ABSTRACT. Coastal communities around the world continue to develop and become more densely populated despite increasing coastal hazards. This concentration of near-shore development has serious implications for communities exposed to coastal threats, as well as marine ecosystems impacted by the adverse effects of shoreline hardening. Coastal wetlands offer a nature-based solution to shoreline protection while also supporting productive habitats. In McKay Bay, Florida, a crumbling seawall borders Historic Palmetto Beach. The city of Tampa is interested in replacing the existing seawall and fortifying the coastline with natural shoreline elements including mangroves, salt marsh, and oyster reefs. Through collaboration with locals, design options have been proposed to improve flood mitigation and meet the needs and vision of the community. For this project, we developed a 2D hydrodynamic model of McKay Bay to evaluate the influence of coastal wetlands on storm surge during a major storm event. We varied seawall and vegetation extent in the model to represent three proposed designs. We then evaluated the performance of the different shoreline types for two simulated tropical cyclones of different intensities, considering inundation depth, extent and velocity. Our simulation results identify the location and magnitude of flood protection provided by the designs in McKay Bay. In addition, we estimated structural damage costs using FEMA’s Flood Assessment Structure Tool to investigate the socioeconomic impacts of design choices. This study quantifies the flood protection provided by coastal wetlands at the local scale and how they may be integrated into the Palmetto Beach communities’ resiliency strategy.

ABSTRACT. Coastal stormwater retention ponds are not typically designed for habitat provision; Nevertheless, fish may naturally enter these ponds through culverts connected to the saltmarsh, or they may be purposefully introduced by pond managers for recreational fishing or nuisance species control. However, research on fish communities in stormwater ponds is limited, especially in brackish ponds within the coastal zone. The goal of this research was to characterize fish assemblages within three tidally connected stormwater retention ponds located at various distances from the natural saltmarsh (e.g., 25 m, 130 m, 300 m) in Mount Pleasant, South Carolina. Fish were collected from each pond monthly from June 2022 to December 2023 using baited minnow pots and an otter trawl. A total of 2,974 individuals representing 21 taxa of both freshwater and saltwater species were collected from stormwater ponds, with the pond nearest the marsh fostering the highest fish abundance (1,909) and species richness (18). Seasonal differences in stormwater pond fish communities were detected, and many species were either absent or collected in lower abundances during colder winter months. The most abundant species collected from all three ponds were sailfin molly (911) and eastern mosquitofish (870), both of which are common freshwater species that consume algae and detritus. Further, several unique species such as non-native blue tilapia and common snook were also encountered. Results indicate that coastal stormwater ponds may support diverse and abundant fish communities, which vary by season, that may influence stormwater pond water quality, nutrient cycling, and terrestrial and aquatic ecology.

ABSTRACT. The threat of sea level rise and increasing storm intensity as a result of climate change is threatening the Sea Gate community in Chesapeake Beach, MD. This municipality is looking to improve the climate resilience of their infrastructure while also increasing biodiversity. Chesapeake Beach is already susceptible to flooding and shoreline erosion due to its low topography and location along Chesapeake Bay. The community is bordered by a three-acre wetland that is hydrologically connected to a twenty-acre inner marshland, with a major highway bisecting the two areas. The combination of storm events and high tides overflow the current storm water system, flooding the highway and threatening both the infrastructure of the Sea Gate community and the surrounding ecosystem. These problems are predicted to worsen as climate change progresses, with part of the Sea Gate community projected to be underwater by the end of the century. Our re-design of the three-acre wetland just south of Sea Gate will serve as a storm water asset with increased biodiversity. In addition, the restoration will explore using this area as a public green space to educate and inform the public about their local ecosystems, sea level rise, and the services the wetland provides to the public. Calculations for projected Total Maximum Daily Load water pollution reductions from the wetland restoration will be presented with the restoration design.

ABSTRACT. This effort is focused on addressing flood mitigation in the town of North Beach, Maryland. North Beach is located on the internal coast of the Chesapeake Bay, where climate change threatens the landscape due to intense sea level rise. The Chesapeake Bay has one of the highest levels of eustatic sea level rise, the combination of rising waters and a sinking landscape. The town of North Beach owns two development parcels behind a public beach and has asked for help designing flood mitigation and best management practices (BMPs). Of the public parcels, one is currently a newly finished public library and another is an undeveloped parking lot. These parcels are in the coastal flooding zone, and are extremely vulnerable to storm surges and water damage from the rising Chesapeake Bay, which are predicted to cause millions of dollars of damages along the Eastern U.S. coast in the future. The design will include data on the hypothesized effectiveness of the mitigation recommendation resulting in the increased resilience of the North Beach area. The design will be centered around ecological solutions to flood mitigation, which will include benefits to local habitats and species, as well as education about the implemented practices.

ABSTRACT. Tradepoint Atlantic, a global logistics center, has redeveloped the former largest in the world Bethlehem Steel site on Sparrow’s Point near Baltimore, Maryland. With hundreds of acres of impervious surfaces that must be mitigated for US-EPA required Chesapeake Bay Total Maximum Daily Load (TMDL) pollutant reduction of stormwater impacts, Tradepoint Atlantic requires large scale mitigation and treatment options. In Fall of 2023, the new ecological engineering team of Green Mechanics Benefit LLC was selected as a participant in Tradepoint Atlantic's competitive Empowerment Academy. Green Mechanics developed an innovative approach to shoreline restoration and water quality improvement to support the logistics hub’s regulatory requirements. The design integrates innovative EPA approved ecotechnologies such as hectares of Algal Turf Scrubber with a kilometer of three-dimensional oyster reef living breakwaters. The reefs are to be supplied annually by tens of millions spat on cultch shell. An estimated 92 million oyster spat will be annually nursed in post-larval fish and invertebrate Biohuts suspended along the site’s kilometers of derelict piers. The ultimate build out of the living breakwaters will allow for the creation of a living shoreline on the eroding site near the mouth of the Patapsco River on Chesapeake Bay. Impervious acre (IA) mitigation TMDL crediting estimates are given for Algal Turf Scrubbers, oyster reef and living shoreline restoration proposed efforts. Through the Green Mechanics collaboration, Tradepoint Atlantic is expecting to achieve its goal of becoming a certified Green Marine Terminal.

ABSTRACT. An increasing number of Americans identify bottled water as their preferred source to meet household needs, even though it is more expensive and often less regulated. Examinations of Safe Drinking Water Act (SDWA) violation data demonstrate that rural low-income communities are significantly more likely to be burdened with unavailable and/or unsafe in-home drinking water. This effort compared in-home and bottled water quality in rural Appalachian communities identified as water inequity hotspots, in order to examine potential health and economic implications.

Twenty-four households in McDowell County, WV, Harlan County, KY, and Letcher County, KY completed surveys detailing drinking water use, perceptions, motivations, and expenditures. Twenty-three in-home, thirty-six bottled water (11 brands), and four roadside spring samples identified as preferred drinking water sources were analyzed for regulated and emerging contaminants via Standard Methods.

In-home and spring water quality was poor: 59% of samples were coliform positive, 22% were E. coli positive, 44% exceeded the aluminum aesthetic recommendation, 18% exceeded the iron aesthetic recommendation, and 56% exceeded the health guideline for sodium. Bottled water samples did not exceed any EPA health-based regulations (MCLs) or Health Reference/Guidance Levels. PFAS compounds were detectable in 87% and 36% of in-home and bottled water samples, respectively. Microplastic particles were detected in all samples regardless of source. Given consistent detection of health-based and aesthetic contaminants, it is not surprising that 71% of homes reported bottled water as their primary drinking water source, though the associated economic burden (>8% annual household income) is considerable for disadvantaged populations.

ABSTRACT. Cities struggle to meet competing demands for limited resources. In the northeastern US, historic sewer systems combine stormwater and wastewater creating overfull sewers during storm events. These systems necessitate overflow of polluted water to waterways (combined sewer overflow); these are areas of environmental injustice. Cities are increasingly addressing this problem with green infrastructure, natural systems that infiltrate stormwater. Many neighborhoods of these same cities suffer from unjust food systems that leave many residents without access to nutritious food (food deserts). Local and community food systems, such as food forest and community gardens, are ways that cities are addressing this problem. The Syracuse Urban Food Forest Project (SUFFP) is responding to both of these justice issues simultaneously through the creation of a 9-mile edible plant community corridor in Syracuse, New York. Over 1000 food-bearing trees, shrubs, and perennials have been planted in community planting events during the past 2 years. Community members have been engaged in this process through design, planting, and educational events. An estimated 2 million gallons of stormwater will be intercepted over the next 20 years from these plantings. This project acknowledges the traditional homelands of the Haudenosaunee nations, where the City of Syracuse is located, through collaboration with the Center for Native Peoples and the Environment in consideration of plantings of cultural importance. The SUFFP is an example of how urban restoration projects can consider multiple perspectives in conceptualization, design, and implementation to meet complex and competing societal and environmental needs simultaneously.

ABSTRACT. Severe storm events create widespread destruction, impacting both human and environmental well-being. With the progression of climate change, the heightened frequency and intensity of storms raise concerns regarding their adverse effects on surface water quality dynamics. Nevertheless, our comprehension of the interplay between flooding, watershed characteristics, and surface water quality remains limited. This study enhances our understanding of floodwater contamination by investigating spatiotemporal patterns of microbial contaminants and identifying the watershed characteristics that best elucidate the water quality signatures in floodwaters.

We conducted a comprehensive analysis after Hurricane Florence, a 1000-year storm event that impacted North Carolina in 2018. Water samples were collected across 51 sites during four visits, and assessments were made for microbial pollutants including Arcobacter, Salmonella, Listeria, E. coli, HF183, and Pig2Bac. Results highlighted the prevalence of pathogens in floodwaters, particularly the pathogenic Arcobacter Butzleri. Furthermore, a statistical model incorporating land characteristics, pollution point sources, and hydroclimatic factors was employed to explain all water quality responses, indicating pollution point sources' heightened importance during flood conditions. Conversely, non-point sources and rainfall played a more significant role in pollutant transport outside of flood conditions.

The pervasive presence of pathogens and fecal indicator bacteria during flood conditions underscores the transport of harmful pollutants facilitated by floodwater connectivity. This discovery accentuates public health concerns linked to human exposure to floodwaters. Particularly noteworthy is the modeling result, revealing potential drivers and sources of water quality contamination across spatiotemporal scales.

ABSTRACT. The William Tyson Wastewater Treatment Plant (WWTP) in Arcadia, FL is under consent order for ammonia exceedances. Following Hurricane Ian in 2022, the Federal Emergency Management Agency (FEMA) Interagency Recovery Coordination (IRC) Community Assistance (CA) Team stepped in to aid local government in building their capacity and capabilities to carry out community-based recovery planning. As a result, Arcadia, a severely underserved and disadvantaged community, was able to improve recovery outcomes and develop a path forward to achieve compliance. The existing WWTP uses trickling filters to treat organic loads but does not provide nitrification. While Arcadia is planning a facility upgrade to meet ammonia standards, FEMA IRC CA contracted support to complete a feasibility assessment of retrofitting existing wastewater ponds as a potential intermediary solution for compliance. The evaluation included comparison of three treatment wetland technologies: fill-and-drain, forced bed aeration, and an oxygenated treatment marsh which were all capable of reducing ammonia from 17 mg/L to less than 1 mg/L within the footprint of existing ponds. The oxygenated treatment marsh was selected due to its low cost, potential for application as a polishing marsh in the long-term, and its ecological value. To promote nitrification, a new treatment marsh is being designed with an oxygenation system using a Speece Cone. This presentation will provide background on how FEMA IRC CA is supporting communities in the aftermath of Hurricane Ian by developing nature-based solutions and highlight this innovative treatment wetland project which is capable of meeting treatment requirements within time and funding constraints.

ABSTRACT. Practicing engineers must satisfy both technical and ethical requirements to support professional licensure and meet societal expectations. Specifically, engineers are called to protect the health, safety, and welfare of the public, although “engineering ethics” typically focuses on individual responsibilities, conflicts of interest, and moral courage. Ironically, many of the environmental problems we are trying to solve stem from historical professional engineering judgement and lack of foresight. Ecological engineering emphasizes benefits to both human society and the environment, leading to an enhanced view of engineering ethics. We suggest that a robust standard of professional care is grounded in ecological engineering principles and practices. Thus, an ethical engineer practices social responsibility and environmental sustainability in addition to individual accountability. In this presentation, we incorporate environmental equity and Aldo Leopold’s “land ethic” as key components of engineering practice. To illustrate a holistic view of ecological engineering ethics, we tell the story of the Gadsden Creek, the last remaining tidal creek in the Old City District of Charleston, SC. A land development corporation proposed to permanently pipe this tidal tributary and fill the associated salt marsh wetlands adjacent to Gadsden Green, a historically Black community on the Charleston Peninsula. The Gadsden Creek Revitalization Project demonstrates how professional engineers can meaningfully support a community of concerned citizens and serve the greater good.

ABSTRACT. Discovery of the many ways generative artificial intelligence (gen-AI) technologies, like Chat GPT-x (a large language model), can be used in an ecological research, design and teaching will be shared. Features in ChatGPT-4 include: 1) a much deeper ability at conversation and writing compared to ChatGPT-3.5, 2) DALL-E image generation, 3) Image detection and interpretation, 4) Web browsing, 5) Code (python) writing for quantitative analysis, 6) Creating and using Custom GPT's, and 7) access to 3rd party Plugins. I will share how I used these features to create novel types of materials, exercises, and imagery for a new course. Examples from the course include: Statistical analysis; Numerical simulation; interpretation of photos, handwriting, and sketches; development and use of a Custom GPT's to serve as a virtual Teaching Assistant; creation of games, and creation of avatars to practice interviewing skills. Universities and education systems must rapidly adapt to the new educational paradigm driven by gen-AI.

ABSTRACT. Excess fine sediments (<2 mm) in gravel streambeds can negatively impact river habitats and ecosystems by reducing porosity and interparticle flow. A range of human activities and land-use changes has increased fine sediment inputs into river systems, exceeding the sediment transport capacities and increasing embeddedness in gravel streambeds. Embeddedness, also referred to as colmation or clogging, measures the fine sediment present in interstitial pore spaces. Unfortunately, measuring embeddedness in the field can be time-consuming and difficult. This study examines the potential of using statistical and machine learning techniques to predict reach-scale embeddedness measurements in Virginia using publicly available data. A dataset collected by the Virginia Department of Environmental Quality includes 1,125 points with embeddedness measurements and a subset that provides remotely sensed bankfull indicators, slope measurements, land-cover percentages, and other parameters. The final gradient-boosting regression model used 24 feature sets of remotely sensed watershed-scale data. The gradient-boosting regression model achieved a cross-validation score of 0.55 and a mean absolute error of 12.3% embeddedness. Future work will consider other remotely sensed data, such as soil composition and bankfull dimensions, to produce a more accurate, physics-informed model.

ABSTRACT. Dissolved Oxygen (DO) concentrations in waters overlying floodplains regulate soil reduction-oxidation processes, and therefore have a significant impact on the internal cycling of nutrients between floodplain soils and floodwaters. As DO concentrations decrease, conditions become more favorable for the internal release of iron-bound phosphorus (P) from floodplain soils, which has important water quality implications. DO dynamics in floodplains are a function of complex, non-linear processes affected by floodplain soil chemistry and biology, incoming riverine water quality and quantity, and floodplain hydrology. Advancements in sensor technology have allowed for near-real time monitoring of DO concentrations, but sensors are spatially limited and expensive, taking significant time and resources to maintain. Therefore, accurate modeling of DO concentrations is of interest to researchers, restoration professionals, water quality managers, and other stakeholders working to protect water quality and restore and/or preserve floodplain habitat. Due to the complex, non-linear behavior of DO concentrations in floodplains, traditional statistical methods struggle to accurately predict DO concentrations. In this work, we illustrate the development and testing of a deep learning (DL) model to predict DO concentrations at intensively monitored floodplain sites in the Lake Champlain Basin of Vermont. Our findings demonstrate that DL methods show great promise for predicting DO concentrations but can struggle to predict the magnitude of anoxic periods. A model capable of accurately predicting DO concentrations would be a valuable tool for water quality managers and could be used to generate forcing data for modeling other complex biogeochemical processes that are driven by oxygen availability.

ABSTRACT. Lake water quality (WQ) degradation is a pressing environmental concern, impacting water supply, aquatic life, and ecosystem services. Lake Okeechobee, a large but shallow subtropical lake, confronts severe WQ challenges, leading to eutrophication and algal blooms. This study employs four machine learning models (XGBoost, LightGBM, Support Vector Regression, and Random Forests) and SHapley Additive exPlanations (SHAP) to predict and analyze four key WQ parameters: total phosphorus, total nitrogen, nitrate+nitrite as nitrogen, and water turbidity to improve lake monitoring and management. Objectives include predicting WQ parameters using easily measurable inputs, identifying spatial patterns, and determining environmental drivers. Two modeling approaches, station-specific and lake-wide, were utilized, with the former revealing spatial patterns using SHAP values and the latter aiding operational decisions. For all nutrients, turbidity was the main predictor, along with water level, temperature, and temporal factors (months, quarters), with XGBoost showing superior performance. Spatial analysis across fifteen stations using K-means identified three distinct lake regions: near-littoral, transitional, and deepest zones with the lowest, moderate, and highest turbidity and nutrient levels, respectively. Given the significance of turbidity, this parameter was predicted using air temperature, wind speed, water level, main lake inflows, and temporal factors, with SHAP values highlighting that turbidity is primarily driven by inflows and water level near inlets, wind speed and temperature in central parts, and water level and seasonality in near-shore regions. This research advances the understanding of WQ dynamics in subtropical lakes for enhanced lake monitoring and management, particularly through frequent monitoring of turbidity and its environmental drivers.

ABSTRACT. Understanding the inherent mechanism of floodplain connectivity in low-sloped agricultural floodplains is crucial for facilitating soil erosion and nutrient transport prediction and management of marginalized agricultural landscapes, as well as for reducing water quality issues (e.g., increased turbidity and entrapped phosphorous, etc.), and river surface-water demand. However, most existing methods of delineating channel networks from a Digital Elevation Model (DEM) use steepest-descent principles, which, due to the underlying assumptions, often fail to capture low-lying, multi-thread channel connectivity. While using satellite images in conjunction can help in this regard, the challenge of defining a representative network persists because of the temporal variation of spatial network connectivity resulting from variable flow and land-cover conditions. Therefore, in our study, we will identify the effectiveness of a relatively new network tool, TTGA (i.e., Topological Tools for Geomorphological Analysis), developed for applications in delta and estuarine environments for predicting floodplain connectivity in the East Fork White River near Seymour, Indiana, where well-developed floodplain channels can be observed. We will use 1.5-m lidar data in combination with the TTGA tool to objectively extract complex floodplain-channel networks. Furthermore, we will quantitatively analyze the network structure using various network metrics to see how the floodplain-channel connectivity compares to delta or estuarine networks and use the floodplain-channel network to better understand fluxes of water, sediment, and nutrients across floodplains. We anticipate that TTGA will be more robust in capturing floodplain connectivity and, subsequently, help us better understand potential soil erosion under varied flow and vegetation patterns.

ABSTRACT. The Sri Lankan government’s 2021 policy to ban imports of mineral fertilizers and shift to green agriculture provides an opportunity to examine the potential for nutrient recycling in a more circular economy. Here, we examine national-level nutrient flows in Sri Lanka to determine the overall capacity to offset mineral fertilizer with alternative nutrient sources. Furthermore, we develop and apply a grid-based resource recovery and distribution model to assess the potential for municipal solid waste (MSW) compost and human excreta to serve as alternative nutrient sources in Sri Lanka, in addition to existing animal manure. For a scenario including MSW compost and early adopters of nutrient recovery from human excreta, offsets of mineral nitrogen and phosphorus fertilizers were ≤ 9%, leaving sizable gaps. Offsetting >50% of mineral fertilizer did not occur under any scenario. Reuse of recovered nutrients in model scenarios was in urban and peri-urban areas distant from much of the nation’s agriculture. Our findings reinforce the need for long-term strategic planning for transitions in agricultural nutrient management. Future policies should consider fundamental constraints on alternative nutrient sources and emphasize increasing capacity for both effective nutrient recycling and efficient mineral fertilizer use.

ABSTRACT. As global population and stress on our natural resources increases, there is need to rethink how we produce food with emphasis on recycling resources such as carbon, water, and nutrients. Controlled environment agriculture (CEA) is gaining increasing attention due to its potential for improving resource use efficiency compared to traditional field-based agriculture. This project investigated an integrated anaerobic/aerobic biological treatment process to recover carbon, nutrients and water from vegetable waste for reuse in CEA systems. Anaerobic digester effluent nitrified via an aerobic membrane bioreactor process (nADE) was evaluated as a nutrient source for indoor hydroponic and greenhouse soilless drip-irrigation lettuce cultivation. Lettuce yield, tissue nutrient content, water quality, and nutrient uptake efficiency were compared between the nADE treatment and a commercial fertilizer control for each CEA system. The lettuce grown on nADE demonstrated similar or higher yields, more leaves, and elevated tissue nutrient content than the control. The nADE media improved N and P uptake efficiency in the drip-irrigation system but decreased K, Ca, and Mg uptake efficiency, possibly from the over-application of these nutrients. Further research is needed to optimize nADE dosing and improve nutrient uptake efficiency. The study demonstrates a circular bioeconomy approach to decrease dependency on inorganic fertilizers while benefiting crop yield and quality.

ABSTRACT. Cattail harvest has the potential to export nutrients from eutrophic wetlands, increase long-term carbon sequestration, and enhance wetland ecological function. However, due to a lack of economically viable uses, such harvests rarely occur. We proposed the use of cattail (Typha domingensis) biomass as a substitute for peat moss in horticultural growing media, thus providing a potentially valuable use for cattail biomass with the added benefit of replacing a product that destroys wetlands and releases large amounts of CO2. The aim of the current study was to further refine our pyrolysis and composting methods to achieve bioproducts with the chemical characteristics (pH, conductivity, and stability) necessary for use in horticulture. Results from this work using invasive Typha x glauca harvested in Minnesota’s Red River watershed will be compared to those of our previous study using T. domingensis harvested in Florida’s Greater Everglades Ecoregion. Finally, we will share the results of an analysis of the economic potential of a cattail-based potting medium, as well as estimates of TP, TN, and carbon sequestration via Typha harvest.

ABSTRACT. Processing animal waste into value-added products can be time-consuming with high upfront costs but also can assist in nutrient management, provide additional revenue streams, and mitigating greenhouse gases (GHGs) emissions. In this analysis, four animal waste technologies were evaluated: anerobic digestion, manure injection, composting, and thermochemical processing (i.e., gasification). Surveys, interviews, and focus groups were conducted in Maryland to understand barriers, opportunities, GHG emissions reductions, and environmental justice (EJ) concerns when determining future siting locations. Results showed that barriers to implementation were lack of technical knowledge, high costs, and unclear permits and policies. Survey respondents (43%) indicated “government regulations” were their primary concern in using waste, while California and North Carolina had the highest policy incentives. The EJ analysis explored the need for agencies that fund these technologies to have community representatives, especially of varied and marginalized communities, on their technical committees. Additionally, those utilizing these technologies should document and share results on reductions in odor, effects of traffic, possible emissions, and use of EJ screening tools with surrounding communities. Anaerobic digestion of dairy manure and poultry litter was shown to reduce GHG emissions by 106% while composting only had a 66.7% reduction. The transport of food waste to manure digesters was shown to increase renewable energy production but decrease GHG emission reductions when the transport distances were high. Economic analysis indicated profit margins are often small compared to other renewable energy sources, as local economics often do not account for GHG emissions or soil amendment benefits.

ABSTRACT. Materials employed by coastal economic sectors such as aquaculture, habitat restoration, and water quality protection are dominated by plastics, contributing to an ever-increasing marine debris problem. Natural materials (e.g., coir, jute, wattle, wood, hemp) have a long history of traditional use in these sectors, but have been largely displaced by non-biodegradable proprietary alternatives (e.g., plastics). The need for new approaches blending traditional ecological knowledge with modern engineering has led to innovative applications of natural materials, but these alternatives cannot gain traction with policymakers until proven effective and logistically viable. Our study aims to explicitly test the efficacy, performance, and economic viability of natural alternatives to plastics in coastal South Carolina economic sectors via quantitative testing from lab to mesocosm to field pilot scales. This work is being conducted in close collaboration with industry partners, state agencies, nonprofit organizations, and historically disenfranchised communities including the local Gullah Geechee people. Through stakeholder workshops and directed interviews, we aim to identify natural solutions of the past and present and provide evidence of their efficacy and utility through rigorous testing. These experiments are being designed to produce quantitative results that inform the development of permitting and management strategies that support methods using natural, traditional materials. This preliminary discussion will highlight our goal of facilitating a sustainable future that combines the cultural knowledge of coastal SC stakeholders with the tools afforded by contemporary advancements in biodegradable materials.

ABSTRACT. Pocosin wetlands provide numerous ecosystem services, in particularly storing incredible amounts of soil carbon. In North Carolina alone, millions of acres of these wetlands have been impacted by drainage, silviculture, and farming. In their current state, drained pocosins are at high risk of catastrophic fire, subsidence, and saltwater intrusion. Although restoring these complex systems while maintaining surrounding uses is challenging, there are few better opportunities for building climate resilience, providing flood protection, and protecting unique and biodiverse habitats.

This presentation will explore current pocosin restoration efforts at several sites in NC, including the 7,500 acre Angola Bay Game Lands Restoration. The basics of pocosin restoration include a deep understanding of hydrology, flood storage benefits, and the implications for carbon sequestration and species habitat. These sites require data collection, groundwater modeling, surface water modeling, and thoughtful approaches for habitat restoration. We will explore each of these in the context of engineering design of weirs, risers, and even beaver dam analogs. We will also discuss recent research results and present lessons learned from active restoration construction.

ABSTRACT. Traditionally, the tenants of wetland structure and function have included three primary components: soil, hydrology, and vegetation. These components serve as a baseline for the general “wetland” designation as well as varieties of classification types. In practice, wetland restoration and monitoring rely heavily on hydrology of reference systems for basis of design, understanding climatic influences, and as benchmarks for meeting success criteria; however, literature suggests that variation (and drivers of) amongst wetland classification types is poorly understood. To further understand relationships between hydrology with geomorphic features, 33 references wetlands with more than 17 years of continuous hydrology data were analyzed. Time series hydrologic data were transformed to ecohydrologic metrics representative of ecosystem health (i.e., magnitude, timing, duration, and frequency) and compared to geomorphic attributes (i.e., area, perimeter, area:perimeter, depth) using redundancy analysis. Preliminary results demonstrate that geomorphology can attribute up to 36% of hydrologic variation of isolated cypress wetlands (e.g., within the same wetland classification type). These results suggest that understanding wetland geomorphology may assist with normalizing monitoring results or better guide the reference wetland selection process. Ongoing work seeks to explore variation within other wetland classification types (marsh, cypress marsh combination, and wet prairie wetlands) and evaluate how climate contributes to ecohydrologic metric variation.

ABSTRACT. Wetland-dominated landscapes provide critical ecosystem services through their ability to sequester carbon. The balance between carbon accumulation and export in wetlands is strongly influenced by hydrology. In hydrologically dynamic wetlands, rain events cause rapid shifts in the terrestrial-aquatic interface as the extent of surface water inundation expands and the surrounding groundwater table rises. Newly re-wetted soils may release pulses of dissolved carbon (dissolved organic matter [DOM]), representing a potential source of carbon to downstream waters. After initial rewetting, there may be lagged groundwater inputs carrying additional soil-derived DOM from the surrounding landscape. To understand the relative magnitude and timing of soil-derived DOM sources along shifting terrestrial-aquatic interfaces, we sampled surface water and porewater during a rain event at two Delmarva Bay wetlands located in the Mid-Atlantic United States. At each wetland, we collected surface water and porewater at four predetermined spots before, during, and after a rain event as the soil-water interface expanded outwards from the wetland center. Samples were analyzed for DOM concentration, DOM composition, and water isotope signatures. At Wetland 1, porewater DOM concentrations were generally higher than surface water and these concentrations were stable throughout the event. In contrast, Wetland 2 porewater concentrations were lower than surface water and the surface water experienced pulses in DOM concentrations. Evaluation of site-specific differences driven by each wetland’s unique hydrology and morphology contributes to understanding carbon cycling within natural wetlands to inform wetland design and restoration.

ABSTRACT. Excessive nitrogen in coastal estuaries can result in toxic harmful algal blooms, benthic hypoxia, and loss of habitat and biodiversity. Ecological restoration of former agricultural wetlands represents an opportunity to attenuate nitrogen pollution while enhancing other conservation goals. Nitrogen loads delivered from surface water and groundwater to wetlands are largely a function of upstream watershed land uses and contributing areas, which can often be delineated using land surface elevation. However, the glacial deposits that characterize groundwater flow in southeastern Massachusetts, where cranberries have been cultivated on wetlands for nearly two centuries, make topographic watershed delineation methods unreliable. Here, we adapted a U.S. geological survey groundwater model to delineate watershed areas for two-thirds (~8,600 ha) of the ~13,000 ha of cranberry farms in Massachusetts. We highlight how spatial variability in watershed characteristics results in a >10,000-fold range in nitrogen loads delivered from surface water and groundwater to cranberry farms. We model potential reductions in nitrogen loads to 26 coastal embayments from ecological restoration of wetlands on retired cranberry farms. We discuss the geographic and design factors that collectively impact the magnitude of nitrogen loads reductions from ecological restoration. Such information is valuable to town managers for total maximum daily load planning, as well as to cranberry growers for farm fertility management, bog renovation, and planning for bog retirements.

ABSTRACT. In the agriculturally dominated Lake Champlain Basin, located along the borders of New York, Vermont, and Quebec, an excess of phosphorus (P) loading in the watershed has impacted water quality, resulting in a phosphorus Total Maximum Daily Load (TMDL) for the lake. Wetland restoration is one method of P load reduction used in Vermont. Wetlands are commonly understood to be nutrient sinks, but high soil P on restored wetlands with a history of agricultural use could affect this function. We have monitored water quality during flood events on five restored, riparian wetlands on formerly farmed land since 2022, including the historic severe flood Vermont experienced in July 2023. We use a combination of field monitoring, laboratory incubations, and modeling to estimate P flux across these wetlands, located in two sub-watersheds of Lake Champlain, and compare results over monitoring year, season, and event magnitude. Preliminary results suggest net P retention at all monitoring sites. Our findings can inform watershed management and wetland restoration efforts and provide a glimpse into the potential impacts of extreme flood events that are predicted to increase in the Northeast.

ABSTRACT. H. T. Odum is thought by many to be the founder of the field of Ecological Engineering. He first suggested the notion that an ecosystem might be engineered for human purpose in a study of a laboratory microcosm published in 1957. Within the microcosm he witnessed the emergence of stable ecosystem structure and function through self-organization under various experimental conditions. This revelation seems to have been a turning point in his thinking. The creation of a microcosm requires intentional design that is related to engineering design. In this presentation Odum’s microcosms are inventoried, highlighting the “engineering” they embodied and the types of ecosystems that emerged in them. The path he took to come up with the concept of Ecological Engineering is explored through review of his publications and correspondence. This discourse relates to the history of Ecological Engineering and, in the present-day, to how we understand the assembly of species that takes place when various treatment ecosystems are designed, constructed and operated.

ABSTRACT. Natural areas and open spaces within urban landscapes provide a vital link for recreation, respite and habitats for city dwellers, including people, plants and wildlife. The emergence of inexpensive environmental sensors, cloud computing and controls represents a frontier in landscape design; the consideration and design of cybernetic ecosystems, capable of optimizing the throughput of energy and matter to maximize the yield of ecosystems services. Giving ecosystems additional information and agency to control their throughputs is likely to become increasingly important to protect the systems from evermore frequent extreme events associated with climate change.

Although ecosystems exhibit some properties of cybernetic systems, such as self-organization and self-adjustment in response to changes through species interactions, information is limited to localized abiotic and biotic sources. The ability of species to adapt and survive has evolved over time within a narrower range of climatic patterns. Moreover, ecosystems are not teleological, do not set goals and have limited agency to anticipate and protect themselves from changes in the patterns to which the community has evolved. The availability of vast geospatial data sets, combined with localized environmental sensors allows for the design of landscapes that can anticipate and prepare for climate extremes without direct human management. Moreover, with additional information and agency, cybernetic landscapes may function as ecological prostheses, delivering critical ecosystem services through reinforcing feedback loops that develop resilient community structure.

ABSTRACT. Privately-held lands dominate Tennessee, the Southeast, and much of the country. Land management activities and ethics adopted by individual landowners can have significant impacts on the health and quality of water and natural resources. Therefore, landowners are an important stakeholder group for watershed management and conservation efforts. As such, targeted outreach programs have been developed and implemented to reach urban, suburban, and rural residents and communities in Tennessee. Topics covered include sustainable landscaping, water stewardship, and riparian protection and restoration. This presentation will showcase strategies for engaging landowners and approaches for transferring technical information in a way that empowers individuals to take action. Specifically, we will overview the Tennessee Smart Yards program, share experiences and lessons learned from Creekbank Repair workshops, and report on a Community Riparian Restoration Program and watershed prioritization tool for these efforts.

ABSTRACT. The beauty of the ecosystemic approach is that everything – water, soil, wildlife, climate, etc. – is part of a connected, functional whole. This interconnectedness means that a number of different levers can be pulled to achieve various environmental goals. Accordingly, Tarrant Regional Water District recognizes that investing in ecosystem improvements has co-benefits for water quality, runoff reduction, and erosion mitigation. In recent years, the Watershed Protection program at TRWD has expanded into co-programming with wildlife-based organizations to achieve compatible goals through habitat restoration. This opens doors to new rural audiences beyond agricultural producers and appeals to many urban audiences, allowing us to capture a greater portion of stakeholders within the watersheds. This presentation primarily focuses on a case study of a pilot partnership with a local nonprofit organization focused on recovery of northern bobwhite quail populations on the Blackland Prairie of North Central Texas.

ABSTRACT. In April of 2001 at the first meeting of the American Ecological Engineering Society in Athens GA, H. T. Odum defined ecological engineering as “…. the study and practice of fitting environmental technology with ecosystems’ self design for maximum performance”. Odum believed very strongly that the idea of managing self-design (self-organization) of ecological systems should be the main organizing principle driving Ecological Engineering. To that end his various definitions of Ecological Engineering always included the management of the self-organization of ecological systems for the benefit of both human and natural systems.

Odum viewed self-organization as a fundamental characteristic of living systems, driving the emergence of complex structures, enabling ecosystems to capture and utilize energy more effectively, in accordance with the Maximum Power Principle. Central to Odum's ecological thought, The Maximum Power Principle posits that systems evolve in such a way as to maximize their power intake, the transformation of this power, and controlling the environment for the system's own advantage. Closely related to the Maximum Power Principle is the concept of self-organization, a process by which systems spontaneously organize and reorganize themselves without being directed by an external force.

This presentation will provide an overview of Odum's thoughts on self-organization within the context of ecological engineering, emphasizing his insights into the principles and applications of this approach.

ABSTRACT. Urbanization increases the quantity and reduces the time of stormwater runoff, eroding channels and impacting water quality. Wet retention ponds are widely used in Best Management Practices (BMPs) to mitigate these impacts. To simplify pre- and post-development runoff calculations, Technical Release 55 (TR-55) was established by the USDA and adopted by engineering firms nationwide. HydroCAD stormwater modeling software utilizes TR-55, meant to help engineers alleviate these pressures. Limitations within these procedures may lead to overestimations of pre-development runoff and under-sizing of BMPs resulting in environmental issues, where development can promote erosion of receiving channels.

This project evaluates these methods using three field sites to test limitations of TR-55 within HydroCAD. To address these limitations, stream flow monitors were installed at two sites around James City County and New Kent County, Virginia, to determine in-situ runoff quantity with a third observational site in the City of Williamsburg. In-situ stream flow velocities, rainfall data, soil samples, and topographic surveys were used to compare model results with site data, hand calculations, and observations identifying accuracy of model outputs and sensitivity of model parameters. This study identifies Hydrologic Soil Groups as the most influential parameter in estimations of pre-development runoff and offers suggestions for adjustments to parameters to increase accuracy. Overall, mapped soils groups are not reliable and can underestimate infiltration in pre-development wooded conditions, leading the model to suggest higher runoff values post-urbanization should be allowed. This study shows that uncorrected model outcomes can lead to harmful effects to receiving channels and watersheds.

ABSTRACT. Urban landscapes homogenize our world at global scales, contributing to “extinction of experience”, a sense of loss of ecological place or “eco-grief”, where people feel disconnected from native ecosystems and the services they provide. Public support improves the likelihood that approaches for combatting extinction of experience will be successful, yet it is presently unclear which approaches are viewed most favorably. We address this knowledge gap by surveying the next generation of leaders and decision makers (1,088 students/staff across four universities in the semi-arid southwest) and using multi-criteria decision analysis to explore the perceived value of three of the most frequently recommended approaches for combatting extinction of experience: ecosystem conservation, nature-based solutions for urban stormwater management (e.g., biofilters, bioswales), and turf replacement programs. Our results suggest that conservation of native ecosystems, particularly coastal sage scrub, is well supported by campus communities, as are programs for replacing turf grass lawns. Support for biofilters and swales was more moderate (and variable), which may reflect their relative newness, both on university campuses and in urban spaces more generally. Not all individuals preferred the same landscapes; preferences differed with degree of pro-environmentalism and university status (undergrad, graduate student, staff). Even so, all respondents exhibited landscape preferences consistent with at least one approach for combatting extinction of experience. This suggests both that the next generation generally supports urban landscapes that buffer eco-grief and that today’s ecologists, engineers and urban planners have a viable set of generalizable tools for creating these landscapes and reconnecting people with nature.

ABSTRACT. The Tarrant Regional Water District (TRWD) has implemented low impact development strategies with its continued landscaping retrofits at its Fort Worth Campus. Applying green stormwater infrastructure (GSI) into its landscape components, it has developed campus-wide BMPs that help clean, slow, and reuse stormwater, leading to the TRWD Rainscapes Program. A re-designed stormwater wetland was created from a malfunctioning detention basin, and now is the first extended dry-detention basin with micro-pools in North Texas. The campus also has incorporated a meandering rock channels, rainwater cisterns, water conservation practices, a raingarden, and a prairie restoration project is coming. The campus has 170 documented vegetation species on its premises, most of which are native to the state. Permeable surfaces, such as gravel pavers and permeable concrete are demonstrated on site. Five species of water efficient turf grasses are also part of the TRWD Rainscapes. The installation and maintenance of each of these features has many lessons learned. The TRWD Rainscapes components on the campus demonstrate benefits to biodiversity and water conservation. These benefits are applicable to residential, commercial, and industrial audiences, who tour the campus every year. The TRWD Rainscapes help to improve the local watershed and clean our stormwater before it reaches the Trinity River. This campus serves as a demonstration for stewards of the land, both urban and rural, showcasing how LID can be applied for stormwater management. Rainscapes Story Map: https://arcg.is/09ffqO0

ABSTRACT. With recent floods in urban areas in Texas, urbanizing areas have a need for comprehensive planning for reduced impact of impervious areas on downstream residential areas and transportation structures. The Upper Trinity watershed on the west side of the Dallas-Fort Worth Metroplex is experiencing growth and fast development that, if unmanaged, could lead to strong negative impacts downstream. A collaboration between several academic institutions, federal agencies, local water districts and the regional council of governments, a project was initiated to integrate transportation and stormwater needs to address the health, safety, and welfare concerns of the region while helping local governments manage their growth and development in a cost-effective manner. The project will inventory relevant data and stormwater structures, study the land, and develop a list of site-specific design considerations, develop plans, through modeling to offset the impact of urban development. This presentation will present details and methodologies of this project including expected outcomes.

ABSTRACT. Saturated hydraulic conductivity (Ksat) is a key performance variable in nature based solutions for managing stormwater such as bioretention. Ksat is well understood from a soils perspective, but not an ecological one; Even plant community effects are not well understood, reflecting the myriad plant traits influencing Ksat, which make it difficult to distil practical design guidance. To address this knowledge gap, we 1) evaluate adaptive strategy theory as an overarching framework for characterizing plant effects on Ksat and 2), explore the implications of this theory for spatial and temporal patterns in plant effects on Ksat driven by regional variability in planting guidance and trajectories of plant succession. Our results illustrate that adaptive strategy significantly influences Ksat, with ruderal plants tending to decrease it and stress tolerant or competitive/stress tolerant plants increasing it. These relationships are indirect, reflecting the impact of adaptive strategy on root traits and soil characteristics. When these relationships are evaluated in the context of established planting guidance, we find that plants recommended in arid climates tend to increase Ksat relative to bare filter media whereas plants in humid climates do not. However, biases in planting preferences can change these outcomes. For instance, established vegetation in our bioretention sites was more competitive/stress tolerant than expected, significantly increasing Ksat. These results illustrate that plants play an important role in bioretention hydrology, and warrant consideration during hydrologic design. They also suggest that adaptive strategy theory is a promising design tool, providing useful insights into plant effects on Ksat.

ABSTRACT. Significant water quality impairment occurs in Iowa from agricultural nutrient pollution. Surface and subsurface drainage systems transport nitrate from agricultural fields to receiving streams and rivers. Edge-of-field conservation practices, e.g., saturated buffers and denitrifying bioreactors, have been implemented to remove nitrate from subsurface drainage and improve water quality. While there is significant research on site-scale efficacy of edge-of-field practices, practice effectiveness at the watershed scale has not been assessed. Recent “Batch and Build” projects in Iowa have intensified edge-of-field practice implementation resulting in treatment of nearly every subsurface drainage outlet in some small watersheds, providing an ideal opportunity to study watershed-scale impacts. This new and ongoing study aims to assess nitrate loading in one of these watersheds, Alleman Creek, a heavily drained, 21 km2 watershed in central Iowa. Saturated buffers and denitrifying bioreactors were installed across the watershed in 2021-2022. Three saturated buffers were monitored for nitrate load reduction from 2022-2024. Stream nitrate load monitoring commenced in 2024 at two locations. Nitrate concentration is monitored through regular grab sampling and an in-situ nitrate sensor. Streamflow is determined from a rating curve developed from area-velocity flow measurements. Stream nitrate loading will be contextualized with nitrate load removal from the three saturated buffers monitored in the watershed. Results from this study will provide novel data on edge-of-field practice effectiveness at the watershed scale and help inform future research and implementation efforts for improving water quality in drained agricultural lands.

ABSTRACT. This study investigates legacy nitrogen (N) remediation from emergent groundwater using denitrifying bioreactors. We evaluate bioreactor performance treating emergent groundwater on a spring in the Shenandoah Valley, Virginia, with nitrate-N concentrations of approximately 6-9 mg/L and flow rates between 1000-3000 m3/d. Over two years (2022-2023), we evaluated the bioreactor's N load removal performance under various conditions, including hydraulic residence time (HRT), ambient bed temperature, bioreactor age, and groundwater N concentrations. Laboratory-based analysis and high-frequency nitrate sensors provided comprehensive nitrate concentration data. Inflow rates ranged between 332 m3/day and 887 m3/day with nitrate concentrations between 6 and 9 mg/L. The bioreactor consistently reduced N concentrations by 2 mg/L across flow rates, resulting in an average nitrogen load removal of 323 kg/yr, with daily removal rates ranging from 0.09 kg/day to 2.22 kg/day. Optimizing nitrogen removal involved manipulating water levels to vary HRT, revealing that operating at lower HRTs (<5 hours) significantly enhanced removal rates compared to higher HRTs (>8 hours). At lower HRTs, the nitrogen removal rate reached 1023 kg/yr, considerably higher than under higher HRTs. These findings underscore the importance of appropriately sizing bioreactors to optimize nitrogen load removal rates. Environmental conditions (temperature and influent N concentration) also influence bioreactor performance. Operational management to enhance N removal rates in emergent groundwater bioreactors will be discussed.

ABSTRACT. Bioretention, a stormwater treatment method, often requires a large portion of the catchment area and is designed at low Hydraulic Loading Rates (HLR) making it unsuitable for urban applications. Bioinfiltration systems are designed to quickly pass water and are more suitable for urban settings, but both struggle with dissolved pollutants. Testing of high permeability gravel (HPG) amended with biochar was conducted to determine the characteristics of the new mixed media and evaluate its effectiveness in a bioinfiltration system for urban deployment. Two pilot scale systems were constructed out of rain barrels, one freely draining from the bottom and the other featuring a raised drain, creating an Internal Water Storage (IWS) zone. These systems were subjected to two design storms, a 10-year event (11.8 cm/min HLR) and a median event (2.4 cm/min HLR), both using synthetic stormwater with dissolved Total Inorganic Nitrogen (TIN) concentrations consistent with urban stormwater runoff (0.8-1.0 mg NOx-N/L, 0.3-0.6 mg NH4+-N/L). Both systems eliminated runoff effectively and showed positive TIN mass removal efficiencies (~15-58%) for both storms. TIN removal efficiency differed by only about 2% between systems within each design storm, suggesting similar denitrification occurred in each. Both systems performed better under the lower HLR, with removal efficiency dropping by about 10% under higher loading. This level of passive nutrient treatment in stormwater is promising, similar systems would be suitable for urban settings where this level of removal is sufficient to bring dissolved N concentrations into regulatory compliance, or as the first line in a treatment train.

ABSTRACT. Submarine discharge of groundwater with elevated nitrogen significantly contributes to the coastal eutrophication. Permeable reactive barriers (PRBs) are a promising technology to intercept groundwater and remove nitrate before it enters surface waters. In woodchip based PRBs, lignocellulose serves as carbon source for microbially-mediated denitrification once anaerobic conditions are established. Oxygen penetration into woodchip media may therefore constrain N-removal performance at high groundwater velocities. High resolution O2 imaging was used in flow-through column experiments to assess oxygen penetration into different woodchip media at different temperatures and simulated velocities. At velocities of 0.5, 1, and 2 m d-1, oxygen penetrated 6, 23, and 44 cm into oak media at 14 ⁰C and 22, 43, and 88 cm at 7 ⁰C and significantly deeper into pine media (35, 61, 100 cm at 14 ⁰C, and 63, 98, and 105 cm at 7⁰C). As expected from oxygen penetration data, nitrate removal significantly varied as a function of woodchip type, groundwater velocity and temperature. At a velocity of 1m day-1, the NOx- removal rate was 4.3 mg N L-1 d-1 in oak and 0.4 mg N L-1 d-1 in pine at 14 ºC and these rates decreased to 1.43 and 0 mg N L-1 d-1 at 7 ºC. These data indicate that oxygen penetration can be a major constraint of NOx- removal in PRB woodchip media. The “loss” of anaerobic PRB media under high flow /low temperature conditions should be accounted for when choosing the thickness of a PRB to warrant complete nitrate removal.

ABSTRACT. Nutrient export from crop fertilizer application via subsurface tile drainage results in water quality damage and potential harm to downstream communities on a local and global scale. Woodchip bioreactors are an emerging ecological edge-of-field technology that hold great promise as an engineered denitrification system. In bioreactors agricultural water interacts with microbial communities from woodchips and corncobs resulting in nitrate removal. Bioreactors are novel technology in that these systems treat nitrate laden water in a smaller physical area. Although we know that bioreactors are an effective conservation tool, the microbial community responsible for denitrification is largely unexplored. Six upflow columns were designed to represent bioreactors in a controllable environment for monitoring of microbial communities, greenhouse gas production, and water chemistry. Three columns contained a carbon source of woodchips and three contain corncobs and were run for six months at two HRTs (8 hr, 16 hr). Preliminary data shows corncobs are more efficient at nitrate removal than woodchips at 8 h HRT; however, corncobs produced more carbon dioxide. The corncobs had a notable initial flush of TOC, potentially causing the carbon dioxide production. Additional trends were observed in ORP, DO, pH, NO3-N, NO2-N, and NH4+ water analysis. Future analysis include analysis of water and media microbial communities relative to explain greenhouse gas production and water chemistry analyses. Further work will determine denitrifying gene presence to assist in developing an optimal performing bioreactor with minimal greenhouse gas production and increased nitrate removal rates.

ABSTRACT. Forest restoration can be implemented at watershed scales and for various intents, including for water resource planning. In some settings, namely lands valued for water supply, strategies such as forest thinning and prescribed fire can increase water yield to surface and groundwater systems. In urbanized, flood-prone areas, however, forests can be targeted as priority areas for flood reduction services. Both objectives require information regarding the role of forests in water storage and removal (i.e., via evapotranspiration; ET). Throughout Florida pinelands, lands valued for water supply, we applied field methods to quantify ET, interception, and water yield in 36 stands ranging in hydrogeology and forest structure. Collectively, leaf area, aridity, and hydrogeology explained 82% of variation in annual water yield; thus, the water supply effect of forest restoration can be quantified and used in payment for ecosystem services programs. To inform urban forest conservation for flood reduction, we used remote-sensing products to quantify water storage and ET across land uses throughout the City of Virginia Beach, an increasingly flood-prone landscape. In total, forest cover contributed approximately 23% of the City’s water storage capacity and 45% of its water removal. Further, wetland forests had the highest ET rates among all land cover classes, contributing 40% of ET across Virginia Beach despite the fact they only occupy 20% of land area. New efforts are incorporating these flood-reduction services of urban forests into stormwater models under different storm-event scenarios. Together, research findings emphasize the role of forests in green infrastructure and water resource planning.

ABSTRACT. In 1975, Hynes published his seminal essay that hypothesized connections between valley characteristics, streamflow variability, and downstream ecosystem function. Nearly 50 years later, researchers are developing predictive understandings of “river corridors” using concepts from across aquatic ecology, geomorphology, and hydrology. However, we still lack key empirical data and theory to unify studies across disparate spatial and temporal scales. To begin to address this problem, we discretize the river corridor into scalable hydrogeomorphic units (HGUs). Operationalizing the intermediate valley-bottom scale, HGUs are defined by distinct geomorphic structure that is both formed by and contributes to unique hydrologic patterns. We employ this spatial unit to quantify hydrologic variability along river corridors across the southeastern US. In these systems, we find that sediment transport properties result in three archetypal HGUs – stream-wetland corridors, stable alluvial corridors, and incised corridors. The incised HGUs are likely the result of land-use legacies associated with intensive agriculture and forest management; and the stream-wetland complexes are the result of sediment deposition downstream of incised HGUs. Using an empirical dataset, we highlight patterns in surface water-groundwater connectivity across these HGUs: incised reaches are typically gaining, stable alluvial reaches are typically losing, and stream-wetland complexes experience both gaining and losing conditions. We then interrogate these patterns further with a distributed, physically based model. Our results suggest that stream incision reduces watershed storage, decreases stream drying, and homogenizes hydrologic functions. Moreover, our results highlight how HGUs can be used to understand connections between the valley, its stream, and ultimately downstream function.

ABSTRACT. Floods provide beneficial ecosystem services, but they can also damage infrastructure and result in loss of life. Enhancing floodplain capacity through river restoration to increase surface water storage along river networks has potential to mitigate such impacts. This potential has been poorly quantified at the watershed scale. We simulated the effect of varying the amount and location of floodplain and Stage 0 restoration in a watershed using HEC-RAS. We modeled a synthetic 4th-order watershed using average stream geometry and hydrology for the Virginia Piedmont with storms ranging in size from the 2-year down to monthly discharges. Model results indicate that Stage 0 techniques were more effective at inducing floodplain exchange and flood wave attenuation than restoring bankfull floodplains. The incremental effect of an individual restoration project varied depending on where it was in the 4th-order channel network, and on the amount of previous restoration that had already occurred in the watershed, with tradeoffs between enhancing flood attenuation and enhancing floodplain exchange. Important future directions include extending this analysis to larger spatial scales and additional processes. Overall, our results indicate that floodplain and Stage 0 restoration approaches have substantial potential to reduce peak flows, increase floodplain storage and provide a positive watershed hydrologic response to increase system resilience to climate change. Within that context we emphasize the importance of viewing watersheds as a whole to understand the potential impacts of projects.

ABSTRACT. Riparian networks are known to promote water quality and buffer aquatic ecosystems from watershed landuse change; however, urban encroachment into these systems remains a common occurrence in some communities. In this study, we assessed the capacity for the riparian corridor network within an urbanizing watershed in the Kansas City metropolitan region (Kansas) to regulate flooding, water quality, under future urban buildout conditions using the PC-SWMM hydrologic model. Carbon storage and sequestration benefits were also assessed. The effect of riparian connectivity – both structurally and functionally – on watershed hydrologic and water quality responses was examined by creating scenarios in which the riparian network was represented either as a contiguous, vegetated system with connectivity to its urbanized upland areas or as a fragmented and disconnected system. The connected buffer system provided greater hydrologic and water quality regulating capacity both locally and up to 10 km downstream. For example, modeled flood volume, depth and peak flows were 10% to 40% lower relative to the disconnected buffer scenario for storm events ranging up to 220 mm (100-year annual recurrence interval). Likewise, predicted nutrient and sediment concentrations were 2 to 5 times lower for the contiguous, connected riparian corridor compared to the fragmented and disconnected riparian system. Carbon sequestration benefits were also greater for the connected buffer, while carbon losses in the developed scenario outweighed sequestration potential . Efforts to use the results of this study to bolster riparian buffer policy in the Kansas City region will be discussed.

ABSTRACT. Methods for reclamation of mined lands and waters, although well-established, often do not lead to ecological restoration and are confounded at sites requiring remediation of hazardous materials. Despite decarbonization efforts and decreases in traditional (e.g., coal) mining activity, the global transition to a renewable energy economy requires continued mining of rare earth elements and other resources. Ecologically engineered nature-based solutions (NBS) are key to building a sustainable future. Much can be learned from NBS applications at abandoned mine sites. Surface and ground waters in the Tar Creek (Kansas-Oklahoma, USA) watershed of the historic Tri-State Lead-Zinc Mining District were deemed to be degraded due to "irreversible man-made damages" 40 years ago, an administrative decision resulting in minimal efforts to address risk from legacy mine waters. Artesian flowing mine waters and tailings pile leachate and runoff contribute elevated ecotoxic metals concentrations to receiving streams. Two full-scale, ecologically engineered passive treatment systems, installed in 2008 and 2017, produce circumneutral pH, net alkaline effluents containing ecotoxic metals concentrations meeting in-stream water quality criteria. Each system includes multiple ecosystem process units designed for specific biogeochemical functions. Annually, the two systems collectively retain approximately 72000 kg iron, 3100 kg zinc, 85 kg lead, 27 kg arsenic, and 8 kg cadmium. The receiving stream has demonstrated substantial water chemical composition improvement and ecological recovery, with documented increases in both fish community richness and abundance, as well as the return of North American beaver and river otter, with no in-stream habitat restoration. Coupling remediation and restoration is possible.

ABSTRACT. Constructed wetlands (CWs) are well-proven ecologically engineered systems that remove nutrients, pathogens, and other contaminants from wastewater. The inherent role of CWs as wastewater polishing systems makes them hotspots for microplastic accumulation. In order to investigate the transport and characteristics of microplastic pollution in full-scale municipal CWs, environmental microplastic samples were collected in the Se7en Wetlands in Lakeland (Florida), one of the largest wastewater CWs in the US (650 hectares). The samples include both water and sediment samples collected at all 11 control stations in each of the seven wetland cells and at six locations in the influent distribution channel to emphasize the importance of the water-sediment linkage in microplastic fate and transport. This study found that the Se7en Wetlands has a near complete retention of microplastics. Microplastic concentrations ranged from 0 to 16.8 particles/m3 in water and 0 to 332 particles/kg dry sediment in sediment. Microplastics were also analyzed for size, shape, and polymer type to inform how their properties change as they travel through the system. Polyethylene and polypropylene were the most abundant polymer types with the highest proportion of particles being fragments between 1-5 mm in size. Particle circularity and solidity in water were found to decrease through the treatment stream, while sediment samples saw no clear trend in shape characteristics. Overall, this study finds that large CWs retain a vast amount of microplastics and that settling is an important characteristic of microplastic transport through these systems.

ABSTRACT. The International Panel on Climate Change (IPCC) has promoted wetlands as “high-carbon ecosystems” with a potential to store carbon as a climate mitigation strategy. Long-term carbon sequestration rates for natural wetlands have been documented, but it is unknown how constructed wetlands sequester carbon long-term. The Olentangy River Wetland Research Park (ORWRP) at Ohio State University is an ideal location to address this knowledge gap with extensive datasets collected over 30 years. We used soil core samples taken across two constructed freshwater wetlands to quantify carbon storages, and paired this data with similar studies at 18-month, 10-year, and 15-year milestones to create a timeline of carbon sequestration across 30 years. Our findings suggest that both wetlands have sequestered relatively equal amounts of carbon since construction and neither have shown a net gain or loss since year 15. Results indicate that these wetlands have reached stability and are not expected to exhibit future net carbon gains or losses under current conditions.

ABSTRACT. Legacy impacts of the historic Tri-State Lead-Zinc Mining District (Missouri, Kansas, and Oklahoma) include elevated trace metal concentrations in various environmental media. The ecologically engineered Mayer Ranch Passive Treatment System (PTS), installed in 2008, addresses artesian mine water sources, retaining more than 90% of targeted contaminants via various biogeochemical mechanisms in 10 process units. The design included two parallel vegetated surface-flow wetlands. After excessively high water levels in 2019 resulted in vegetation loss, one wetland was replanted in 2020 with common cattail (Typha latifolia) and the other was left unplanted. Water quality has been monitored for 15 years, but limited evaluation of ecological processes has occurred. This research investigated the role of phytoextraction (plant uptake of trace metals) and resulting potential risk. Water, soil, root, rhizome, and shoot biomass were collected from the replanted wetland and analyzed for trace metals. Estimated ingestion rates and resulting hazard quotients (HQs) were used to assess potential risk to muskrats (Ondatra zibethica). Effluent water quality data indicated that both wetlands effectively retained Cd, Fe, Pb, and Zn from the water. However, in comparison to annual mass retention, presence of cattails showed little effect. Soil and cattail roots, rhizomes, and shoots showed elevated levels of Cd, Fe, Pb, and Zn, with the greatest biomass concentrations in the roots. HQs for muskrats consuming shoots and rhizomes were elevated for Cd (27), Fe (298), Pb (6), and Zn (13). This potential risk to wildlife should be considered when emergent vegetation is included in mine water PTS design.

ABSTRACT. The use of low impact best management practices, such as constructed treatment wetlands, as a secondary treatment method for wastewater effluent from package treatment plants and distillery stillage has potential to be innovate, sustainable method for improving water quality in the Central Kentucky region. However, the use of constructed wetlands to treat stillage and wastewater treatment plant effluent is limited. Therefore, the objectives of this study were to: 1. Quantify constructed wetland removal potential as a secondary treatment method a distillery’s wastewater; 2. Explore the potential to utilize constructed treatment wetlands to remove nutrients from bourbon stillage; 3. Optimize treatment design to meet wastewater effluent discharge limits. Four free water surface flow treatment wetland mesocosm experiments were completed during the summer of 2023. Denitrifying conditions were measured along with collection of daily water quality grab samples over the 10-day experiments. The constructed wetlands removed nitrate-N between 50 to 99%, E. coli 99%, and phosphate-P between 61 to 99%, depending on influent and period of the growing season. Similarly, nitrate-N removal rates ranged between 0.08 to 2.41 /day depending on influent and period in the growing season. Bourbon stillage was found to enhance removal of nutrients when added to the wetlands in combination with the wastewater effluent. Findings support constructed treatment wetlands as a potential mechanism for secondary treatment for distillery wastewater and bourbon stillage.

ABSTRACT. Increased water demands have pushed utilities into tapping non-pristine water sources. After blending with other sources, the effluent-dominated Santa Ana River is part of the drinking water supply for 2.5 million people in arid southern California. Nitrate is expensive to remove with conventional techniques so 1998 saw the construction of the 23 cell, 500-acre Prado constructed treatment wetland designed to remove nitrate from up to 2 m3/s (~ 32,000 gpm) diverted from the river. Over the 24 years, ~1,200 tons of NO3-N have been permanently removed from the river and released as N2-gas. Summer inflow averaged 6.1 mg-N/L and outflow 3.7 mg-N/L - efficiency 57% (winter efficiency 45%). All-year rates were 129 mg NO3-N/m2/d (apparent “k” 47 g/m2/y) - a reasonable performance considering the short water retention time (2-4 days; loading rate 10-20 cm/) and its configuration for both nitrate removal and duck hunting (= more open water). The treatment of large rivers like the Mississippi, Rhine, Thames will require very large treatment wetland and will need to become public parks, flood control, & hunting areas as well.

ABSTRACT. Harmful algal blooms (HABs) present an increasingly concerning issue both in the Great Lakes region of the United States and across the globe, posing a significant risk to both human and ecosystem health. The annual blooms seen in the Western Lake Erie Basin (WLEB) are driven largely by non-point source nutrient pollution, particularly phosphorous export from agricultural fields. Numerous governmental programs have sought to incentivize the implementation of best management practices (BMPs) that limit phosphorous export. These programs often provide cost-sharing incentives to meet the gap between landowners’ individual ability to pay for and the monetary costs of BMP implementation. One decision-making tool utilized by federal conservation planners to evaluate the potential for a BMP to address the resource concerns on a given land area is the Stewardship Tool for Environmental Performance (STEP). While arguably more accessible and field-specific than more intensive modelling tools such as SWAT, STEP utilizes nutrient export risk thresholds established using nationally aggregated data, creating concern for its applicability in the WLEB. This study aims to assess the ability and accessibility of STEP to effectively evaluate the likelihood of nutrient runoff under different management scenarios in sensitive watersheds. Edge-of-field monitoring data was input into STEP to compare its output with varying agronomic management techniques and subsequent environmental outcomes. The results of this effort will be used to inform the use of decision-making tools in conservation planning.

ABSTRACT. Non-perennial streams, or streams that dry regularly, comprise over 50% of the global river network and influence the physical, chemical, and biological characteristics of downstream waters. In the southeastern US, non-perennial streams often occur in the headwaters of river networks, yet <5% of stream gages in the region actually capture drying due to placement bias towards perennial systems. Despite our understanding of these headwater systems being data-limited, we predict the spatial heterogeneity of watershed features that control streamflow generation plays a key role in spatial and temporal variation in streamflow persistence. Our goal is to develop a predictive understanding of spatiotemporal patterns of stream drying across watersheds representative of three physiographic regions in Alabama: the Coastal Plain, Piedmont, and Cumberland Plateau. To do so, we characterized longitudinal network connectivity over two annual drying cycles with empirical water presence sensor data dispersed at 20 locations throughout each watershed. We also characterized watershed structural features, including elevation, slope, and valley shape, using publicly available data. With the combination of these datasets, we evaluated the spatial and temporal patterns of network drying to identify potential drivers among the watershed features. Our initial results suggest that each physiographic region has a drying regime driven by unique watershed attributes, and that within watersheds, heterogeneity in those attributes drives the spatial patterns of drying. Our work provides insight into the drivers of stream drying in the Southeast, better informing our understanding of the structure and function of these important stream networks that are not fully understood.

ABSTRACT. Light availability on freshwater surfaces is important for water quality and aquatic ecosystem metabolism. This light directly impacts the amount of photosynthesis that occurs, which influences the nitrogen and carbon cycling. The amount of sunlight that reaches the surfaces of water bodies depends on atmospheric conditions, topography, channel azimuth, and the density of canopy cover. Estimating light availability for a single location is challenging as it requires deploying high-frequency light monitoring sensors. However, estimating light availability at a larger scale can also be challenging and requires modeling to extract estimates. Here we present results from an adapted version of StreamLight applied to the Contiguous United States. StreamLight is driven by in situ measurements for site parameters and uses remotely sensed and modeled data for downwelling shortwave radiation flux, leaf area index, and riparian canopy height. If in situ measurements are not available, StreamLight assumes that the channel conditions are bankfull with steep slopes. Our adapted version of StreamLight is fully driven by remotely sensed data and model driven hydraulic geometry estimates to approximate river water and channel geometry. The results show the distribution of light availability in terms of photosynthetic active radiation for river networks across the United States. Future research efforts to determine model improvements by analyzing readily available in-situ measurements will also be discussed.

ABSTRACT. Best Management Practices (BMPs) are implemented in agricultural and urban landscapes to reduce nutrients in individual parcels. However, BMPs effectiveness at reducing watershed-wide regions remains an open question. Besides, lake regulations control water quality in lakes and downstream waters. This study aims at evaluating the effectiveness of BMP implementations in reducing watershed-wide phosphorus and nitrogen loads and identifying optimal discharges to mitigate lake nutrient exports. Lake Okeechobee was used as a case-study connecting a large watershed, 10,600 km2 of agricultural and urban lands, with two estuaries. Hydrological and nutrient transport processes in the watershed were simulated using Watershed Assessment Model, while Lake Operation Optimization of Nutrient Exports was employed to model lake water-balance and nutrient dynamics. Four watershed-wide BMP implementation scenarios were simulated: No-BMPs, current conditions (1032 km2), maximum potential scenario (5923 km2), and optimal BMP placement. Simulations suggested that current BMPs reduce phosphorus and nitrogen loads by 3% and 13%, respectively. Further implementation of BMPs could reduce phosphorus and nitrogen by 37% and 31%, respectively. Optimal BMP distributions would reduce phosphorus and nitrogen by 12% and 6% while maintaining cost-effectiveness. Additionally, we evaluated the effects of these nutrient reductions on Lake Okeechobee nutrient exports. Optimal Lake discharges were identified that could reduce phosphorus and nitrogen loads into Caloosahatchee and St. Lucie by 26-48% associated with different watershed management scenarios. Overall, the integration of watershed management with lake operations emerges as a promising approach to enhance water quality not only within Lake Okeechobee but also in Caloosahatchee and St. Lucie.

ABSTRACT. In gravel bed rivers, excess deposition of fines is considered a contributor to habitat degradation for aquatic biota. Embeddedness is the extent to which these fine sediments (>2mm) accumulate around coarser stream substrate. This metric is commonly used when assessing habitat quality in gravel bed streams and is physically measured as an average for a stream reach. Currently, there are no widely used methods to estimate or predict embeddedness from remotely sensed data.

Our results from Virginia and North Carolina show that we can calculate bankfull shear velocity and predict embeddedness from publicly available, remotely sensed stream variables. We further analyzed embeddedness correlations with biota, and the predictive capability of our model across the U.S. with the Environmental Protection Agency’s National Rivers and Stream Assessment data sets, which include a multitude of physical habitat, fish, and macroinvertebrate measurements.

We demonstrate that embeddedness can generally be predicted across the U.S. with a +/-15% error. Also, we found negative correlations in selected regions between embeddedness and intolerant fish taxa (R2 = 0.42) and EPT (Ephemeroptera, Plecoptera, and Trichoptera) macroinvertebrate individuals (R2 = 0.38). We are measuring embeddedness at a few sites in Virginia to examine how embeddedness changes over time in response to changing flow conditions and to what extent our predictive relationship holds. Ultimately, we can make predictions of embeddedness throughout entire gravel-bedded river networks, which can lead to more robust assessments of aquatic habitat and biota.

ABSTRACT. Water monitoring for PFAS in drinking water has primarily focused on community water systems, with limited attention given to private drinking water wells. Private well water quality is a significant concern due to minimal treatment before consumption, existing rural health disparities, and emerging health concerns associated with chronic exposure to very low PFAS levels. This study aims to address this gap by: 1) identifying patterns of PFAS incidence in water from private wells in Montgomery County, Virginia; 2) comparing PFAS concentrations using solid phase extraction (SPE) versus direct injection (DI) methodologies; and 3) establishing an integrated research-Cooperative Extension model for future PFAS monitoring campaigns in rural communities. Participants are recruited via an existing private well stewardship program through Cooperative Extension and provided kits to collect water samples at the point of use (i.e., kitchen faucet). Surveys covering water, well, and septic system characteristics, household demographics, and prior PFAS knowledge are also collected. Sampling began in December 2023 and is expected to continue through 2024. Among the 45 initial participants, common PFAS products included aluminum foil, sunscreen, and nonstick cookware. The average well depth was 408 feet, and the most prevalent treatment units were water softeners (n=31) and sediment filters (n=14). One fifth of homes (20%) reported an unpleasant taste, odor, or appearance in their water. Preliminary results show that 29% of participants' samples violated at least one health-based or aesthetic drinking water standard, with detectable lead in 86% of samples. PFAS results are forthcoming (available by conference).

ABSTRACT. Agricultural drainage channels are an essential means for transporting excess runoff from agricultural fields to a receiving water. In the Western Lake Erie Basin, agricultural drainage channels are essential for maintaining crop health due to the poorly drained nature of the soils and low topographic relief. This creates downstream water quality issues due to sediment and nutrient transport in the agricultural runoff, which have the potential to be controlled based on the design of the channel (i.e. two-stage ditches and self-forming channels). In this study, upstream-downstream water quality monitoring was conducted in agricultural channels with automated ISCO 6712 samplers used to obtain samples of wet weather flows. Water quality signatures of each channel will be established and then the channel shape will be modified to encourage sediment and nutrient deposition. Post-construction monitoring will be used to compare the effectiveness of the conservation channel designs and the differences in water quality. Hydrologic data and multiple storm event samples were captured from sites across Northwest Ohio in the first year of pre-construction monitoring that will allow us to establish baseline nutrient loading values for the respective channels before construction. In the future this will allow for a more in depth understanding of the nutrient reduction potential of conservation channel design practices in agricultural settings.

ABSTRACT. Infiltration rates of soils are important for determining water management practices in both agricultural and urban areas.  For example, the effectiveness of urban low impact development practices like bioretention basins and stormwater wetlands are substantially impacted by the fraction of water that infiltrates.  It has been long established that vegetation in these sites influences its hydrological characteristics. However, previously conducted studies on the role of plant roots in affecting infiltration have yielded conflicting results on which root type is more conducive to infiltration.  Research was found supporting the hypothesis that tap roots have the greatest influence on infiltration rates, while refuting research found that fibrous roots have the greatest influence. Additionally, research has largely utilized new bioretention and wetland sites; therefore, the effects of wetland plants in the long-term are largely unknown. Our project aims to clarify the influence of vegetation on infiltration in established bioretention and wetland sites while developing methods for a citizen science approach to assessing infiltration rates due to plants.  Infiltration rates over multiple types of vegetation and bare soil were measured at multiple established bioretention and wetland sites. An increased rate of infiltration when plant roots are present was observed, with the greatest infiltration rates being in the presence of tap roots. Significant differences are expected to be seen based on plant type and site characterization as more locations are added. Ultimately, this research will characterize plant root impacts on infiltration, which allows for more detailed infiltration models to be built based on plant type.

ABSTRACT. Stormwater management on the University of Maryland campus currently involves campus facilities employees physically driving to each green infrastructure spot and taking photos to document the state of each site. This process can be time consuming and is overall inefficient. To save resources and improve efficiency, this project is digitizing this process by placing cloud-linked soil moisture sensors in stormwater infrastructure, such as bioretention ponds and rain gardens. The sensors transmit soil moisture data to a dashboard that displays the data. Data trends alert campus facility employees when a bioretention site is experiencing saturation over a sustained period. The project results will be presented, including data analytics utilized and how the results can be used to increase efficient stormwater management and increase technology usage in the field.

ABSTRACT. Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic compounds known as “forever chemicals,” due to their persistence in the environment. PFAS are used as an additive in various industrial and household applications, including rain protective clothing, fire retardants, food packaging, and have multiple pathways into water and soil. Exposure to PFAS can disrupt endocrine systems in various ways, e.g. reducing reproduction of aquatic organisms, increasing the risk of cancer in humans. Given the emergent threat posed by PFAS exposure, the US Environmental Protection Agency (USEPA) has begun monitoring PFAS concentrations, particularly at identified high risk areas such as PFAS production sites and centralized water treatment facilities, with plans for future mandatory monitoring and remediation. Because private drinking supplies such as wells are outside the USEPA’s purview, data describing PFAS contamination in drinking water in rural areas where reliance on private wells is common is limited. This effort aims to merge data from multiple ongoing PFAS surveillance efforts, along with accompanying household survey and additional metadata, into a single, interactive database format. A database format allows for a deeper understanding of the geospatial aspects of PFAS incidence in private drinking water systems can assist environmental regulators and public health authorities in creating effective policy and communication materials for the public. This database will serve as the foundation for future efforts to collect more PFAS data, and more critically, to explore patterns of incidence across Virginia.

ABSTRACT. Per and Poly-Fluoroalkyl substances (PFAS) are synthetic chemicals used in a variety of applications that persist in the environment. The extent of their presence in stormwater systems is relatively unknown. This research aims to understand the occurrence and sources of PFAS in the stormwater systems of four Virginia coastal communities selected using a combination of GIS infrastructure data and EPA’s Environmental Justice Screening and Mapping Tool (EJScreen). Water and sediment from the targeted sites of the stormwater systems of the four communities were collected. Samples were collected once at base flow, and then before and after a storm event and then analyzed for 30 PFAS using the EPA method 1633. All water and sediment samples contained PFAS, ranging from 22-692 ppt, and 455-8918 ppt (dry weight basis), respectively. Total PFAS concentrations were slightly lower in the post storm water samples compared to the baseline and pre-storm water samples. Total PFAS levels in sediment were similar comparing pre- and post-storm. The PFAS levels in the sediment pore water ranged from 33-1330 ppt, 2.5 times higher than those in the free-flowing water samples, suggesting sediment can be a long-term reservoir for PFAS and has the potential to continuously release of PFAS back into the water when the partition equilibrium is disturbed, for example, by storm events. Further research is needed to compare results to other communities and understand the release mechanisms of PFAS accumulated in the sediment.

ABSTRACT. The Upper Scioto River Watershed drains 6,513 mi2 and supplies water to Columbus, Ohio, and eventually drains to the Gulf of Mexico. Runoff from agriculture fields in this watershed contributes to water quality issues in the Gulf of Mexico, such as the second largest hypoxic zone worldwide. Agricultural fertilizers contain nutrients like nitrate-nitrogen that can runoff and impact drinking water supplies and contribute to downstream eutrophication. While conservation practices are often used to reduce runoff, there is a pressing need for methods that will allow us to predict optimal locations for these practices to maximize water quality gains. The Upper Scioto River Watershed experiences recurrent spikes in the levels of nitrate-nitrogen contained in runoff; therefore, it is imperative that this watershed is evaluated for conservation practices to improve water quality. This study will evaluate the ability of ACPF(Agricultural Conservation Planning Framework) to predict locations for conservation practices and impacts of adjusting ACPF parameters upon these locations and water quality improvements. ArcGIS (Geographic Information System) Pro and the ACPF Tool will be used in conjunction to identify three parameter sets for locating different locations for conservation practices. Afterwards, these three maps of conservation practices will be evaluated with SWAT (Soil and Water Assessment Tool) to determine impacts on water quality. We expect results will identify parameter sets for ACPF that will identify the most advantageous locations for conservation practices.

ABSTRACT. Freshwater harmful algal blooms (HABs) occur worldwide and in many cases are dominated by cyanobacteria. In freshwater systems, alterations to ecological conditions and increased stressors of climatic extremes are believed to intensify cyanobacterial HABs. Under specific conditions cyanobacterial blooms may release harmful toxins to the surrounding environment. Toxins associated with HABs pose health risks to humans and animals and subsequent closures of public waters negatively impact local economies. Cyanobacterial HABs have been documented and monitored in several Kansas reservoirs, including Marion Reservoir. This research aims to explore the relationships among environmental variables and bloom responses to better understand the occurrence of cyanobacterial HABs in Marion Reservoir. Site specific monitoring data and supplemental environmental datasets will be analyzed and utilized to inform watershed (SWAT), lake (GLM), and cyanobacteria growth models. Collected monitoring data includes discrete, spatially distributed water quality samples and continuous, in-lake monitoring with a multiparameter sensor. Model development efforts aim to better understand how watershed management effects runoff characteristics, and how the magnitude and timing of nutrients delivered from the watershed combine with internal lake processes to influence the occurrence of cyanobacterial HABs in Marion Reservoir. This work is intended to advance applications of coupled watershed-lake modeling to cyanobacterial bloom prediction and to provide insights to waterbody managers regarding the timing and duration of blooms. Ultimately, this work will contribute to efforts to improve management responses to cyanobacterial HABs.

ABSTRACT. Contamination from plastic packaging and other emerging contaminants is a key challenge for food waste diversion efforts. Many studies have used life cycle assessment (LCA) to evaluate the environmental impact of different food waste management strategies, yet few have quantified flows of nutrients and microplastics associated with each scenario. We coupled traditional LCA with materials flow analysis in a novel ecological accounting approach to evaluate the environmental impact associated with managing food waste streams by 1) composting, 2) anaerobic digestion and 3) landfilling. A mass balance-based process model was used to estimate the energy, C, N, P, and plastic flows associated with each strategy. Two distinct food waste streams were modelled: a packaged pre-consumer waste stream and a source-separated post-consumer was stream. Model outputs were transferred to OpenLCA for impact analysis using the ReCipE 2016 midpoint metrics “global warming potential”, “freshwater eutrophication potential” and “marine eutrophication potential”. A novel impact category “microplastic pollution” represents the flow of microplastics to agricultural soils under each management scenario. Key uncertainties in model parameters were evaluated using MonteCarlo simulation, generating a distribution of values for each impact category. Together, these metrics illustrate the environmental tradeoffs associated with each scenario and can help policymakers and waste management practitioners determine the optimal management strategy for different food waste streams.

ABSTRACT. Excess fine sediment deposition (<2mm) is harmful to river ecosystems. Increased human-induced, land-use change and activity has increased the input of fine sediments in river systems causing high embeddedness in gravel streambeds that deteriorates habitats vital to aquatic species. Fish have a variety of responses in their sensitivity to fine sediments which influences population outcomes. Fish that are sensitive to embeddedness that rely on low embeddedness for survival are threatened by increased embeddedness in gravel streambeds. With embeddedness emerging as a predictor of aquatic species and the difficulty in accurately measuring embeddedness in the field, it would be beneficial to predict embeddedness from remotely sensed variables. This study examines the potential of using the National Hydrology Dataset to calculate embeddedness throughout a reach using bankfull shear velocity, where bankfull shear velocity is calculated from bankfull depth and channel slope, calculated using hydraulic geometry relationships and provided by the dataset, respectively. Estimates of bankfull shear velocity can then be used to predict embeddedness. The main focus of this study is to use network-scale predictions of embeddedness to assess whether some aggregated statistics of the embeddedness values within a neighborhood of a biotic measurement is more predictive of sediment-sensitive species than the “point” field measurement of embeddedness. We focus our study area to sites in the Piedmont region of Virginia and North Carolina. Being able to quickly determine potential locations of sediment sensitive aquatic species will be important to protecting aquatic species and improving future restoration efforts.

ABSTRACT. A primary goal of many stormwater best management practices (BMPs) is to reduce nutrient loading from runoff into aquatic ecosystems. While these practices can demonstrate local benefits to water quality in some cases, the overall environmental benefits and burdens of BMPs are infrequently assessed. The background life cycle impacts of a BMP include five stages: acquiring raw materials, transporting the materials to the construction site, construction activity, maintenance, and end-of-life treatment (e.g., landfill disposal). In some cases, the lifetime nutrient removal achieved by the system in the foreground may not exceed the embodied background nutrient emissions to the environment. In this study, two stormwater sand filters with media comprised of 95-97% sand and 3-5% drinking water treatment residuals (DWTRs) were monitored in the field to inform estimates of phosphorus load removal performance. In tandem, life cycle analysis (LCA) was conducted using openLCA to estimate the embodied freshwater eutrophication potential (FEP) for the five stages of the BMP’s life cycle, using Monte Carlo analysis to account for uncertainty. Preliminary results indicate that it is highly likely the sand filter systems enhanced with DWTRs could provide a net benefit for global freshwater sources.

ABSTRACT. The city of Greenbelt in Prince George’s County, Maryland was a novel planned community founded in the 1930s under President Roosevelt’s New Deal. From 1935-1937, local businesses and residential sites were constructed to support the economy. This development contained impervious surfaces that have led to increased runoff and pollution for the local Greenbelt Lake, which in turn feeds into Indian Creek and the Anacostia River, tributaries of the Chesapeake Bay. To mitigate excess runoff, this project assesses the stormwater management at the City of Greenbelt’s “Roosevelt Center” and proposes a solution including best management practices as applicable to the site. Data will be presented on the percent impervious acreage, volumes, and rate of flow into the creek and Greenbelt lake/Anacostia River tributaries to estimate the amount of stormwater impacting this system. The research aims to develop a technical design and plan to maximize infiltration on-site and channel precipitation into local waterways by reducing polluted runoff and sediment loads and nutrient pollution by staying within Total Maximum Daily Loads(TMDLs) benchmarks for the region. The proposed design uses ecological engineering as a solution including many Best Management Practices(BMPs) such as bioswales, green roofs, rain gardens/bioretention, regrading existing parking lots, and adding cisterns along the edge of commercial buildings. The BMP recommendations will be tailored to best support the local watershed, high visibility aesthetics, and habitat value and survivorship to the environmental conditions. Design plans for this effort will be presented alongside TMDL credits for the city of Greenbelt.

ABSTRACT. Urbanization results in increased impervious surfaces, leading to changes in stormwater quantity, rates, and timing. Stormwater management (SWM) practice using storage ponds was originally developed to reduce flood peaks, without addressing increases in the runoff volume, resulting in increased downstream channel erosion. This prompted revisions to stormwater regulations, with a focus on encouraging the infiltration of stormwater. Environmental Site Design (ESD) employs multiple distributed practices to increase infiltration and hydrograph lag time. To evaluate the impact of ESD on watershed hydrology, a Storm Water Management Model (SWMM) was developed, calibrated, and validated for the Minebank Run watershed in Maryland, which was urbanized prior to the development of stormwater regulations. The model was used to simulate the impacts of developing the watershed with SWM. Three hypothetical scenarios were evaluated reflecting different approaches to SWM - storage ponds only, ESD only, and a combination of both storage ponds and ESD. Study results indicate that if Minebank Run had been developed with ESD, annual maximum peak flows would be 49.6% lower. While the ponds-only scenario yielded a 43.6% reduction, combining ESD with ponds resulted in a 52% reduction. This study aids in identifying an optimal combination of storage and infiltration practices that lead to noticeable reduction in peak flows at a watershed scale.

ABSTRACT. Duckweeds, the small, free-floating, aquatic plants of the family Lemnaceae, have demonstrated abilities as phytoremediators of nutrients, metals, and organic pollutants. Phytoremediation is a function of plants and their associated microbiota. Plant exudates play a large role in influencing microbial community composition. Understanding duckweed exudates is therefore an important strategy for improving phytoremediation. Our research indicates that exudate profiles of duckweed depend on species as well as geographic source. Larger differences in exudate profiles were observed between geographic source than between species; despite sterilization and laboratory acclimation. Additionally, the sterile duckweed from multiple sources were inoculated with identical microbial communities, and significant differences in exudate profiles were still observed. This further indicates that exudate profiles are more strongly affected by the source environment than by microbial community. We will build upon this initial finding, and introduce sulfamethoxazole (SMX), a common antibiotic contaminant of aquatic systems to our exudate experiments. We expect to observe conjugate species of SMX similar to those already reported in a similar experiment utilizing Arabidopsis. We also expect to see increased exudation of stress-related compounds. SMX would greatly affect the native microbiome, therefore future work will examine the relationship between the release of these conjugate species and other signaling secondary metabolites with microbial community composition.

ABSTRACT. The West Virginia Water Research Institute has been monitoring water quality in the Monongahela River Basin since 2009 through its Three Rivers Quest (3RQ) initiative. Working alongside coal mines, 3RQ aims to reduce acid mine drainage (AMD) discharge during low flow periods to lessen its negative impact on water quality. To date, there has not been a substantial analysis of the water quality data. The purpose of this study was to examine 3RQ data for trends in the water quality of the Monongahela River Basin. Temperature, pH, electrical conductivity, and total dissolved solids (TDS) were measured monthly during 2009-2023 from 18 monitoring sites. River discharge was recorded from a USGS gage when available and calculated when needed. Statistical analysis was completed using R and consisted of non-parametric Mann-Kendall and seasonal Kendall tests to determine if there were monotonic trends (i.e., increasing trend, decreasing trend, or no significant trend). An alpha of 0.1 was assumed. In this acid mine drainage impacted region, pH increased at 10 sites (> 50% of sites), electrical conductivity decreased at 10 sites (> 50% of sites), and TDS decreased at 12 sites (> 65% of sites). Few trends in temperature were observed. Evidence presented through this study supports the continuation of long-term water quality monitoring programs like 3RQ. This initial analysis will be expanded to evaluate trends of additional water quality parameters. In addition, the downstream water quality signal in response to varying AMD treatment strategies (e.g., centralized versus distributed) will be evaluated.

ABSTRACT. Arundinaria gigantea, or rivercane (a native grass), is considered a culturally important species to Native American communities who use it for sacred ceremonies, tool making, and hunting and gathering purposes. Established rivercane stands can grow into a dense configuration called a canebrake, an important riparian ecosystem in the southeast and southcentral United States, which have an interlocking rhizomic root structure with excellent soil stabilization potential. Less than 2% of original rivercane ecosystems still exist in U.S. Considering the known cultural and ecological importance of this species, rivercane restoration has potential to serve as a multi-benefit nature-based solution (NBS) to help address environmental issues associated with urbanization, climate variability and other stressors. The watershed-based model Gridded Surface/Subsurface Hydrologic Analysis (GSSHA) may help evaluate the NBS role of rivercane. GSSHA is a US Army Corps of Engineers-developed multi-dimensional physics-based hydrologic simulation of physical processes, impacts of restoration alternatives, and methods for decreasing or preventing pollution to surface water. GSSHA allows assessment of the effects of NBS like rivercane restoration or wetland creation on water quality and quantity in riparian settings. The objectives for this effort are to create a calibrated and validated hydrologic model representative of the study site (Illinois River basin of Oklahoma and Arkansas) and evaluate riparian NBS for water quality improvement, flood mitigation, and ecosystem restoration.

ABSTRACT. The release of excessive nutrients, including nitrogen (N), from agriculture and other anthropogenic activities has become a great concern over the past few decades. The discharge of legacy N from springs in the Chesapeake Bay watershed contributes to eutrophication and hypoxic aquatic zones. Denitrifying bioreactors have been implemented primarily in tile-drained agricultural fields to mitigate excess nitrate in drainage water. The goal of this research is to determine if bioreactors may be a suitable option for mitigating groundwater derived legacy N from spring water. Specifically, we will explore the impacts of bioreactor substrate type and temperature on nitrate (NO3-N) removal. Unlike tile-drainage water, spring water maintains a cooler temperature year-round (10 – 15 °C) and a constant flow both of which are hypothesized to impact N removal performance. To test for N removal, we will conduct a laboratory-based bioreactor column study. Each bioreactor column (12 total) will receive local groundwater amended to achieve a concentration of 20 mg NO3-N/L at hydraulic retention times (HRTs) of 2, 5, or 8 hours. Treatment factors also include varying media type (woodchips or bark) and influent water temperature – room temperature (20-25 °C) or groundwater (10 – 15 °C) – in triplicate. Water quality parameters, including NO3-N, pH, dissolved oxygen concentration, conductivity, temperature, and oxidation reduction potential will be routinely measured from the influent and column effluent. We expect NO3-N removal rates to decrease as HRT and temperature decrease. Results from this study will inform future design and recommended operation of spring bioreactors.

ABSTRACT. With projections indicating a substantial increase in municipal solid waste (MSW) generation by 2050, the characterization of MSW serves as a fundamental input in designing bioenergy systems that can utilize this waste as an energy source. This study examined the characteristics of MSW for bioenergy production and is creating geographic and temporal mapping for understanding variations in bioenergy potential from different sources, including institutions, restaurants, grocery, and landfills. Quarterly samplings were conducted in locations throughout the US to assess waste composition across different seasons. MSW sample was characterized into 27 categories. Results showed that the food waste comprises the majority of MSW (36%), followed by paper (18%), yard waste (7%) mixed food and plastic (6%), cardboard (5), film plastics (5%). Seasonal variations revealed higher high moisture organics (HMOs) content in the entire sampling period of April to December 2023. The calorific value of MSW ranged from 19 – 29 MJ/kg, showing the bioenergy potential of this wasted material. The HMOs were quantified for bioenergy potential via anaerobic digestion to produce biogas, which can be used for renewable energy. The methane yields were 595, 420, 414 and 139 mL/g VS for grocery, restaurant, school, and landfill HMOs samples respectively. Findings of this study show that biological and thermal chemical energy conversion pathways for processing, treatment, and handling MSW could help maximize resource recovery, reduce environmental impact, and contribute to renewable energy production. Implementing strategies like source separation, anaerobic digestion and gasification is important for maximizing the benefits of a circular bioeconomy.

ABSTRACT. Green stormwater infrastructure (GSI) is a strategy increasingly used to manage runoff in cities. In addition to stormwater management, GSI also has potential to provide other ecosystem services; however, there is limited measurement of these other functions of interest, such as microclimate regulation, carbon sequestration, and cultural services. We have focused on GSI in Lancaster, PA, conducting fieldwork to gain insights into the effectiveness of GSI in providing multiple ecosystem benefits. Data has been collected at 20 bioswales, representing various sizes, ages, and vegetation characteristics; several lawns and parking lots were used as references. Here we will present insights from selected measured functions. Infiltration data was collected using a mini-disk infiltrometer. Soil samples were collected and analyzed for soil carbon and metals accumulation, and soil greenhouse gases were measured. Micro-climate characteristics were quantified using a portable heat stress sensor to calculate mean radiant temperature (MRT), which is a metric relevant to human heat stress. Additional data is being collected on vegetation diversity and cultural services. Preliminary data analysis substantial variability in infiltration rates. Soils data reveals that metals like zinc are being retained in the GSI inlet soils, facilitating water quality improvement. Soil carbon accumulation patterns are less clear. Micro-climate analysis indicates that GSI without trees do not demonstrate clear reductions in heat levels; however, GSI with trees and associated shade led to lower MRT levels. We hope that this study will help generate insights on some of the lesser-understood co-benefits of GSI in addition to primary stormwater management benefits.

ABSTRACT. As the impacts of climate change continue to intensify, the need for resilient watercourse crossings becomes increasingly evident. Our research examines the advantages of constructing watercourse crossings that can withstand environmental challenges while improving ecological connectivity and promoting safety. Due to land use changes and urban development, traditional infrastructure struggles to adapt to the escalating watershed alterations. The Southeast's vulnerability to severe flooding is compounded by a significant increase in heavy rainstorms. Furthermore, wildlife-vehicle collisions (WVCs) pose significant risks due to the ecosystem barrier effects of roads. Therefore, innovative solutions that balance infrastructure needs with ecological preservation are required. Our research proposes a paradigm shift in watercourse crossing design by integrating nature-based approaches and innovative engineering. Our recommendations aim to reduce flood risks, prevent WVC occurrences, and improve ecosystem connectivity. We use spatial multi-criteria decision analysis (MCDA) to identify optimal locations for upgrading watercourse crossings, considering landscape elements, underpasses, improved channel stability, and flood vulnerability assessments. This research examines the potential of resilient watercourse crossings to transform infrastructure by adapting to climate change, promoting environmental conservation, and enhancing community resilience. The MCDA matrix proposed in this work can be used as a tool to improve culvert design guidance, increasing the likelihood of achieving optimal resource allocation for culvert replacement or upgrades.

ABSTRACT. Persistent eutrophication threatens Lake Champlain water quality and reducing the phosphorus (P) load from the Vermont portion of the Lake Champlain Basin is required under a Total Maximum Daily Load established by the US EPA. Restoring riparian wetlands on former agricultural lands is considered a nature-based solution to reduce downstream P loading, but there is some uncertainty as to whether these systems will achieve net P retention. Quantifying both the particulate and dissolved pools of P within wetlands is important for accurate mass balance estimates. This study focuses on accretion and phosphorus content of particulates and organic matter deposited on wetlands during flood events. Prior to seasonal flooding at these sites, ceramic tiles and artificial turf pads were installed at five restored wetland sites within two watersheds in the Lake Champlain Basin to collect sediment and organics accretion. Accretion samples were dried and weighed, then analyzed for loss-on-ignition, total P, inorganic P, and organic P. These data highlight spatial and temporal variability in the bulk mass and P content of accretion between sites and across two sub-watersheds over two years of flood monitoring and include results from Vermont’s historic severe flooding in July 2023.

ABSTRACT. Riparian wetlands buffer nutrient movement from runoff and impact downstream water quality. Soluble reactive phosphorus (SRP) is a plant-available, water-soluble form of inorganic phosphorus. Phosphorus (P) can be a limiting nutrient in freshwater ecosystems, and excess P loading can result in a cascade of ecological disturbances, including eutrophication. Riparian wetlands can serve as a sink or source of SRP and can contribute to nutrient loading downstream under certain conditions. The purpose of this study was to determine the effects of aerobic and anaerobic conditions on SRP dynamics in flooded, restored riparian wetland soils with a history of agricultural use. Intact core incubation experiments were conducted to simulate the potential P flux from soils into surface waters under different flood conditions across four wetland sites in the Lake Champlain Basin, Vermont. Two treatment groups of submerged soil cores from each plot were treated with either room air (oxygen) to simulate well-oxygenated conditions, or nitrogen gas to create anaerobic conditions for fourteen days. We observed within and across site variation in SRP release under the two treatments. A comparison of laboratory results with field samples collected during three years of water quality monitoring during flood events provides context for field results and suggests positive outcomes for these restoration efforts.

ABSTRACT. Urbanization increases total impervious cover, which results in greater quantities of runoff. Grey infrastructure, including pipes and catch basins, dominates urban landscapes and contributes to the transport of pollutants into local waterways. Bioretention is a common form of green infrastructure (GI) which may be distributed throughout watersheds to help mitigate both runoff quality and quantity issues. High rate biofiltration (HRBF), an alternative to bioretention, has a higher hydraulic conductivity relative to bioretention allowing for the surface area of the filter to be reduced while still providing water quality improvement. HRBF systems are ideal for parking lots, which are substantial contributors to pollutant generation. A review of HRBF design and function will be reported on in this poster, along with the results of a recent field monitoring HRBF study in a marina parking lot in Huron, Ohio. In this study, the sequestration of metals, TSS, and particulate nutrients was observed, while relatively little treatment of dissolved nutrients occurred. Three HRBF systems, designed in collaboration with Advanced Drainage Systems (ADS), are to be installed in parking lots on Ohio State University’s campus in Columbus, Ohio. These will be highlighted in the poster as upcoming work. The intent of this study is to monitor water quality improvements provided by HRBF. One system will be planted with a tree while two will remain unplanted; media type and depth will be consistent between treatments. Results of the study will be used to understand how design choices affect the biofiltration efficiency of the HRBF.

ABSTRACT. Stormwater ponds in older developments are facing challenges related to shoreline erosion and sediment accumulation. Dredging to maintain pond functionality is a conventional engineering solution, but it is a reactive approach compared to more natural restoration alternatives. Given the prohibitive cost of dredging, a range of comparably low and moderate cost measures could be used to stabilize and naturalize a shoreline depending on the problem severity. To address these issues systematically, we developed the Pond Shoreline Assessment Tool (PSAT). PSAT offers an objective framework for evaluating and cataloging shoreline erosion and prioritizing restoration efforts. Here we present the Seaside Farms development with 13 stormwater ponds and approximately 6 miles of shoreline constructed approximately 20 years ago. Our initial observations, along with input from the community, highlighted a preference for nature-based solutions. This tool enables the HOA Board of Directors to allocate resources effectively and fairly, establish a timeline for addressing erosion, and thereby preserve the community’s environmental and aesthetic values. PSAT can be applied to stormwater ponds in other settings, and the supporting materials assist with landowner education.

ABSTRACT. Eutrophication is an increasingly concerning issue impacting the health of important bodies of water such as the Chesapeake Bay. When algae caused by eutrophication die, heterotrophic bacteria consume it. As their population expands, the oxygen levels in the water deplete. This results in what are known as “dead zones.” According to the Chesapeake Bay Program website, there was a 16 percent increase in nitrogen loads and a 38 percent increase in phosphorus loads in the Bay from 2020 to 2021. A significant contributor to this increase in nitrogen and phosphorus pollution in the Bay is runoff from impervious surfaces. This project is a proposal for the M-NCPPC parking lot located in Largo, Maryland to minimize impervious area and convert it to implement bioretention practices and create a usable space for the community. In order to do this, the smaller parking lot to the left of the main parking lot was transformed into a rain garden. Ideally, this garden will function as a pollutant filter that will reduce runoff by soaking up the excess nutrients. Research included investigation of topography and water flow, suitable trees and plants for the climate and harsh conditions, the area of impervious surface of the parking lot, county and state regulations and available credits, and long-term trends in rainfall. The hope for this project is not only to minimize the environmental impact of this building but also to serve as a framework for future projects for reducing runoff by transforming areas to incorporate best management practices.

ABSTRACT. In response to recurring harmful algal blooms in Harsha Lake (Clermont County, Ohio), this work seeks to improve water quality by means of a constructed riverine wetland complex. The wetland complex is located in the floodplain of the East Fork Little Miami River which drains to Harsha Lake and ultimately the Ohio River. Research objectives include: quantify wetland performance in terms of runoff retention and peak flow mitigation; determine sequestration of nutrients and solids; estimate ROI (e.g. lbs P removed/$ spent); estimate functional life to inform maintenance frequency. Wetland construction and instrumentation were completed in December 2022 and April 2023, respectively. The project made use of a retired drinking water reservoir to provide retention and slow release of water into the constructed wetland. The wetland complex is expected to provide stormwater storage and treatment during approximately 30 storm events per year. Flows into the wetland have been less frequent than expected due to early storm flow sedimentation which obstructed the wetland inlet, coupled with drought conditions in the months following construction. Progress to date includes: estimation of sediment buildup at inlet; Fall 2023 soil and vegetation nutrient analysis; 2 storm flow water quality sampling events (Winter 2024); baseflow water quality sampling (Winter-Spring 2024); initial characterization of wetland hydrology. Sedimentation at the inlet continues to be monitored and maintained; maintenance frequency is being assessed to ensure the inlet remains open for these types of floodplain wetlands. Wetland performance will continue to be evaluated through December 2024.

ABSTRACT. Excess phosphorus (P) contributes to the eutrophication of freshwater bodies and subsequent Harmful Algal Blooms (HAB). This is an increasingly urgent problem in freshwater systems globally, including the Lake Champlain Basin (LCB). Agriculture, including dairy farming, is a prominent part of the landscape within the LCB and contributes a significant portion of the P load entering Lake Champlain. There are promising edge-of-field practices that may reduce dissolve and total P loads from agricultural surface and subsurface runoff. A Conservation Effects Assessment Project (CEAP) Stacked Practices and Innovative Phosphorus Removal project was initiated as a field-scale study in 2021. The field study takes place in Bridport, Vermont. The study will evaluate the ‘stacking’ of multiple conservation practices at the field-scale including manure injection, no-till, cover cropping, and edge-of-field phosphorus removal technologies, including surface ditch filters and subsurface tile drain filters. Both filter systems are comprised of iron oxide material mixed with pea gravel with the goal of reducing dissolved and total P loads. Results of surface and subsurface flow monitoring from study fields will be presented, as well as updated performance data for the phosphorus removal structures.

ABSTRACT. This study addresses the treatment of sidestream wastewater originating from an aerobic digestor at a biological nutrient removal municipal wastewater treatment plant (WWTP) in eastern NC. The approach involves on-site pilot-scale implementation of a hybrid constructed wetland (HCW) to further remove nitrogen and phosphorous, crucial for addressing the high nutrient content in digester decant water (average ammonium and phosphate concentrations of 30.53 mg N/L and 353 mg P/L, respectively), which is returned to the head of the WWTP and responsible for decreasing the overall nutrient removal efficiency of the WWTP. HCWs, a novel approach predominantly used in Europe and Asia, incorporate various zones of vertical and horizontal subsurface flow as well as surface flow CWs. To tackle the nutrient challenge, on-site pilot-scale HCWs were established and monitored weekly beginning in October 2023. The aim was to identify the nutrient reduction efficacy through each stage of treatment. The system comprises multiple stages including: #1 pretreatment through an intermittently fed vertical flow gravel cell; #2 horizontal flow through zeolite; #3 horizontal flow through crushed concrete; #4 horizontal flow through a woodchip bioreactor; and finally, #5 a floating treatment wetland (FTW) planted with pickerelweed. Preliminary results show an average ammonium reduction of 99% and a phosphate reduction of 55%, with most of the ammonium reduction occurring in the zeolite cell and most of the phosphate reduction occurring in the crushed concrete cell. These preliminary results demonstrate the potential of hybrid CWs to address nutrient challenges as a supplementary treatment approach at WWTPs.

ABSTRACT. One important challenge for critical source management is field scale identification of soil wetness patterns. Several studies have used topographic indices (TI) to model wetness patterns. One approach has been using TI values for model parameterization -- where classifying TI values become a reasonable step to limit the number of unique landscape elements. However, there is a lack of recommendation on the optimum way for classification. In this work we used soil moisture data collected on 25 points across a 4-ha pasture field to inform TI classification. To identify soil wetness patterns clustering analysis is performed. The clustering analysis is used to identify multi-dimensional dissimilarities. The 25 soil moisture sampling locations form the number of observations and the days of sampling form the dimensions. We used Euclidean distance to calculate dissimilarities between soil moisture observations. The cluster analysis is based on k-means clustering. The optimum number of partitions are selected by using scree plot analysis. The outcome of the clustering analysis informed classification of TI values into classes. TI values are classified into the number of cluster groups identified from the clustering model. Using several classification approaches equal area, equal interval, and natural breaks three distinct TI classes are generated. Misclassification rate is then calculated by comparing the output of the clustering analysis, which is derived from measured soil moisture data, and class determination from the TI classification approaches. The analysis informed which TI classification approach provides optimum TI class characterization.

ABSTRACT. Aquaculture operations are challenged with effectively treating wastewater amidst increasingly stringent regulations aimed at reducing nutrient levels. As production scales up, the volume of waste also rises, compounding the challenge. To address this, a hybrid-constructed wetland system has been developed, utilizing various materials to optimize contaminant reduction within a limited space. This system, piloted in collaboration with the North Carolina State University Marine Aquaculture Research Center, tailors treatment methods to individual aquaculture facilities' needs and builds upon mesocosm scale research. Components include gravel beds for nitrification, concrete media for phosphate sorption, woodchips for denitrification, and floating wetlands for nitrogen and phosphorus uptake. Preliminary findings from Fall 2023 indicate successful nutrient removal across all parameters. Ongoing data analysis using ANA-pro spectrometer readings, in-field data loggers, and R-coded retrieval aims to solidify the efficacy and cost-effectiveness of this natural treatment approach for aquaculture wastewater.

ABSTRACT. Organophosphorus such as inositol phosphate (IP) may serve as a source for orthophosphate (OP) in freshwater. In the absence of OP, competent aquatic microorganisms up-regulate the production of specialized enzymes to obtain growth-sustaining OP from organic-P. The contribution from recalcitrant organic-P to the OP pool has been overlooked due to the lack of tools capable of accurately measuring OP production from organic-P. A study designed to quantify recalcitrant organic-P mineralization is underway. The objective is to quantify IP concentrations in streams draining agricultural and suburban watersheds, and to quantify OP production from IP, a surrogate form of recalcitrant organic-P. Experimental results showed that IP was found in sediments samples collected in downstream areas of agricultural fields. IP levels ranged between 2 and 5% of the total organic-P extracted from these sediments, highlighting the availability of recalcitrant P in freshwaters. No significant levels of IP were found in water and sediment samples receiving water from a wastewater treatment plant. A fluorescence probe serving as a substrate analog for phytic acid was used to measure enzymatic activity for IP mineralization to accurately quantify OP production from IP. Results from microcosms experiments operated under different conditions (i.e., aerobic vs. anaerobic) showed that IP mineralization was possible in the absence of excess OP. IP mineralization rates were higher in anaerobic and reduced environments than in aerobic environments. Although IP abundance and IP mineralization rates were relatively low, results highlighted the importance of considering recalcitrant organic-P as a viable source for SRP in freshwater.

ABSTRACT. Urban stormwater runoff is a common water quality concern that impacts communities and ecosystems alike. Rain gardens are one solution used to alleviate the impact of stormwater runoff by mitigating its flow, nutrient content, and pollutants. Rain gardens have a low spatial footprint and can be completed in rudimentary forms by independent groups or individuals, making for a popular community-based project. Community-based projects are powerful teaching tools and can supplement the needs of municipalities and larger organizations; however, they often lack sustainable, long-term management plans. Rain gardens are a form of green infrastructure and are often thought of as sustainable by nature. Rain gardens, however, do not take care of themselves. They require maintenance and attention over time to prevent obsolescence, something that informal gardens do not always receive. Student-led organizations at college campuses are common paradigms of motivated groups that complete projects without established organizational oversight. Student organizations rotate membership frequently; thus, their work requires detailed documentation and strong communication to be sustained. With that in mind, the Ohio State University’s student branch of the American Ecological Engineering Society worked to revitalize the rain garden built by its predecessors 15 years ago. Future management options were investigated along with opportunities for continuous educational and local enrichment.

ABSTRACT. Observations from modeled hydrologic conditions and accrual of sediment and microplastics in a headwater stream system in Blacksburg, Virginia, suggest the potential influence of ecological restoration on transport processes. This study was conducted from October 1, 2021 to June 28, 2023 on a 1.25km reach of Stroubles Creek. Stroubles Creek, an ecological restoration site, is subdivided into three sections of varying restoration degrees. Restoration treatments include regrading the channel’s banks and reintroduction of native vegetation. Observations about hydrologic and transport processes were made at the treatment level to determine the degree of influence of prior restoration efforts. Physically-based hydraulic modeling, involving historic stage and velocity time-series as inputs and calibration values in HEC-Ras, allowed us to discern the more restored sections have a higher inundation frequency, greater vegetative roughness, and lower surface velocities. Sediment accumulation was assessed by installing five cross sections of ceramic tiles at surface elevation in each of the floodplains of the three treatment sections. Sediment accumulation was found to increase with the level of restoration and proximity to the channel. Finally, microplastic samples were taken at five locations within each treatment section and analyzed using FTIR spectroscopy. It was determined further restored sections, especially in areas with high vegetative density, had more microplastic accumulation. In tandem, these observations show regrading of a channel’s banks and reintroduction of native vegetation can alter hydraulic properties and subsequent transport processes. Therefore, ecological restoration processes likely hold significance in the sediment and microplastic transport processes of a headwater stream system.

ABSTRACT. This outreach project is entitled "Sowing water: the drop of the future that we can save" and is led by the Department of Biosystems Engineering of the University of Costa Rica. It involves the populations of ASADAS, the pipelines and sewer associations, and elementary schools in the towns of Monteverde (upper watershed), Sardinal (middle watershed), and Chomes (lower watershed). In this area, due to climate change, the dry periods have been extended, and the amount of rainfall is the same, but falls over a short period of time. The problem lies in that, due to soil waterproofing and high-intensity rainfall in a short period, runoff occurs instead of infiltration. Therefore, groundwater recharge is impacted and, during summer, less water is available for the ASADAS to provide drinking water to the population. To promote infiltration, water sowing systems are proposed. In 2023, workshops were held with the ASADAS and elementary schools to explain: 1) the hydrological cycle, 2) causes of low infiltration, and 3) water sowing systems. A pre-test and a post-test were conducted to demonstrate the improvement of knowledge in the target population. The workshops were successful as the population understood that under the current precipitation behavior and landscape conditions, the water sowing systems became a possible solution for water resource management. In 2024, training will be provided to design and install a water sowing system in one of the schools. This will be a demonstration site for the entire population in order to encourage its application in more places.

ABSTRACT. Water quality and flow were monitored at two tributaries in Randolph Co. to 1) gauge the effectiveness of cattle exclusion fencing and riparian buffer establishment and 2) quantify the nutrient and sediment reductions associated with implementing a regenerative stormwater conveyance (RSC) channel in an agricultural setting. North Tributary (NT) and Tributary 1a (UTA) were severely incised streams draining small watersheds (23 and 25 acres) used for beef cow grazing and application of swine waste. Fencing was installed 50 to 100 feet away from the streambanks in Nov. 2015. NT was filled with a sand/mulch filter media and a rock step channel was constructed atop the media to convey storm flows in June of 2021. UTA was not modified to facilitate a paired watershed study to gage the success of RSC in a high-nutrient load agriculture setting.

Pre-implementation monitoring was established at the downstream end of both streams on 8/1/14 and continued for two years after fencing. Monitoring was suspended (10/23/17-7/13/21) during the RSC construction and then restarted on 7/13/21. Both nutrient and sediment export were reduced in both tributaries due to fencing and the reductions significantly improved after four years of vegetation growth.

TP concentrations increased for NT, likely due to phosphorus leaching from the RSC media. NOx-N and OP concentrations decreased for NT, but increased for UTA, indicating a treatment effect for the RSC. Total export of NOx-N decreased by 30% for NT compared to only 5% on UTA during the same period, indicating increased denitrification from the RSC.

ABSTRACT. The widespread use of antibiotics in agriculture, their persistence, resistance to antimicrobials, and detrimental effects on human health and aquatic habitats have made antibiotic pollution a severe problem. Due to limited degradation, veterinary antibiotics excreted from animals are released into soil and water contributing to a negative impact on the environment. According to the WHO, antimicrobial resistance is one of the three main risks to human health. Up to 90% of antibiotics are excreted in their biologically active forms directly into soil or water. Every year, around 2.8 million antibiotic-resistant illnesses happen in the United States. In this study, we investigate the removal of five frequently used antibiotics by ecological engineering techniques like woodchip biofilters along with biochar, peat moss, Cu, and Aluminum using our currently developed method at Analytical Services Laboratory, NCA&T University. We have set up twelve woodchip bioreactors that include metal treatments: Copper (Cu) and Aluminum (Al) as well as an alkaline stabilization treatment composed of biochar and sphagnum peat moss in the greenhouse and also set up three hybrid wetlands comprised of surface and subsurface flow wetlands. This research intends to improve the design of a passive woodchip bioreactor for drained agricultural areas by identifying the most efficient treatment method that uses readily available materials and resources and the removal efficiency of constructed wetlands along with the removal mechanism for antibiotics. The outcomes will clarify how antibiotics are removed from agricultural runoff using ecological engineering approaches while also protecting the environment and human health.

ABSTRACT. GenX is in the family of perfluorinated or per or polyfluoroalkyl substances (PFAS) which has created a critical environmental concern due to their widespread utilization in many industrial and agricultural applications. In agricultural fields, the main sources of PFAS including GenX contamination are contaminated ground waters used for irrigation for cultivation of crops and the use of biosolids as fertilizer. Owing to the physicochemical properties of GenX and their fate and transport directly related to the physicochemical and adsorption properties of the agricultural soil is poorly understood. Biochar application to agricultural soil is an emerging technique that has exhibited the efficiency to remove many organic compounds from runoff and leaching. We aim to study the fate and transport of GenX and how it is adsorbed into soils and biochar amended soils. We have constructed 12 soil columns where three biochar levels (3%, 4%, and 9%) and a control (0% biochar) are applied to soil spiked 20 ppb and 100 ppb of GenX concentration. The leachate water from the columns is analyzed following solid phase extraction (SPE) USEPA Method 8327 with LC/MS/MS for concentrations of GenX in the leachate. The adsorption capacity in soils allowing us to study how the fate and transport of GenX are affected by the presence of biochar. The knowledge of the mechanism will help the policy maker better understand how the application of biochar can affect water quality, and allow to make decision, especially in regions where GenX contamination and biosolids land applications are prominent.