This year, cybersecurity attacks against our nation's critical infrastructure sectors have continued to challenge the operational integrity of our manufacturing environments and threaten our way of life. Cybercrime is an economic and national security sustainability threat. As we know, threat actor motives are often rooted in financial gain, as well as ideological differences. In short cybercrime is here to stay. Minutes matter, seconds count and the only control we have as people are over the decisions we choose to make to better protect our communities. As a result of consistently high cyber-attack attempts and incidents, recent changes to Federal and State administrative and civil laws have evolved to drive cyber risk management accountability. The time to act as a collective in the Water and Wastewater community is now because the quantifiable risk and liability associated with cyber-attack incidents has grown to an unsustainable level. To further contextualize, several states have waived sovereign immunity privileges relative to risk management, which directly places municipalities at risk from a Civil-tort liability perspective. Our goal as an organization is to help our customers on three fronts: fiduciary risk quantification, OT risk identification, and the development of a feasible OT system hardening roadmap that is tailored to your organizational needs. In this session, we will review the tactics, techniques, and procedures that every utility should know to protect themselves and build a comprehensive, unified IT/OT cyber resilience plan accounting for all potential security risk before, during, or after a cyber event. Additionally, a detailed explanation of next-generation OT networks and describe why traditional network isolation cyber defenses are no longer adequate for these mission-critical environments. We will offer a detailed cyber strategy and architecture to protect these networks' enhanced capabilities, along with common pitfalls and lessons learned. It is no surprise — Industrial Control Systems (ICS) are in the crosshairs of opposing nations and criminal organizations. Water and Wastewater facilities specifically need a heightened awareness due to their key role in the global supply chain. In addition to known bad actors, the modern facility is connecting to the outside world at an exponential pace and with greater connectivity comes greater security risk. Even well-intentioned actions can mistakenly impact network availability, interrupt operations, and halt productivity. Water and Wastewater organizations need a— including (but not limited to):

*Asset Inventory / Installed Base Identification

*Vulnerability & Risk Analysis

*Qualified Patch Management

*Cybersecurity Policy Development

*Endpoint Protection

*Perimeter Hardening (IDMZ) & Microsegmentation Deployment

*Zero-trust & Secure Remote Access

*Real-time Threat Detection

*Disaster Recovery Planning & Incident Response The best approach is risk-based in alignment with industry best practices with complete organizational adoption. Unfortunately, even the most sophisticated organizations can't manage all aspects of IT/OT cybersecurity alone — you need an ecosystem of trusted experts and partners by your side to extend your protection against next-gen security threats. To secure modern operational equipment — Computer OS Security, Network Security, Endpoint Protection, and continuous Security Monitoring. We will also review the emerging Managed Security Services leading the industry in data-driven cyber protection and response so that you can have confidence running a world-class ICS cybersecurity program.

Introduction. In 2020, Tohopekaliga Water Authority ('TOHO') initiated a significant effort to rehabilitate its aging sanitary gravity collection system. Through a series of acquisitions of surrounding utilities in the growing Central Florida area, TOHO inherited infrastructure nearing, and in many cases exceeding, its functional life resulting in increased frequency of emergency repair situations. TOHO initiated a comprehensive gravity sewer collection system rehabilitation program (Program) to address the issues it was facing. This presentation describes how TOHO worked with the Water Infrastructure Finance and Innovation Act (WIFIA) to help fund improvements to these acquired systems. Objective. Information related to TOHO's WIFIA application and adhering to loan conditions for the improvements of approximately 110,000 linear feet of gravity sewer mains, replacement and rehabilitation of approximately 1,200 manholes, and 200+ point repairs will be explained during this session. Status. As of January 2024, TOHO has completed approximately 95% of the improvements. This includes the gravity sewer mains ranging in size from 6- to 24-inch diameter, replacement and rehabilitation of manholes, and point repairs with much of the work at depths of up to 25-40 feet. The schedule looking ahead includes construction completion of the projects underway and closeout items necessary document the work performed and confirm owner and regulatory compliance. Methodology. To get ahead of increasing costs, regulatory considerations, and customer dissatisfaction associated with the challenges of maintaining an aging collection system, TOHO embarked on a comprehensive program to review the existing gravity collection system and prioritize projects for meaningful impact. This effort included assessment of existing records and collection of new data through. The new data was collected utilizing industry standards to prioritize assets based on criticality which included high consequence gravity interceptors, gravity mains within primary roadways, and mains within known high infiltration areas of the system. Once the critical nature of the effort was understood, TOHO developed an action plan and budget to begin addressing the major issues and pursued funding through WIFIA. TOHO engaged in the application process and in 2020 was awarded a loan for an approximately $82M program with a 49/51 percentage split. This provided TOHO with the ability to accelerate the rehabilitation program with a goal of completion within 5 years from initiation of the loan. Additionally, WIFIA documentation was collected and submitted to meet loan conditions. WIFIA loans are federally funded and, at the time required adherence to regulations such as the American Iron and Steel Act (AIS) and the Davis-Bacon Act. Compliance with all regulations was strongly monitored throughout the loan duration. The Program also included the need to address unforeseen emergencies within the gravity collection system. For these emergencies, a stage-gate process was utilized to facilitate proper decision-making and logical completion of the work utilizing available resources undertaking the critical work within the Program. Communication between TOHO, the engineer-of-record, nearly ten contractors, stakeholders and residents throughout the Program was paramount for its successful completion, which set the stage for continuation of the rehabilitation beyond the performance period of the initial WIFIA program. TOHO's efforts and rapid implementation of this program throughout this 5-year performance period included the establishment of a Program Management Office (PMO) to facilitate and track the design, bidding, and construction. Findings and Significance. To date, TOHO has completed nearly 40 projects, resulting in successful rehabilitation and replacement of over 110,000 linear feet of gravity sewer mains ranging in size from 6- to 24-inch diameter, replacement and rehabilitation of approximately 1,200 manholes, and 200+ point repairs with much of the work at depths of up to 25-40 feet. The ability to leverage and comply with WIFIA funding were significant pieces to TOHO's program.

Introduction: PFAS, a group of chemicals widely used in various applications due to their water and oil resistance, are persistent, toxic, and accumulate in the environment. Disposal of products containing PFAS in landfills can result in PFAS contamination in the landfill leachate that is discharged to water resource recovery facilities (WRRFs) andwhich can lead to groundwater contamination (REF1). Foam fractionation (FF) is a process that utilizes the surfactant nature of PFASs to separate them into foam, which is collected as a concentrate for further treatment (REF2). FF significantly reduces the volume of PFAS-containing waste, making it an ideal first step in a PFAS treatment process. This study evaluates four different FF technologies and provides insights for their implementation based on bench scale comparison results. Materials and methods: In this study, four technologies were evaluated for PFAS removal. The technologies and their providers are listed as TechA, TechB, TechC, and TechD in Table 1. Equalized volume samples (55 liters) were collected from an anonymous facility's EQ-tank and distributed to different technology providers for testing. Leachate wet chemistry parameters samples were determined in accordance with APHA standard methods. Table 2 lists the analyzed parameters. A total of 40 PFAS compounds were quantified using the EPA 1633 method, the Total Oxidizable Precursor, and the Total Organic Fluorine assay. Table 3 provides a complete list of these compounds and their concentrations before FF. Results and discussion PFAS Removal Efficiency: The study evaluated the removal efficiency of different PFAS into the foam phase for the four FF technology providers. The findings, depicted in Figure 1, align with previous literature: longer fluorocarbon chains and the presence of a more surface-active sulfonic acid head group result in greater PFAS removal compared to its carboxylic counterpart. The study also shows that removal efficiency improves exponentially with longer fluorocarbon chains, and chains longer than six carbons resulted in undetected levels. This supports previous research that suggests chain length has a greater impact than head group. Longer fluorocarbon chains make PFAS less soluble and more hydrophobic, enhancing its ability to adsorb onto air-water interfaces due to their superior surface properties. Impact of Process Configuration: Technology providers employed different strategies in using FF as indicated in Table 1. A notable finding from comparing these technologies is the effectiveness of cationic co-surfactants in removing PFAS. The cationic headgroup of these co-surfactants allows for binding to PFAS at the water-air interface. TechA and TechB tested a wide range of co-surfactants at 100 mg/L and found that CTAB-based surfactants are favorable in reducing the short-chain compounds up to 50% removal. The consistent observation of the use of co-surfactants showed enhanced stability and density of the foam that helps accumulate more foam and minimize the extent of interstitial liquid drainage before the foam is harvested (REF4). However, TechC experiments showed no impact of using 8 mg/L co-surfactant compared to the absence of co-surfactant. This can be attributed to reduction of additive performance due to electrostatic uptake by competing contaminants in leachate, suggesting the need for a higher dose. For TechC it was found that a 45-minute contact time is sufficient to achieve non-detection levels of long-chain PFAS in a leachate primarily dominated by PFCAs. The study also assessed the impact of the number of FF units in series, with the consensus being that using two to three treatment units is adequate to achieve the desired removal. TechD's proprietary model approach showed that increasing the treatment stages from 3 to 5 resulted in a 10% increase in the removal of short-chain PFAS, while long-chains remained non-detectable in both cases. TechC's unique two-stage method involves de-foaming the leachate from the first fractionation unit and then re-foaming the primary foamate generated over repeated primary fractionation cycles (Figure 2). This approach significantly reduces generated foam volumes, condensing the volume of foam by up to 180 times in the secondary foamate, minimizing the capital and operating costs associated with downstream destruction technologies. Conclusions 1.Findings of this work are illustrated in Figure 3. 2.Long-chain PFAS have been effectively removed to below detection limit, while short-chain PFAS require a polishing step using adsorptive media due to their low removal rate. However, this poses challenges due to the high fouling potential of the media. Therefore, the implementation of FF and modifications to its configuration strongly depend on treatment objectives and upcoming regulations. 3.For the specific leachate that was tested, a 45-minute contact time of and up to three treatment stages in series were sufficient for removing long-chain PFAS. However, these factors may vary based on the quality of the leachate water being treated. 4.FF is a highly selective method for removing surfactants without altering effluent water quality. This results in an effluent with similar water quality to the influent but significantly reduced concentrations of PFAS, VOCs, total suspended solids, and iron.

Introduction Alternative delivery methods in the water and wastewater market are proven to provide owners with value added and risk reducing approaches for executing capital projects. These delivery approaches are often associated with large utilities completing projects with hefty budgets. However, the same approaches can have equal, if not greater, advantages to small utilities providing resources for limited staff, minimizing design changes, and saving time and money. Objectives The primary objective of this case study is to investigate the benefits and challenges of alternative delivery implementation at two small wastewater utilities. The City of Fruita, Colorado (Fruita) conducted two construction manager at risk (CMAR) projects on their wastewater system in 2023 for a total construction budget of approximately $3.0M. The City of Laramie, Wyoming (Laramie) is currently conducting their first CMAR project for their wastewater utility. Both utilities struggle with similar issues complimentary of the CMAR approach: 1) Technically understaffed for wastewater capital project execution 2) Budgetary victims of ever climbing cost of work, 3) Location and project size limit contractor interest in open bid opportunities Status Fruita took a unique approach to alternative delivery. Located approximately four hours from any major metropolitan area, Fruita found it difficult to entice contractors to pursue projects delivered with a traditional design bid build (DBB) method. As such, Fruita selects an on-call CMAR firm every five years and issues work packages with negotiated guaranteed maximum prices (GMPs) to address their on-going capital improvements program. In 2023, Fruita conducted two CMAR work packages — replacement of their oxidation ditch aeration grids and collection system improvements to mitigate hydrogen sulfide (H2S) generation (H2S project). The on-call CMAR contractor commenced work with a pre-construction contract at, or around the 30% design level to provide value engineering, constructability review, cost estimating, and scheduling. Both projects included critical construction sequencing operations with significant cost ramifications. For example, the H2S project included significant bypass pumping associated with manhole replacement. The engineer, CMAR contractor, and Fruita collaborated early to determine exact manhole designs and construction sequence of operations to minimize bypass pumping time. The resulting construction was completed approximately 25% ahead of schedule and under the GMP. Cumulatively, Fruita was returned approximate $400k in deductive change orders from the CMAR contractor from the $3M GMPs. Laramie has traditionally delivered their capital projects in a DBB method — selecting the low price bidder without direct attention to qualifications. Like Fruita, Laramie is understaffed and has budgetary restrictions. Low bid DBB projects were found to be taxing the already overstretch engineering staff to their limits on ability to deliver projects on time and under budget. Laramie's first CMAR project is the West Laramie Main Lift Station Replacement with construction anticipated to begin in the summer of 2024. Originally budgeted for a mere $2.0M, Laramie realized the breadth of their project goals could not be accomplished with their budget. As such, the engineer, selected CMAR, and Laramie began the value engineering process early in the design phase to find options to meet Laramie's goals within an attainable budget. This started with a 'wants, needs, and must haves' workshop identifying scope elements to be included in the project. Considerations on phasing, alternate materials of construction, and facility location adjustments led the team to lock in on an overall design meeting Laramie's goals and budgetary restrictions. Findings and Significance Several key takeaways will be discussed for session attendees. 1) Partnerships between contractor, engineer, and owner are key. While alternative delivery is an excellent approach to delivering projects for small communities, effective working relationships are vital. A healthy balance of support and doubt between the engineer and contractor allow for best value approaches to emerge successfully. Similarly, owner trust in the design process allows for vetting of many options providing value. 2) Contractor and engineer experience in alternative delivery is vital to success of the project. Limited owner staff with limited alternative delivery experience requires more attention to the design and construction process from trusted engineering and contractor teammates. Ideally, engineer and contractor have past relationships (for CMAR delivery). 3) Begin GMP development early to mitigate late-stage design modifications. Regular cost model check-ins are helpful to make sure the project is keeping within budget. Laramie's pause and realignment happened following 30%, minimizing design changes and extra project cost.

Introduction Since its discovery in the 1980s, significant research continues to be conducted in Anammox process where, anaerobic ammonium-oxidizing bacteria utilize nitrite as an electron acceptor to oxidize ammonia to N2 gas, with about 10% of nitrogen being converted to nitrate (1). While nitrite is essential for anammox, nitrogen in wastewater primarily exists in the form of ammonium, thus ammonia-oxidizing bacteria (AOB) are employed to initially oxidize a portion of the ammonia to nitrite. Nitrite-oxidizing bacteria (NOB) however, compete with AOBs by oxidize nitrite rapidly to nitrate and hinder the anammox process. In side-stream treatment, effective NOB suppression is possible due to elevated influent temperature, pH, and NH4 concentration. These merits however do not exist in mainstream. To overcome these limitations and achieve stable partial nitritation (PN), various methods to suppress NOB have been employed (2; 3). The goal of this research is to improve the performance of PN in the mainstream process with an innovative and repeatable strategy to control growth of NOB, by employing available resource at a treatment facility with minimal process disruption and using supernatant from an anaerobic digester (AD) presents the best solution for this. AD supernatant offers the advantages of; warm temperature and environment to instantaneously inhibit NOB as well as alkalinity to buffer pH changes. Method A lab-scale reactor was operated for 2 years to derive basic and optimized operational parameter Based on these results; a pilot plant was operated at the city of LA's Hyperion WWTP for 8 months. Lab-scale (Proof of concept): Three different media types with diverse surface areas (M-1, M-2, M-3) were used in the lab-scale reactors. The innovative NOB control protocol involved a 100% fill and decant cycle (fig 1.1a), DO/NH4 ratio target was maintained as 0.2. Instant introduction or AD supernatant when effluent nitrate concentrations consistently exceeded 5mg/L. Monitoring of free ammonia (FA) and free nitrous acid (FNA) was done to help stimulate the growth and performance of AOBs. Pilot Scale: Based on the optimized results from lab-scale operation, a 1.3 m3 pilot plant operation (fig 1.1b) was carried out in a similar manner using M-2 (highest PN performance media) and the secondary effluent of the Hyperion WWTP as the influent, with an average concentration of 50+/-3.5 mgNH4-N/L for about 250 days. Two (2) different supernatant exposure methods were tested in the pilot based on pH control. Results Fig 1.2 shows the effluent nitrogen concentrations over the operational period. The 100% fill and decant cycle strategy significantly helped in shortening the start-up phase relative to other mainstream processes (2). To optimize the PN performance and economically control NOBs, two different inhibition methods (mainly based on initial supernatant pH control) were adopted to monitor the time required between each inhibition reaction before effluent NO3-N exceeded the set mark of 5mg/L, at which point optimal PN is hindered. It was identified that employing exposure method I (no initial pH control) took fewer days and enhanced the inhibitory potential of NOB and help maintain effluent NO3-N levels below 5mg/L for longer periods relative to exposure method II. Supernatant exposure method II involved controlling initial pH of supernatant to 8.5 by dosing with phosphoric acid and this pH level maintained for first 10 hrs prior to an inhibition reaction. Since pH and temperature determine the reactors instantaneous FA and FNA concentrations, these were monitored for the two distinct exposure methods. Fig. 1.3 shows drastic reduction in NH4 and FA in the exposure method I. Thus, for mainstream PN processes at plants where AD is available, direct application of the AD supernatant without pH control in a regular and recurrent manner can successfully inhibit NOB while improving the performance of AOB in treating higher N-loads. To confirm the effectiveness of the inhibition reaction with AD supernatant a validation of AOB performance and a corresponding effective NOB inhibition was carried out for 20 hrs using NH4-N and NO2-N as the batch experiment substrate, respectively (Fig. 1.4). The minimal nitratation (fig. 1.4b) that occurred at relatively low NO2-N substrate levels confirms the successful inhibition and absence of NOBs after employing the innovative supernatant exposure inhibition reaction. Summary and Recommendation This research successfully achieved a stable mainstream PN operation at high N loading rate both in the lab-scale and pilot scale by employing a reliable, economical, and repeatable NOB inhibitory method, using AD supernatant. By implementing a 100% fill and decant sequence, relying on elevated AD supernatant temperatures, regular inhibition reaction could be carried out when effluent NO3-N recurrently exceeds 5 mg/L. This new strategy utilizes available plant resources, thereby reducing cost of employing alternative NOB inhibitory techniques. However, other control measures must be selected at those plants that do not have digesters. The next phase of this research involves direct application in the full-scale plant, identification of inhibitory sequence for a smooth operation in a full-scale plant as well as investigation of alternative environmentally friendly control measures for plants without ADs.

Introduction At WEFTEC 2019, data from one year of operation of a newly built sidestream fermenter for a biological phosphorus removal (BPR) system was presented. This paper covers the first 5 years of operation of the Wakarusa River wastewater treatment plant (WWTP) at Lawrence, Kansas. New processes are always scrutinized by the industry. Was the pilot operation a fluke? Can its performance be repeated? Is the system lightly loaded? Is the process resilient and reliable? Data from the last 5 years shows that sidestream fermentation is reliable, but there were periods of degraded performance. The Wakarusa River WWTP was designed to treat 2.5 mgd (9 500 m3 /d) annual average flow of domestic sewage. The Wakarusa facility is essentially a new train located at another site for the Kansas River WWTP. Flow to Wakarusa has averaged about 2 mgd over the 5-year period (80 percent of the design capacity). The Wakarusa Facility is a 3-stage Bardenpho process with a flow-through anaerobic zone, an anoxic zone, and an oxidation ditch for aerobic treatment plus a sidestream fermenter for enhanced biological phosphorus removal (EBPR). The raw influent to Wakarusa is fairly 'fresh' with a little VFA (12 mg/L) and a low rbCOD to TP ratio (50% of the time less than 13.5). Not enough rbCOD was available for good BPR performance. The Bad: Impact of Return Flows on EBPR Performance Figure 1 shows the effluent orthophosphate (OP) concentrations from an online analyzer, and effluent total phosphorus (TP) concentrations from operator collected data and 24-hour composites for 2019. This graph contains over 150,000 data points from the on-line analyzer. Figure 2 shows the 30,000 points spanning from Nov 2019 to Sept 2020 and it is much easier to see the periods of good effluent from the not so good effluent quality. The permit limit is 1 mg/L TP on a 365-day rolling average. The Figure 1 graph show periods, highlighted by the pink transparent boxes, of high effluent P coinciding with periods when biosolids land application was delayed by excessively wet fields. This pattern repeats each year. Solids build up in the plant MLSS (or system increased SRT) and the basin MLSS concentration rises significantly which interferes with sidestream fermentation efficiency. A process model was developed in SUMO (Dynamita) to simulate the plant performance at increasing SRT conditions. Model simulations indicated that the VFA production in the fermenter decreased as the SRT in the activated sludge basin increased while maintaining a constant flow to the fermenter. Model simulations are continued to further explore this phenomenon to determine if operational conditions can improve fermenter performance. In 2022 there was an upset between Sept and Nov in system performance. The centrifuges had been in operation for 4 years and erosion/ wear of internals resulted in poor solids capture. The net result was poor BPR performance in Sept through Nov of 2022, highlighted on Figure 1. Poor solids capture resulted in the recycling of high concentrations of BOD, TSS and TP to the plant influent (Figure 3). Once the centrifuges were repaired and solids capture was under control, the effluent OP and TP returned to very low concentrations. After 5 years of operation, no ferric chloride has been added nor has there been any supplemental addition of a carbon source. After the high inventory of MLSS was reduced, the fermenter bounced back and produced a very low effluent OP concentration. The Good: Impact of Low DO Operation on TN and TP Removal Performance and Microbial Ecology Figure 4 shows the nitrogen profile in the system during the summer of 2022. The abrupt decline in the effluent nitrate concentration was intentional. The facility has two online DO probes located in the outer curve and the inner curve of the ditch system. The DO setpoints were initially set at 0.8 mg/L and 0.5 mg/L during start-up and during the summer of 2022 plant staff lowered the DO setpoints to around 0.2-0.3 mg/L. Effluent nitrate concentrations dropped to below 1 mg N/L. The effluent phosphorus concentration remained very low (Figure 1). During the July — August 2022 timeframe, the effluent OP and TP concentrations remained very low. Near the end of this trial period, centrifuge performance began to deteriorate and excessive solids in the system interfered with good BPR. These results indicate that low DO operation did not have a negative impact on phosphorus uptake as well as nitrification. As the DO setpoints were lowered, the AOB (ammonia oxidizing bacteria) population declined and the population of Commamox increased. Recent studies demonstrated the prevalence of Comammox Nitrospira can be dominant ammonia oxidizers in a mainstream low DO nitrification reactor. The Good: Impact of Fermenter SRT on VFA Species and PAO/GAO Population A study performed by University of Kansas on fermenter SRT and operating parameters showed the impact of SRT on the quantity of VFA formed and the diversity of VFA species (Figure 5). Acetic acid is still the predominant VFA present in the fermenter effluent. Figure 6 shows the PAO versus GAO as a fraction of the overall microbial population in the anaerobic zone. Very few GAOs were present in the system. Summary The sidestream fermentation process has been reliable and consistent in producing a low effluent OP concentration while at plant loading of 80% of design capacity

Our world is driven by data across all industries, and the water sector is no exception. This ranges from enterprise systems that have been in place for decades to smart systems that are generating data at an exponential rate. It is increasingly important to incorporate practices to make sound decisions from these systems and implement controls to ensure trusted data. WSSC Water completed efforts to identify processes to improve their data-driven decision-making, and this abstract will present two strategies used to improve their performance across many departments through automation, standardization, and visualization of data. Strategy 1: Enterprise Data Warehousing: A large portion of the data used by decision makers resides in systems of record that are operated by their functional teams. While this data is usually accurate and up to date, it requires an expert from the team to extract it from the system or understand the data that is produced. It is also more granular than decision makers require, and the teams reporting on it consistently aggregate it to produce the intended results. To address these issues, WSSC Water automated the creation of datasets in these functional groups, all of which were a part of their Enterprise Data Warehouse. In the use case for this strategy, they will show the automated Commission Performance Report and Human Resources Dashboards. These items reduced the time spent developing recurring reports, leveraging Power Bi for automated and interactive reporting. Strategy 2: Non-Enterprise Data Management and Application Development: Unlike the enterprise data, WSSC Water identified many users who are managing critical data in their own spreadsheets or other tools. To standardize and automate some of the processes, they worked with these users to provide low-code platforms to manage data in their existing IT infrastructure. These tools included the development of SharePoint data-structures, Applications and Workflows to allow users to edit and maintain datasets in a collaborative environment, with the increased auditability that these tools provide. In the use cases for this strategy, they will show the Transition Plan Tracking Application and Community Investment/Engagement Application. These converted existing series of over ten spreadsheets into a single data source, provided a low-code application for the teams to enter data, and Power Bi Dashboards for reporting. The combination of these two strategies allows groups to take small steps into the world of data-driven decision making. Teams are beginning the process with Strategy 2 by standardizing their reporting, with the intent to be automated into an enterprise solution under Strategy 1 in the future. In the past, tools such as the ones outlined in these strategies were limited to IT Departments and professional programmers. With the advent of modern data management strategies, they are much simpler to implement and maintain, but still in line with IT standards and supported by their department once they are in production. In the end, WSSC Water identified significant time savings, data quality, and visualization capabilities as a result of taking a data-driven approach to managing some of their manual efforts.

INTRODUCTION VCS is Denmark's third largest and oldest water utility with more than 150 years of operational experience and a strong tradition of innovation, with a focus on implementing triple-bottom-line sustainability practices and emerging technologies to manage the water-energy nexus. The utility 8 water resource recovery facilities (WRRFs). In 2009 IT initiated the Beyond Energy Neutrality program, aimed at improving resiliency and sustainability through turning their largest facility, the Ejby Mølle WRRF with a 410,000 population equivalent (PE) capacity from a large electrical power consumer to a net producer of electricity and heat energy.This biological nutrient removal facility meets very stringent nutrient limits (6 mg/L total nitrogen and 0.5 mg/L total phosphorus) prior to its discharge into a small, local river. By 2014, the Ejby Mølle was net energy positive as the result of implementing several innovative technologies, including ammonia-based aeration control, sidestream deammonification, optimized combined heat power capacity from sludge digestion, and induced biomass granulation through hydrocyclones, which also improved process resiliency during wet weather events (Nielsen and Sandino, 2020). DEMONSTRATION TESTING - UNDERSTANDING MABR'S POTENTIAL The Beyond Energy Neutrality program continued to investigate ways to further provide sustainable water resource recovery at the Ejby Mølle WRRF. Between 2017 and 2020, VCS conducted an industry-first demonstration program focused on how membrane aerated biofilm reactors (MABR) might deliver further energy savings, while reducing greenhouse gas emissions and requiring a much smaller facility footprint, which would be of great importance to other large facilities in need to increase capacity or achieve higher levels of treatment within constraint sites. This emerging technology relies on membranes capable of gas transfer to deliver oxygen to a AOB-rich biofilm that is attached to the membrane. The direct supply of oxygen to the biomass growing in the biofilm makes the theoretical oxygen transfer efficiency, a key parameter for efficient and low energy aeration, close to 100%. The testing program aimed at answering several questions that need to be addressed regarding the applicability of this emerging technology in full-scale and of the installation of MABR modules purchased from two different manufacturers in the last anaerobic zone ahead of the aeration ditches at Ejby and in remote containers next to the tanks, and their operation during a three-year period (Figure 1). FULL-SCALE IMPLEMENTATION — BETTING ON DISRUPTION Based on the encouraging results and further understanding of the anticipated operational and maintenance requirements of the technology gathered from the demonstration testing stage, VCS decided to implement MABRs at their Søndersø¸ WRRF. This 20,000 PE nutrient removal facility was built in 1990 and is configured with two treatment trains running in parallel, each consisting in two oxidation ditches operated under alternate aerobic/anoxic conditions (BioDenitro process). During heavy precipitation events, the maximum incoming flow is more than four times the yearly average incoming flow, when the facility is under stress and its performance worsens, resulting in ammonia peaks discharged in the effluent. Given this challenge, VCS decided to couple the MABR with induced granulation capabilities via heavy biomass selection using hydrocyclones, based on their earlier positive experience at their Ejby Mølle facility. A key component in the road to the full-scale implementation of this emerging and potentially disruptive technology was VCS's ability to secure funding from the LIFE programme, the European Union's funding instrument for the environment and climate action. Essentially, the programme financed 50% of the implementation costs at Søndersø. Improvements at Sonderso included the retrofit completed in 2023 of one of the two oxidation ditches with seven MABR modules, becoming one of the largest facilities with this technology currently operating in the world (Figure 2). Results to date show an average aeration energy saving of 25% compared to the control train. The MABR units are showing an average oxygen transfer rate of 11 g O2/m2/d (Figure 3). Nitrification rates from the MABRs are averaging 2.4 g N/m2/d, corresponding to approximately one fourth of the total nitrogen load to the treatment plant. Normalizing these nitrification rates per volume of reactor used, the MABRs are successfully removing 0.5 kg N/m3/d, which is 25 times more intensive than the existing activated sludge train. These results indicate that the incorporation of this emerging technology does in fact provide significant additional capacity, while reducing energy consumption and maintaining low N2O emissions (Uri-Carreño et al, 2023). RELEVANCE This paper will show how a water utility has successfully embarked in transforming by adopting emerging technologies that have a very high disruptive potential. MABR is one of these them, promising significant process intensification and energy reduction while also resulting in a very low carbon footprint for biological nutrient removal applications. This paper is intended to illustrate the role water utilities can play on moving a promising emerging technology in the water resource recovery industry, a much-needed step in meeting the umprecendented challenges we are facing.

Introduction Mesophilic Anaerobic Digestion (MAD) is commonly used in larger WRRFs to stabilize solids and generate biogas for heat/energy (CHP) or injection into natural gas pipelines (RNG). The benefits of acid digestion ahead of MAD and post-aerobic digestion (PAD) after MAD have been generally understood and implemented at several facilities to improve operations. Those two MAD 'add-ons' had traditionally been only used independently. However, some very interesting and useful outcomes develop when a recycle loop is employed to send nitrite from the nitrifying PAD to the Acid Reactor for denitrification. Process Background More frequently discussed in the nutrient removal world, the presence of nitrate makes a reactor 'anoxic' not 'anaerobic'. The nitrate-laden recycle from the PAD helps the Acid Reactor by increasing pH, reducing corrosivity and creating optimal conditions for hydrolyzing bacteria. Because of this, the methanogens in the anaerobic digester are more efficiently able to produce more biogas with a higher methane content. The nitrates present in the Acid Reactor are denitrified in a reaction that is biologically and energetically preferred over sulfate reduction. Nitrate has been used to control odors within sewers, at headworks and elsewhere by suppressing the population of sulfate-reducing bacteria (SRBs). Within the world of anaerobic digestion, the nitrate pathway serves to significantly decrease the concentrations of Hydrogen Sulfide (H2S) in the biogas. Because of the recycle, the effects of the nitrification-denitrification occurring within the biosolids treatment process decreases the concentration of ammonia within the anaerobic digester. Since both ammonia and H2S can be inhibitory to methanogens, lower concentrations contribute to increased biogas production. Pilot Studies Recent pilot studies at several facilities in Indiana, California, Arizona and Michigan have shown some consistent and significant results that are summarized here. Additional data and discussion will be provided in the paper and presentation: H2S concentration in the biogas was consistently reduced by at least 90%, without the addition of ferric chloride or other chemicals, which would significantly extend the life of H2S removal systems and reduce odor and corrosion challenges and lower chemical costs. Biosolids mass (and hauling costs) are reduced in at least four cumulative ways: Increased volatile solid (VS) destruction, No metal salt precipitates, improved dewatering, and decreased liquid-stream solids production (through reduced loadings in dewatering return flow). Since pH is lowered and ammonia concentrations are lower, the stoichiometry is not conducive to struvite formation. Ammonia and H2S toxicity on methanogens is reduced. The combined effect of increased VS destruction and a richer (higher methane %) in the biogas results in a significant (~10%) increase in the net energy yield from the digesters. Dewatering significantly improved with added VS destruction and because aerobic biology more effectively breaks down the Extracellular Polymeric Substances (EPS) produced by cells during anaerobic digestion. In one pilot study, coagulant was eliminated, polymer dose dropped and the dewatered cake achieved 32% total solids. Nutrient control within the solids process eliminates the need for additional sidestream tankage, heating and additional processes. Conclusion The recycle from the PAD to the Acid Reactor promotes the nitrate pathway over less favorable (sulfur) pathways. Through reduced chemical use, optimized digester chemistry and biology, increased solids destruction, enhanced methane production and other consequential benefits, the capabilities of this process offer savings and solutions for several common MAD challenges. By harnessing the power of biology in creative ways, the entire anaerobic digestion system becomes more robust and resilient: less reliant on chemicals and external inputs.

Potable water reuse typically relies on treated wastewater from a conventional water resource recovery facility (WRRF) with further treatment through an advanced water treatment facility with chemical oxidation followed by membrane filtration. Conventional activated sludge (CAS) is used at WRRFs for bulk chemical oxygen demand (COD) and nutrient removal. Chemical oxidation and membrane filtration are employed to remove micropollutants and achieve additional pathogen inactivation. Although CAS is commonly used, it is not without challenges, such as sludge production, long detention times, susceptibility to treatment upsets, and lack of complete micropollutant removal2. In contrast, chemical oxidation can remove COD, making it suitable not only for advanced water treatment, but possibly for bulk COD removal as well1,3,5,6. It would be beneficial to evaluate the efficacy of replacing a sequence of CAS, chemical oxidation and membrane treatment with a simpler sequence of chemical oxidation (i.e., ozonation) followed by membrane treatment (i.e., reverse osmosis (RO)). This proposed system may achieve secondary treatment goals while also providing micropollutant removal and pathogen inactivation for potable reuse in a simpler process. However, no R&D reports were found that advance the proof-of-concept to eliminate CAS when chemical oxidation and membrane treatment are employed for municipal wastewater reuse. Currently, the scenario to eliminate CAS is at technology readiness level (TLR) 2 (concept and/or application formulated), whereas more work remains to move to TLR 3 (invention and research moving to proof of concept) and beyond4. In this study, bench-scale research was performed to prove the concept of ozonation followed by RO as a technology for municipal wastewater reuse (ozone-RO). Municipal wastewater primary effluent COD removal kinetics during ozonation were determined and compared to removal observed from CAS at a full-scale WRRF. Additionally, COD removal and nutrient fate and removal across ozone-RO were determined. Results were compared to COD and nutrient removal values achieved at a full-scale CAS followed by RO (CAS-RO). To determine ozonation COD removal kinetics, municipal primary effluent (PE) 24-h composite samples were collected from a WRRF (Fox River WRRF, Brookfield, WI). The CAS system fully nitrifies, with alum added to the secondary clarifiers for phosphorus removal. PE was ozonated in a 3-L batch ozone contactor at three different temperatures (7 degrees C, 22 degrees C and 34 degrees C). Ozonated gas was generated using a nozone generator (TG-10 Ozone Generator, Ozone Solutions, Hull, IA). A total applied ozone dose of 33 g O3/LWater over 3 h was used (45 g/m3 ozone gas with a 184 mg/L-min ozone application rate). To determine nutrient fate and removal, experiments were carried out using PE in the ozone contactor at 22 degrees C for 3 h. After ozonation, the water was sparged with nitrogen gas to remove residual ozone before a flat sheet RO membrane (FilmTec BW30XFRLE brackish water membrane) held in a cross-flow membrane cell (CF-106, Sterlitech). Pressure was held constant at 250 psi for 24 h. The RO process was then repeated with the same operating parameters but treating a 24-h composite sample of CAS effluent. COD, total and reactive phosphorus, total nitrogen, ammonia, nitrate, nitrite, and organic nitrogen concentrations were determined using commercial kits (Hach Company). Batch COD removal curves were fitted to the data using a first-order model with respect to COD concentration (Fig. 1) and the first-order rate constant (k) values were 0.0043 + 0.00037, 0.0046 + 0.00042, and 0.0067 + 0.0011 at 7 degrees C, 22 degrees C and 34 degrees C respectively. An ANNOVA test indicated that these k values were statistically different (p=0.0126). The resulting Arrhenius temperature coefficient value ( was 1.077. The CAS system had a 7-h average hydraulic residence time (HRT) before 1-hr secondary clarification compared to the ozone HRT of 3-h. Both COD and sCOD removal values with ozone and CAS were similar, and both treatment systems resulted in final effluent COD <5mg/L after RO treatment. Ozonation removed some phosphorus and converted some nonreactive phosphorus to reactive. It is hypothesized that phosphorus removal occurred by precipitation since a white precipitate was observed in the ozone contactor. Precipitation may have occurred due to a pH increased from 7.7 to 8.4 during ozone contact. Future experiments are planned to determine if this is the case. Final phosphorus and nitrogen concentrations from ozone-RO and CAS-RO systems were relatively low and similar. For example, total phosphorus concentrations for both effluents were below detection (<0.15 mg/L PO43--P) after RO. Although ozonation did not result in nitrogen removal, it did oxidize ammonia to nitrate (Fig, 4), which was subsequently removed by RO. This is significant since ammonia is not effectively removed by RO. No nitrite was detected (<0.6 mg/L NO2--N) in any samples. The concept of ozonation followed by membrane treatment was verified for municipal wastewater potable reuse and advanced from TLR 2 to TLR 3. Ozone rapidly oxidized PE COD under the conditions studied. In addition, quasi first-order kinetic constants and an Arrhenius temperature coefficient was established for ozonation of PE. Additionally, ozone-RO achieved final COD and nutrient concentrations similar to CAS-RO treatment. These data can inform system scale-up for R&D.

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.

Introduction The application of the AquaNereda® process, were aerobic granular sludge (AGS) is applied in a sequencing reactor, is often seen as a replacement for the conventional activated sludge process. AquaNereda(R) is a sequencing process that utilizes a single tank for react and settle phases, and therefore is often not compatible as a retrofit with existing activated sludge systems that utilize separate tanks for reaction (aeration basins) and settle (final clarifiers). While this can be seen as a limitation for the application of AquaNereda(R), there is an opportunity to construct an expansion of facilities with AquaNereda(R), and then integrate the AquaNereda(R) in parallel to a conventional activated sludge plant. Four Rivers Sanitation Authority (FRSA), located in Rockford, Illinois, is currently working towards this integrated overall facility. While maintaining 40 mgd of average day flow capacity in a more conventional biological nutrient removal (BNR) activated sludge facility, FRSA is adding an additional 10 mgd of average day flow capacity with a new AquaNereda(R) AGS facility. The AGS facility will be operational in 2025, with the BNR upgrades being completed in 2026. During design of the new facilities at FRSA, the largest question for integration of the processes became how to manage the waste activated granular sludge (WAGS). Given the characteristics of WAGS in terms of percent solids as well as the sequencing wasting schedule from AquaNereda(R), it was decided to send the WAGS into the activated sludge system and then to waste to solids handling (see Figure 1 for a process flow diagram). The waste activated sludge (WAS) would then contain flocs from the activated sludge process as well as WAGS. This simplified operation, but there were major questions related to the impact of WAGS on the activated sludge process. Potential oxygen demand impacts, nitrification rates, and settling rates were all of interest to FRSA to understand the impact of WAGS. While most facilities would rely solely on process modelling to assess these impacts, FRSA has access to WAGS for testing. The AquaNereda(R) demonstration facility is on site and operating with FRSA wastewater. This facility (treating 200,000 gpd) generates WAGS that can be utilized for testing. Approach and Methodology To help understand the impacts and strategies to manage WAGS from the AGS facility, a series of bench scale tests were completed using WAGS from the AquaNereda(R) demonstration facility and WAS from the existing FRSA aeration basins. Three sets of bench scale tests were completed:

*Settling rate testing to identify potential enhanced settling, as outlined by Daigger, Redmond, and Downing (2017)

*Specific oxygen uptake rate (SOUR) measurement, utilizing standard methods, to assess the oxygen demand of the WAGS. The WAGS have the potential to exert a significant oxygen demand, as past work has shown a biomethane production potential of WAGS that is similar to primary sludge (Guo et al., Digestibility of waste aerobic granular sludge from a full-scale municipal wastewater treatment system, 2020).

*Nitrification rate testing, as outlined by Melcer et al (2003), to identify any potential seeding effect from WAGS. Results and Outcomes To evaluate the effect of WAGS on the settling characteristics of the existing waste activated sludge (WAS), batch settling experiments were performed using WAS and a mixture of WAGS-WAS at various dilution ratios to generate settling curves. The WAGS-WAS mixture proportions were calculated based on the predicted WAGS flows from the new AGS facilities. Figure 2 provides the settling rate impacts. Addition of WAGS increased the settling rate of the activated sludge biomass. The effect on settling rate would increase the peak flow capacity of the activated sludge facilities from 110 mgd to 130 mgd. SOUR testing indicated that the WAGS would have a 25% higher oxygen uptake rate than WAS (Figure 3). This indicates that there will be an oxygen demand associated with either particulate COD bound in the WAGS or potentially stored carbon. This oxygen demand is considered during aeration operation in the activated sludge system. The nitrification rate of WAGS (4 mgN/gVSS-hr) was similar to the nitrification rate of WAS (3.9 mgN/gVSS-hr). This was an unexpected result, as the WAGS likely contains a high VSS content of particulate COD from the influent. The benefit is that the WAGS will be adding a significant load of nitrifiers into the activated sludge system, increasing system resilience. The outcomes from this testing highlight how construction of an AquaNereda(R) facility in parallel to an activated sludge facility can provide a net benefit to the activated sludge facility. Applicability AquaNereda(R) has been sold as the evolution of activated sludge, but the requirement for a sequencing reactor can been seen as a limitation. The work completed highlights how an AquaNereda(R) process can be constructed in parallel to an activated sludge system, with positive impacts on the activated sludge facility. Audience Appeal Anyone looking at process expansion, nutrient removal requirements, and aging infrastructure would benefit from this presentation.