ABSTRACT. Over the past 32-years, the Tampa Bay Estuary Program (TBEP) and its partners focused on reducing nutrient loads for the benefit of restoring seagrasses in Tampa Bay. Significant water quality and ecosystem improvements occurred and were documented with established, long-term ambient monitoring programs. Seagrass coverages peaked in 2016, and since this time, new nutrient load management challenges have emerged. Declines in water quality and seagrass resources, particularly within the Old Tampa Bay segment, are re-invigorating efforts to better manage nutrients and address other stressors affecting Tampa Bay's overall estuarine health. This presentation will focus on the history of Tampa Bay's initial recovery, contemporary stressors and challenges in maintaining a healthy bay, and the TBEP's role to facilitate and coordinate on these efforts. New nature-based stormwater retrofits are now considered vital to effectively reduce nutrient loads and provide resiliency co-benefits to a continuously urbanizing watershed into the future.

ABSTRACT. Between 2016 and 2022, Sarasota Bay lost approximately 26% of its seagrass coverage. These losses are attributable to a number of impacts, such as Hurricane Irma in 2017, a severe red tide event in 2018, and the release of industrial wastewater from Piney Point in 2021. Because of our highly urbanized watershed, very wet years don’t just bring us “naturally elevated” nutrient loads, they also bring about increased urban stormwater runoff and impacts from overwhelmed wastewater infrastructure. Managing seagrass recovery will require us to offset the nutrient load increases our bay has experienced in recent years. However, maintaining this anticipated recovery will become more difficult in the near future, as we anticipate a deeper bay with warmer water – both of which will make it harder to sustain our seagrass meadows in Sarasota Bay. Similarly, the mangrove forests in Sarasota Bay are currently stressed by illegal trimming, and the ability of mangroves to persist over time will require creative thinking to allow mangroves to retreat upslope in response to the expected impacts of future sea level rise. For Sarasota Bay to remain a climate resilient system, we will have to do a better job with nutrient management over the next few decades, and we will have to create the opportunity for mangroves to respond to anticipated rates of sea level rise.

ABSTRACT. Gaining research experience as an undergraduate has been shown to be effective for improving retention, learning critical thinking skills, and increasing a student’s desire to enter a graduate program. Many students experience obstacles to participating in research as an intern with faculty. Course-based Undergraduate Research Experiences (CUREs) provide an opportunity for undergraduate students to participate in research while taking the classes they need to graduate, which removes multiple barriers to getting research experience.

Our team has implemented two different approaches to integrating ecological engineering research into junior and senior level courses. The junior level water quality and water/wastewater treatment courses are linked to provide a year-long CURE experience where students design and test a nature-based solution to treat a specific contaminant. Students in the senior level groundwater hydrology course are partnered with students in geology and biology to investigate how a recently constructed regenerative stormwater conveyance functions and how hydrologic conditions influence wetland microbial function. The CUREs have looked different during each of the three years due to changes in course scheduling, changes in faculty research priorities, learning from experience and COVID-19. One of our goals this year is to increase interaction and team building amongst the engineering, geology, and biology students. This presentation will include a description of how the CUREs have been implemented, lessons we have learned, and how we are making changes to improve them.

ABSTRACT. Professional certification is an important outcome for development of professional expertise for many fields of endeavor and industry. The American Ecological Engineering Society has long had a program for Certified Ecological Designer to support the professional needs of the society membership. The program was early on designed to advance the professional needs for designation and certification, to provide a resource for expertise in ecological design, and to secure the field of ecological engineering and design as a province of the Society. Early interest in the program resulted in a moderate number of certifications, and models for sustainability of the program were developed and implemented. More recently, waning applications for certification suggest a mismatch between the goals and services provided by the program and the needs and values of Society members and their industry environment. A reassessment of the program for recalibration to suit membership needs and values is currently under way for ultimate delivery of a sustainable and viable certification program that meets the goals of the Society. This talk and panel discussion will review the history and current state of the CED program, and engage in conversation with membership to develop a vision for the future state of certification in AEES.

ABSTRACT. Since the beginnings, recruiting and retaining student members have been a primary focus of effort of the American Ecological Engineering Society (AEES). This is evidenced by the involvement of students at every level of society activity, from representation on the Executive Committee to active recruitment and retention efforts. Student members often make up a significant portion of the total attendance at annual conferences. Since the occurrence of regular annual meetings of the AEES began in the early 2000s, the majority (but not all) of meetings featured a student design competition as a means to engage students in scholarly activity, encourage interaction among the student population, and showcase their talents to the larger membership. These events ranged in composition and subject matter, but often concluded in some form of academic “spectacle.” This presentation will share a summary of the various student design competitions held at the annual meetings of the AEES and propose best practices for future occurrences.

ABSTRACT. Even though the high value of practice and hands-on activities is unquestionable, engineering education is traditionally lecture-based. When the opportunity to apply a project-base approach is limited, it becomes crucial to use it wisely, emphasizing different abilities and characteristics. To address this, the "Crawfish Project" has been integrated into the curriculum of Auburn University's Biosystems Engineering program as a capstone project for junior-level students. The objective of the project is to design and fabricate a standalone microcosm, capable of supporting a community of crawfish, as a closed system. The microcosm must consider various factors such as oxygen production and circulation, nutrient availability and cycling, aeration, and behavioral challenges. Undergraduate students engage in team-based activities with designated roles such as Team Project Manager, Water Quality Manager, Biology Manager, and Engineering Manager, allowing them to develop their teamwork and communication skills. Graduate students, on the other hand, are tasked with conducting literature reviews and serving as consultants to undergraduate teams. The Crawfish Project serves as an opportunity for students to apply the concepts and skills learned in their courses, as well as to develop their design, problem-solving, and communication abilities. It highlights the importance of project-based training in complementing traditional lecture-based methods and reinforces the significance of hands-on experiences in engineering education.

ABSTRACT. Positive influences from an ecological design charrette continue to ripple out. When we created the charrette component of the AEES Certified Ecological Designer program one goal was to bring together ecological engineers, landscape architects, ecologists, and other scientists from across the country and the world and have them collaboratively apply their expertise to a local community problem. "Ecological Design in the Ozarks" held in Fayetteville, Arkansas on May 15-17, 2013, was one of those events. Forty participants tackled Lake Frances and its surrounding lands as their subject.

Lake Frances is a small run-of-river reservoir on the Illinois River. The dam, in Oklahoma, is just west of the border with Arkansas. Tangible consequences of the charrette include the Walton Family Foundation making a $32 million investment to implement an idea that first surfaced in the charrette. They are creating a kayak bypass around the aging dam. This kayak park bypass will be an attraction in itself, allow boater access on a formerly inaccessible reach of the river, and will improve fish passage upstream. The Oklahoma Secretary of Energy and Environment purchased 260 acres of former lake bed explicitly to implement the vision of wetland restoration, creation, education, interpretation, and recreation born in the charrette. Two cohorts of ecological engineering students from the University of Oklahoma, led by Dr. Bob Nairn, have used the river and surrounding lands as senior capstone research and design projects. Most recently, the Northwest Arkansas Land Trust purchased 830 acres on the hill above the river to be managed for both ecological enhancement and recreation.

As AEES considers whether and how to rejuvenate the CED program, I hope the story of the Lake Frances charrette will inspire you to look for opportunities to do something similar in a place important to you.

ABSTRACT. Extreme events, including regional floods caused by hurricanes, have the potential to mobilize and transport nutrients across the landscape, creating public and environmental health concerns. Several studies have characterized the contaminants in floodwaters, but few studies offer insights into which watershed characteristics explain flood water quality signatures. To address lack of understanding on flood water quality descriptors, we aimed to explain floodwater nutrient concentrations as a function of different environmental variables. Specifically, we quantified nitrogen and phosphorus concentrations in floodwaters across the Atlantic Coastal Plain of North Carolina (USA) after Hurricane Florence, a major tropical storm that delivered up to 700 mm of rainfall to the region during September 2018. We also constructed a multivariate, spatial Bayesian model to explain nutrient responses as a function of different hydroclimatic factors, land use classifications, and nearby pollution point sources. Nutrient samples were collected at 51 different sites at four different time points spanning a year after Hurricane Florence impact: during major flood conditions and after floodwaters had receded. Samples were assessed for total Kjeldahl nitrogen, total ammonia nitrogen, nitrate and nitrites, total phosphorus, and orthophosphate. Results from this analysis show that nutrient concentrations were very low in floodwaters, with the exception of several sites that exhibited excessively high total Kjeldahl nitrogen, total phosphorus, and orthophosphate concentrations. Furthermore, modeling results indicate that swine production facilities (concentrated animal feeding operations; CAFOs), wastewater treatment plant (WWTP) proximity, and precipitation variables were important in explaining nutrient concentrations in floodwaters. This research suggests that swine CAFOs and WWTPs were likely sources of nutrient exports associated with Hurricane Florence, with rainfall amount being a primary driver.

ABSTRACT. The need for reliable forecasts has seen a rapid growth in the last decades linked to the accelerating impacts of environmental and climatic variability and the increasingly complex network of global socioeconomic interactions. Recent research in data-driven approaches to solve time series forecasting (TSF) problems evidence a trending interest in applying Transformer neural networks (TNNs), which have been a paradigm shift in other areas of deep learning, from natural language processing to computer vision. However, despite of the available knowledge in advance given by weather forecasts to inform more accurate predictions, TSF TNNs applications are mainly focused on using historic observational data to predict future events. This work explores the potential of TNNs to perform TSF of different environmental variables: streamflow, gage height, water temperature and specific conductivity. The TNN is tested in forecasting each response variable one- to fourteen- days ahead, using posterior observations from both natural and anthropogenic source and spatially distributed weather data from the National Land Data Assimilation System (NLDAS). Two scenarios in which the variables of interest have high ecological importance were selected, the Peace River Watershed (Florida), and the Northern Gulf of Mexico (Louisiana), where estuarine conductivity is anthropogenically influenced by the openings of the Bonnet Carre Spillway. A sensitivity analysis is performed to highlight the influence of each of the input variables on the response variables’ forecast, informing better feature selections. The results evidence the state-of-the-art potential of TNNS to be used in TSF decision making problems and the importance of including the weather forecasts and human forcing factors (0.85<NSE<0.99 for all variables and forecasts horizons).

ABSTRACT. Coastal water quality regimes regulate the structure and dynamics of nearshore aquatic ecosystems and the human activities they support, including fisheries, aquaculture, and outdoor recreation. Forecasting the impacts of climate and land use change on terrestrial fluxes to the coast and the resulting water quality regimes is critical for the sustainable management of estuarine ecosystems. Estuarine water quality is primarily governed by the dynamics of riverine freshwater discharge and associated solute fluxes, with the riverine inputs impacted by climate and land use of the contributing watershed area. Landscape hydrologic models can forecast freshwater and solute fluxes to the coast as a function of land use and climate; however, such models typically cannot translate fluxes into spatial estuarine water quality predictions required by downstream ecosystem and food web models. Coastal hydrodynamic models can simulate estuarine transport and mixing to produce spatial water quality predictions but are often difficult to implement and have significant computational and data requirements. In this study, we took an alternative approach, using a data-driven Estuary Linkage Model (ELM) to translate simulated riverine and coastal groundwater fluxes from a landscape hydrologic model (SWAT-MODFLOW) into spatial water quality predictions for one of the most pristine estuaries in the USA, the Suwannee River estuary (SRE). The ELM generates daily predictions of salinity, water temperature, nitrate concentration, dissolved oxygen concentration, and colored dissolved organic matter concentration for locations within the SRE and was calibrated using only remotely sensed and in-situ water quality observations. Results indicate that ELM can reproduce expected spatial distributions in all five simulated water quality metrics (e.g., discharge-dependent size of river plume). The ELM’s predictive ability enables it to link SWAT-MODFLOW and SRE ecosystem models and suggests similar data-driven models could be applied to other estuaries.

ABSTRACT. This project is focused on the development of empirically-based, numerical functions to predict the flooding along south Atlantic coastal communities. Data from several field gaging stations will be analyzed to ascertain patterns and relationships among driving variables of rainfall and tidal water levels, and the resulting storm flows and water levels in conveyance channels within developed areas. GIS-based numerical simulations of a hypothetical, simplified coastal landscape will also be performed to further elucidate the patterns and relationships among driving variables and resultant flooding.

ABSTRACT. Coastal environments around the globe are subject to anthropogenic stresses due to dense coastal populations. The response of development activities on dynamic estuarine ecosystems, influenced by tidal forces, freshwater flows, salinity variations, and intricate coastal land morphology, is often uncertain. This case study evaluates how connectivity and coastal geomorphology influence flow patterns by modeling the effects of a proposed hydraulic reconnection project on water movement between the Manchester Waterway, a coastal residential community, and Charlotte Harbor, a large open water estuary in the Gulf of Mexico. An unstructured grid, 2D model was developed utilizing Delft3D Flexible Mesh to simulate estuary hydrodynamics under proposed conditions for four different weather conditions, including recorded 2021–2022 weather, future sea level rise, an extreme weather event, and a combination of extreme weather and sea level rise. Simulated flow results for proposed conditions were compared to present day flow patterns for analysis of the predicted changes in water levels and velocity magnitudes in the waterway. The results show that increased connectivity between the Manchester Waterway and Charlotte Harbor is expected to increase tidal amplitudes largely due to a lowering of minimum water levels in the waterway. During storm events, water elevations are predicted to drop to lower elevations following peak storm surge due to proposed conditions, which may provide flooding relief. Model simulation results will aid hydraulic reconnection and guide a more comprehensive ecological restoration plan. This case study will also improve understanding of the major influencing forces in intricate estuarine environments and how ecosystems may respond to land development, sea level rise, and increasing magnitude and frequency of tropical storms.

ABSTRACT. Natural capital stocks are the durable physical or biological elements of nature that persist through time to contribute to current or future economic production. In October of 2022 the White House Office of Science and Technology introduced a national strategy to develop statistics for environmental decision making and proposed creating a system of natural capital accounting and associated environmental-economic statistics. While restoration ecologists have used multiple measures for determining the success of restoration projects, it is important that the measures used represent an accurate accounting of environmental capital stocks and flows produced by nature-based restoration projects, and provide meaningful accounts of natural capital stocks and flows. We have demonstrated natural capital increases for several nature-based environmental restoration projects in Alabama and Louisiana using natural capital accounting techniques. For example, for a living shoreline project in South Mobile County, Alabama we have demonstrated a 4:1 increase in habitat benefits, in terms of marsh and food chain production, and 3:1 BCR on a dollar:dollar basis. This accounting considers both the value of the environmental assets (stocks) of the various ecosystem elements (primary, secondary and tertiary producers standing crop) as well as an estimate of the annual productivity the habitats generate (ecosystem services or flows). We illustrate the increase in natural capital for several current projects including living shorelines , marsh creation and forested wetlands (Pointe aux Chenes) nature based restoration projects. These projects show significant increases in net-natural capital benefits and illustrate the methods used to provide meaningful quantitative measures, which can be used to document the natural capital values of nature based restoration projects.

ABSTRACT. Marine dead zones are a growing problem worldwide. In dead zones, water below the pycnocline is anoxic. The Baltic Sea and the Chesapeake Bay are well known dead zones. The Baltic Sea dead zone is permanent below the halocline except for brief periods on decadal scales. Anoxia in the Chesapeake Bay occurs spring to fall below a thermocline. In either case, it is highly unlikely that control of watershed nutrients will remediate the problem. Both are locked in alternative stable states where anoxia causes sufficient internal loading of nutrients to perpetuate the dead zone in a vicious cycle.

The physical and biogeochemical dynamics of marine dead zones are closely related to seasonal dead zones in freshwater lakes and reservoirs. Injection of pure oxygen into the hypolimnion is a proven method to restore aerobic conditions to the hypolimnion and quench internal nutrient loading. The same method can be used in marine dead zones. The most important difference is scale. The largest hypolimnetic oxygenation system injects 350 tonnes per day into the hypolimnion. Oxygen demand in the Baltic Sea is 10,000 to 15,000 tonnes per day, the Chesapeake Bay 2,000 tonnes per day. Moreover, there obviously are important differences between freshwater and coastal dead zones that need to be empirically explored. How can huge pure oxygen systems be demonstrated for marine dead zones at scales that are not huge?

Both the Baltic Sea and the Chesapeake Bay are fjord problems. A shallow sill at the mouth prevents deep water exchange with the ocean. Each has smaller fjords that have seasonal anoxia. These fjords have oxygen demands at scales in freshwater reservoirs. This presentation will explore design of large-scale oxygenation pilots in fjords to provide the essential scale to demonstrate how oxygenation will work at huge scales.

ABSTRACT. It is estimated that more than eighty-five percent of oyster reefs along the South Carolina coast have been lost. Although many of the environmental benefits and functions that oysters provide are widely understood (e.g. water quality improvement, wave energy dissipation) relatively little is known about the holistic contributions of the oyster to the physical structure and geomorphic processes that characterize and sustain salt marsh and their tidal channels. Furthermore, as oyster populations have sharply declined over the last century or so, the widespread deleterious effects of dredging, boat wake, stormwater runoff, and other environmental stressors have increased.

The growing number of small-scale oyster restoration and oyster-based living shoreline projects offer some insight, as they trigger the rapid healing of an eroded bank by promoting the accretion of sediment and the expanded growth of vegetation, thereby changing both the form and the processes of the marsh edge. These observations beg the question: how has the widespread loss of oyster reefs changed the physical structure and geomorphic processes of salt marsh and tidal creek systems on a larger scale?

In the last several years—working with graduate interns and academic collaborators—the authors have surveyed tidal creeks and marshes, collected tidal hydrology data, performed hydrodynamic modeling, and designed salt marsh restoration and living shoreline projects. This presentation will share the data, hypotheses, and results from these projects, with hopes of creating new opportunities for collaboration with researchers and workers in attendance.

ABSTRACT. E.G. Simmons Park is Hillsborough County’s only public swimming area with 1,700 feet of beachfront along the eastern shore of Tampa Bay. Coastal wave action and ship traffic has claimed more than 30 feet the park’s unprotected shoreline, resulting in a loss of more than 3 acres of waterfront property. Working with Tampa Contracting Services (TCS) and Living Shoreline Solutions, our engineering staff directed bathymetric and benthic surveys, seagrass surveys, threatened and endangered species studies, and coastal wave modeling efforts beginning in 2014 to establish design criteria for an engineered shoreline protection feature known as Wave Attenuating Devices (WADs). This project undertaking required close coordination with agencies through a team-permitting approach that involved joint meetings with the US Army Corps of Engineers (USACE), National Marine Fisheries, the US Coast Guard, Florida Department of Environmental Protection (FDEP), and Port Tampa Bay (PTB). TCS manufactured the precast structures (WADs) and installed them along approximately 2,000 LF of shallow tidal flats and shoreline. The project was completed in mid-2018. Four (4) years after construction and following multiple tropical events (including Hurricane Ian), the WAD features have proven to be stable and very effective in limiting further loss of the shoreline while promoting the areal coverage of seagrass and essential fish habitat. This paper presents a comparison of the time-zero and current shoreline environmental conditions that demonstrates the advantages of an engineered shoreline system. The discussion will include post construction videos of documented wave energy dissipation, and presentation of a quantitative assessment of increased essential fish habitat (EFH) coverage that has occurred as a result of the project construction.

ABSTRACT. Phosphogypsum, an industrial byproduct of fertilizer manufacturing, has marginal economic value leading to its accumulation in phosphogypsum stacks. When not properly maintained, these facilities can become a source of nutrients and threaten coastal water quality. Nutrient-rich industrial wastewater from the Piney Point phosphogypsum facility has been discharged into the Tampa Bay estuary several times since the 1960s. These discharge events prompt concern about their effect on water quality, nutrient cycling, aquatic biota, and ecosystem services. This study investigated how historic discharge events from Piney Point contributed to sediment, nutrient, and radionuclide accumulation using bulk nutrient concentrations and stable- and radioisotopes. Additionally, pigment biomarkers were used to assess if these events are linked to regime shifts in phytoplankton assemblages. At both sites photosynthetic pigment concentrations were highest in the top sediment intervals with the greatest increase in pigments associated with diatoms, green algae, and cyanobacteria. At Bishop Harbor, the mean ²²⁶Ra activity (3.9 + 0.8 dpm g^-1) was ~10-fold greater than at Piney Point Creek (0.4 + 0.3 dpm g^-1). Likewise, the excess ²¹⁰Pb inventory (82.4 + 13.5 dpm cm^-2) at Bishop Harbor was ~3-fold greater than at Piney Point Creek (27.0 + 1.7 dpm cm^-2). Total phosphorus concentrations and accumulation rates at Bishop Harbor ranged from 8.7 to 14.4 mg g^-1 and 141 to 293 g m^-2 y^-1, respectively, suggesting that an excessive amount of phosphorus from these discharge events was deposited in the sediments. This legacy phosphorus may be susceptible to remobilization by diffusive flux and resuspension events, such as storms, which may further contribute to coastal eutrophication.

ABSTRACT. H.T. Odum began the Center for Wetlands (CFW) with a $1 million ($7.6 million today) grant from the NSF and Rockefeller Foundation to study the use of cypress wetlands for recycle of treated wastewater. Since then, the CFW has enjoyed 50 years and nearly $50 million in research related to the overall system of humanity and nature. From the beginning, its research was broad, multi-disciplinary, and timely. Over the years, we conducted research on wetlands, forests, lakes, rivers, springs, beaches, estuaries, watersheds, biomes, cities, regions, states, countries, Earth and dabbled a bit at the scale of the cosmos.

Here we provide a comprehensive list of the entire portfolio of research and actors (students, faculty and friends), dwell on a limited number of important milestones and analyze trends all the while emphasizing the contributions of the University of Florida’s Center for Wetlands.

ABSTRACT. The fifty-year history of the legendary H.T. Odum Center for Wetlands has produced highly original systems science and much of the foundation of ecological engineering that ultimately helped improve the relationship between people and the planet. Dr. Odum influenced generations of scholars and practitioners with his distinctive view of the world; giving us energy systems diagramming, computer simulation mini-modeling and emergy-based environmental accounting. Drawing from my personal experience of collaborating with Drs. Brown and Odum during the 1990s, as well as my "24-year old rearview mirror" perspective and two decades of academic experience, I aim to elucidate the impact of the Center's work from the 1990's and foretell some path's for its next fifty years.

ABSTRACT. H. T. Odum developed a model of ecological self-organization during the 1960s based primarily on his past experiences with Florida springs, Texas estuaries and the tropical rain forest in Puerto Rico. When he moved to the University of Florida in 1970 he continued to develop the model with new focus on wetlands. In this presentation Odum's work at the Center for Wetlands on self-organization of treatment wetlands is examined. The addition of pollutants to wetlands creates a selective force on ecosystem structure and function that drives self-organization. Changes caused by the pollutants are apparent when a polluted system is compared with an unpolluted reference system. Studies of wetlands used to treat pollutants reinforced and expanded Odum's understanding of the self-organization process and contributed to the overall development of the treatment wetland concept. Results of research supervised by Odum during his years at the Center for Wetlands on treatment wetlands receiving domestic sewage, pulp and paper plant effluent, lead, sulfate and agricultural wastewater are reviewed and related to ecological engineering design.

ABSTRACT. Depressional wetlands, often considered as geographically isolated wetlands, are common landscape elements in many low-relief regions, ranging from West Coast vernal pools and Midwestern prairie potholes to myriad systems in the Southeastern coastal plain. These wetlands are characterized by limited surface water connectivity to other waters, augmenting water storage both locally and cumulatively across landscapes. This water storage enables specific hydrologic (e.g., floodwater attenuation and groundwater regulation), biogeochemical (e.g., sediment and nutrient retention), and biological (e.g., refugia) functions. Quantifying these water storage functions at local to regional scales requires a portfolio of empirical and modeling approaches to examine hydrologic and associated biogeochemical processes. Our group’s work focuses on empirical observations and explicitly representing water storage functions within models that range in spatial scales. In doing so, we seek to better understand the drivers of wetland water storage and flows and their associated functions, ranging from habitat for threatened species to carbon processing. In this talk, I will give an overview of projects that demonstrate datasets and modeling approaches to assess wetland functions and to inform landscape management.

ABSTRACT. NBS [Nature-Based Solutions] is ecological engineering revisited. But it is described as a synthesis of several ideas related to the pursuit of sustainability including ecological engineering, natural capital, green and blue infrastructure, and ecosystem services. Ecological engineering was defined 30 years ago as the design of sustainable ecosystems that integrate human society with its natural environment for the benefit of both. NBS has been defined as building with nature and for nature, pretty much matching the definition of ecological engineering from 30 years ago. Examples of what is ecological engineering/NBS and what is not will be described in the context of the restoration of the Florida Everglades. Wetlaculture will be described as a relatively new approach to ecological engineering for solving agricultural nutrient pollution of lakes, rivers, and estuaries in Florida and Ohio while also restoring our wetland resources. Connections of ecological engineering to Howard T. Odum and the 50 year old Center for Wetlands at University of Florida will be described.

ABSTRACT. Over a third of the global population is concentrated within 100 km of the coast, with some of the fastest growing megacities located next to deltas. This concentration of development along our coastlines exposes dense human populations to coastal hazards such as storm surge and tropical storm winds, while also altering the natural landscape and reducing associated ecosystem services. Coastal wetlands such as mangroves have been recognized for their ability to attenuate wave energy and reduce inland flooding, though mangrove cover continues to decline globally. In this study, we evaluate a 2-dimensional hydrodynamic model of Charlotte Harbor during Hurricane Ian (2022), which passed through Port Charlotte as a Category 4 hurricane. The model, developed in Delft3D FM, features a high-resolution flexible mesh with grid lengths ranging from approximately 15 to 300 meters. Water level sensor data deployed before the storm by USGS, high water marks, and aerial imagery collected after the storm are used for model verification. We compare inundation levels and water velocity magnitudes in urban areas with and without mangrove forest buffer. Simulation results demonstrate the value that coastal wetlands serve for flood mitigation and indicate the potential role that wetland restoration and design may play in protecting tropical and subtropical regions from future extreme weather events.

ABSTRACT. In urban regions of Florida, stormwater ponds are often constructed to reduce runoff and nutrient discharges to surface water resources in efforts to protect the environment. However, in underserved communities, which typically have less greenspace and more hardscaping, these ponds often do not function according to design and instead threaten human and environmental health by concentrating water that becomes impaired by P, N, industrial and commercial contaminants, failing septic systems, sewer overflows, and solid waste. This poster describes the results of a community-engaged university seminar on environmental justice where students considered the disproportionate environmental health impacts of neglected stormwater ponds in Belmont Heights, Jackson Heights, and College Hills-- three historically segregated African American communities in East Tampa. Students conducted research on archival documents and existing data, water quality (dissolved oxygen, pH, total coliform, nutrients, heavy metals), and interviews with area residents and city officials about challenges and opportunities regarding cleanup and redevelopment. These data were organized according to: proximity/exposure to environmental hazards, the presence of susceptible populations, unique exposure pathways, multiple and cumulative impacts, vulnerable stormwater/transportation infrastructure, and ability to participate meaningfully in decision making about pondscape management. The results, which included a series of videos that feature the voices and perspectives of community members, are being used to create redevelopment plans to turn neglected ponds into community assets as identified and prioritized by local residents.

ABSTRACT. The Peace River basin is located in southwest Florida and comprises 2334 mi2. The river begins in northern Polk County and flows 105 miles downstream to the Charlotte Harbor Estuary. The Peace River is an important source of water for domestic and agricultural supplies, as well as for regional ecology and recreation. The flow of water and nutrients from the Peace River into Charlotte Harbor directly affects the estuary's health. While phosphorus loads have declined in recent decades, nitrogen loads have increased. In the last 150 years, there have been substantial changes in the Peace River watershed, and there is concern and uncertainty over the ecological impacts of future development and climate change in the region. To explore alternative potential watershed futures, a hydrologic model of the Peace River basin was developed using the Soil and Water Assessment Tool (SWAT). SWAT uses information about watershed soils, topography, land use, and climate to calculate river flow, evapotranspiration, and nutrient flux, among others. Topography was extracted from the USGS 30-m digital elevation model, soils data came from the USDA STATSGO database, and land use was compiled from the Florida Department of environmental protection, with cropping systems confirmed using the USDA CropScape database. Weather data was extracted from North American Land Data Assimilation System. The Peace River SWAT model is currently being calibrated using measured flow and nutrient data along the main stem and multiple tributaries, and once calibrated, will be used to identify critical nutrient source areas and simulate the effects of future climate and land-use changes. Scenarios of interest are being developed with regional stakeholders, with a focus on understanding how alternative land-use and climate change scenarios affect Peace River flows and nutrient fluxes and their ultimate effects on the Charlotte Harbor Estuary.

ABSTRACT. The progression of climate change has produced rising sea levels, leading to increased soil salinities in low-lying coastal lands by the process of saltwater intrusion (SWI). Increased saltwater flux into fresh and brackish bodies alters soil chemistry in adjacent areas during flood events. Elevated soil salinities induce less suitable conditions for vegetative growth. The Mapping Salty Soils Project (MSS) seeks to improve resilience of agricultural systems by exploring the relationship between elevation and salinity on Maryland's Eastern Shore farms. Previous research on SWI indicates a negative correlation between salinity and elevation; the MSS project investigates this relationship further, across varied elevations. Soil samples were collected across farm sites in close proximity to water bodies. Water-sample mixtures were then filtered to isolate aqueous components, from which the respective EC values were derived. This analysis presents a strong negative correlation between elevation and salinity. These findings agree with previous knowledge and theory that low-lying lands are more susceptible to saltwater intrusion. Improved understanding of SWI and its extent from the MSS project can instruct future best agricultural management practices for vulnerable locations.

ABSTRACT. Climate change is expected to cause a rise in the mean global air temperature, thereby impacting precipitation patterns around the world. Research has shown that there will be an increase in rainfall intensity, duration, and frequency (IDF), and some of these changes are able to be observed retrospectively for the midwestern United States. This has significant impacts on the design of stormwater control measures (SCMs) as it relates to resiliency against these more extreme storms. Currently, engineers are using outdated rainfall IDF values for stormwater design, as the NOAA Atlas 14 data set was created from data measured prior to 2004. This study aims to fill this gap of knowledge for the Central Ohio region by retrospectively analyzing regional precipitation data and making comparisons to current measurements and future projections of precipitation. The Hazen Method was used to determine the probability of a storm event’s depth, dry period length, and duration using historical and recently collected (over the last 7 years) Columbus, OH precipitation data. The data suggest that storm events are becoming larger and occurring over shorter durations in the Central Ohio Region, meaning that rainfall intensity has increased since the 1950s. Future work will include applying future climate data for the region to understand how resilience can be assured in current SCM design. Using metrics for SCM design, we will quantify changes to the water quality volume and flood control storms for this region to identify how SCMs would need to be designed across the decades to ensure the same performance. This work will help ecological engineers to understand how to modify SCM design in light of climate change.

ABSTRACT. The climate change is a burning issue of present days. The increase in temperature is causing alteration in physical condition of lands, waters, agricultures and urban areas. Temperature is one of the most important abiotic factors of ecosystem that affects the salinity of soil and water. Temperature increase results in decrease pH. Therefore, it is crucial to understand the impact of climate change induced warming on the water ecosystem and other physical and chemical parameters such as pH, DO, etc. In the present study, an attempt was made to establish an association between temperature, pH, DO, EC, TDS and Secchi depth in Nainital Lake of Kumaun region, Uttarakhand, India. 41 samples were collected from the lake which was geocoded with the help of GPS. The geocoded samples were interpolated in GIS environment. Along with, correlation matrix was also prepared for the assessment of correlation analysis. It was found that there is a positive correlation between TDS and EC and a strong negative correlation between temperature and pH. TDS and Secchi depth also bear negative correlation. It is one of its kind studies conducted in the lake of Kumaun that provides insight into the physico-chemical conditions the water ecosystems of the region.

ABSTRACT. Researchers, practitioners, and land managers often need more environmental physicochemistry data than budgetary constraints allow. Thus, flexible, reliable, and affordable systems for collecting environmental sensor data are needed. For example, wetlands provide benefits such as flood protection, nutrient retention and removal, and carbon sequestration. However, one negative impact of wetlands is the production of methane. The primary drivers of wetland methane release (flux) are still being determined because of a significant degree of variability across systems and a lack of sufficient volumes of high-quality data. Current methods of recording methane fluxes from wetlands and other freshwater systems often use expensive sensors requiring supervision. As a result, these methods have a small window of data collection time. Previous studies have developed and lab-tested low-cost and accurate sensor measurement systems. However, the assembly and programming of such systems in field-based studies require considerable technical knowledge. This study develops and field tests a measurement system emulating other methane flux chambers that maintain their low production cost, while additionally requiring minimal technical skills from users. Our system uses open-source hardware and software from the River Restoration Intelligence and Verification (RRIV) platform. The flux chamber consists of a collection chamber from an inverted bucket, and exterior electronic casings that contain the hardware and cables. A Figaro NGM2611-E13 methane sensor and a DH22 humidity and temperature sensor periodically measure data while a 2.5 LPM air pump will circulate outside air every hour during operation. We will present the results of applying this platform of methane sensors at scale and share approaches for adopting the platform for other environmental sensors. Future collection and analysis of high-density field data will provide insight into the flux of methane over long periods. Our research is furthering the development and use of user-friendly, low-cost water system monitoring.

ABSTRACT. Water quality monitoring plays a critical role in the upkeep of water resources. However, many water resource professionals do not have access to expensive commercially available solutions. Conventional water monitoring techniques, like ‘Grab Sampling’ and ‘Auto-sampling’, are slow and take a few days to furnish actionable information. These techniques require some technical expertise and regular trips to the monitored site for maintenance and data retrieval. Moreover, these methods lack high temporal resolution and do not provide information on the spatial variation of water quality. Hence, deducing when and where the pollutants originate becomes difficult. Spatiotemporal monitoring can provide a more comprehensive picture of the state of a water body over time as well as space when visualized using charts and a map. This project aims to address aforementioned issues by using a low-cost free-flowing water quality monitoring buoy that reports spatiotemporal water quality in real-time using web-based visualization tools. The buoy enclosure is 3-D printed, enhancing the reproducibility and customizability of the buoy. Widely available hardware and electronic components were used, bringing the cost per unit under $1000. The buoy uses MKR NB1500, an Arduino-compatible microcontroller, which supports NB-IoT/Cat-M network connectivity. The buoy records physiochemical water metrics – pH, temperature, dissolved oxygen, electroconductivity, and the location using a GPS module. These physiochemical metrics serve as proxy metrics for detection of anomalies in the water quality. The buoy also includes micro-SD storage for data backup, and Bluetooth module for on-field diagnostics. In summary, GatorByte aims to provide a real-time spatiotemporal monitoring solution while being economically viable and enabling timely and precise deduction of when and where pollution events occur.

ABSTRACT. Community and residential gardens have been growing in popularity across the United States including Tampa Bay, serving as local innovation and cultural hubs for addressing food security, food sovereignty, healthy lifestyles and other topics that converge around environmental sustainability and economic prosperity. While the series of benefits from these practices have been well documented in the literature, far less studies exist highlighting the tradeoffs involved in these practices such as water quantity and quality entering and exiting the system as well as people’s relationships with these resources. Analogous to tailwater recovery systems as a best management practice (BMP) for large scale agriculture activities, stormwater ponds have the potential to be a BMP for urban agriculture while promoting food security, environmental justice, and minimizing nutrient loads into local water sources. This poster discusses the relationships between urban agriculture initiatives and water resources in coastal communities particularly through a case study in Tampa Bay focusing on frontline communities such as East Tampa. East Tampa’s historical relationship with stormwater ponds and food production as well as economic opportunities makes it an important community to spotlight. Results from a synthesis of current recommended BMPs for residential and community gardens along with interviews from BMP experts will be presented. These results will be compared with interviews conducted with community and residential gardeners on topics such as fertilizer use, water use, maintenance, involvement in community-based gardening programs, and perspectives on gardening practices, nutrient management, and water sources. The water quality of a case study stormwater pond will also be discussed and include parameters such as total nitrogen, total phosphorus, chlorophyll, pathogens and heavy metals.

ABSTRACT. Stormwater and agricultural Best Management Practices (BMPs) are effective in controlling flooding and improving water quality to limit the nutrient entering waterbodies and mitigate the occurrence of harmful algal blooms; however, a comprehensive assessment framework considering environmental, technological, social, ecological, economic, and managerial criteria is lacking. A review of peer-reviewed papers and governmental agency reports was conducted to develop a framework for assessing BMPs holistically. The weighted sum was the chosen multi-criteria decision making method to evaluate BMPs. The proposed framework was verified through a comparison with a previous study on technology evaluation for nutrient management within the Northern Everglades. The framework was then applied to select BMPs for Upper Kissimmee (UK) subwatershed. It was found that wet detention pond and constructed wetland were ranked high due to high scalability and high cost-effectiveness. This demonstrated the importance of including scalability and effective cost in the assessment framework.

ABSTRACT. The University of Tennessee has an off-site stormwater mitigation crediting program that capital projects on campus may participate in if they meet a specific set of requirements. Often, mitigation projects will be constructed in the form of green infrastructure that can take up large amounts of land area relative to overall campus size. Bank stabilization using “green” living shoreline methods will be assessed as an option for potential future mitigation projects as part of the stormwater mitigation crediting program. Erosion along the length of the Tennessee River is a major contributor to poor water quality. The contribution of total suspended solids (TSS) from a linear foot of eroding shoreline will be quantified and compared to that of a stabilized area using tested and proposed methods. The prevention of further increased levels of TSS in the Tennessee River will be equated to the typical amount of TSS that would be required to be removed from stormwater through the use of traditional green infrastructure. In addition to the prevention of water pollution, the use of these living shoreline methods along the bank of the Tennessee River rather than the more conventional hard armoring methods will add functional aquatic and riparian habitat back to the shoreline, stop future loss of valuable land and increase overall aesthetics.

ABSTRACT. In the Lake Erie watershed, eutrophication is largely driven by nutrient loads from agricultural fields. Of these, fields which have accumulated phosphorus (P) levels above agronomic needs (legacy-P fields) are of particular concern as these sites are expected to disproportionately release greater P. However, monitoring has shown that not all legacy-P fields pollute at increased rates. It is unknown why these variations occur, but one likely factor is soil texture properties which are known to influence P buffering and desorption kinetics. To examine this, soil textures were calculated using weighted-average areas of soil map units within contributing areas of ten legacy-P fields. Generalized linear models were then developed explaining P loss as a function of soil texture (either: sand, silt, or clay content) and soil test P concentrations. Both concentration and areal loading rates of dissolved reactive P(DRP) and total P (TP) were considered. Of the strongest predictors, silt was found to explain 0.82 of variance of spring subsurface DRP concentrations and 0.93 of variance of annual surface DRP concentrations. For comparison, sand was found to explain 0.65 of variance in annual subsurface DRP loading, while clay was found to explain 0.60 of variance in annual surface DRP loading. These initial results indicate the importance of silt as an indictor influencing loading rates from legacy-P fields. The model developed using soil test P and silt could help predict which legacy-P fields are likely to discharge greater loads to better guide the location of management practices.

ABSTRACT. Oyster gardening has developed into an increasingly common and accessible method for coastal communities to support ecological restoration and nature-based solutions. This practice involves using modular, suspended oyster recruitment substrates to create removable oyster reefs, allowing individual community members to support oyster growth from private docks and bolstering local oyster populations and water quality. However, oyster gardening has traditionally relied on the use of conventional materials such as PVC and metal cages, with little research done to optimize sustainable alternatives. Here we present an experiment that evaluated a variety of alternative oyster garden structures and materials with the aim of testing which materials best enhance recruitment, durability, and environmental sustainability. Additionally, the occurrence of Hurricane Ian during the deployment period provided insights into the ability of these structures to withstand severe storm events. We conducted an experiment on docks in the residential canal system of Sanibel Island, Florida, testing the following structures: (1) specially designed concrete reef disks produced by GROW Oyster Reefs, LLC.; (2) drilled oyster shell on steel wire; (3) porous tubes of jute fiber coated with calcium sulfoaluminate cement; (4) BESE biodegradable plastic matrix panels; and (5) BESE biodegradable plastic mesh bags filled with oyster culch. The structure types varied in performance, with the concrete structures demonstrating strong oyster recruitment and growth, and the metal and plastic structures demonstrating lower durability. Integrity through Hurricane Ian was generally high for all structure types. This experiment has applied value for future oyster gardening programs by revealing relative pros and cons of alternative materials, thereby supporting the development of more effective, successful practices to meet restoration goals.

ABSTRACT. Our society is currently facing many environmental challenges such as natural resource depletion, pollution of soil, water and air, waste disposal, and climate change. To best solve environmental challenges, society needs graduates ready to enter the workforce with an understanding of natural processes and the ability to incorporate these processes into traditional solutions. Therefore, a new course in Ecological Engineering and Science (EES) was introduced at NCA&T State University to teach students how to incorporate nature and lessons learned from nature to solve environmental problems and ensure environmental sustainability. However, students lacked adequate background and preparation in EES and data science. Thus, an effort was made to immerse students in Biological Engineering and Environmental Science to experiential learning by developing laboratory exercises and semester-long project-based teaching materials. The project designed laboratory exercises and hands-on learning to teach ecological engineering skills and to prepare students for important skills including leadership, teamwork, and communication through the course projects. The content of the developed course as well as experiences developing the course will be shared. The experiential approach to learning is expected to increase student interest in the course and enhance the learning of EES.

ABSTRACT. This project applies 2022 Solar Energy and Environmental Justice research to several large apartment building complexes in Greenbelt, MD as models for future microgrid development within Prince George’s County and Maryland. Microgrid models from across the country were reviewed, looking at their size, financial structure, governance, etc. Different solar grid design options were reviewed by using the measurements and solar aspects of the existing buildings’ roofs. Using these calculations, estimated energy production, cost, cost savings, required funding and potential funding mechanisms were reviewed as well as safety requirements of such large-scale energy production with implications on battery storage locations. Also examined were how the energy and financial savings could be distributed between building owners, residents, and funding organizations. Other benefits beyond financial savings were investigated by looking at overall resilience, greenhouse gas reductions, health impacts and the community impact of the microgrid in times of disaster and difficulty. Additionally, students will look beyond solar PV to include passive solar design elements into the apartment complex’s build environment including tree placement, green walls and roofs and other elements to support them including stormwater capture and reuse to support the green elements.

ABSTRACT. Bioretention cells are capable of capturing and infiltrating stormwater to decrease runoff quantity and improves water quality. Installing these systems may be especially beneficial in areas such as Alachua County, where high nitrogen levels from stormwater runoff have impaired the surface and groundwaters. Testing different media mixtures and the benefits of internal water storage will help determine what configurations make bioretention most useful for improving impaired waters in this area. A four-cell bioretention system was constructed in Gainesville FL, to evaluate the benefits of internal water storage and two media mixes on nitrogen removal. Research on this site is ongoing; influent runoff and effluent flows are measured and sampled, with monthly laboratory testing for nutrient concentrations. Preliminary results show an overall decrease in nitrogen concentrations between the inflow and outflows, with some nitrogen species showing even greater removal in the cells with an internal water storage zone. There is also an increase in total phosphorus as the water moves through the system. This may be due to leaching from the installed media. The change in water quantity moving through the outlets is significantly lower in those with internal water storage as well, due to slower flow-through rates than the free draining configurations. The data and results will be used to determine how nutrient loading reduction are affected by the design of bioretention cells and the overall ability of these configurations to meet the stormwater requirements for Alachua County.

ABSTRACT. Substrate electrical conductivity (EC) measurement is a required Best Management Practice (BMP) for the application of supplemental fertilizers in the nursery and greenhouse industries. The EC measurement is conducted to determine the conductivity of the liquid fraction of the substrate or extractable liquid that is considered representative of that encountered by the roots. This measurement provides producers with immediate information for guiding fertility management. The current method of measuring substrate EC in this application is through the Pour-through (PT) procedure, a multi-step method in which representative plants are selected for EC measurement, and a predetermined volume of water is poured on the surface of each test plant. The resulting leachate is collected, and EC is determined using an EC meter. This process can be extensive for large-scale nursery production zones, requiring a significant amount of time and manual labor. Therefore, with the personnel shortages that exist in production nurseries, technologies are needed to improve and speed the steps of measuring EC and recordkeeping so the BMP is effective. This project aims to develop a new, sensor-based method for determining EC to reduce the time invested by the producers compared to the current PT method. The digital results of such a sensor-based method can automatically become a part of the producer records. In this study, a variety of soil-based EC sensors were selected for measuring container substrate EC. Data collected using these sensors was compared to EC data obtained using the PT procedure to develop a protocol for sensor deployment in nurseries. Additionally, a wireless communication was established to remotely collect sensor data. A mobile application will be developed to assist in sensor data collection and recordkeeping, and an educational event will be conducted to introduce industry personnel to the new method for measuring container substrate EC.

ABSTRACT. Climate change and land use change are two important factors for flood management since they both directly and indirectly impact on the functionality and performance of urban stormwater drainage infrastructures. Though there is a large body of knowledge on different drivers, there are limited studies investigating their coupled effects. This research analyzed the coupled effects of climate change and land use change on urban drainage systems in terms of surface runoff quantity and flood area changes using EPA SWMM. The results show that climate had a greater effect on both runoff volume and flood area, although there was a clear cumulative effect of climate change and land use change. Additionally, the flood area variations are not only influenced by runoff quantity changes due to climate and land use change, but also by the terrain elevation of study sites. Specifically, for low-relief areas with shallow depression sinks, these two variables have no additive effects, while for surface with deep depression sinks, there are additive effects from climate change and land use change. The results of this study would assist stakeholders in city planning and flooding control for urban areas facing future climate and urbanization challenges.

ABSTRACT. University of Maryland Department of Environmental Science and Technology (ENST) 2018 graduates were a part of an interdisciplinary design team (Ripple) that won an international sustainability art design competition (Land Art Generator Initiative) to be installed at the Burning Man Fly Ranch in Nevada in 2022. The design team joined others at the 2022 Burning Man festival in the desert where up to 80,000 people had to sustain themselves for a week, managing to bring and then take away without a trace their food, water, shelter, waste and energy. This effort by ENST undergraduate students for their Senior Integrative Experience analyzed Burning Man reports, population estimates, remote imagery and first-person evidence supported by Ripple and other Burning Man team’s design members to calculate the carbon use impact of the event. In addition, the analysis determined the potential of and developed scenarios for solar and wind power production and energy distribution at the site as well as concepts for human and food waste to energy and potable water regeneration. Project objectives included developing a carbon use analysis of the Burning Man Festival event. In addition, assumptions and calculations are made and presented for creating scenarios for alternate renewable energy at the site including solar, wind and waste to energy. The intent of the analysis and a major objective of the effort is to develop student skills and knowledge in carbon alternatives to facilitate a more rapid transition of the Burning Man event away from fossil fuel supports. A final goal of the effort is transferring that information and approach to facilitate other small to medium sized population centers toward rapid societal carbon decent and regenerative ecotechnologies.

ABSTRACT. Anaerobic digestion (AD), the conversion of organic matter, is a potential biological solution to treat food waste (FW) while producing renewable energy. In this project, FW was fermented to create bioplastics using a halophilic bacteria that uses volatile fatty acids (VFAs) produced during fermentation of FW using two inoculum sources: anaerobic dark fermented (ADF) inoculum and micro-aerobic dark fermented (MADF) inoculum. After fermentation, the VFAs in the liquid component were used for bioplastic production, however, the residual solids still contain organic substrate that can be either refermented for more VFA production or processed via AD for renewable energy production. The objectives of this study were to: (1) determine the additional VFAs that could be produced from ADF and MADF solids; and (2) compare energy production, via methane (CH4), for the two residual solids using an anaerobic methanogenic inoculum. The solids were fermented for 23 days, and the energy production potential operated for 36 days. Gas chromatography was used to measure the biogas quality and VFA production for each treatment. The total solids, volatile solids, and chemical oxygen demand were measured pre-experiment and post-experiment. The results showed that the MADF residual solids in MADF content produced 35% more VFAs (5.62 g/L to 8.18 g/L) and ADF solids in ADF content produced 10% more VFAs (3.96 g/L to 4.93 g/L). The MADF residual solids produced 8% more CH4 production (429 mL/CH4/g VS) than ADF solids (395 mL/CH4/g VS). The carbon conversion efficiency of FW to CH4 was 38.1% and 41.5% for ADF and MADF residual solids, respectively, compared to only 32.7% for refermenting the solids into more VFAs. Using anaerobic digestion for the solids remaining after VFA fermentation is an efficient method to create a value-added bioplastics production in addition to renewable energy from food waste.

ABSTRACT. Drought frequency and variable rainfall is predicted to become more severe over the coming years and has implications for causing detrimental effects on essential ecosystem services that are governed by soil fauna. Drought may heavily impact free-living nematode enrichment opportunists that are essential for nitrogen (N) cycling. This study aims to investigate the impact of drought on biological nitrogen cycling within two contrasting systems, a perennial polyculture and row-crop system. This study was conducted at the KBS-LTER (Hickory Corners, MI), where drought was induced on early successional and row-crop no-till systems. Soil samples (10 cm depth) were taken during pre and peak drought in no-till and early successional systems using a 1.05 cm diameter soil probe. Samples were then analyzed for soil protein and abundances of nematode enrichment opportunists (nematode families that respond rapidly to N input). Results indicated that soil protein was greater in irrigated early successional communities than compared to all drought and no-till systems (p<0.05). In addition, nematode enrichment opportunist abundances were significantly greater in all irrigated systems when compared to drought systems (p<0.05). Abundances of enrichment opportunists were also greater in no-till systems when compared to early successional systems (p<0.05). These results indicate that drought has the potential to cause detrimental effects on nematode enrichment opportunists and have implications for N cycling. Systems with greater perennial diversity have the potential to increase the resiliency of biological N cycling under drought conditions.

ABSTRACT. The methods of embodied energy (Emergy) analysis and Life Cycle Assessment (LCA) were used in determining the energy/carbon/costs invested in the US Department of Energy’s (DOE) Solar Decathlon house entries from the University of Maryland. Questions aside from the valuation of the inputs to houses include the accessibility and affordability of the designs and technologies to most people. Can these houses be made to be affordable? Data available through the DOE’s Solar Decathlon information storage site and UMD’s own data files will provide student researchers access to UMD’s 2007 Second Place entry LeafHouse, 2011’s First Place entry WaterShed and 2017’s Second Place entry reACT. Information in the DOE online accessible data storage files include competition required uploads of all plans, specs, materials and equipment models used in each of the entries. The UMD Solar Decathlon faculty leaders for each of these entries are still available and active directly and indirectly through UMD. Student interviews with these competition faculty leaders, as well as attempts to identify and interview student leader participants from the past projects were made to help inform the assessments in terms of faculty and student participation levels as well as external professional involvement. The value of the Solar Decathlon to student educational development is assessed relative to the actual costs of carbon in the built structures and their intended offsets in renewable energy production and building approaches.

ABSTRACT. Small business owners invest heavily in their properties, and they are vulnerable to losing value in their investment at the hand of stormwater impacts. Joe’s Movement Emporium in Mt Ranier, Maryland knows this first hand, and has spent many years investing time and energy in their property to find creative stormwater solutions that support native ecosystems while protecting their business from harm. Joe’s team wants to help other small businesses in similar situations. All along the Route 1 corridor, there are structures built before the 1960s which are very susceptible to stormwater damage. Voluntary stormwater renovations in these types of buildings and in heavily urbanized regions often run into obstacles, and businesses struggle to find a way forward. This project aims to put together a manual detailing stormwater management practices for small businesses in urban areas. Using Joe’s Movement Emporium as an example and as a guide, students gathered a variety of resources and compiled them into a deliverable for Maryland Department of Natural Resources which can benefit the business community in the State of Maryland.

ABSTRACT. Montgomery County, Maryland is a Washington, D.C. urban and suburban jurisdiction which is providing leadership in climate resiliency planning in the state of Maryland. With numerous public school properties and years of bioretention and other green infrastructure projects implemented, the county was interested to understand the relative degree of carbon processing and sequestration that its projects at its school properties could provide. An analysis of the inventory of green infrastructure projects at county schools was completed with estimates of the potential for carbon accounting to determine the levels of carbon sequestration at the properties.

ABSTRACT. Though wetlands are routinely constructed to capture nutrients and sediments, relatively few studies have investigated their efficacy at the watershed scale. Our study uses the modeling programs PTMApp and ArcSWAT to determine the area of new wetlands necessary to significantly reduce nutrient and sediment loads to the outlet of a 805 km2, ‘Impaired Waters’, Clean Water Act Section-303(d) listed watershed in North Dakota. To determine the influence of spatial arrangement, we compare the results for three different wetland-construction scenarios: (1) one large wetland near the watershed outlet, (2) wetlands at the confluences of streams, and (3) numerous small wetlands throughout the watershed. Ecological, economic, and management considerations for each of the scenarios will be discussed.

ABSTRACT. Coastal communities are facing threats presented by climate change, worsened by failing infrastructure and impacts from upland development. Increasingly, these communities are pursuing nature-based solutions to achieve coastal resilience. It is important for nature-based solutions to create goals that are holistic in order to maintain resiliency long term. Nature-based solutions should not be independent but work together as a system to perform multiple functions, such as flood management, soil stabilization, carbon sequestration, nutrient cycling, and habitat creation. Regenerative Stream Conveyance (RSC) is a nature-based solution that can be applied across various scales of stream restoration and stormwater management and is a commonly used stream restoration technique in the Mid-Atlantic region. The principles of an RSC approach are based on mimicking nature to create conditions that facilitate ecosystem regeneration. RSC’s mimicry beaver dams through grade control structures support the restoration of stream-wetland complexes by reestablishing stream and floodplain connections. Dynamic living shorelines is another nature-based approach that uses natural techniques to stabilize shorelines through marsh establishment and the creation of headlands and shallow coves which provide habitat for aquatic flora and fauna. Dynamic living shorelines adapt over time, gaining strength through coastal forces that weaken traditional shoreline stabilization infrastructure. This presentation will highlight a site on Nabbs Creek in which two nature-based solutions, an RSC emergency repair and shoreline mitigation, operate independently from each other and have experienced shortcomings with resilience. It will also showcase a project that was designed and built integrating RSC and dynamic living shoreline together achieving a resilient system for the community.

ABSTRACT. In 2020 the AEES Body of Knowledge (BOK) Committee renewed efforts to outline the fundamental knowledge within the field of ecological engineering (EcoE). Specifically, the committee sought to identify the knowledge, skills, and abilities that academic programs should incorporate into an undergraduate EcoE program. To establish this knowledge, the committee first identified 15 example design projects (applications) that a recent EcoE graduate might work on. Example applications included the design of a treatment wetland and the development of a prairie restoration plan. Then, the specific tasks required by the graduate to complete the designs and the underlying knowledge or skills needed for each task were outlined. Additionally, the necessary level of learning for each knowledge area was qualified, ranging from simple knowledge of facts to integration of knowledge across engineering and ecology to develop designs. Each application area was reviewed by the committee and two outside EcoE practitioners. Following the development, review, and revision of the application areas, the knowledge, skills, abilities were condensed by identifying the common knowledge across the applications. This common knowledge is currently being summarized in the first EcoE BOK report. In addition to supporting the approval of ABET program criteria in ecological engineering, this document will provide academic departments guidance in developing EcoE curricula.

ABSTRACT. Amazon floodplain ecosystems are attuned to forest-climate interactions, which have governed species composition, ecological life cycles, and the timing and distribution of carbon, water, and energy cycling for millennia. The intensifying intrusion of wildfire into this flood-adapted ecosystem raises questions about future floodplain forest resilience under future climate change scenarios. While a handful of field-scale studies have assessed floodplain forest dynamics following fire and flooding in nutrient-poor igapo ecosystems, less is known about these effects in nutrient-rich várzea wetlands, which we hypothesize have greater sensitivity to fire disturbance. To test this hypothesis, we used Landsat 7 Normalized Difference Vegetation Index (NDVI) from 1984 to 2021 to analyze how fire affected forest resistance (percent change), resilience (autocorrelation coefficient), and coefficient of variation (CV) for 27 case studies across central Amazon floodplain forests which had been burned, burned and recovered, or undisturbed. Forests were further grouped into upland, floodplain, or seasonally flooded floodplains and igapo or várzea. Changes in annual NDVI were strongly associated with increasing fires (R2 = 0.92), especially in varzea floodplain forests (p < 0.01). For both igapo and varzea seasonally flooded floodplains, magnitude and variation metrics were of greater magnitude compared to nearby uplands (p < 0.05), indicating that floodplain forests exhibited higher responses to fire disturbance. Forest resilience, characterized by autocorrelation, was found to be 15% higher in várzea wetlands, suggesting decreased resilience relative to disturbed igapo wetlands. Using remote sensing indices of fire severity and forest response, we confirmed floodplain forest sensitivity to fire and found that whitewater floodplain ecosystems exhibited greater shifts in variance and autocorrelation, suggesting these understudied ecosystems may be more sensitive to wildfire disturbance than previously studied ecosystems. Additional field-scale studies remain critical for understanding how remotely sensed NDVI translates to post-disturbance vegetation composition and long-term forest resilience in Central Amazon floodplains.

ABSTRACT. Constructed wetlands play a role in the removal of nutrients, pathogens, and other contaminants from wastewater streams before discharging to natural bodies of water. The inherent role of constructed wetlands makes them hotspots for microplastic accumulation as millions of microplastics leave wastewater treatment plants through effluent every day. These microplastics flow through the wetland system aimed by natural and dynamic forces and can undergo physical, chemical, and biological transformation through the processes of fragmentation, degradation, biofouling, and settling. In order to investigate the transport and characteristics of microplastic pollution in a natural constructed wetland, environmental microplastic samples were collected in the Se7en Wetlands in Lakeland, FL, one of the largest wastewater constructed wetlands in the US (1600 acres) and has been polishing secondary treated municipal wastewater since 1985. The samples include both water and sediment samples collected at all control stations in each of the seven wetland cells. The collected microplastic samples were analyzed for size, shape, polymer type, and surface irregularities to inform how microplastics of different properties travel through the system. This study looks to inform how the dynamics of natural systems affect the fate and transport of microplastics and how constructed wetlands fare for the removal of microplastics from treated wastewaters.

ABSTRACT. Periphyton-based biofilters are a promising technology for water treatment and nutrient recovery in recirculating aquaculture systems (RAS). In this study, we examined the effect of system hydrodynamics on the performance of two pilot-scale (2,500 L) RAS with integrated periphyton biofilters, which were used to grow Ariopsis felis (hardhead catfish). Periphyton was harvested from polyethylene nets suspended in the biofilters on a weekly basis for use as fish feed. Conservative tracer tests on the RAS operated at varying hydraulic residence times (HRTs) revealed deviations from theoretical HRTs, indicating the presence of dead zones along the edge of the biofilter tanks, although low energy mixing occurred in the bulk of the tank. Growth of periphyton biomass was found to be primarily dependent on the nutrient mass loading rate; however, mass transport of aqueous nutrients to the periphyton increased with increasing fluid velocity. Dissolved oxygen (DO) production by periphyton photosynthesis also increased with increasing fluid velocity. The mass balance analysis on C, N, and DO gathered the physical, chemical, and biological results to elucidate the nutrient transformation pathways and quantities. The DO analysis revealed that periphyton provided 1.31 ± 0.20 mg DO/(L*m2*day) during daytime hours, which was nearly enough to support microbial and fish respiration without the use of a blower. Periphyton and filamentous algae, Oscillatoriaceae, removed 32 ± 4% of the input nitrogen from the feed that was not taken up by the cultured fish and 61 ± 3 % of the feed carbon input. The overall water quality goals for the catfish were either met or exceeded through application of periphyton biofilters.

ABSTRACT. Contaminants of potential concern (CPCs) are becoming a major source of water impairment throughout the world. Land use practices within urban and rural areas have shown to be sources of CPCs. Contaminants enter the environment through direct application or waste disposal with runoff and soil leaching depositing CPCs into streams and lakes. Therefore, this study sought to characterize the nutrients, heavy metals, pesticides, human pharmaceuticals, and personal care products appearing in streams across varying Kentucky landscapes. Field sampling included using both Polar Organic Chemical Integrative Samplers and water grab samples from March-October 2022 at four stream sites in an oil and gas, urban, mining, and agricultural regions of the Commonwealth. Results exhibited occurrence of contaminants varied by location, season, and flood conditions. The major contaminants appearing in surface waters across Kentucky are sulfate which reaches 1250 mg/L in the predominately mining watershed. Caffeine concentrations were found to be greater than 550 ng/L measured in the urban watersheds. Acetaminophen (19 ng/L in March) and Imidacloprid (83 ng Imidacloprid desnitro/L in May) were also found in the urban watershed. Atrazine concentrations were found in both agricultural and urban watersheds with concentrations of 2200 ng/L in June. The veterinary antibiotic, Sulfanilamide was present (49 ng/L in April). This study is the necessary first step in reaching the UN’s Sustainable Development Goals by developing a comprehensive understanding of land use impacts on contaminant presence and concentration in surface waters. Further, findings from this project will be incorporated into the design and placement of best management practices to limit the impact of CPCs.

ABSTRACT. Agricultural phosphorus contributions to water quality degradation are a significant concern within the Lake Champlain Basin (LCB) of Vermont. Agricultural conservation practices such as no-till and cover cropping have been introduced into agricultural systems to reduce erosion and loss of particulate-bound nutrients, which was traditionally assumed to extend to dissolved nutrients as well. However, this assumption has been shown to not always hold true, particularly in fields with mineral-rich soils and tile drainage. When paired with tile drainage, there are concerns that no-till and cover cropping are decreasing losses of particulate-bound phosphorus (P), but potentially increasing losses of dissolved P (DP). From a water quality perspective, a trade-off of particulate bound P for DP is not beneficial, as DP is more biologically available than particulate bound P and could lead to worsening eutrophication and harmful algal blooms (HABs), which are growing environmental problems in freshwater ecosystems across the world, including the LCB of Vermont, New York, and Quebec. Therefore, it is of great importance to develop agricultural conservation management practices that address the loss of DP. This study aims to evaluate the performance of four edge-of-field iron-based filters for the removal of DP from surface and subsurface agricultural drainage from two fields in corn silage production in the LCB of Vermont. Results of surface and subsurface monitoring from study fields will be presented, as well as an analysis of the preliminary performance data for the phosphorus removal structures.

ABSTRACT. Bioretention systems are shallow depressions in the landscape that capture and treat urban and agricultural runoff. However, removal of dissolved reactive nitrogen species in these systems is limited due to short hydraulic retention times and lack of environmental conditions that promote biological nitrogen transformations. In this study, we evaluated the use of biochar amended bioretention systems for nitrogen removal in agricultural runoff from a plant nursery. The treatment of nursery runoff is important because it holds excess fertilizer with a unique mixture of nitrogen species, phosphorus, and other micronutrients. Biochar was added to high permeability porous media because of its high cation exchange capacity, which retains ammonium ions in the system allowing more time for nitrification. Biochar also has a high specific surface area for biofilm growth. Two pilot-scale bioretention units were used to compare wood chips and sulfur pellets within an anoxic internal water storage zone, to promote denitrification. Prior results by our group for treatment of dairy farm runoff showed that biochar improved average total nitrogen removal efficiency from 77% to 95%. Bioretention cells that included both biochar and plants had the highest total nitrogen removals. New results from an ongoing field studies at a plant nursery will be shared at the meeting.

ABSTRACT. Craft breweries produce large amounts of waste, which can cause environmental degradation without proper management and the waste management can be an economic burden for the breweries. However, recovering resources from wastes such as capturing carbon dioxide CO2 from fermentation and reusing it in the brewing process can reduce operating costs and CO2 emissions. This study evaluated the potential for onsite resource recovery from craft brewery wastes through anaerobic digestion (AD) and CO2 recovery. An EXCEL spreadsheet tool has been developed to investigate the cost and benefits of implementing AD and CO2 recovery systems for craft brewers at different scales, including energy generation, waste diversion savings, and GHG reduction. The tool also included various options of biogas utilization that may impact their facility economically. The tool’s input interface included the general information, waste amount and management, energy consumption, and CO2 consumption of brewery. The tool’s output interface provides: 1) AD system design, biogas production, net energy value, and CO2 offset potential; 2) waste diversion savings; and 3) initial capital investment, operations, and maintenance costs. The payback period for various biogas utilization scenarios was determined using estimated cost data, avoided costs, and revenues. Based on the spreadsheet tool, using AD and CO2 recovery systems in craft breweries could be feasible if the brewery’s annual production is over 50,000 hL (~43,000 barrels)/year. Some other positive impacts were difficult to monetize and not included in the tool, such as reducing the loading to treatment plants and potential future governmental carbon credits.

ABSTRACT. Florida has > 200 craft breweries providing > 160,000 jobs, and > $1.2 Million in tax revenue.  However, breweries have high water and energy demands, and generate large quantities of high-strength waste including spent yeast, grains, hops and effluent wastewater. This waste can be remediated naturally through anaerobic digestion (AD) in which microorganisms convert organic matter to methane (a usable energy source) in the absence of oxygen. However, hops contain alpha acids, which have antimicrobial properties that can be toxic to anaerobic microorganisms. The effects of co-digestion of hops with spent yeast are unexplored.   The objective of this study was to evaluate the effects of hops in AD through batch and anaerobic sequencing batch reactor (ASBR) studies. Co-digestion of yeast and hops was tested by setting up batch bioassays with varying hop concentrations of 20% and 40% based on chemical oxygen demand (COD). An assay with pure yeast, and no hops was used as a control. Three identical ASBR reactors were operated at a hydraulic residence time of 55 days, a solids residence time of 50 days, and an organic loading rate of ~2,000 mg COD/L/day. ASBRs were fed with spent brewery yeast, with added hop waste of 0%, 20%, and 40% by COD. Results showed that spent brewery yeast is highly biodegradable under AD conditions, resulting in rapid volatile fatty acid production that can decrease pH, resulting in poor methane yields. This can be prevented by co-digestion of yeast and hops. Specific methane yields from the batch study were 1.5 mlCH4/gCOD, 106 mlCH4/gCOD, and 88 mlCH4/gCOD, for 0%, 20% and 40% hop addition, respectively. ASBR studies are ongoing, and results will be presented at the meeting.

ABSTRACT. Tertiary treatment can be used to prevent eutrophication in streams or lakes where wastewater may be disposed of and to allow the possibility of reuse of treated wastewater. This project builds on previously published research which established the process of making and testing alginate macrobeads containing co-immobilized bacteria (Azospirillum brasilense) and microalgae (Chlorella sorokiniana). These macrobeads were found to successfully remove nitrogen and phosphorus from synthetic and municipal wastewater when the system was treated as a batch reactor. However, the effectiveness of the bead reactor at removing nitrogen and phosphorus from other wastewater types, and using other reactor designs, has not been tested. The aim of this research is to optimize a general reactor design to increase nutrient removal from aquacultural wastewaters. This involves designing the system as an activated sludge process where the macrobeads are recycled back into the system. The design of the system as an activated sludge process is predicted to increase nutrient removal and lower cost through a lower requirement of macrobeads. Results from preliminary trials at the benchtop scale are presented, and considerations for scale up are considered. In the future, the reactor design will be repeatedly optimized to suit treatment of specific agricultural wastewaters.

ABSTRACT. Anaerobic digestion is the process by which microorganisms break down organic matter in oxygen-absent (i.e., anaerobic) conditions, producing biogas. Composed of methane (CH4) and carbon dioxide (CO2), biogas can be used as a renewable energy source. In this study, food waste underwent dark fermentation followed by anaerobic digestion. The study objectives were to determine and compare the CH4 production of two fermented food wastes and non-fermented food waste. The experiment had three triplicate treatments and one triplicate control: (1) anaerobic dark fermented food waste + inoculum (DF); (2) micro-aerobic dark fermented food waste + inoculum (MADF); (3) non-fermented food waste + inoculum (FW-only); and (4) inoculum only (Blank). A biochemical methane potential (BMP) test measured the biogas production (CH4, CO2) in batch conditions over 37 days, at which time the daily biogas production was less than 1% of the cumulative biogas produced. Gas chromatography was used to measure the quality of the biogas produced over the testing period. Total solids (TS), volatile solids (VS), chemical oxygen demand (COD), and soluble COD (sCOD) were measured pre- and post-digestion. The results showed that CH4 production was 62.7% and 63.2% greater in DF and MADF treatments (701 and 707 mL CH4/g VS, respectively) compared to non-fermented food waste (443 mL CH4/g VS). There was less than 1% difference between DF and MADF energy production, but MADF had a greater percent CH4 in the biogas (74.1%) than DF (69.9%). On average, the VS concentrations decreased by 43.2% and the COD values decreased by 50.7% from pre- to post-digestion, showing the conversion of organic matter to biogas. The study results found that fermented food waste produced more renewable energy than without fermentation. Fermentation can be used prior to bioplastic production from food waste or anaerobic digestion of food waste.

ABSTRACT. In North Carolina, the use of constructed stormwater wetlands is often avoided due to higher construction costs as a consequence of their size. But recent studies have found that current design recommendations may be resulting in oversized systems from a water quality treatment standpoint. One study of a linear three-part wetland found that 80% of pollutant removal occurred in the first section, with diminishing returns thereafter. The reason this occurs is that stormwater wetlands are typically sized in the same way as stormwater ponds: based on temporary storage of a treatment volume. We are exploring an alternate design methodology based on wastewater treatment wetlands, which are optimized to handle specific flow rates rather than specific volumes. To test this, a pump-driven flow-through wetland, sized using the relaxed tanks-in-series (P-k-C*) model adapted for stormwater wetlands, is being constructed in Wilson, NC. Water samples will be collected from various points along the wetland flow path during storm events and during baseflow conditions between storms to analyze nutrient removal capability. The results of this study will be used to inform and potentially modify current design practices in North Carolina to make stormwater wetlands a more cost-effective SCM.

ABSTRACT. Stormwater runoff is often assumed to be an important pathway for microplastics from the terrestrial to the marine environment, although few studies have attempted to quantify the significance of this pathway or the interactions between stormwater infrastructure and plastic pollution. The objective of this study was to determine what factors influence the concentrations and behaviors of microplastics in stormwater ponds. Samples were taken from the water and bottom sediments of six stormwater ponds in Tampa (Florida, USA) using a neuston net and a sediment dredger. They were processed using a combination of density separations, visual sorting, and Raman spectroscopy. Concentrations ranged by several orders of magnitude between sites and rounds of sampling (0.0–55.5 items/m3 in water, 2.5–203.0 items/kg dry weight in sediment). The ratio of impervious drainage area to pond surface area was found to be positively correlated with sediment concentrations. Particle shapes in water were more variable than those found in sediments, suggesting that regular-shaped plastics tend to settle first. Circularity was identified as an important parameter in determining settling behaviors. Shape characteristics were similar to those observed in a downstream river, suggesting that degradation leading to the observed shapes occurred prior to entering the ponds. This study highlights the importance of stormwater infrastructure in understanding plastic transport and how plastic shape characteristics can impact their behavior in the environment.

ABSTRACT. Phosphorus (P) total maximum daily limits (TMDLs) have been established for the Vermont portion of the Lake Champlain Basin in response to the threat excess nutrients pose to water quality and aquatic ecosystems. VTrans, the Vermont Agency of Transportation, is working to improve its P removal in stormwater infrastructure along transportation networks to help meet watershed P load reduction targets. There is a need for effective P removal media in filter-based best management practices. In this project, we are studying roadside sand filter performance in the field to determine the benefits of incorporating drinking water treatment residuals (DWTRs). VTrans recently constructed three stormwater treatment systems that include alum-based DWTRs. These DWTRs were shown to be promising for P removal in previous laboratory studies at UVM. Here, we are monitoring the retention of total P, soluble reactive P, dissolved organic P, particulate P, and chloride during storm events. Results from this study can inform efforts by transportation agencies to implement sustainable, low-cost, and low-maintenance practices that reduce phosphorus contents in runoff in transportation networks.

ABSTRACT. The use of commercial insecticides to control insect populations have increased dramatically since the early 2000s. Pyrethroid compounds specifically have dominated the global pesticide market due to their high insecticidal activity within agricultural and urban environments. However, leaching of these compounds via direct application or surface water runoff can distribute toxic residues into groundwater systems and harm non-target species within an ecosystem. This leads to contaminated soil and water sources, which presents a need to develop strategies to remediate sites with pyrethroids and their degradation products. Woodchip bioreactors have been extensively studied for their ability to reduce high nutrient load from agricultural runoff. The goal of this study is to evaluate the fate of two popular pyrethroids (cypermethrin, lambda cyhalothrin) in a passive woodchip biofilter. Twelve woodchip biofilters were constructed using PVC tanks for four treatments in triplicate, consisting of Cu metals, Al metals, combination of soil amending materials biochar and peat moss, and control (woodchips only). It was hypothesized that the pyrethroids would be removed by biodegradation, adsorption into media, and other environmental factors including pH, temperature and light. Two separate stocks were made to dissolve 100 ppb of cypermethrin and 25 ppb of lambda cyhalothrin in acetonitrile. Compounds were spiked in source tank at a volume of 50 L with a flow rate of 6.48 mL/min and HRT of 9 days. A five-day flushing period was followed while collecting effluent samples and analyze concentrations using the Quechers Extraction method and GC-ECD. Statistical analysis was performed to compare the removal efficiencies among treatments. The research can potentially aid the design of low-cost, passive treatment biofilters that can efficiently remove pesticide residues and keep water resources clean.

ABSTRACT. Agrochemicals are needed to produce food on a mass scale for an ever-growing world population. However, there is a recurring issue of agrochemicals, namely pesticides and antibiotics, finding their way into the environment after application as they leach or run off into water bodies, enter the atmosphere through spraying and volatilization, and persist in soil and water. According to the WHO and UNEP, there are 26 million poisonings and 220,000 deaths from pesticides per year worldwide. Constructed wetlands (CWs) have been studied as a cost effective and sustainable application with the goal of remediating agrochemicals found in the environment through a combination of physical, chemical, and biological processes involving plants, microorganisms, and soil medium. In this ongoing experiment, we study the removal of eight commonly used agrochemicals- glyphosate, lambda cyhalothrin, cypermethrin, atrazine, 2-4-D, oxytetracycline, sulfamethazine, and ceftiofur. Synthetic wastewater containing the chemicals flowed through three hybrid wetland microcosms consisting of surface flow wetland and horizontal-subsurface flow wetland with a 6-day hydraulic retention time and flowrate of 16.3 L/D. A peristaltic pump was used to establish the flowrate of influent to the systems. The surface flow wetlands contained duckweed, while the subsurface flow wetlands contained bulrush and cattail plants with large pebbles, granular pebbles, and sand as substrates. Influent concentrations were determined based on detection level and the literature. Analysis of water samples after passing through surface and subsurface flow wetlands was used to evaluate the removal of agrochemicals from the influent. The first chemical analyzed, glyphosate, was removed at greater than 98% by the hybrid wetland systems. Evaluation of the nature-based passive treatment solutions to agricultural non-point source pollution is important to help keep our water safe and clean.

ABSTRACT. Eutrophication of freshwater systems threatens water quality, aquatic ecosystems, human health, and recreation. In freshwater systems like Lake Erie, phosphorus (P) is commonly the limiting nutrient. Thus, international efforts are underway to reduce P loads, aiming for a 40% reduction across the Lake Erie basin. Targeting best management practices (BMPs) may accelerate progress towards this goal by addressing fields responsible for disproportionately greater P loads. Models have been effective at demonstrating the value of targeted management but have neglected to incorporate soil test P (STP) data representing legacy-P field contributions. This study quantified the benefits of targeting a BMP (P-filters) to legacy-P fields as opposed to random placement using a field-scale Soil and Water Assessment Tool (SWAT) model. A Monte-Carlo simulation was conducted to determine the uncertainty in this benefit. A SWAT model of the Maumee River watershed was updated to include a representative distribution of STP concentrations observed across the region. The computed tile and surface soluble P losses were studied to estimate soluble P loads from agronomic fields (< 100 ppm STP) and legacy-P fields (>= 100 ppm STP). Equivalent acreages were randomly selected to estimate the P-filter load reductions for a targeted approach versus a non-targeted approach. A Monte Carlo simulation was applied to elucidate the uncertainty of each at incremental amounts of adoption (10-100%). Further, different rates of P reduction were assumed for the P-filters (30-50% reduction). Legacy-P fields were responsible for greater soluble P concentrations (0.231mg/L) compared to agronomic fields (0.084mg/L) in the SWAT model. Assuming P-filter adoption across the equivalent areas totaling all legacy-P fields showed that a targeted approach yielded 2-fold greater P load reductions compared to a random placement approach (7.4% vs. 3.5%).

ABSTRACT. Excess nutrients, such as nitrate (NO3-) and phosphate (PO43-), in waterways is a global concern that results in harmful impacts to human and aquatic health. This research evaluates autotrophic denitrification as a strategy to reduce NO3- and support PO43- adsorption from contaminated water. More specifically, it examines the use of two abundant materials, sphalerite and oyster shells (OS), to facilitate autotrophic denitrification of wastewater in bench-scale sequencing batch biofilm reactors (SBBRs). Bench-scale SBBRs packed with sphalerite and OS were constructed and monitored to track nutrient removal using ion chromatography. The microbial community of the SBBRs was also characterized to uncover the mechanisms of NO3- removal using 16S rRNA amplicon sequencing. NO3- decreased at a rate of 0.26 ± 0.043 mg NO3--N/(L · d) in the SBBRs, while PO43- removal declined from 64% to 45% over 230 days. 16S rRNA amplicon sequencing indicated that species of Chromatiales, Burkholderiales, and Nitrosomonadales played a role in NO3- reduction. Media from the SBBRs are currently being analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS) to elucidate the mechanisms of PO43- adsorption. Results from the SEM-EDS analysis will be presented at the 23rd America Ecological Engineering Society Meeting. Knowledge from this work will provide a comprehensive understanding of nutrient removal during sphalerite and OS-driven denitrification, which was previously unknown. Based on the results so far, sphalerite and OS could be used in autotrophic denitrifying technologies. However, slow NO3- removal rates and moderate PO43- removal efficiencies may limit the application of this process. Nature-based designs that maintain long hydraulic residence times, such as horizontal subsurface flow constructed wetlands, might be suitable to harness sphalerite and OS-based denitrification for NO3- removal. Future research should explore the use of sphalerite and OS in constructed wetlands and investigate strategies to improve nutrient removal.

ABSTRACT. A growing population and increased need for nutritious foods in conjunction with a finite amount of space and limited resources has created an opportunity for innovation in our current food system. Aquaponics is one method being explored to couple production of protein-rich fish with the growing of various vegetables using relatively small amounts of space and water. These systems require an understanding of numerous concepts related to ecological design and engineering, including nutrient cycling, water chemistry, biological wastewater treatment, plant fertility, fish rearing, and food systems. At the University of Vermont, a group of 9 students with the guidance of Dr. Eric Roy and Dr. Theodore Willis designed and constructed a 600-gallon aquaponics system to further understand nutrient cycling as well as to grow produce to be donated to the UVM Campus food shelf, Rally Cat’s Cupboard. The initial construction phase consisted of researching designs examining different hydroponic methods such as deep-water culture (DWC), nutrient film technique (NFT), or ebb and flow design. Supply chain delays and shortages caused the group to construct a lot of the materials instead of purchasing them prebuilt. Water quality monitoring was also a very important aspect of the aquaponics system and to do this an Arduino-based system was created to monitor dissolved oxygen, pH, conductivity, and temperature on an hourly basis. The aquaponics system has been in smooth operation since summer of 2022, with fish and plants both growing well. Data are now being used by another group of students at UVM to further understand nutrient cycling with a focus on the nitrogen cycle. This system has also been used as an educational tool with the Eco Design Co-Op at UVM and as an introduction to alternative agriculture for students at Chittenden County’s technical high school.

ABSTRACT. Non-point source nutrient pollution is a “wicked” problem that persists as a global environmental challenge. A significant non-point nutrient source in Florida is legacy phosphorus from agriculture and mining activities embedded in sediments and soils. Aquatic Nutrient Reduction Barriers (ANRBs) are a new technology proposed for addressing legacy phosphorus sites, such as our study site at Cargill Ditch in Lakeland, Florida. In these systems, surface water flows through a permeable barrier to filter and settle particulate phosphorus. The novelty of this project is the amendment of aquatic barriers with an adsorbent medium. Adsorbent-amended ANRBs have the potential to remove total phosphorus by combining filtration, sedimentation, and adsorption mechanisms. In this study, we evaluated the effectiveness of candidate adsorbents in removing dissolved phosphate directly from surface water within the constraint of the short contact time available through the ANRB in flowing water bodies. Four adsorbent materials were initially screened to design a pilot-scale ANRB, including three biochar-based materials and one proprietary adsorbent. Adsorption equilibrium, phosphate uptake kinetics, material characterization, and hydraulic conductivity studies showed that adsorbent contact time would vary based on materials between 1.5 and 3.2 seconds per inch of the barrier. The proprietary material showed the best potential for phosphate adsorption, but all materials showed the potential for anion removal at an hourly time scale. Rapid small-scale column tests are in progress to further investigate phosphate removal rates under similar hydraulic and phosphate loads as historically monitored at Cargill Ditch. The pilot ANRB will be deployed this spring at a former phosphate mine at the Cargill Ditch in Lakeland, Florida, which encounters intermittent algal blooms from legacy phosphorus.

ABSTRACT. Anaerobic bioreactors that host sulfate-reducing bacteria (SRB) are an effective tool for treating trace metal contaminated water by precipitating dissolved metals into insoluble metal sulfides. These systems are generally designed with natural organic substrates submerged in water to create anoxic conditions that favor dissimilatory sulfate reduction and subsequent sulfide production by SRB. Although this is a naturally occurring biogeochemical process in aquatic sediments and is widely observed in treatment wetlands, the bioreactor design amplifies biological sulfide production compared to treatment wetlands due to greater organic matter in the substrate providing more carbon for the heterotrophic SRB, increased natural or added sulfate concentrations, and longer contact time between the water and the anaerobic zone of the system. This research analyzed a vertical flow bioreactor with a mixed substrate of mushroom compost, woodchips and limestone sand at the Tar Creek Superfund Site in Ottawa County, Oklahoma, part of the Tri-State Lead-Zinc Mining District, once one of the most prolific mining areas in the world. This bioreactor is one of two in a larger treatment train at the Mayer Ranch Passive Treatment System that has effectively treated sulfate rich (> 20 mM) net alkaline mine drainage for 15 years. Detailed information on the microorganisms involved in bioremediation at this site is currently limited so analyses of the SRB and microbial community were performed. SRB were isolated from the bioreactor substrate with enrichment cultures to characterize their tolerance to trace metals and a prokaryotic environmental DNA survey using 16S rRNA gene sequencing was performed to gain insight into the microbial community in the bioreactor. At least 16 putative SRB isolates have been cultured and further research will seek to characterize the physiological and genetic characteristics of selected isolates related to mine drainage remediation.

ABSTRACT. In the Lake Champlain Basin that occupies most of western Vermont, the degradation of water quality combined with increased and stronger flood events impact ecosystem function and human health. Riparian wetlands and floodplains allow for trapping of sediments, collection of sediment-bound nutrients, and decreased flow during flood events. Restoration of riparian wetlands on former agricultural lands through conservation easement programs may benefit both people and the environment. We monitored five restored riparian wetlands during several flood pulses to quantify phosphorus (P) accretion on the soil surface. Rates of P accretion were measured at multiple locations at each site using tile or artificial turf markers placed prior to flooding and collected during summer when plots were dry. Sediment, plant litter, and detritus accumulated on the surface markers during the year and were analyzed for P, as well as nitrogen and carbon. Spatial variation in P accretion across individual sites provides insight into flood dynamics and wetland P cycling. Flood water source and caliber of suspended sediments described some of the variability in P accretion patterns. Results can inform ecosystem models used to estimate net P retention in these environments.

ABSTRACT. A greenhouse ecosystem, often referred to as a Living Machine®, is a technology for biological wastewater treatment. This technology has a small footprint relative to traditional on-site systems, can manage high strength wastewater and can provide a high level of treatment to allow reuse for purposes such as irrigation, toilet flushing, and landscaping (Worrell Water Technologies, San Fransisco Water Power Sewer Website) . Craft beverage wastewater (winery, brewery, and cidery wastewater) is a high strength wastewater with high concentrations of chemical oxidation demand (COD), nitrogen, and phosphorus, which is difficult to treat in a traditional wastewater treatment systems. This project explores the use of a greenhouse ecosystem to treat craft beverage wastewater on site. Feasibility is being tested at the bench scale and includes a control system and two replicates, each with three reactors in series with 5 species of plants native to Michigan (Acorus americanus, Decodon verticillatus, Schoenoplectus pungens, Typha augustifolia, and Lemna minor). Synthetic wastewater is being tested first to determine the effect of high concentrations of salt, yeast, sanitizing chemicals, caustic chemicals, and COD on plant health and growth and microbial communities around the roots. Thereafter, actual wastewater will be run through the system. Nitrate, nitrite, COD, pH, dissolved oxygen, salinity, and oxidation-reduction potential (ORP) will be monitored, as well as visually inspecting the plants and checking microbial viable cell count by cytometry.

ABSTRACT. One source of reactive nitrogen to the environment is incomplete wastewater treatment from onsite wastewater treatment systems (OWTS). This study is being conducted in the context of Laughing Bird Caye National Park (LBCNP), in Belize where reactive nitrogen has led to excess algal growth that negatively impacts coral reef ecosystems. A complicating factor at LBCNP is the use of seawater for toilet flushing, due to the lack of available freshwater resources. Seawater is used to flush toilets in a number of coastal regions including Hong Kong, Avalon (California), Marshall Islands, and Kiribati. Seawater chemistry can make wastewater treatment more difficult and interfere with microorganisms involved in biological nitrogen removal (BNR). The goal of our research is to test the viability of using BNR in passive onsite wastewater treatment systems that treat wastewater generated from seawater-flushing toilets. This will inform the design of a full-scale onsite wastewater treatment system at LBCNP. Passive onsite BNR systems rely on 2-stage biofilters, with passive aeration in the first stage to promote nitrification and second-stage submerged biofilter containing a solid phase electron donor to promote denitrification. Bench scale column and batch reactors were set up in our laboratory and operated with domestic wastewater (~ 50 mg/L total inorganic nitrogen) amended with ocean salts to increase wastewater salinity. Stage-1 biofilters achieved 78% conversion of ammonia to NOx (Nitrite plus Nitrate) at 3% salinity. For Stage-2 biofilters, locally available agricultural waste products, sugarcane bagasse and banana stem, were tested alongside conventional solid-phase electron donors, elemental S0 and pine woodchips. Pine woodchips and banana stem achieved the highest denitrification rates, with a zero-order denitrification kinetics of 31 and 34 mg-N/L·day respectively at 3% salinity. The results indicate that passive BNR systems are a technically feasible alternative for regions where seawater is used for toilet flushing.

ABSTRACT. Treatment of stormwater run-off in Ultra Urban environments is complicated by high peak flow-rates, low pollutant concentrations and low land availability for attenuation. Conventional methods such as retention ponds have high land requirements and are ineffective at removing dissolved nutrients such as ammonia and nitrate. High nitrogen loads to surface water systems can proliferate algal blooms leading to eutrophication and ecosystem collapse. The objective of this study is to test the efficacy of nitrogen removal in pilot scale biofilters containing high permeability media amended with biochar. Biochar is produced by controlled combustion of biomass such as wood waste that results in high surface area, high ion exchange capacity, and novel surface chemistry and hydraulic properties. Media characterization and a bench scale column studies were performed to compare solute capture performance for each drain style. Pilot systems were then constructed by two filling rain barrels with 0.76 meters of amended media each. Two different drain styles were compared, one elevated with an anterior outlet and the second free draining with its outlet under the barrel. Moisture probes were placed in the media to provide water content data every 0.08 meters. Hydrus simulations were used to study the media’s dual-porosity properties. Testing of these pods is currently underway, using nitrogen contaminated stormwater run-off at varying hydraulic loading rates to mimic real storm events. Preliminary data suggests 50% total nitrogen removal enhanced biological nitrification of both biopods due to adsorption of organic N and ammonia on biochar and denitrification.

ABSTRACT. The growing population has tripled the consumption of the earth’s natural resources leading to an increase in waste generation. In 2018, the U.S. produced 292.4 million tons of municipal solid waste (MSW). MSW consists of mainly organic material that can be used as feedstock for biogas production however the heterogeneous nature of its characteristics affects the bioconversion energy pathway. As weather changes and the MSW sources may affect the bioconversion efficiency, there need to assess the spatial-seasonal variations and physio-chemical properties of High moisture OSW for SS-AD. Manual sorting of MSW from the university, restaurant, grocery, and landfill was conducted to understand the composition MSW. Preliminary study results show that MSW mainly consists of 93% organic fraction, the rest being inorganics. The organic solid waste (OWS) was divided into three streams namely, Low moisture, High moisture, and Recyclables. High moisture organics (food and yard wastes) dominated at 48.5% followed by low moisture organics (film plastics, paper, styrofoam) at 28.7 %, and the recyclable organics (heavy plastics, cardboard, rubber, fibers, and textiles) at 15.8%. The physio-chemical characterization of High moisture OSW revealed a pH range of 4.3-5.8, Total solids, 24-33.9%, Volatile Solid content 21.9-38.6%, COD 255-572g/L and Bulky density 172.2-1021g/L. The C/N ratio for Low moisture ranged from 67.8-1696.3. Our results show that biogas production using SS-AD may be impactful due to the high total solid and volatile content of the High moisture OSW. This multi-scale characterization study is a novel attempt to assess in-depth variation in the MSW composition and characteristics in different seasons. It will help to expound on properties that independently and synergistically influence preprocessing, and Solid-State Anaerobic Digestion (SS-AD) of OSW. This will lead to characterizing circularity of the entire MSW value chains to produce biogas, avoid landfill and promote circular carbon economy.

ABSTRACT. The use of treatment wetlands offers a cost effective and low maintenance solution to nutrient based pollution carried by runoff from agricultural. Wetlands are efficient denitrifying environments where excess nitrate is converted to dinitrogen gas. However, one of the drawbacks to using these systems is the potential for release of N2O during incomplete denitrification and the production and release of methane from anaerobic zones inherently found in wetlands. Plant selection for these systems is critical as variation in aerenchyma tissue can influence plant facilitated gas release. Further, carbon quality of plant detritus and root exudates has been shown to affect biological activity, and therefore the rates of denitrification and N2O and CH4 production. We will use mesocosm experiments to study the direct and indirect effects of vegetation on greenhouse gas production and emission pathways different plant species may exert in wetland mesocosms. Rice cutgrass (Leersia oryzoides), reed canary grass (Phalaris arundiacea), American water plantain (Alisma subcordatum), and an unplanted control mesocosm have been selected, and planting will occur in Spring 2023 for measurement through the growing season. Plant facilitated gas release will be measured by comparing gas flux measured in samples from non-steady state flux chambers placed over plants, to flux chambers placed on water which will capture the net flux from plants, diffusion and ebullition through the water column. We will measure dissolved N2, N2O, and CH4 collected from samples of the water column and CH4 concentrations in the water using sensor data. We will compare rates of denitrification and methanogenesis across different plant treatments. Pathways of production and release of CH4 and N2O will be tracked to evaluate how plant community composition alters greenhouse gas emission. These findings will help wetland managers identify optimal plant communities to maximize benefits and minimize drawbacks of wetland restoration.

ABSTRACT. The Algal Turf Scrubber is a biotechnological innovation that utilizes periphytic communities of filamentous algae in channels of flowing water to remove pollutants, while efficiently producing biomass that is usable for creating valuable products. Although the ATS has been employed in limited applications for nutrient recovery from impacted waters, advancement has been limited by difficulties with experimentation at scale. There has been a need for an approach for replicated study at the bench scale to advance the research and understanding of ATS systems. This research summarizes an approach being developed for replicated study of ATS systems at the bench scale. To fulfill this need, prototypes were made using off-the-shelf materials requiring limited specialized assembly. The proposed system unit is an individual flow lane, with isolated controls for flow rate and light intensity. Lids produce a semi-isolated environment to minimize contamination that may affect experimental results while carefully controlling individual conditions. The small size of each system allow containment of multiple systems within a rack, allowing for effective space usage while maintaining the length needed to simulate the stream effects to grow filamentous green algae, while disconnectable and modular parts allow for easy removal for harvest and sterilization. The utilization of inexpensive materials such as PVC pipe for the base and drain, 3D printed sections for select parts, and LED strip lights as the energy source make the systems economically replicable. Prototypes were built and tested in a series of colonization and growth trials using characteristic filamentous green algae. Overall, growth rates were positive and comparable to other candidate systems at the same scale. Future experiments with the system are planned that explore the role of bacteria and the overall bacterial community in the initial attachment and colonization stages of the algae after inoculation, for which the systems were designed.

ABSTRACT. The use of the EPA Chesapeake Bay Program approved Best Management Practice Algal Turf Scrubber (ATS) is applied to a regional tidewater park on Anacostia River in Maryland. Bladensburg Waterfront Park has become a demonstration area for novel ecotechnologies. The operation of the ATS at the park at pilot scale has developed algal biomass production rates which can be applied to a proposed scaled-up 1,000m2 ATS at the park. The designed integration of an anaerobic digestion system to accept the biomass and convert it to methane is calculated. The hypothetical use of the methane in a microbial fuel cell to create electricity for use in the park is assessed as well as the potential of the ATS to mitigate the impervious surface impacts for nutrients and sediment at the park are presented.

ABSTRACT. Landfill leachate is highly contaminated with ammonia, refractory organic matter, color and heavy metals, which interferes with wastewater treatment processes. Hybrid subsurface flow constructed wetlands (CWs), consisting of a Vertical Flow (VF) CW followed by a Horizontal Flow (HF) CW, have been used for onsite leachate treatment. However, these systems cannot meet advanced wastewater discharge or reuse standards. This research investigated the potential of amending hybrid CWs with low-cost adsorbents, zeolite and biochar, to enhance leachate treatment. Two mesocosm scale hybrid CWs were constructed at the Southeast Hillsborough County landfill in Florida. Control-CW was filled with conventional gravel medium. Adsorbent-CW was amended with 10% (v/v) of zeolite in the VF CW and 13% (v/v) of biochar in the HF CW. Both systems were planted with cattails (Typha spp) and cordgrass (Spartina alterniflora) and operated at varying hydraulic retention times (11d, 7d, and 4.5d) for ~2 years. A HF CW containing wood chips (Woodchip-CW) was added downstream of the Adsorbent-CW during the final 6-months of operation to enhance denitrification. Results showed that zeolite addition to VF CW significantly increased nitrification rates by 16-93% due to cycles of ammonium adsorption and bioregeneration under intermittent loading conditions. Biochar addition increased removal of organic matter (21-26% to 29-44%) and color (1-18% to 7-49%), and dramatically improved wetland plant growth and nitrogen uptake due to lower free ammonia concentrations and enhanced rhizosphere microbial activity. Addition of the Woodchip-CW reduced nitrate accumulation, resulting in total nitrogen removals of up to 79%.

ABSTRACT. This proposed research aims to develop a bench-scale system for small batch growth of filamentous algae in varying flow environments. The motivation behind this experiment is the need to understand the colonization of surfaces by filamentous algae in small-scale replicated experiments. While larger units used for research have shown success in algae cultivation, they generally require more time, space, and resources, and are difficult to control and replicate. Furthermore, these larger models are susceptible to contamination from competing microorganisms as they are generally in open environments. The objective of the proposed small-scale models is to minimize resource consumption, reduce production time, and enable easy sterilization and containment. The smaller models would also provide flexibility in changing variables, such as nutrient dilution, without the need for large volumes of water. On this poster the proposed methodology is shown.

ABSTRACT. The marine alga Asparagopsis taxiformis (AT) has been shown to produce metabolites that are anti-methanogenic in ruminant digestive tracts, but large-scale cultivation of AT remains elusive. The goal of this this research project is to optimize the growth and production of AT's antimethanogenic secondary metabolites in a scalable format of an algal turf scrubber (ATS) approach to find an economical approach to farming AT.

The first objective is to conduct a bench-top experiment to understand the effect of fluid shear stress on AT growth and production. Following that, the second objective is to adapt the AT into an ATS system and investigate its response to cultivation at a larger scale. Additional experiments will explore the effects of lighting intensity, flow rate, and nutrient concentrations on growth and secondary metabolite production.