Introduction Partial nitrification/denitrification coupled with anaerobic ammonia oxidation (PdNA, PANDA) process has the potential to result in capacity, chemical and energy savings at water resource recovery facilities (WRRFs). In this process, ammonia oxidation is controlled to achieve a specific NO3/NH3 ratio. Partial denitrification driven by supplemental carbon addition (e.g., methanol) is then used to stably generate NO2--N accumulation. Anaerobic ammonia oxidizers can then remove both nitrite and ammonia to achieve effluent NH3 and TN limits. Successful PdNA/PANDA has been documented in pilot and full-scale. This work documents advancement and implementation of PANDA at the Fairfax County Noman M. Cole Pollution Control Plant (NCPCP) to achieve TN limits less than 3 mg/L. Specifically, the work will discuss full-scale results demonstrating effective anoxic ammonia removal via the PANDA mode of operation Materials and methods Full-scale reactor setup. The full-scale MBBR system was commissioned in 2013 and is comprised of six trains, five of which are currently equipped with fixed-film media and ancillary equipment. Each train includes two anoxic denitrification cells (approximately 2.4 MG in total volume) in series followed by a single re-aeration cell (approximately 0.6 MG in volume). The anoxic denitrification cells are equipped with mixers and flat screens for media retention. The re-aeration cells are equipped with medium bubble aeration diffusers and cylindrical screens. All cells are equipped with K1 media, which provide the surface area necessary for attached growth of nitrifying and denitrifying bacteria. Methanol dosing was controlled via feed-back nitrate paced addition. Ammonia and nitrate for the tertiary MBBR PANDA demonstration was provided via process control adjustments to the secondary process, including changes to step-feed configuration, DO and airflow setpoints, load paced equalization and methanol feeding. Results and discussion Full-scale results — Full-scale demonstration testing of PANDA mode commenced in Q3 of 2022 and is ongoing. Results indicated:

*Anoxic ammonia removal between 1 and 2.0 mg/L has been observed since startup and the full-scale facility has been able to maintain weekly effluent ammonia concentration below 0.5 mg/L, monthly effluent TN concentrations of between 2 and 4 mg/L and an average annual effluent TN of 2.9 during the past 12 months of operation (2023).

*Unit methanol use at the facility has decreased by approximately 20% and unit energy demand at the facility has decreased by approximately 5% relative to 2021-2022 plant operations since operating in PANDA mode.

*Full-scale demonstration has confirmed that partial denitrification/anammox is sensitive to the NO3/NH3 ratio in the MBBR influent. Optimal performance (greater than 90% anoxic ammonia removal, COD to Nitrate removed less than 4.0 and influent ammonia above 1.1 mg/L) has been observed at NO3/NH3 ratio of 3.1 to 5.1.

*The FFX NCPCP has historically observed intermittent spikes in secondary effluent ammonia concentration. Potential causes of these spikes may be attributed to load peaking and/or suppressive compounds in the wastewater. A recent ammonia spike resulted in secondary effluent ammonia of 3.6 mgNH3-N/L to the MBBR. The PANDA mode of operation reduced 2.7 mgNH3-N/L to achieve a MBBR effluent ammonia of 0.9 mgNH3-N/L and MBBR effluent TIN of 2.5 mgTIN/L at a NO3/NH3 ratio of 1.5.

*NCPCP operators have easily shifted from PANDA to conventional mode of treatment when necessary to manage outside factors that might interfere with normal operations. Cumulatively, this work is the first to effectively demonstrate full-scale deammonification via PANDA while meeting stringent nutrient limits. Ongoing efforts are focused on optimizing the NO3/NH3 ratio, stabilize phosphorus removal while continuing to reduce energy and methanol associated with nutrient removal at the NCPCP.

Background Fishermans Bend is Australia's largest urban renewal area and planned to be Australia's largest Green Star Community. At 485ha, or over twice the size of Melbourne Central Business District (CBD), it stretches from the CBD to the mouth of the Yarra River and Port Phillip Bay. Currently dominated by low scale industrial and warehousing uses, the precincts' planned transformation into a high-density mixed use and employment precinct creates an ideal opportunity to build a city where water plays a pivotal role in ensuring economic, social, and environmental sustainability. The Challenge Fishermans Bend experiences drainage and flooding challenges at present and stormwater, riverine and coastal flooding are anticipated to increase in the years ahead from climate change, coupled with Victoria's climate becoming drier and warmer leading to water scarcity. This project addresses those challenges and seizes the opportunity to apply innovative solutions to enable and enhance the liveability of the area, by using novel and proven technology to address issues like flooding and provision of recycled water, and also by connecting this important and valuable piece of land to the Melbourne CBD to create a new residential, learning and economic centre, while building a climate resilient community. The Response The Fishermans Bend Water Sensitive City Strategy (WSCS) is an ambitious water sensitive urban design project that articulates how the precinct will become a thriving leading example for environmental sustainability, liveability and innovation. Publicly released by the Victorian State Government in May 2022, and underpinned by 10 years of planning and collaboration between multiple agencies, it required new ways of working to apply world's best practice in managing water as a resource and the impacts of climate change in urban environments. It will facilitate development, improve climate resilience, reduce potable water demands and sewage discharges, boost biodiversity and urban ecology, and reduce pollution from storm water runoff. As an innovative, whole-of-government, whole-of-precinct, whole-of-water-cycle, integrated approach to water management, the WSCS builds on three overarching pillars: Flood Management, Climate Resilient Water System and Urban Ecology. It responds to environmental, geotechnical, and spatial constraints - embedding water initiatives at precinct, street and building scales and across public and private realms. Key technical innovations include distributed green infrastructure storages featuring water in the landscape and 'smart' rainwater tanks at all buildings as part of a suite of actions to mitigate flooding, reducing drainage infrastructure capital costs by 30% while meeting broader liveability and resilience goals. A water recycling plant to treat the community's sewerage, for toilet flushing, washing and irrigation, reducing potable water consumption and wastewater discharges. Together with the rainwater tanks, this will halve average and peak day potable water demands, and there is now a target to reduce per capita demand below 100 L/p/d. In addition, there was an Australian first application of biodiversity-sensitive urban design at this scale. The Approach Alongside community and industry consultation, the Strategy brought together insights from across disciplines of urban planning, architecture, engineering, and urban design. Key process and governance innovations included independently led co-design processes such as the 'Ideas for Fishermans Bend' design charrettes by the Co-operative Research Centre for Water Sensitive Cities (CRCWSC), and a supporting governance model through the Water Sensitive City Working and Steering Groups. These groups were co-ordinated through the Fishermans Bend Taskforce, a specially convened State Government entity with responsibility for delivering the precinct, and included representation from Melbourne Water, South East Water, City West Water, City of Port Phillip, City of Melbourne and the independent advice of the CRCWSC. Whilst planning and decision making occurred across myriad processes between 2012 - 2022, at key points in time consultants were engaged to lead the development of foundational strategic plans and servicing strategies underpinning the broader Water Sensitive City Strategy. These included an IWM (or One Water) Plan in 2015 focussed predominantly on water, wastewater and drainage; a Water Sensitive Drainage & Flood Strategy in 2018 that resolved the approach to drainage and flood management, and an Urban Ecology Strategy in 2019 that brought together a strategic approach for the Urban Forest, Urban Heat Island, Biodiversity & Wind Strategies. Learnings The outcomes achieved for Fishermans Bend were the result of genuine, ongoing collaboration across different levels and parts of government, and with research and industry partners — who recognised a shared call to action in response to climate change, flooding, and water management issues in the precinct. Outcomes from the WSCS are transferrable to other places which is particularly relevant for coastal cities impacted by climate change and high-density urban renewal developments. More generally, as an industry leading One Water example both the processes used to achieve the outcomes and the barriers and mis-steps offer useful insights for One Water planning.

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals that have been widely used in various industries and products, such as firefighting foams, non-stick coatings, and textiles. Due to their high stability and resistance to degradation, PFAS can persist in the environment and accumulate in living organisms, posing potential risks to ecological and human health. Therefore, there is an urgent need for effective and efficient methods to remove PFAS from different sources of contamination, such as industrial wastewater, landfill leachate, and Aqueous Film Forming Foam (AFFF). This presentation will introduce and demonstrate a novel approach that combines two established technologies, foam fractionation (FF) and supercritical water oxidation (SCWO), to achieve the concentration and destruction of PFAS from various waste streams. FF is a separation technique that uses air bubbles to capture and enrich PFAS from dilute solutions, resulting in a concentrated PFAS-rich foam. SCWO is a thermochemical process that uses water at high temperature and pressure to oxidize organic compounds, such as PFAS, into harmless products, such as carbon dioxide, water, and salts. By applying FF and SCWO in tandem, PFAS can be effectively removed from contaminated water, leaving behind PFAS-free water that can be safely discharged or reused. The main objective of this presentation is to share the practical experience and results of operating a commercial-scale SCWO unit that has been treating PFAS concentrate from various sources. The presentation will provide analytical data and performance indicators from the treatment of PFAS concentrate derived from raw leachate and industrial wastewater that have been pre-treated with FF. Moreover, the presentation will discuss the process and outcomes of treating AFFF concentrate and rinsate that have been generated from fluorinated foam replacement projects. A key aspect to be highlighted is the benefits and challenges of the integrated FF and SCWO approach, covering design considerations, operational conditions, and field outcomes from full-scale implementation. Attendees will also learn about the prerequisites and steps for field deployment and the regulatory compliance issues related to air and water emissions. The following are the learning objectives of this presentation: 1. To gain an overview of the capabilities and readiness of FF and SCWO technologies for treating PFAS-impacted waste streams. 2. To learn about the best practices and strategies for working with state and municipal regulators to ensure compliance with air and water quality standards. 3. To acquire valuable lessons and insights from the deployment, commissioning, and ongoing operation and optimization of a full-scale SCWO unit.

Introduction There have been substantial changes to the Federal Emergency Management Agency's (FEMA's) Portfolio of Programs under Hazard Mitigation Assistance (HMA) over the past 3-years, including corresponding funding at historic levels. One of the most impactful changes was FEMA's development of Community Lifelines to increase effectiveness in disaster operations and better position FEMA to respond to catastrophic incidents across the Country. In August 2023, FEMA modified Community Lifelines to include a new, stand-alone 8th Lifeline for Water Systems. Previously considered an aspect of the Food/Water/Shelter Lifeline, this structural change reflected FEMA's recognition and increased prioritization of the water sector in FEMA's efforts to create more resilience within America's infrastructure landscape. This technical session provides an update on Mitigation Funding Programs along with examples of relevant mitigation projects in Nebraska, Kansas, Iowa, and Montana. This increased knowledge of the transformative benefits of risk and disaster mitigation for wastewater utilities will educate attendees on opportunities to increase resilience by taking steps to harden facilities and decrease overall risk. Objectives The presentation aims to provide wastewater utilities with insights into how best to maximize benefits of FEMA's HMA programs. Emphasis will be on opportunities presented by the newly created Water Systems Lifeline. Attendees will learn about resilience projects previously funded by FEMA, new potential mitigation activity types including addressing sea level rise, developing hardened water pipelines, flood-proofing water pollution control facilities, creating resilient power for treatment plants, and rehabilitating sewer systems. Understanding these funding avenues is crucial for utilities to position themselves effectively for assistance. Status The past three years have seen a dramatic shift in FEMA's Hazard Mitigation programs, with an unprecedented level of funding leading to expanded opportunities for wastewater utilities to enhance resilience and mitigate risks. This presentation provides an update on these developments, with a particular focus on how the addition of the Water Systems Lifeline reinforces the emphasis on wastewater sector resilience. Case studies and examples of utility projects benefiting from these changes will be highlighted. The examples will include projects drawn from FEMA's Mitigation Action Portfolio (MAP) along with previously submitted sub-applications to the FEMA Building Resilient Infrastructure and Communities (BRIC) Program: In specific, these examples will include: -City of Lincoln, Nebraska's Wastewater Treatment Plant — Flood Mitigation Project -Chippewa Cree Tribe, Montana's Rocky Boy's Reservation — Lagoon Relocation Project -Kansas/Nebraska Multijurisdictional Utilities - Ice Hardening Project -Denison (Iowa) Municipal Utility (DMU) — Ice Hardening and Retrofit Application Methodology The Bipartisan Infrastructure Law (BIL), also called the Infrastructure Investment and Jobs Act (IIJA) provides unprecedented levels of funding to both new and existing FEMA Mitigation programs. Approximately 35% - 45% of the IIJA's total is distributed through grants for which states and localities compete. Including in this funding is $3.5 billion for the FEMA Flood Mitigation Assistance Grant Program (FMA). An additional $1 billion is earmarked for FEMA's BRIC Program and Congress has taken a truly unique step in providing $500 million to help implement the Safeguarding Tomorrow through Ongoing Risk Mitigation (STORM) Act, which establishes the Revolving Loan Funds (RLF) eligible to provide local match for hazard mitigation projects, which were authorized by the previous legislation. In terms of perspective, only $200 million was available for FMA in FY2020 and $160 million was available in FY2021. Twenty-six states did not submit FMA applications in FY2020 and 31 states did not apply in FY2021. The FMA program is now funded at $700 million each year through FY2026. The Justice40 Initiative is also an important program. With both the FMA and BRIC identified as programs belonging to one of 21 agencies across the Federal Government engaged in Justice40, the program intends to direct 40% of funding within identified programs towards low equity/low agency communities. Findings and Significance The presentation will focus on the importance of identifying and overcoming barriers to accessing the transformative funding described. By addressing these challenges, wastewater providers can leverage the significant opportunities provided by FEMA's enhanced focus on the Water Systems Lifeline. The session will emphasize the types of resilience projects currently receiving funding and offer strategies for utilities to navigate the application process effectively, thereby positioning their systems for optimal funding assistance.

BACKGROUND The Metropolitan Wastewater Management Commission (MWMC) Eugene/Springfield Water Pollution Control Facility (WPCF) in Eugene, Oregon is a 35 MGD plant that generates 400,000 to 500,000 cubic feet per day of biogas from four (4) anaerobic digesters. For over 10 years the facility has operated a combined heat and power cogeneration facility, however changing priorities and the desire to fully utilize all their digester gas, caused the plant to investigate alternative biogas utilization strategies. This presentation will highlight technology selection, challenges with equipment procurement and construction, coordination with stakeholders, and lessons learned along the way. The Renewable Natural Gas (RNG) Upgrades Project (Project), commissioned in December 2021, is the first RNG facility at a Publicly Owned Treatment Works to come online in the state of Oregon. PROJECT OBJECTIVES The specific objectives of this project are to:

*Maximize beneficial use of biogas created by anaerobic digesters

*Avoid costly ongoing maintenance and upgrades to an existing internal combustion engine

*Produce RNG, consistent with the Federal Renewable Fuel Standards Program

*Reduce greenhouse gas emissions by up to 7,500 metric tons of CO2 annually

*Sell RNG to provide the MWMC with additional revenue TECHNOLOGIES CONSIDERED The following biogas upgrading technologies were considered as part of the initial screening for the Project:

*Water wash

*Pressure swing adsorption (PSA)

*Amine scrubbing

*Membrane separation FACILITY DETAILS The constructed Project includes hydrogen sulfide (H2S) and moisture removal, PSA technology to scrub the biogas to a high-BTU, natural gas quality product gas, and compressors to meet the gas utility's injection criteria. A tail gas stream comprised of carbon dioxide (CO2) and trace amounts of methane and volatile organic compounds (VOCs) not captured by the PSA is conveyed to a regenerative thermal oxidizer for destruction. A Receipt Point Facility operated by the gas utility, Northwest Natural, was constructed at the WPCF site to take transfer of the gas while simultaneously monitoring the quality, pressure, temperature, and quantity of product gas. The MWMC is working with Anew to register and broker the sale of renewable energy credits, including federal RINs and state carbon fuel standard credits. The Project is designed to utilize 100% of the biogas produced by the WPCF and upgrade the biogas to RNG for injection into the gas utility pipeline (approximately 300 scfm at 175 psi). LESSONS LEARNED Following are examples of the challenges that were encountered and associated lessons that were learned during the design, bidding, construction, and operational phases of the Project:

*It is important to maintain strong and balanced partnerships across all stakeholders, and encourage open lines of communication.

*There are safety concerns inherent with producing medium-pressure RNG at a WWTP. Provisions should be made to limit risks and educate plant staff.

*Look at pre-selecting RNG equipment to limit design scope; pre-procurement can be challenging due to the high cost of equipment.

*Having a focused member of the operations staff available for start-up is imperative.

*Consider providing a dedicated flare for off-spec gas rather than a dual-use flare.

*Test various engineered media for performance in removing hydrogen sulfide. CONCLUSION The Project was designed to have the capability to run continuously in response to fluctuating biogas availability, and automatically adjust operations to consistently meet project performance requirements. Plant staff have worked in collaboration with the Biogas Upgrading Equipment vendor Greenlane Biogas to fine-tune operation and troubleshoot issues, which has been critical to the overall success of the project. The Project had a capital cost of $14.5 million and an expected simple payback, which is highly dependent on RIN values) of 8 years based on an average uptime of 85%. Over the first two years of operation the uptime has fluctuated, resulting in monthly RNG production ranging from negligible to nearly 9,000 decatherms, but the Project is on track to provide the anticipated return-on-investment.

INTRODUCTION & BACKGROUND The City of Hollywood, Florida, developed a Stormwater Master Plan (SWMP) to evaluate and model the City's watersheds and identify resilient stormwater and flood prevention capital investments for today, tomorrow, and decades to come. The master plan includes modeling the effects of sea level rise (SLR), rising groundwater tables, and increased rainfall intensities. It also considers anticipated development growth and climate change data, providing the tools necessary for the City to create a forward-thinking capital plan that anticipates and prioritizes funding and infrastructure needs. Program goals were established to create a vision and metrics for the future. Topics include:

*Flood control

*Water quality protection

*Aquifer recharge and water supply

*Conservation and stormwater harvesting

*Operation and maintenance

*Long-term financing

*Community acceptance The City of Hollywood encompasses approximately 45 square miles (Figure 1). The stormwater service area is divided naturally by elevation, topography, and infrastructure into three major basins. These basins interact with Broward County, Central Broward Water Control District (CBWCD), South Broward Drainage District (SBDD), Florida Department of Transportation (FDOT), City of Hallandale Beach, City of Dania Beach, and South Florida Water Management District (SFWMD) stormwater systems. APPROACH Using the United States Environmental Protection Agency's (EPA) Storm Water Management Model (SWMM), the SWMP hydrologic and hydraulic models were developed for the City's primary stormwater management system (PSMS). The models included a study area of 29,000 acres, 2,228 sub-basins, consideration of offsite basin and major canal contributions, 80 backflow preventers, 12 stormwater pump stations, 217 miles of stormwater pipes, 29 miles of canals, 15 bridges, 33 miles of exfiltration trench, 250 outfalls, and a one-year tidal stillwater elevation of 2.5 feet North American Vertical Datum (NAVD). The SWMP involved coordinating the City's geographic information system (GIS) to update the existing stormwater atlas, populating an asset management database. Simultaneously, a city-wide stormwater model was developed, accounting for pervious and impervious areas in the urban landscape. The data collection effort included a survey of stormwater structures and the development of a Digital Elevation Model (DEM) based on Light Detection and Ranging (LiDAR) topographic data. The data collected was validated with the City's existing infrastructure and bathymetric data to develop a City-wide model for the major watersheds that accounts for varying rainfall events, tidal and groundwater influences, and future SLR impacts in coordination with Broward County, SBDD, CBWCD, Dania Beach, Hallandale Beach, FDOT, and SFWMD stormwater systems. Modeling inputs and parameters required extensive manipulation and analyses using GIS tools such as the Geographic Watershed Information System (GWIS) schema and ArcHydro. The modeling provides a comprehensive basin-by-basin analysis of the flood control level of service (LOS) for existing and proposed stormwater systems. It also considers the effects of projected climatological conditions for the future. The City conducted a series of public meetings for citizens to provide locations of reported problems. The input, combined with the City's stormwater complaint system records and Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps (FIRM), defined flooding problem locations and system connectivity (Figure 2). The project team used SWMM to estimate flood stages and inundation maps (Figure 3). They evaluated the flow rates and volumes for storage, conveyance, exfiltration, recharge wells, and potential pumping. The plan included conditions for the April 2023 flood event, ranging from a five-to-1,000-year event. Individual neighborhood capital improvement projects were tailored, specifically in areas most susceptible to flooding. Swales, detention systems, and exfiltration systems were evaluated, along with time-varying storage operations and recharge wells. The team is also considering seawall height extensions for the City's 140 miles of shoreline and backflow prevention for the 250 outfalls. SUMMARY This paper will present the results of the SWMP focusing on coastal resilience. It encompasses hydrologic and hydraulic models, historical storm tidal surge evaluations, LOS evaluations, cost-effective alternatives assessments, and associated Capital Improvement Program (CIP). This presentation includes a summary discussion on stakeholder coordination and prioritization strategies.

Introduction and Project Objectives Today's municipal water utilities are facing unprecedented challenges ranging from current and emerging regulatory drivers, climate change impacts, and affordability challenges while striving to achieve the levels of service that customers expect. Utilities must also address new challenges introduced by Climate Change, which increases the need of One Water approaches. At the same time, emerging contaminants add to the complexity of One Water management, such as the urban water cycle of per-and polyfluoroalkyl substances (PFAS). Water Research Foundation's Navigating One Water Planning through Municipal Water Programs: Meeting Multiple Objectives and Regulatory Challenges (WRF 5175) provides insights and strategies for water utilities to use One Water principles to strategically comply with Clean Water Act (CWA) and Safe Drinking Water Act (SDWA) requirements. This research aims to provide a One Water Planning Guidance that can be tailored to specific programs. This presentation will provide participants with a research approach overview, water sector engagement results, PFAS control strategies, and the initial One Water decision-making framework. We will discuss key challenges facing water utilities, potential regulatory solutions to balance CWA and SDWA obligations, and capital planning approaches to deliver higher value investments. Research Approach The research approach (Figure 1) of this study is a streamlined process of building the vision, an in-depth literature review, meaningful water sector engagement, and the opportunity to update Collaborative Water Quality Solutions: Exploring Use Attainability Analyses (WRF 1186). Using information gathered from the literature reviews and water sector engagements, the project team will develop a comprehensive One Water Planning Guidance document and decision-making framework. Water sector engagement will be a key component of this research, incorporating perspectives from 45 participating utilities throughout the United States and Canada and stakeholders representing regulatory agency representatives, subject matter experts, and sector associations. The final research report will be a utility-facing One Water Planning Guidance. The planning guidance will provide long-term planning strategies using partnerships across water sectors, interconnected CWA and SWDA requirements, regulatory navigation strategies, decision-making frameworks for integrated investments, and linkages to One Water Cities and Program Management (WRF 4969 and 5196). The guidance will include:

*Proven One Water planning approaches.

*A user-friendly decision-making framework that can be applied to municipal programs of all types and sizes.

*Guidance to select appropriate decision-making tools for investment prioritization.

*Proven, collaborative approaches to engage regulators and other stakeholders.

*Recommended implementation strategies that prioritize the simultaneous achievement of financial objectives, community priorities, and regulatory obligations. Preliminary Findings This presentation will share early findings from technical studies and water sector engagement. This targeted outreach seeks to accelerate broad adoption of a One Water approach to identify strategies that address multiple community and environmental objectives while addressing regulations.

*One Water Visioning. Results of the project visioning with the 45 participating utilities, the Project Advisory Committee, and WRF will be presented. This visioning session will collect current and emerging challenges, regulatory issues, and opportunities for multiple benefits from municipal water investments.

*Use Attainability Analysis (UAA) Study. An initial study addresses understanding of Use Attainability Analyses in municipal wastewater and stormwater programs. The focus will be to document identified success factors to use UAAs as a path toward affordable water quality improvements.

*PFAS Guidance. An initial study addresses the challenges presented by PFAS as constituents of emerging concern that transcend traditional water silos of drinking water, wastewater, stormwater, and reclaimed water. This includes interrelated and contradicting regulatory requirements, source control, fate and transport, treatment, and product stewardship.

*Synthesis of One Water Literature. Key findings from published studies of One Water management will capture principles, drivers, approaches, decision analysis methodologies, analytical tools, and implementation examples. The presentation will include a tabulation of Key Metrics for Success.

*One Water Sector Engagement. Strategic engagement is designed to provide valuable insights into key challenges and success factors to direct the One Water Planning Guidance. Results of the engagement activities with the 45 participating utilities and a broad group of water-sector stakeholders will be previewed in this presentation. The initial results of focus groups will be discussed.

*One Water Planning Guidance. The research team will create a One Water decision-making framework based on literature findings, water sector engagement, key success factors, and effective planning methodologies. The presentation will provide the initial decision-making framework and approaches that will be refined through the remaining research effort.

Background Water resource recovery facilities (WRRFs) around the world are constantly faced with significant challenges 1, 2. It is estimated that WRRFs are operating at an average of 81% of their design capacity, while 15% of systems are at or have exceeded that threshold3. As the most prevalent biological nutrient removal (BNR) process, any improvements to conventional activated sludge (CAS) processes are highly desirable in our industry4. However, upgrading CAS trains is costly and alternative technologies often tend to be more energy-intensive, expensive1, and time consuming to install, commission, and operate. Thus, the use of physical selectors (e.g., hydrocyclones) for biomass densification has emerged as a front-runner for increasing secondary clarifier capacity and improving nutrient removal. Objective and Approach Despite the many studies exploring the advantages of densified activated sludge (DAS) systems compared to CAS systems, DAS impacts on microbial communities and fecal indicator bacteria (FIB) are unknown2, 5. In 2023, the Water Research Foundation funded a tailored collaboration with the Metro Water Recovery (MWR) in Denver. The collaboration aimed to investigate FIB removal and disinfection kinetics. This study focused on CAS and DAS treatment trains at three North American full-scale operating WRRFs (Figure 1). The WRF project aims to: A) Compare E. coli concentrations over a 15-month period and investigate factors influencing differences (e.g., granulation size distribution, floc/granule mass fraction, floc/granule aSRT, microscopy, COD, Turbidity, TSS, NH3, pH, Temperature, Color, UV-254, TKN, TP, TOC). B) Determine how changes in Secondary Effluent (SE) properties between DAS and CAS affect disinfection efficacy using chlorine, peracetic acid (PAA), performic acid (PFA) and ultraviolet disinfection (UV) seasonally (n=12), with the same water quality parameters listed in Objective A. C) Assess impacts of operational variables on DAS and provide utilities with recommendations. These can include how to utilize modeling and statistics to improve performance using demand and decay values and mechanistic disinfection efficacy models D) Determine if additional analyses (e.g., protozoa counts, granule sieving analyses) provide operational value to utilities adopting DAS. Results Data collected for one year at the MWR Hite Treatment Facility highlights the statistically significant difference in E. coli concentrations between the CAS and the DAS trains (Figure 2). This could be explained by a variety of variables that have not yet been evaluated. FIB counts may be impacted by the predator protozoan community5, but this has yet to be supported by data (Figure 3). While percent mass fraction (Figure 4) and seasonality (Figure 5) have been hypothesized to impact DAS E. coli counts6, this has not been shown by the preliminary data collected, which highlights the importance of a more detailed study to explain the differences observed . Summary DAS is able to be implemented with low capital cost while increasing the capacity of CAS systems. However, there is little data on how SE from DAS systems impact downstream disinfection processes. This WRF project will evaluate the impact DAS systems have on disinfection processes compared to CAS systems. Data collection and testing for this project will begin in April 2024.

For many years, reverse osmosis (RO)-based advanced treatment (RBAT) using membrane filtration, RO, and UV advanced oxidation process has been an established standard for treating municipal wastewater effluent to drinking water standards for potable reuse. However, most inland water service providers and others with limitations on RO concentrate disposal will require alternative potable reuse approaches. Building upon the success of the full-scale facility in Windhoek, Namibia, nearly half a dozen years ago, the City of Altamonte Springs' pureALTA project piloted the first carbon-based advanced treatment (CBAT) train for direct potable reuse using ozonation, biological activated carbon filtration (O3/BAC), UF, granular activated carbon (GAC) adsorption, and UV disinfection. This award-winning project offered a market-changing innovative solution to inland utilities looking for sustainable approaches to water augmentation. The yearlong pilot demonstrated the use of several process control measures for optimized performance, such as ozone dose control based on influent total organic carbon (TOC) and nitrite concentration, empty bed contact time in the BAC filter for maximum TOC removal, and analysis of simultaneous removal of TOC and per- and polyfluoroalkyl substances (PFAS) in the GAC adsorber. Challenge testing using non-pathogenic surrogate organisms confirmed log removal values for Cryptosporidium, Giardia, and enterovirus at 10.6-log, 10.6-log, and 12.7-log, respectively, far exceeding the site-specific goals of 3.9-log, 4.2-log, and 11.2-log, respectively. This permanent demonstration facility has also been leveraged for public education and has hosted multiple tours for other water purveyors interested in similar solutions, and the presentation will highlight the cascading effect of the City's bold vision. Similar projects are developing across the US: The City of South Jordan in Utah, and inland utility, is currently piloting a similar treatment train for DPR downstream of membrane bioreactors (MBRs) and working with state regulators to pave the path for potable reuse in Utah. Colorado Springs Utilities' PureWater Colorado Mobile Demonstration Project, a traveling DPR demonstration system, meets stringent drinking water regulations and provided valuable data to the Colorado Department of Public Health and Environment in developing DPR rules for the State. Hampton Roads Sanitation District's SWIFT project in Virginia aims at performing managed aquifer recharge for eliminating effluent discharge to the Chesapeake Bay and mitigating saltwater intrusion, and is advancing the design and construction of full-scale CBAT for over 100 mgd of managed aquifer recharge. Clay County Utility Authority (CCUA) in Northeast Florida is exploring CBAT for indirect potable reuse with groundwater injection at Project Quench to meet future water demands in this growing part of the State, and is constructing a permanent demonstration facility. Polk County Utilities' (PCU) One Water Polk project is exploring CBAT for DPR in their northwest region which has limited groundwater supply. This project is testing the need for pre-treatment for enhanced TOC removal within a CBAT train using enhanced coagulation, and their permanent demonstration facility is currently in operation. The knowledge base generated by comparing the technical and implementation experiences of these projects can be used to inform a robust foundation for wide-spread adoption of CBAT. This presentation will offer highlights for each project, compare technical similarities and differences, and discuss lessons learned in CBAT application for potable reuse. Attendees will learn about the alternatives available to RBAT if brine management is not feasible for their service area, giving them the tools needed to evaluate the feasibility of implementing potable reuse schemes for addressing future water supply challenges.

The Chimborazo Interceptor Sewer serves a portion of the Church Hill area to the northwest of historic Chimborazo Park in the City of Richmond, Virginia. The combined sewershed drains to the interceptor, stair stepping down the steep hillside adjacent to the park near the intersection of East Grace Street and North 32nd Street. Due to the torrential rainfall from Tropical Storm Gaston in August of 2004, the slope failed and caused a portion of the downstream combined sewer to collapse. The City was faced with a unique challenge to address structurally damaged portions of the 48-inch circular brick step sewer residing within and near the steep hillside that is prone to failure. An emergency sewer repair was completed in 2005, which involved reconstructing a portion of the step sewer upstream of the existing junction chamber and installation of a 42-inch ductile iron pipe within the existing distressed 48-inch brick sewer downstream of the junction chamber. Another emergency sewer repair was completed in 2017, which involved the installation of a special steel pipe with concrete encasement at a step failure. The emergency sewer repair work was a temporary solution, and the design and construction of a phased permanent solution to prevent future failures of this critical asset was incorporated into the City DPU Capital Improvement Plan. A Preliminary Engineering Report was developed, which included a holistic review of collected background information, field investigation, hydrologic and hydraulic review, topographical survey, subsurface geotechnical investigation, and a cultural resources study. Using this data, phased alternatives and recommendations for a comprehensive permanent solution were developed. Due to the location, geography, subsurface conditions, and hydraulics, an unconventional design approach was developed for the abandonment and replacement of Phase 1 of this original combined sewer which dates to the late 1800's. This presentation will showcase the final design, equipment selection, bid phase, construction phase, planning, and coordination efforts that went into the construction of this replacement sewer. Phase 1 features a 60-inch inlet sewer; a 10-ft diameter, 30-ft deep inlet chamber; an 18-ft diameter, 100-ft deep vertical drop shaft chamber, which houses a fabricated siphon spillway drop unit (with 30-inch inlet, 6-inch air switch, 30-inch overflow, and 24-inch drop pipes); and a 60-inch outlet sewer. It also includes 5 new manholes, 900-ft of 60-inch gravity sewer replacement via micro-tunneling and open-cut techniques, and upstream and downstream connections to the existing 60-inch brick sewer. From utilizing an innovative technology new to the City, encountering unknown utilities and subsurface conditions, and navigating coordination with all types of stakeholders (federal, state, and local agencies, neighborhood groups, civic associations, and nearby homeowners), this presentation will highlight the project successes, challenges, and lessons learned. This project is currently under construction with an estimated final completion in March 2024.

Introduction The largest reclaimed to water wetlands system in the world was placed into operation over a decade ago in Panama City Beach, Florida. The 3,000-acre Conservation Park (Park) site has been a success story for the City of Panama City Beach (City) in multiple ways including surface water nutrient reductions, ecological restoration, new parks and recreation facilities, eco-tourism, and public education. At the same time, with over 10-years of operation, the City has a better understanding of the Park's nutrient uptake performance as well as made improvements to the Park and collected different lessons learned. Objectives This presentation explains the system operations over the last 10-years with performance data associated with nutrient uptake by the receiving wetland system and quantified reporting of ecological habitat improvements. Information related to system facilities and improvements implemented over the last 10-years along with lessons learned since implementation will be presented. Status The City achieved 100% reclaimed water use in the fall of 2012 with their public access irrigation and reclaimed water to wetlands systems. The flows from the City's Water Reclamation Facility (WRF) to the wetland system have ranged between 3 - 12 MGD over the past 10-years and have typically been 1.5 times the flow to the City's public reclaimed system. Nutrient concentrations leaving the Park have been tracked in effluent leaving the WRF and at the discharge point from the Park and show the nutrient levels 25% to 50% below those observed in the WRF effluent. Based on quarterly sampling, the total nitrogen (TN) and total phosphorus (TP) have remained below the permitted discharge limits. The Park has also become established as a destination for locals and tourists with top rankings on trip websites such as TripAdviser and AllTrails as well as the location for guided bird walks. In addition, the City has implemented a program to restore nearly 30% of the site from silviculture to it's natural habitat through physically removing evasive plant species, natural plants and tree plantings, and incorporating control burns. Methodology The hydraulic loading of the eight (8) natural wetland cells on site is based on their natural composition, function, hydroperiods, and habitat value and sized for up to a maximum flow of 32 MGD. All the cells are interconnected through various surface water interactions ultimately draining to a single location in the northern most basin. Each wetland cell was designed and constructed with the unique ability to control the hydraulic loading to maximize storage capacity based on WRF flows with lessons learned in topographic mapping of the drainage basins. The City has taken extensive steps to restore site habitat from when the lands were primarily used for silviculture (i.e., to grow trees) and fast-growing slash pines were densely planted in replacement of upland and wetland habitat. The City determined several prudent ecological activities should be incorporated, including tree harvesting, invasive plant thinning, native tree and wiregrass seedling planting, and prescribed burning. These efforts have made a marked difference on site where large areas of historic wire grass and long-leaf pine communities are now thriving with 269 acres documented as being restored or in process of restoration. In addition, along with the tree thinning and harvesting, a prescribed burning regimen was introduced to remove excessive buildup of organic detritus leading to devastating fires. Restoring periodic fires to the plant community has promoted growth of native species depending on fire to stimulate germination, provided additional sunlight through the canopy, and opened serotinous pinecones for seed dispersal. Lessons learned include routine maintenance for over 24 miles of hiking trails including over a mile of boardwalk through cypress domes is a necessity. At the same time, guided Audubon bird walks, volunteer, and recreational programs for Park guests are offered seasonally and in high demand since the site opened which brings an added need for routine Park maintenance. Findings and Significance The City's project is an excellent example of beneficial use of reclaimed water to replenish and restore native habitats. In addition, the performance of nutrient uptake in the receiving wetland system and the successful restoration of native habitat provide examples for other communities to consider in their efforts to remove surface water nutrient loads. Finally, the project has set an example for how a nature-based solution can be leveraged as a parks and recreation amenity and promote eco-tourism.