BACKGROUND Silver Springs, located in North Central Florida, is one of the state's largest first-magnitude springs and has attracted visitors since the 19th Century. World famous for its crystal-clear waters, it is the ecological and economic engine in the area. However, flow and water quality data over the past nine decades show a significant decline in spring flow and increase in nutrient concentrations which has led to the ecological degradation of the Silver Springs and Silver River systems. OBJECTIVES While not yet required by regulation, the visionary City of Ocala, located within the Silver Springs springshed, constructed a treatment wetland designed for groundwater recharge to beneficially reuse their reclaimed water by offsetting their groundwater use and nutrient loads to Silver Springs associated with municipal wastewater management. Known as the Ocala Wetland Groundwater Recharge Park, this 35-acre infiltration wetland system receives and treats up to 5 million gallons per day (mgd) of reclaimed water and stormwater to recharge the Upper Floridan Aquifer (UFA), protects water quality, and recovers and enhances the flows to Silver Springs. The Silver Springs system is subject to restrictive Total Maximum Daily Load (TMDL) regulations for nitrate and has a recovery strategy to help meet its established Minimum Flows and Levels (MFL). The Ocala Wetland Groundwater Recharge Park project supports both nitrate load reductions and recharge to help augment flows in the springshed. The Florida Department of Environmental Protection (FDEP) listed the wetland park as one of the stakeholder projects to reduce nitrogen sources in the Silver Springs Basin Management Action Plan (BMAP) area and provided Springs Funding due to its benefit to the region (FDEP, 2012 and SJRWMD, 2017). METHODOLOGY In support of the design and permitting of this project, an onsite hydrogeologic investigation, consisting of soil borings and the construction of pumping and monitoring wells across the site, was conducted to produce site-specific data. A groundwater model was then calibrated to this site-specific data and was used to evaluate the site's capacity to recharge the aquifer and the fate of the applied water to recover flows in the Silver Springs System. These efforts included innovative applications of a calibrated groundwater model combined with a wetlands treatment model to quantify recharge while ensuring the protection of water quality. It was determined that this system would have a capacity of up to 5 mgd, infiltrate an average of 5 in/day, and reduce nitrate levels to background concentrations. The designed wetland system consists of 35 acres of infiltration wetlands divided into 3 cells to receive up to 5 mgd of reclaimed and stormwater on a project area of 60 acres. The design included organically shaped cells graded in-place without the need for import of export of material to construct berms. Wetland habitat diversity was maximized by creating different ecotones across the cells that range from deep open water to shallow wetlands, islands, and rookery areas. The design also included an innovative distribution header that controls flow to each cell independently based on water level setpoints in each wetland cell. This allows for seasonal operation of water levels to maximize recharge and wetland ecological value by mimicking wetland hydroperiods that are driven by seasonal rainfall patterns. RESULTS AND CONCLUSIONS As shown in Figure 1. nitrate concentrations in the monitoring wells located within the UFA, approximately 100 feet below the wetland park, show a downward trend following park start-up and wetland planting. Nitrate concentrations in the intermediate well (within the influence of the wetland) decreased from 0.5 mg/L to 0.1 mg/L and nitrate concentrations in the compliance well decreased from approximately 1 mg/L to 0.5 mg/L after the application of reclaimed water to the site and start-up of the park. In addition, onsite recharge rates average 5 in/day, achieving the infiltration rates predicted in the groundwater model (Figure 2). The Ocala Wetland Recharge Park provides a unique case study of beneficial reuse management that addresses water supply and water quality while also giving back to the community. Since opening in the September of 2020, the park has seen over 171 bird species and an average of 3,700 visitors per month. Designed to also serve the community, the Park includes 2.5 miles of ADA-accessible trails, interactive educational displays, and some of the best birding in the County as the park was designated a Great Florida Birding and Wildlife Trail site by the Florida Wildlife Commission in 2023. The City has also developed a website and social media for the wetland park to provide the public with park photos, activities, and educational information. Further serving as an amenity to the community, the park also hosts field trips for local schools and meetings for environmental organizations like the Marion Audubon Society. In 2021, the wetland recharge park's innovation was recognized by the National Recreation and Park Association as they awarded the park with both the Innovation in Conservation Award and the 2021 Best in Innovation Award. The park represents a multi-benefit nature-based solution that should be considered for other areas in need of addressing both water supply and water quality in an innovative and natural way.

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.

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.

Introduction Intensification is a new term describing upgrades at WWTP's which increases treatment capacity in existing tankage. Waste Activated Sludge (WAS) using hydrocyclones increase process throughput, provide more stable performance via the selection of dense sludge aggregates with improved settling rates and promotes enhanced biological phosphorus removal (EBPR). Increased density leads to improved settling characteristics, preventing loss of biomass and subsequent treatment disruption, especially during wet weather scenarios. There are over 50 installations worldwide using the WAS hydrocyclone technology (inDENSETM), however none have been installed at STP's with an operating SRT between 2 and 2.5 days and warm operating conditions (25oC - 35oC). The purpose of this project was to verify if WAS hydrocyclone technology could improve sludge settleability operating under warm operating conditions, thereby demonstrating a higher flow could be treated with the existing infrastructure. Project Background Ajman Sewerage Private Company Limited (ASPCL) was founded in 2002 and was granted by the Government of Ajman Emirate (United Arab Emirates) a Concession Contract to Finance, Build, Own, Operate, Maintain and Transfer its main wastewater infrastructure. ASPCL shareholders are the Government of Ajman, Besix and Veolia. ASPCL appointed Moalajah as its Operator. The infrastructure constructed by ASPCL since its inception includes: 950 km of network, 220,000 properties connected (a connection rate of 92%), 35 pumping stations, and a centralised wastewater treatment plant (Ajman Sewerage Biorefinery) that treated the wastewater and produced more than 15 GWh of electricity in 2023. Ajman Sewerage Biorefinery WWTP was developed in two main phases (Phase 1 and Phase 2), which can treat a combined maximum volume of 137 MLD. Phase 2 of Ajman WWTP was commissioned in January 2017. Phase 2 consists of two aeration tanks and four rectangular clarifiers. Due to the increase in flows to Ajman WWTP, ASPCL investigated an option to increase the capacity of Phase 2 from 40 MLD to 60 MLD. Due to poor sludge settleability the maximum capacity of Phase 2 was 45 MLD was unable to be reached. As an interim solution, ASPCL investigated if WAS hydrocyclone technology could improve the poor sludge settleability and increase the plant capacity. As part of the full-scale implementation, four (4) inDENSE skids were installed. Each hydrocyclone treats 10 m3/hr, resulting in a total capacity of 200 m3/hr. A new higher capacity of pump (i.e. 200 m3/hr, 2.1 ~2.4 bar operating pressure) was installed. Figure 1 shows an inDENSE skid, the influent manifold piping, overflow piping collecting in the effluent waste and underflow collection pipe which returns the heavier biomass back to the system. Figure 2 shows a process flow diagram of Ajman WWTP (Phase 2) with inDENSE System implementation. The hydrocyclone skids were installed and commissioned in October 2022 with minimal impact to the operating plant. Figure 3 shows the hydrocyclone skids installed at Phase 2, Ajman WWTP. Full Scale Demonstration Results The hydrocyclones at Phase 2, Ajman WWTP started up in November 2022. Figure 4 shows changes in the mixed liquor SVI since the hydrocyclones were commissioned. Prior to hydrocyclones, the mixed liquor SVI varied significantly between 50 to 250 mL/g. Since the hydrocyclones started up, SVI improved significantly averaging around 80 mL/g and remained below 100 mL/g. Figure 5 presents the changes in solids loading rates (SLR) after the installation of the hydrocyclones. Solids loading rate (SLR) is a key parameter used to assess the capacity of secondary clarifiers. Higher SLR indicates higher flows can be conveyed without impacting the effluent quality. Since the hydrocyclones have been in operation, the SLRs have increased from 3.8 kg/m2/hr to 5.8 kg/m2/hr while maintaining the effluent quality target. Figure 6 presents the MLSS concentration trends since the hydrocyclones were commissioned. It should be noted that increasing the MLSS was not intentional. The early increase of the MLSS from Feb to May was mostly due to insufficient wasting due to frequent clogging of the cyclones (e.g. issue with the inlet screens). One key project objective was to see how much more flow could be treated in Phase 2 while maintaining effluent compliance. Since the hydrocyclones have been in operation, the influent flow rates to Phase 2 have gradually increased from 40 MLD and reached 58 MLD within 6 months operations of hydrocyclones. It is to be noted that the limitation to 58 MLD does not come from the clarifiers (settleability) but from the downstream disc filters capacity. It was believed that the biological treatment capacity could be increased above 58 MLD if more disc filters were added. Table 1 summarizes the impact of hydrocyclone operation at Phase 2, Ajman WWTP. Since the hydrocyclones are in operation, the capacity of Phase 2 has been increased by approximately 45% as the SVI improved significantly. This resulted in significant CAPEX and OPEX savings for Ajman WWTP. Conclusions The long term hydrocyclone operation at Phase 2 demonstrated that the improved SVI resulted in treating more flow in the existing secondary treatment infrastructure without major capital expenditure. The outcomes of the lessons learned from the long term hydrocyclone operation from Phase 2 will be incorporated into a Phase 3 upgrade.

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 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.

Common phosphate minerals in wastewater treatment plants such as struvite (MAP, MgNH4PO4*6H2O), calcium phosphates such as amorphous calcium phosphate (ACP, Ca3(PO4)2), and iron salt precipitates such as vivianite (Fe3(PO4)2*8H2O) have been recognized as a maintenance and operational nuisance for their tendency to scale and deposit within anaerobic digesters, in pipe bends, and on dewatering equipment downstream of anaerobic digesters. Precipitation of these minerals occur if the concentrations of the ionic constituents exceed the solubility product (Ksp) of the solid which is measured as scaling tendency (ST) or scaling index (SI). The solubility of these precipitates is dependent on factors such as pH, temperature, other competing ions, and nucleation sites. Chemical thermodynamic modeling could be used in evaluating the parameters that contribute to scaling and, thereby, safeguard process equipment from scaling-induced damage, improve treatment efficiency, and regulate phosphorus sequestration to produce nutrient rich biosolids. In this study two commercially available models were evaluated: (i) Visual MINTEQ Version 4.0 and (ii) OLI Studio. The model inputs were gathered at a pilot-scale experimental setup at Hampton Roads Sanitation District's (HRSD) Atlantic Treatment Plant (ATP), Virginia Beach, VA. The pilot evaluates the impact of aeration, mixing, and chemical addition of thermally hydrolyzed pretreated, anaerobically digested solids on scaling tendency. Critical parameters such as pH, temperature, alkalinity, orthophosphate (OP), ammonia (NH3), and major cations and anions concentrations were measured as model inputs. The solids formed during these evaluations were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM)/Energy Dispersive X-Ray Spectroscopy (EDS), and Raman Spectroscopy analysis to validate prediction by the two models. The pilot set up at ATP consists of four tanks (Figure 1). Each tank is 11 feet tall and can hold up to about 63 gallons of digestate. The tanks are operated as daily batch fed continuously stirred tank reactors maintained by pump recirculation at a 3-day solids retention time (SRT). The tanks are aerated with fine bubble diffuser membranes which can be operated at constant or intermittent air flow rates, via dissolved oxygen (DO) or pH set points. Chemical injection lines will be added to measure the effects of calcium hydroxide [Ca(OH)2] and magnesium hydroxide [Mg(OH)2] at varying dosages. The modelling process was based on the pilot influent solution compositions depicted in Table 1 of anaerobic digestate. In both modeling programs, anaerobically digested solids at a temperature of 30 degrees C, a pH of 7.4, and initial parameters from Table 1 were analyzed to determine the pilot influent potential precipitate formation. Figure 2 represents the fractions of solids predicted to form at equilibrium in Visual MINTEQ and Figure 3 displays similar results produced from OLI, both in mg/L. The two model predictions are closely related, listing siderite, struvite, and calcite as the top three controlling precipitates, respectively. This is a prediction of what is forming currently in the digesters, prior to manipulation in the pilot from aeration or chemical addition. A pH sweep from 7 to 8.5 as well as a temperature sweep from 20 degrees C to 40 degrees C were also analyzed in both modeling programs to understand the effects of aeration within the pilot on pH, biological activity, and how the solubility of scaling precipitates were affected. These results, as well as future work that includes modeling the effects of chemical addition in the pilot, will be presented. Precipitate Characterization was conducted in a contract laboratory for XRD, SEM/EDS, and Raman Spectroscopy to determine precipitate identification. The major peaks in XRD patterns produced likely matched with struvite. Further testing will be completed and presented to validate the solids predicted to form by the models. The presentation will showcase the outcomes derived from each model, offering insights into their respective abilities to predict the potential precipitation of controlling solids. The precipitate characterization analysis will also be compared to determine the validity of results and to further optimize both modeling software.

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.