatic Biota, Contaminants of Emerging Concern, Rivers, Streams, and Floodplains
Track IV: Aquatic Invasive Species and Carp Management
Session ID: 1090 – Six Years Later: Results of a Multiyear, Innovative Carp Management Program
Primary Author: Matt Kocian, Rice Creek Watershed District
Common carp density in the Long Lake/Lino Chain of Lakes system has been high for decades, exceeding the ecological damage threshold by a factor of seven. Algae blooms were common, and lakes were listed as impaired for excess nutrients. In 2018, we presented a talk at the MN Water Resources Conference titled “Building a Carp Management Program in the Rice Creek Watershed.” Now, six years later, the Rice Creek Watershed District’s carp management program has achieved its management goals. Over 400, 000 pounds of carp have been removed from the system, and carp density has been reduced by nearly 90%. Along the way, new and innovative management technologies were developed. A consistent yet flexible management approach has been used, paying close attention to the changing efficiencies of different management tools. Lake response has been positive, with decreasing nutrient levels and increasing macrophyte coverage and diversity; however, response among lakes in the system has not been uniform. We will present details on program methods and lake response to a successful, long-term carp management program.
Topic Area(s): Invasive Species, Lakes, Nutrients
Session ID: 1017 – Evaluating the Effectiveness of Carp Management in 14-Lake System in Minnesota
Primary Author: Jill Sweet, Minnehaha Creek Watershed District
Common carp management can be an effective tool to improve water quality or aquatic vegetative conditions by reducing adverse effects of carp on lake sediments and was identified in a diagnostic assessment of the Six Mile Creek-Halsted Bay Subwatershed as a critical step to improving the quality of lakes. From 2014 to 2016 Minnehaha Creek Watershed District (MCWD) partnered with the University of Minnesota to assess the extent and impact of common carp (Cyprinus carpio). In 2017, MCWD implemented a carp management project that targeted reducing carp biomass below 100 kg/ha to restore habitat and improve ecosystem health in the 14-lake system. MCWD has taken a holistic and comprehensive approach to manage carp consisting of three management strategies that include removing adult biomass, restricting movement, and suppressing recruitment to ensure success. By 2023, the management efforts had concluded, with biomass targets met across the majority of lakes, which has resulted in diverse lake responses in the vegetation and water quality conditions. These results suggest that additional factors such as the extent of carp disturbance, in-lake phosphorus concentrations, and maximum depth may impact a lake’s response to carp management (see presentation from Jake Walsh).
Topic Area(s): Aquatic Biota, Invasive Species, Lakes
Session ID: 1018 – Evaluating the Effectiveness of Carp Management in Minnesota: A Statewide Look at Carp Management Projects
Primary Author: Jake Walsh, UMN-TC Dept. of Fisheries, Wildlife, and Conservation Biology
Common carp management can be an effective tool to improve water quality or aquatic vegetation conditions by reducing adverse effects of carp on lake sediments. Carp management benefits can vary depending on the magnitude of carp biomass reduction and complex, context-dependent ecological interactions between lake processes, carp, watershed characteristics, and other ongoing management actions. To better understand the factors that contribute to successful carp management, the University of Minnesota and the Minnehaha Creek Watershed District have partnered with collaborators at the Minnesota Department of Natural Resources and Pollution Control Agency to evaluate responses of Minnesota lakes to carp management. The study will investigate changes in carp populations, water quality, and aquatic vegetation using data from 14 lakes within the Minnehaha Creek Watershed (see presentation from Jill Sweet), and statewide datasets on water quality, aquatic plants, and carp management. The goal of the project is to better understand diverse lake responses to carp management by quantifying relationships between carp, water quality, and aquatic plants at statewide, watershed, and within-lake scales. These results could be used to more reliably prioritize lakes for carp management efforts.
Topic Area(s): Aquatic Biota, Invasive Species, Lakes
Session ID: 1016 – Tools Work! Boat Cleaning Tools Increase Removal of AIS from the Interior of Boats
Primary Author: Holly Wellard Kelly, Natural Resources Research Institute/University of Minnesota Duluth
The state of Minnesota allocates over $10 million to counties for aquatic invasive species (AIS) prevention programs because AIS are negatively impacting Minnesota’s aquatic resources. Drying boats for 5+ days is recommended to prevent AIS spread, but sometimes anglers relaunch boats into different waterbodies on the same day. Some boat launches have self-service tools to remove AIS from boats. The methods available vary from no tools (e.g., hand removal only), to waterless tools (e.g., vacuum/air blower), to low pressure hoses. The effectiveness of the different cleaning methods at removing AIS from the interior of boats is uncertain because most studies have focused on boat and trailer exteriors. We tested the effectiveness of 4 different cleaning methods on the interior and livewell of a typical angling boat: 1) hand removal alone; 2) waterless tools (e.g., cloth wipe or vacuum); 3) low-pressure water rinse; and 4) combinations of all methods. We found that using the combination of all methods (hand removal + vacuum + low-pressure rinse) or using just the vacuum removed the highest proportions of surrogate AIS. For cleaning livewells, using additional tools (e.g., wipe, vacuum, or low-pressure rinse) increased the removal of surrogate AIS over hand removal alone. Removal effectiveness also depended on the type of AIS (e.g., spiny water fleas versus plant materials). Our results provide guidance to state agencies and managers on the best cleaning tools to provide at boat launches to prevent the spread of AIS and maximize their investment return.
Topic Area(s): Aquatic Biota, Invasive Species
Session ID: 1015 – Which Water Bodies in the Upper Mississippi River Basin Are Prone to Invasion?
Primary Author: Grant Vagle, Minnesota Aquatic Invasive Species Research Center, University of Minnesota
Aquatic invasive species pose a serious threat to waterbodies in the Upper Mississippi River Basin (UMRB), affecting water quality, ecosystem functioning and services, and economic and recreational value. However, identifying at-risk waterbodies is a difficult task given the multitude of potential invaders and the wide variety of characteristics exhibited by waterbodies in the region. Here, we used a machine learning model (boosted regression trees) to predict the potential occurrence of aquatic invasive species across the UMRB. We used species records from the Global Biodiversity Information Facility and included publicly available covariate data including hydrology, climate, land use / land cover, anthropogenic impacts, and water quality. We modeled occurrence for multiple aquatic invasive species known to be threats in the region including zebra mussels, starry stonewort, Eurasian watermilfoil, spiny water flea, and common carp. We constructed models at two scales: one with global context (including species’ native range), and one with regional context in the UMRB (with more specific covariates). Together, these two models integrate global information with regional high-resolution datasets only available within the UMRB, in order to provide the most accurate predictions for the UMRB. For each species, we identified waterbodies at high, medium, and low risk of invasion, and combined these predictions to create a multi-species risk measure for waterbodies across the UMRB. Additionally, we identified the primary environmental characteristics of these waterbodies that increased (or decreased) their susceptibility to invasion. With our model predictions identifying risk across the region for multiple aquatic invasive species, managers will be better able to prioritize where they direct their prevention and early detection and rapid response efforts.
Topic Area(s): Aquatic Biota, Invasive Species
Track V: Special Session
HEC-RAS Developments: What's New & What's Coming
Adam Howard, Jeremiah Jazdzewski, US Army Corps of Engineers, Saint Paul District; Cameron Ackerman, US Army Corps of Engineers, Institute for Water Resources, Hydrologic Engineering Center
This special session is hosted by the US Army Corps of Engineers Saint Paul District and Hydrologic Engineering Center (HEC) staff. The session will focus on highlighting some of the recent additions to the HEC-RAS software, showcasing some of the up-and-coming additions and major changes, and ending with open discussion with USACE staff. Come learn about the future of RAS and chat with some of the RAS team.
Concurrent Session II
Track I: Lake Impairments and Treatments
Session ID: 1068 – Navigating Salinity Shifts: A Multifaceted Approach to Understanding Freshwater Salinization in Urban Lakes
Primary Author: Hailey Sauer, St. Croix Watershed Research Station
In Minnesota, the quality of our urban lake waters is facing a growing challenge due to increased salt levels. Each year, about 78% of the 350, 000 tons of road salt applied in the state remains in our lake ecosystems, affecting water quality and the health of aquatic life. This has significant implications not just for biodiversity but also for lake-based recreational activities and water sources.
Our team has been closely examining how salt affects 15 urban lakes across the Twin Cities and Alexandria, through various scientific techniques, including regular water monitoring, sediment analysis, DNA studies, and lake ecosystem modeling. Our ongoing research is revealing the complex ways that salt buildup interacts with other nutrients to impact lake health.
The insights from our study are crucial for creating effective strategies to reduce salt pollution. These strategies need to tackle both the immediate effects of salt on our lakes and the long-term health of these vital ecosystems. By addressing these issues, we can better protect our lakes, ensuring they continue to provide valuable services to our communities, from recreation to clean drinking water.
Topic Area(s): Emerging Issues, Lakes
Session ID: 1076 – Are There Viable Solutions For Chloride Pollution? Parkers Lake Study Advances Options for Chloride Source Assessment and Treatment
Primary Author: Greg Wilson, Barr Engineering Co; Laura Jester, Bassett Creek Watershed Management Commission
Parkers Lake, in the City of Plymouth, is impaired due to high chloride concentrations. Stormwater monitoring data shows that most chloride enters the lake from industrial and commercial areas northeast of the lake. There was some belief that lake water only left the lake when water levels were high, leaving salty water to continuously accumulate in the bottom of the lake, but detailed analyses had not previously been done. This study resulted in the development of mass-balance modeling to evaluate how historical stormwater chloride loadings impacted surface and bottom-water lake chloride concentrations. The modeling revealed that the lake and chloride-laden water flushes about once every 1.4 years (consistent with the lake water residence time). Regardless of flushing, the lake currently does not meet State water quality standards, which necessitates significant chloride reduction measures.
The Bassett Creek Watershed Management Commission and Barr Engineering Co. worked with the City of Plymouth to study viable options for sufficiently removing chloride from Parkers Lake to meet the MPCA water quality standard. The study analyzed two primary alternatives to reduce chloride in Parkers Lake, including pumping lake bottom water directly to the sanitary sewer, and pumping/treating lake bottom water with either ion exchange or reverse osmosis treatment technologies and returning it to the lake.
This presentation will highlight the difficulty of meeting the State’s lake chloride standards, the impact of climate, and lessons learned, including an alternative management approach that quantifies and targets the source load reductions necessary to consistently meet the chronic and acute chloride criterion.
Topic Area(s): Engineering Solutions and Applications, Lakes, Stormwater
Session ID: 1089 – Improving Wilmes Lake, One Dose at a Time
Primary Author: Kyle Axtell, South Washington Watershed District
Wilmes Lake is a 30-acre shallow lake within the South Washington Watershed District (SWWD) and City of Woodbury. With a 3, 200-acre rapidly developing suburban watershed, Wilmes Lake suffers from excessive nutrient loading and has been listed on the Minnesota Section 303(d) impaired waters list since 2006.
SWWD completed a regional Best Management Practice (BMP) study in 2019 which identified a stormwater treatment facility with in-line chemical dosing as the most cost-effective and impactful option to reduce phosphorus loads to Wilmes Lake. HR Green joined SWWD’s team in 2020 to complete an alternatives assessment to determine the preferred chemical dosing and a concept design for the stormwater treatment facility within an adjacent City of Woodbury park. The resulting concept pumps water from the primary influent channel of Wilmes Lake to the chemical dosing station where alum is mixed into the stormwater and the resulting flocculent settles out in a constructed basin before treated stormwater drains to the lake. With treatment flows of 1–3 cfs during open water seasons, the facility is expected to remove between 95 and 283 pounds of phosphorus per year in addition to other associated pollutants, achieving SWWD’s overall phosphorus reduction goal for Wilmes Lake. Improving Wilmes Lake water quality is also expected to reduce phosphorus loading to Colby Lake downstream by up to 100 pounds per year.
The alum treatment facility’s capital cost of $4.5 million is reflective of its importance to the watershed district and its expected impact. SWWD has budgeted an additional $180,000 per year to fund operation of the facility by Woodbury’s experienced public works staff. The project is expected to achieve a cost/benefit ratio of $1,900/lb P/year.
The Wilmes Lake Alum Treatment Facility is a great story of partnerships, planning, and regional treatment. Construction began in the summer of 2023 and is expected to be complete in the summer of 2024.
Topic Area(s): Innovative Technologies, Nutrients, Stormwater
Session ID: 1096 – The Importance of Setting Appropriate Goals for Alum Treatments in Lakes
Primary Author: Dendy Lofton, Stantec
Decades of phosphorus (P) loads to lakes from the surrounding drainage area often leads to accumulation in lake sediments, which can then diffuse from the sediments and contribute to algal growth and poor water quality conditions. Consequently, internal P loads may need to be managed along with watershed load reduction actions to improve water quality in lakes. In these cases, an aluminum sulfate (alum) treatment can be implemented to reduce internal P loading from lake sediments. Attainment of water quality standards should be the overarching goal for all management actions. However, recognizing that alum is not the only management action needed to improve water quality in degraded lakes, what are appropriate goals for measuring success of an alum treatment? What data should be collected pre- and post-treatment to determine if the treatment is functioning as intended? Using recent case studies in Minnesota and elsewhere in the United States, this presentation will discuss the importance of setting appropriate, specific goals for alum treatments and the lines of evidence to determine how well an alum treatment is working to mitigate internal P loading compared to pretreatment conditions.
Topic Area(s): Lakes, Nutrients
Track II: Clean Water History and Future
Session ID: 1088 – The History of Minnesota’s Public Waters Inventory
Primary Author: Jenifer Sorensen, Minnesota Department of Natural Resources
Minnesota Statute 103G.201 directs the Minnesota Department of Natural Resources (DNR) to maintain a public waters inventory (PWI) map of each county to show which waters of the state are designated as public waters. Work in public waters is regulated by the state’s public waters rules, and the PWI is used to identify whether a water of the state is a public water. This presentation will outline the history of the PWI process that was undertaken in the early 1980s to create a PWI map and list for each county in Minnesota, the distinction between the definition of public waters and the PWI, and the resources available to view the PWI.
Topic Area(s): Hydrology
Session ID: 1029 – 20 Years of Lake Nutrient Impairment Delistings in Minnesota
Primary Author: Jeff Strom, Minnesota Pollution Control Agency
According to Minnesota’s 2024 inventory of impaired waters, a total of 64 nutrient impaired lakes have been removed (“delisted”) from Minnesota’s 303(d) list of impaired waters. Recently, the MPCA completed a retrospective of Minnesota’s delisted lakes that included common lake and watershed features and management activities that contributed to delistings. This talk will present an overview of the retrospective, key findings, and lessons learned. We will conclude with a brief discussion of the future of lake delistings in Minnesota and potential ways to document, track, and share management actions and successes going forward.
Topic Area(s): Best Management Practices (BMPs), Lakes, Nutrients
Session ID: 1060 – Insights from of 11 Years of Stormwater Training Evaluation Data
Primary Author: Amit Pradhananga, University of Minnesota – Department of Forest Resources and Center for Changing Landscapes
The University of Minnesota Erosion and Stormwater Management Certification Program has offered training in stormwater topics since 2002, and end of class evaluations are part of the standard operating procedures for workshops. Standardized evaluation forms were used from 2009 to 2020 and with the program training approximately 3000 attendees per year, this has resulted in a large data set for statistical evaluation. We assessed the impact of the program on participants’ knowledge and implementation of best practices. While this is of interest for understanding the effectiveness of training over the decade, it is also useful to understand how to better collect data in future training and track effectiveness of training.
Some of the specific insights learned from this effort include the benefit and efficiency of using a standardized form and well-organized database; the benefits of pre- and post-workshop evaluations and ways this can be achieved; the variations of learning effectiveness that might occur over a decade; the benefits of tracking and comparing returning cohorts of attendees.
Topic Area(s): Education and Citizen Involvement
Session ID: 1104 – Clean Water Council's New Strategic Direction for the Clean Water Fund
Primary Author: Paul Gardner, Minnesota Clean Water Council
The Clean Water Council recommends how to spend the Clean Water Fund, which is one-third of the revenue from the increased sales tax created by the 2008 Clean Water, Land and Legacy Amendment. The Legacy Amendment expires in 2034, and the Clean Water Council has completed a new strategic plan to help guide its funding recommendations for the next five years. The presentation will highlight key strategies the Council will focus on in its FY26–27 biennial funding recommendations. It will also cover key metrics the Council is using to measure success.
Topic Area(s): Policy and Standards
Track III: Engineering for the Future
Session ID: 1074 – 35W Stormwater Storage Facility Design, Construction and SWPPP Implementation
Primary Author: Dwayne Stenlund, MnDOT
Last of an ongoing effort to reduce flood-risk along 35W from downtown to the Crosstown commons. The project includes construction of a stormwater storage facility (SSF) consisting of six 42-foot diameter underground storage tanks set into approximately 100 ft of soil to store 14.7 acre feet of storm stormwater runoff and reduce the depth, frequency, and duration of flooding on I-35W. With a limited footprint, the project included removing 35,000 cu yd of soil, located within a few feet of the drive lanes, accomplished without stopping traffic flow along 2nd Ave and 35W. While the implementation of the SWPPP was challenging, SWPPP compliance was actually the easy part due to good people on both sides of owner and operator. Construction challenges included holding up the noise wall and 2nd Ave, keeping 35W functional at all times, mitigating ground water intrusion to the excavation, vertical excavation, and integrating these phases into the SWPPP process and document. This is a story about how stormwater benefits were designed, followed by construction process for pollutant management, SWPPP amendments during all phases of the work for 4 continuous years of construction.
Topic Area(s): Engineering Solutions and Applications, Innovative Technologies, Stormwater
Session ID: 1026 – Flood Resiliency, Water Quality, and Play: Reconfiguring a Landlocked Low Point with 7.4 Acre-Feet of Underground Infiltration
Primary Author: Connor Fortune, Alliant Engineering, Inc
As part of Ramsey County's Hodgson Road (CSAH 49) Reconstruction project in Shoreview, the design team took on the challenge of reconfiguring the low point of the project area to handle the increased runoff from the urbanization of the corridor. The existing low point is a landlocked multi-purpose field behind a church that receives and infiltrates stormwater runoff from a nearby neighborhood. The field is owned by the church and enjoys regular use as a recreational area for the families.
The project had to overcome several challenges head-on. First, despite this low point acting as the receiving basin for the existing storm sewer, it lacked official status as a drainage facility and the landowner reasonably had concerns about losing their field to construct a surface BMP.
Secondly, the reconstruction of Hodgson Road and the installation of a new storm sewer trunkline meant that the volume of runoff routed to this basin would more than double. A new outlet from the area also had to be constructed and connected to existing storm sewer, limiting the available vertical envelope for a storage facility.
Join us in this session to find out how close coordination between the County, City, Landowner, and design team resulted in an economical solution that provided the necessary storage to control flooding, allowed the project to benefit from the infiltration provided by existing soils, and maintained the field as a recreational area during all but the largest storm events. Spoiler: it has something to do with 489 StormTrap chambers.
Topic Area(s): Best Management Practices (BMPs), Engineering Solutions and Applications, Stormwater
Session ID: 1020 – Increasing Resiliency of Brown's Creek Headwaters with County Road Improvements
Primary Author: Dan Elemes, Moore Engineering Inc
Washington County has the goal of “lead[ing] by example in county operations with regards to water management” in its 2040 Comprehensive Plan. County public works staff seek opportunities to incorporate stormwater management practices with its road projects, regardless of State or Local permitting requirements. One such project was the realignment of CR61 and CR15. Historically CR61 intersected with CR15 at a 45 degree angle and had more accidents than the average intersection.
CR61 was identified for pavement maintenance and realigning the intersection. Additionally, the County desired to address adverse drainage conditions. Runoff from the road was discharged through a farm field and stockyard before discharging to the headwaters of Brown’s Creek, a trout stream. Moore Engineering provided stormwater management design services to treat runoff from the road and reroute the existing drainage path to route flow through a stormwater pond and a series of wetlands prior to discharging to the Creek. The design consisted of blocking a culvert, constructing a wet pond, and installing four different control structures for the pond and onsite wetlands such that the nuisance drainage conditions were addressed while meeting Watershed permitting requirements.
With increasing precipitation trends, the sediment and nutrient load directly to the headwaters of Brown’s Creek would continue to increase over time. Rerouting the drainage path increases the resiliency of Brown’s Creek. Less sediment and nutrient loading to its headwaters will help over the long term maintain water quality, biodiversity, and overall health. Additionally, a series of riprap check dams were included to infiltrate runoff and to cool water discharged from the pond, and an onsite wetland was improved by excavating cattail and canary reed vegetation, and replanted with a native seed mix. The project reduced the amount of TP discharged to Brown’s Creek headwaters by approximately 11 lb/yr based on modeling.
Topic Area(s): Best Management Practices (BMPs), Climate Change/Resiliency, Engineering Solutions and Applications
Session ID: 1105 – Complex River Bridge Hydraulic Design – A Team Effort
Primary Author: Eric Roerish, SRF Consulting Group
The design of the new State Trunk Highway 130 Bridges over the Wisconsin River took a coordinated effort between the Department of Transportation, Contractors, Geotechnical and Water Resources Engineers, Bridge Designers, Regulatory Agencies, and the FHWA Hydraulic Team. The existing crossing is comprised of three truss bridges and the new crossing consists of two prestressed concrete girder bridges totaling 2,031’ in length. The new alignment is 800’ downstream (West) of the existing. SRF conducted the hydraulic analysis for the project.
At the crossing there are two channels, the outlet of Long Lake and the Wisconsin River. The channels are connected by high value wooded wetland floodplain. Some challenging characteristics of this design included a dynamic channel bottom with ever-changing dune structures, shallow bedrock (erodible sandstone), and an expedited design schedule as a Design Build Project.
Regulatory modeling of the bridges was completed with 1-D HEC-RAS, and SMS SRH2D was used for scour assessment. FHWA Toolbox (HEC-18, Evaluating Scour at Bridges Fifth Edition) was employed for scour computations with SMS output, including the NHRCP 24-20 abutment scour. To assess the erodibility of shallow bedrock, we used the 2017 Predicting Scour of Bedrock in Wisconsin. The results were coordinated with the Design Build Team to optimize foundation types and construction methods. Weekly coordination meetings were held with DNR and USACE staff to ensure approval of the process.
Special design consideration was given to the extensive causeways required to build the bridges in the condensed timeframe. During the month of May 2023, the entire project was shut down due to flooding. However, the skilled Contractors were able to reevaluate the schedule and sequencing to make up for the lost time.
Construction started in the spring of 2023. Bridge construction will be completed in October 2024, ahead of schedule, and the removal of the old structures will occur in 2025.
Topic Area(s): Rivers, Streams, and Floodplains
Track IV: Applied Agriculture
Session ID: 1004 – Agriculture and Septic Systems Influence Rural Groundwater Across the Border: Nitrate, Pathogen, and Fecal Contamination of Private Wells in Western Wisconsin’s Karst Aquifer
Primary Author: Joel Stokdyk, US Geological Survey
Private well water can be degraded by contaminants like nitrate and pathogens from agriculture and septic systems. One in five Minnesotans rely on private wells, and well water is especially vulnerable where fractured bedrock allows contaminants to move quickly through groundwater, like in the karst geology of southeastern Minnesota. In neighboring western Wisconsin, karst aquifers supply rural residents with private well water that is vulnerable to contaminants from the land surface. For three western Wisconsin counties where >40% of residents use private wells, objectives were to 1) determine the extent of private well contamination, 2) identify pathogens and sources of fecal contamination, and 3) identify factors related to contamination. First, in 2 sampling events with a total of 840 randomly selected well water samples, 42% (fall event) and 27% (spring event) of wells were contaminated by total coliform bacteria or had nitrate greater than 10 mg/L. Second, in a subset of 138 wells, pathogens were tested using 19 genetic tests, and 66 wells were positive. Analysis of host-specific microbes identified fecal sources as human wastewater (46% wells), bovine manure (26% wells), and swine manure (9% wells). Finally, land use, geology, hydrology, and well construction risk factors were examined using multivariable modeling. Nitrate contamination was greater for wells near cultivated land and for wells drawing water from the upper aquifer, which is not protected by the shale aquitard. Human wastewater contamination was greater following rain, and manure contamination was associated with cultivated land. Older wells were more likely contaminated by total coliforms and nitrate. Results may inform efforts to protect groundwater in rural, agricultural areas of the upper Midwest with karst geology, including areas of Minnesota where residents use private wells. The study was completed in 2022; work is ongoing to estimate the risk of illness from consuming private well water.
Topic Area(s): Agricultural Water Issues, Contamination/Remediation, Groundwater
Session ID: 1003 – How Do We Achieve Minnesota’s Nutrient Reduction Strategy? The Role of the Minnesota Agricultural Water Quality Certification Program and Site-Specific Nutrient Loss Reduction Strategies
Primary Author: Gregory Klinger, Olmsted County Soil & Water Conservation District
Minnesota’s Nutrient Reduction Strategy, developed in 2014, calls for 45% reductions in phosphorus and nitrogen loads in the Mississippi River by 2040. While promising changes have been observed for some metrics over the last 20 years, such as average phosphorus concentrations, changes in other metrics, such as total nitrogen and phosphorus loads, have been less promising. The Nutrient Reduction Strategy contains a number of approaches to help achieve its goals, including getting farmers and landowners certified through the Minnesota Agricultural Water Quality Certification Program (MAWQCP). This voluntary program involves a whole-farm assessment of water quality risks and has, to date, certified over 1 million acres and added close to 3000 new conservation practices across Minnesota’s landscape. The goal of the program is to recognize and support farmers who are leading the way in conservation efforts as well as helping farmers make incremental changes that will improve water quality outcomes in Minnesota.
When assessing the value of a given program or strategy in addressing nutrient pollution, it is worthwhile to consider a few questions along the way. What conservation practices will be most effective in both cost and nutrient reduction potential? Are we getting conservation practices done in the places where they will be most effective? Are we getting them done at the times when they will be most effective? Lastly, in promoting specific conservation practices, are we improving water quality across the board or simply trading one water quality challenge for another?
Using specific scenarios that illustrate site-specific challenges and solutions to agricultural nitrogen and phosphorus pollution, the role of whole-farm conservation strategies in general and MAWQCP specifically plays in addressing these issues will be discussed.
Topic Area(s): Agricultural Water Issues, Best Management Practices (BMPs), Nutrients
Session ID: 1007 – Lessons Learned from Conversations with Farmers – They Really Do Care About Soil, Water, and Conservation
Primary Author: Mark Deutschman, Retired
Conversations with farmers from North Dakota, Minnesota, and Wisconsin participating in the International Water Institute's Stewardship Program (SP) indicate a common challenge. Operating a viable (profitable) agricultural business necessitates managing the soil resource, while adjusting to variable input costs, sifting through new technologies, responding to weather, and navigating the commodity market. Decisions are made largely informed by experience. In the absence of experience, farmers regard changing crop production methods and implementing "new" conservation practices as risky.
The SP decreases risk and lowers the barrier to changing production methods and implementing conservation by providing information about net return, land stewardship and water outcomes, at the field and farm levels. Conversations with SP farmers revealed important lessons about how to achieve government agency goals for water management and quality improvement. Sharing these lessons can lead to more effective ways to engage farmers in discussions about soil health, managing excess water and maintaining and improving water quality.
Topic Area(s): Agricultural Water Issues, Innovative Technologies, Social Science/Human
Session ID: 1008 – Evaluating State Policies Aimed at Reducing Nonpoint Source Pollution: Results of Interviews with Agency Professionals
Primary Author: Bonnie Keeler, Humphrey School of Public Affairs, University of Minnesota
Nonpoint source pollution, primarily from agricultural sources, remains the most pressing threat to surface and groundwater quality in the US In response, states have adopted a variety of policies and programs designed to reduce nutrient pollution and improve water quality. Strategies enacted by states can take different forms, from regulatory to voluntary, with varying approaches to implementation, monitoring, and enforcement. As agencies and advocacy groups consider future interventions to address non-point source pollution, there has been little evaluative work that compares existing state-level programs across a range of objectives. In collaboration withThe Nature Conservancy’s State Ag-Policy Accelerator and researchers from Cornell University, we conducted a qualitative study of state-specific non-point source pollution reduction programs. Our review included Minnesota’s Buffer Law, Groundwater Protection Rule, and the Minnesota Agricultural Water Quality Certification Program; Wisconsin’s programs on Adaptive Management and Nutrient Management; and the Illinois Partners for Conservation Cost-Share Program. We conducted semi-structured interviews with agency staff who participated in the design and implementation of these programs, asking questions about program effectiveness, monitoring, enforcement, and implementation challenges. In this talk, we report on our findings from these interviews, including insights and recommendations for other states or entities looking to adopt similar policies in other geographies.
Topic Area(s): Agricultural Water Issues, Nutrients, Policy and Standards
Track V: Special Session
Innovations and Integration: Sensing, Data Science, and Water Technology
Tian Cui; Ardeshir Ebtehaj; Shaobo Deng
Integrated and innovative solutions are needed to address water resource concerns. This session will combine emerging interdisciplinary research in three domains: sensors and sensor development; data-enabled environmental monitoring, modeling, and management; and water treatment technologies for urban and agricultural settings. Potential areas of innovation and technology development include recovery of nutrients, reducing costs and improving technology for water monitoring, improving and “greening” urban water infrastructure, and agricultural and industrial water recycling and reuse.
Concurrent Session III
Track I: Stormwater BMPs and Maintenance
Session ID: 1071 – Inspecting and Maintaining Active Stormwater Filtration Media
Primary Author: Craig Fairbaugh, Contech
Stormwater treatment regulations are generally focused on total suspended solids and particulate-bound pollutants. With widespread research demonstrating that dissolved pollutants contribute to water body impairments, many stormwater filtration medias incorporate active amendments providing various sorptive mechanisms to remove dissolved pollutants. Commonly used active amendments in bioretention and cartridge filters include iron, alumina, biochar, GAC and water treatment residuals. While many active medias enhance dissolved pollutant removal over inert medias, the reduction in sorption capacity of the active component and media replacement frequency is not well understood. This research examined new and spent media from a phosphorus filtration project in the Capitol Region Watershed District. Spent media composed of perlite with activated alumina was collected after 23 months of operation from a 53-cartridge underground filtration system. New media was collected and preserved from the same initial batch. Physical characteristics were evaluated including particle size distribution, porosity, bulk density, moisture, pH, and surface area. Elemental and adsorption characteristics were evaluated via scanning electron microscopy, x-ray fluorescence (XRF), fertility, and isotherm tests. Results from comparative analysis between the new and spent media will be discussed to determine when replacement is required. Additional discussion will include methods for active media evaluation, the practicality of site owners and municipalities to conduct these evaluations, and insight into the inspection and maintenance implications as it relates to design. As maintenance enforcement becomes more stringent, a better understanding of maintenance and replacement of active media is needed to protect impaired water bodies.
Topic Area(s): Emerging Issues, Operation and Maintenance of BMPs, Stormwater
Session ID: 1101 – Phosphorus Removal Performance at Rosland Park’s Active Stormwater Filtration System
Primary Author: Andy McCabe, Barr Engineering Co.
In collaboration with the City of Edina, the Nine Mile Creek Watershed District constructed a unique surface water filtration system at Rosland Park to address external phosphorus loading to Lake Cornelia. The filtration system consists of a series of constructed concrete basins with an anthracite prefilter for particulate removal and three parallel up-flow reactive media filters for dissolved phosphorus removal. The filter is positioned between a large pond and Lake Cornelia. Water discharged from the pond is actively pumped to the filtration system for treatment. The impetus for this filter design was to treat a relatively high volume of water while maintaining a relatively small footprint to preserve the park's green space. Construction of the filtration system was completed in July 2022, and performance monitoring began in August 2022. Performance monitoring samples have been collected at eight sample locations: the filter influent, after the aeration manhole, the effluents from anthracite filter cell and the three reactive media cells, and the anthracite cell backwash. The overall removal efficiency of total phosphorus is 40%, which equates to approximately 13 pounds of phosphorus removed since start-up in July 2022. The typical filtered flow is approximately 180 gallons per minute. This presentation will focus on the reactive media filter cells' phosphorus removal performance and address operational challenges and potential solutions at a high level. The next steps of this project are to complete the two-year performance monitoring program, which will ultimately inform design improvements and final media selection for long-term operations.
Topic Area(s): Nutrients, Operation and Maintenance of BMPs, Stormwater
Session ID: 1032 – Creating New Pond Vegetation Management Standards
Primary Author: Rich Harrison, Metro Blooms Design+Build
Many local governments struggle with the evaluation and care of their publicly owned and managed stormwater ponds. With the goal of improving and increasing native habitat at its stormwater facilities, the City of Minneapolis, in conjunction with Metro Blooms Design+Build, has developed standards for the ongoing care of vegetation associated with the City’s stormwater Best Management Practices. Completed in 2023, these standards were developed to establish vegetation monitoring strategies and achievable, measurable goals to increase healthy, valuable native vegetations at these BMPs. The standards are a part of the City’s new Pond Vegetation Management Guide and direct vegetation maintenance efforts towards invasive species reduction and the establishment of valuable native habitat. Included is a new score chart and rating system which can be used to evaluate vegetation to ensure that it is contributing to the successful function of the BMP and providing valuable habitat. The rating system looks at Vegetation Coverage (including erosion, bare soil, vegetation coverage, sedimentation), Invasive Species Presence (MN Noxious Weeds, Aggressive Weeds) and Native Plant Diversity (Species diversity, native species coverage, seasonal bloom). The score chart and rating guide uses a red, yellow, green color system to easily and graphically document the existing vegetation and direct ongoing maintenance activities. The Pond Vegetation Guide and Vegetation Score Chart were used in the evaluation of 26 of the City’s BMPs to create a baseline for the vegetation at each site and to direct focused efforts for ongoing maintenance activities with the goal of increasing valuable native habitat at these sites.
Takeaways: Local governments can establish benchmarks and clear metrics to measure vegetation area progress and success. Introducing a novel tool for evaluating and managing habitat-enhancing vegetation. The Vegetation Score Chart for BMP evaluation is easily replicable.
Topic Area(s): Best Management Practices (BMPs), Operation and Maintenance of BMPs, Policy and Standards
Session ID: 1084 – Changes in Stormwater Basin Infiltration Rates with Age
Primary Author: Anthony Parolari, Marquette University
Stormwater infiltration is the preferred stormwater treatment method in Minnesota, as defined in the National Pollutant Discharge Elimination System (NPDES) Construction Stormwater and MS4 permits. These permits require that stormwater infiltration facilities achieve minimum and maximum stormwater infiltration rates post-construction. However, it is unknown whether infiltration rates remain constant, increase, or decrease over time. The ability to monitor and forecast stormwater infiltration rates is critical to identifying basins that meet or fail to meet infiltration rate criteria and, therefore, to prioritize scheduling and maintenance investments. In this study, we quantified stormwater basin infiltration rates with age. We measured soil properties and infiltration rates at 30 stormwater basins across a range of age from 1 to 26 years. The data indicate that soil organic matter, soil fine particle fraction, and infiltration rate all increase with age. A multiple-linear regression model was developed to predict infiltration rate with age and soil fine particle fraction as explanatory variables. Vegetation density was not related to soil properties or infiltration rate. Improved understanding of basin soil and vegetation conditions, as well as ages, that are typically associated with a failure to meet post-construction infiltration criteria will allow agencies tasked with infiltration basin maintenance to better plan and prioritize maintenance investments.
Topic Area(s): Green Infrastructure, Hydrology, Operation and Maintenance of BMPs
Track II: Assessment and Improvement of Ecological Systems
Session ID: 1117 – Development of a State-Wide Hydrogeomorphic Classification System for Calcareous Fens in Minnesota
Primary Author: Callie Postier, University of Minnesota Duluth/Earth and Environmental Sciences
The classification of calcareous fens (CFs) in Minnesota is based on four technical criteria: hydrology, soils, water chemistry, and vegetation, which depend on field verification. Upwelling groundwater conditions are generally considered a requirement to maintain saturation for peat development. Other studies of CFs have shown that precipitation or riparian water inputs can sustain CFs without groundwater input. The hydrogeomorphic (HGM) classification of wetlands was adopted by the US Army Corps of Engineers to study the relationships among hydrology, geomorphology, and wetland function. The HGM setting of CFs leads to improved conservation, management, and restoration efforts.
We present a GIS-based HGM classification for CFs based on the geomorphology, derived attributes describing physical parameters of geomorphic units, fen location within drainage basins, proximity to streams and lakes, and topographic gradients. The foundation of this classification is the original geomorphology layer for the State that was compiled at a scale of 1:100, 000, and subsequently modified into the land-type association layer of the Ecological Classification System.
The geomorphic setting of individual CFs is first categorized by geomorphic association, which characterizes the general lithologic setting. Topographic expression and sedimentary association then describe runoff and surficial aquifer characteristics. Depth to bedrock is used to determine the relative influence of surficial vs. bedrock aquifers. Surrounding elevation describes the local hydraulic gradient, and distance to streams or lakes refines possible sources of water to the fens. Principal components analysis is then used to evaluate relationships among variables.
Preliminary results indicate that CFs in Minnesota can be subdivided into six major HGM groups with multiple subgroups. The HGM classification scheme is used to identify settings with a high probability of containing yet unidentified CFs.
Topic Area(s): Wetlands
Session ID: 1116 – Ecosystem Health Action Plan for Riley Purgatory Bluff Creek Watershed District
Primary Author: Fred Rozumalski, Barr Engineering Co.
A distinct link exists between the loss of hydrologic function in natural water bodies and upland ecosystem degradation issues such as soil health, biodiversity, habitat quality, urban heat island effect, urban forest degradation, and climate change. RPBCWD has worked for decades to protect its natural water bodies through the management of stormwater runoff from hard surfaces. We have now developed an Ecosystem Health Action Plan that expands this mission to directly address green space runoff – runoff from lawns, woodlands, abandoned agricultural fields, and a few remaining patches of agriculture - to take the next step to protect and restore water resources and regenerate a healthy urban ecosystem. Through a series of workshops with municipalities within the District and other local and state agencies, strategies for improving the urban ecosystem were identified. The purpose of this plan has been to identify strategies, programs, and projects that can be undertaken to initiate ecosystem recovery to protect and restore water resources.
Topic Area(s): Watershed Management
Session ID: 1023 – Campus Greening: Bringing Natural Processes Back for Water, Habitat, and Education
Primary Author: Anthony Randazzo, South Washington Watershed District, Watershed Restoration Specialist
Watershed Districts and Conservation Organizations are always on the lookout for areas to achieve a meaningful expansion of habitat and natural cover in urban areas but often look past opportunities right at our feet. Beginning in 2018, the Campus Greening Program is an ongoing collaboration between the South Washington School District and the South Washington Watershed District using an ecosystem based approach to address stormwater quality by restoring and enhancing large open spaces on campuses in lieu of installing more conventional treatment practices like ponds and infiltration basins. The Districts have restored more than 50 acres of prairie, wetland and savanna on school campuses throughout South Washington County. Where possible, the Districts are involving students and staff, as well as city and state agencies to help expand natural areas on campuses and connect these to larger regional landscapes. Native plants and their natural communities develop deep roots, build healthy soil ecosystems and infiltrate stormwater where the rain falls right on campus. They also provide sources of food and habitat for a broad range of animal species. The program has been an incubator for education programs, attracting community members and organizations, students, teachers, and professional staff in engaging in hands-on habitat restoration in the field. Additionally, in-classroom educational programs spurred by the program are reaching all students as they move through the middle schools located within the Watershed District. The program brings nature on a large scale right to the doorstep of students and community in a very intentional and public way.
Topic Area(s): Best Management Practices (BMPs), Education and Citizen Involvement
Session ID: 1073 – Lake of the Woods: Southern Shore Barrier Island Erosion Investigation – Phase I
Primary Author: Zachary Morris, AMI Consulting Engineers, PA
This presentation will provide an overview of the geomorphology for the Pine & Curry, and Sable Islands located in the Lake of the Woods, MN. These barrier islands have degraded over the last century and there is significant community interest in determining cause(s) for the erosion, as well as providing options on ways to restore the islands. This presentation will focus on the field work conducted, development of a lake-wide circulation model and 1D sediment transport model, most probable causes for the degradation of the islands, potential solutions, and future work required (Phase II).
Topic Area(s): Engineering Solutions and Applications, Hydrology, Rivers, Streams, and Floodplains
Track III: Rivers and Streams
Session ID: 1098 – Updating Pollutant Trends for Streams in the Twin Cities Metro Area
Primary Author: Hong Wang, Metropolitan Council Environmental Services
The Metropolitan Council (Met Council), in its capacity as a regional planning agency, conducts water quality monitoring and assessment in the Twin Cities Metro Area. This study focuses on the examination and update of pollutant trends, specifically total suspended solids (TSS), total phosphorus (TP), and nitrate nitrite (NOx), across 18 metro streams and rivers that discharge into the Mississippi, Minnesota, and St. Croix Rivers. The primary objective is to understand temporal changes of water quality in regional streams and their consequential impacts on the major rivers, providing invaluable information and insights for water resource management in the region.
Building upon the groundwork laid in the previous assessment work of TSS, TP, and NOx trends through the year 2012 for the Council’s large stream monitoring and assessment program—the 2014 Comprehensive Water Quality Assessment of Select Metropolitan Area Streams, this presentation delves into the recent efforts of the Council to evaluate and update these pollutant trends through the year 2021.
The analysis of trends employed the recently published USGS R version of the statistical model QWTREND. The findings reveal that concentrations of TSS and TP exhibit a predominantly favorable trend, characterized by continuous decrease or stability from 2012 to 2021 across most streams. Noteworthy is, where an increase in concentrations contrasts with the established decrease trend.
Nitrogen concentrations present a mixed trend, with instances of decrease, increase, or no observable change. Overall, the results suggest a positive trend in the water quality of regional streams and tributary rivers, particularly concerning TSS and TP, indicating a continuous improvement over the assessment period. This study contributes valuable information essential for informed decision-making in the ongoing management of water resources in the Twin Cities metro area.
Topic Area(s): Monitoring, Rivers, Streams, and Floodplains
Session ID: 1100 – Identifying Sediment Sources in the Forested Little Fork Watershed with Sediment Fingerprinting and Sediment Budget Methods
Primary Author: Anna Baker, US Geological Survey
The Little Fork River has over 100 miles of sediment-related impairments and has been identified as a disproportionate contributor of sediment and phosphorus loading to the Lower Rainy River and downstream Lake of the Woods. In response, the Minnesota Pollution Control Agency (MPCA) has established Total Maximum Daily Load (TMDL) targets for sediment load reduction for the Little Fork. In support of TMDL implementation, the U.S. Geological Survey is partnering with the MPCA and the Soil and Water Conservations Districts of Koochiching, North St. Louis, and Itasca Counties to investigate sources of sediment and sediment bound phosphorus using geochemical sediment fingerprinting and sediment budget techniques. Sediment fingerprinting uses elemental chemistry to tie fluvial suspended sediment and streambed sediment to its sources in the landscape. For the forested Little Fork watershed, this study evaluated upland sources including mature and harvested forest, roadways, and agricultural fields, and near channel sources including ravines and streambanks, from headwaters to the mainstem.
Preliminary results of both the sediment fingerprinting and stream corridor sediment budget analysis suggest the primary importance of near channel erosion to sediment loading in the Little Fork watershed and highlight the role of ravines as contributors to storm driven sediment mobilization. This presentation will detail the source apportionment of sediment loads from a network of stream gages and streambed sampling locations across this large 1, 872 square mile basin and will lead into a discussion of how this science will be used to inform management actions by our partnering agencies.
(This presentation should be paired with “Creating effective partnerships to build bridges from science to management in the forested Little Fork Watershed” to be presented by Mike Kennedy, Sam Soderman, Phil Norvich, and Matt Gutzmann.)
Topic Area(s): Monitoring, Rivers, Streams, and Floodplains, Watershed Management
Session ID: 1083 – Can Downscaled Gravity Recovery and Climate Experiment (GRACE-TWS) by Knowledge-Guided Machine Learning Improve Streamflow Prediction Model? An Experiment at Central Minnesota, MN
Primary Author: Pai-Feng Teng, University of Minnesota
Since its launch in 2003, the Gravity Recovery and Climate Experiment (GRACE) has been able to monitor water storage distribution at a continental level. The GRACE Total Water Storage Anomalies (GRACETWS) have been tested for storage-discharge relations since 2009 and downscaled to monitor the localized level of the water balance. Nevertheless, the current downscaling process emphasizes downscaling them to small resolutions that cannot reflect the geographic and hydrological characteristics of the watershed, and its application to streamflow predictions remains underdeveloped. This research uses knowledge-guided machine learning (KGML) to combine two concepts. First, the GRACETWS is downscaled to a smaller, 1747 sub-watershed using the Long Short-Term Memory (LSTM) network between 2009 and 2015 at the Upper Mississippi River Watershed in Minnesota. Secondly, the improvement of streamflow prediction is assessed by inputting the downscaled GRACETWS, along with monitored weather data in Central Minnesota, for the universal LSTM rainfall-runoff model. This experiment aims to (a) examine whether downscaled GRACETWS can represent geographic features, hydrological characteristics, and the hysteretic relation between storage and discharge at a smaller scale and (b) assess whether downscaled GRACETWS can complement existing rainfall-runoff models.
Topic Area(s): GIS/LiDAR, Hydrology
Session ID: 1082 – LOMRs and Turtles and Riffles, Oh My! Fourteen Years of Elm Creek Restoration Benefits to the City of Champlin
Primary Author: Heather Nelson, City of Champlin
In 2010 the City of Champlin began planning a multiphase restoration effort focused on Elm Creek. The City of Champlin identified the following restoration priorities: water quality improvements, reduced flood risk, habitat improvements, and improved opportunities for recreation within the parks which are located within the creek corridor. The City of Champlin partnered with the State of Minnesota to use bonding dollars and grant funding to complete the projects and achieve stated project goals.
The restoration began with the reconstruction of the Elm Creek Dam, then focused on restoration of the Mill Pond, and finished with restoration of the Elm Creek. A total of 2.7 miles of creek have been restored. The Dam reconstruction resulted in approximately 55 homes being removed from the FEMA designated floodplain during the LOMR process. The Mill Pond restoration project involved the removal of approximately 240,000 cubic yards of accumulated sediment to improve water quality and create deeper habitat for a more diverse fishery. The Elm Creek restoration focused on designing a stream that would respond to the flashy flows that were present due to upstream urban development in the watershed. The two final phases of stream restoration focused on channel remeanders to maintain floodplain connections (2,600 feet) and large wood structures to protect existing banks (2,300 feet). Restoration phases also included archeological assessments and construction monitoring of sensitive cultural sites, protection of state-endangered Blanding’s turtles, and property buyouts to reduce flood risk to residents and allow for enhanced public spaces.
Topic Area(s): Flood Protection, Rivers, Streams, and Floodplains, Stream Restoration
Track IV: Managing the Quality and Quantity of Agricultural Drainage
Session ID: 1005 – Agricultural Drainage Water Recycling: Momentum Toward a Win-Win Solution for Water Quantity and Quality Challenges
Primary Author: Spencer Pech, ISG
Drainage water recycling (DWR), capturing and reusing subsurface drainage water for supplemental irrigation, offers the potential to increase climate resiliency and reduce nutrient losses of crop production. This presentation will provide an overview of current progress and future opportunities for the implementation of DWR throughout the agricultural landscape of Iowa. Highlights of progress includes a review of existing DWR sites, water quality data, yield data, landowner outcomes, testimonials and lessons learned. Future opportunities include a review of additional sites in development and design, unique irrigation opportunities, precision agriculture, drainage benefits, flood mitigation, and planning for implementation at the watershed scale throughout the Midwest. These studies and testimonials are being used for landowner outreach to identify high priority pursuit areas for practice implementation. The presentation will include a review of the variety of factors to be considered when siting a DWR project, including soils, topography, crop types, drainage infrastructure, climate, and more. Well-sited DWR projects can provide production benefits to the farmer, drainage benefits to neighboring lands, and downstream water quality benefits. DWR has the potential to transform crop production on drained lands, creating cropping systems that are more resilient to climate risks and promoting long-term sustainability.
Topic Area(s): Agricultural Water Issues, Engineering Solutions and Applications, Water Reuse
Session ID: 1006 – Using Natural Channel Tendencies to Inform Future Drainage Management
Primary Author: Jon Lore, Minnesota DNR
Since European settlement in Minnesota, a landscape once covered with prairie and wetlands has succumbed to row crop agriculture, cities and towns, roads, and other human infrastructure; leaving only small percentages of the land in its natural form. All forms of drainage, especially ditches, have been necessary to achieve modern day agricultural and infrastructure needs. According to the Minnesota Pollution Control Agency’s Altered Watercourse Layer, 52% of waterways in southwest and south-central Minnesota are considered altered while only 25% are considered in natural condition. Consequently, altered hydrology remains one of the main drivers of impairments in southern Minnesota.
The natural tendency of channel evolution after disturbance is to incise and detach from its floodplain, then widen out to an extent where the channel develops a floodplain at its new incised base level. Many drainage ditches in southern Minnesota are built to transport water, but not sediment, resulting in the channel building a floodplain to achieve quasi-equilibrium (i.e. two-stage ditch). These ditches often are subject to a repair, where the channel is excavated to match how it was originally built. The repair process resets channel evolution while creating habitat and water quality issues locally and downstream.
The Minnesota Department of Natural Resources has been monitoring naturally formed two-stage ditches, recent repair projects, and self-recovering two-stage ditches to inform future drainage management practices to benefit water quality initiatives while reducing costs to drainage systems and their benefited landowners. We propose the enhancement of floodplain area instead of channel excavation in these situations so future repairs are limited and the channel can become self-maintaining. This practice can help with water quality treatment, flood peak reduction, and habitat improvements to delist existing impairments and prevent future ones.
Topic Area(s): Agricultural Water Issues, Engineering Solutions and Applications, Watershed Management
Session ID: 1001 – Drainage Ditches: A Potential Water Storage Option for Minnesota
Primary Author: Jeffrey Strock, University of Minnesota
Drainage ditches are an underutilized, existing, potential water storage domain providing multiple possible co-benefits: flood mitigation, peak discharge attenuation, reduced nutrient losses, carbon sequestration, and providing irrigation water and wildlife habitat. Drainage ditches have the potential to be used for temporary water storage on the landscape which would lead to fundamental changes in agricultural drainage water management from the existing paradigm that focuses on rapid water conveyance through ditches, which drastically limits water storage and nutrient cycling, to a new paradigm where intelligent drainage water management is seen as a valuable resource for improving water quality, enhancing groundwater recharge, and reducing peak flows. Not every ditch in Minnesota would be suitable for temporary water storage. Our goal was to assess the suitability of selected ditch segments for water storage and to estimate the potential volume of water storage in this watershed’s drainage ditches. A GIS-based method to evaluate ditch storage potential was used to evaluate watershed features and ditch characteristics (e.g., watershed area, soils, channel length, slope, and geometry) in a small watershed in southern Minnesota. We used existing ditch and LiDAR datasets. The current effort will allow us to infer results to ditches in other parts of Minnesota and other states where ditches are common.
Topic Area(s): Agricultural Water Issues
Session ID: 1002 – Protecting Drinking Water with Rural Best Management Practices: Case Study of Martin County Ditch No. 28
Primary Author: Chuck Brandel, ISG
National Agricultural Drainage Expert, Chuck Brandel, PE, will present an innovative approach to agricultural drainage projects, emphasizing best management practices for improved water quality. Discover how ISG led the design and implementation of an outdated public drainage system, draining into the Fairmont Chain of Lakes, the City of Fairmont's drinking water source. Through the implementation of a Clean Water Funded, nutrient treatment train, including a 9-acre nutrient treatment wetland and an 8, 000-linear-foot two-stage ditch, attendees will gain insights into mitigating nutrient runoff effectively while reducing flooding downstream. This collaborative effort involving diverse stakeholders, including agencies, landowners, and the City of Fairmont, showcases the successful upgrade of the Martin County CD 28 system, ensuring improved drainage infrastructure and protecting downstream drinking water sources.
Topic Area(s): Agricultural Water Issues
Track V: Special Session
Equity in Drinking Water: Beliefs, Education, and Policies
Heron Mahr, Clean River Partners; Emily Kreiter, University of Minnesota, Center for Changing Landscapes; Carrie Raber, Minnesota Department of Health; Tannie Eshenaur, Minnesota Department of Health
Safe and sufficient drinking water is essential to healthy people and communities. In this session, we will discuss people's beliefs and values around drinking water in Minnesota, policies in place to support equitable access, and what policies or programs are missing. Participate in a panel discussion and interactive activity to brainstorm actions we can take at different levels of government and advocacy organizations to increase equitable access for everyone.