Conference Papers

Nutrients and sediment are consistently identified as major contributors to water quality impairments and have resulted total maximum daily loads (TMDL) being developed for numerous water bodies. Theoretically the TMDL will include allocations for point sources and nonpoint sources with expectations for reductions of nutrient and sediment loads. The primary source of these pollutants is open to debate; however, publicly owned treatment works (POTWs) and urban/suburban stormwater discharges are known contributors of nutrient and sediment loads along with agriculture nonpoint sources (NPS). There is no mechanism to easily address nonpoint sources, so the focus immediately centers on the point sources. This focus then leads to lower limits for publicly owned treatment works (POTWs) regardless of whether that source is a significant contributor, and increasingly, MS4 permits also include difficult to achieve nutrient limits. In the case of the POTW, the lower limits then require the POTW to consider additional treatment which often includes increases in energy and chemical costs. Urban and suburban areas are also a focal point for growth and development which will require planning to address increased pollutant loads, and development will have impacts upon water resources which leads to the need for mitigation (Clean Water Act (CWA) 404 permits) and construction stormwater permits. The USEPA has a long history of supporting water quality trading and made it clear that one of the ways to achieve water quality standards and water quality-based limits is through trading (USEPA 2003, 2009, 2019). Despite this strong support, trading is only used in a few states and generally is only in the form of point source to point source trading. In places where it is used it has been quite successful, Virginia's Nutrient Exchange is a very good example, though it is primarily point to point trading. This minimal use of an effective tool raises the question of why its use is so limited and how might this be changed. Given the need to address pollutant loads from nonpoint sources, trading needs to be expanded to incentivize point to nonpoint trading. Clean Water Act section 402 provides the primary driver for control of stormwater discharges. The specific control mechanism is the NPDES permit and owing to that fact the controls are focused on water quality rather than quantity. This focus has been emphasized in litigation where the courts have ruled that quantity of water is not a 'pollutant' and therefore cannot be directly limited in a NPDES permit. Stormwater discharges result from many different activities: runoff from municipal surfaces, industrial sources and also from development activities. In the case of development activities, depending on the location of the development and the impact on water resources a CWA 404 permit may also be required. This brings us to the intersection of urban/suburban development, stormwater, mitigation and the need to reduce discharges. Stormwater discharges are primarily regulated under CWA section 402 while compensatory mitigation is under CWA section 404. Section 402 focuses on pollutants while section 404 focuses on adverse physical impacts to aquatic resources. One potential adverse impact is related to quantity of flow. Quantity of flow has a direct connection to water quality given the fact pollutant load is directly impacted by the volume of flow. Flow reduction means reduction in pollutant load. Depending upon the size of the municipality, there could be hundreds or thousands of individual outfalls. Putting treatment on each outfall is physically and economically impossible. Also, as touched upon earlier, these may not be the largest source of the pollutants. This issue of the need to focus on the largest sources, not just the point sources was highlighted almost twenty years ago in a watershed-based approach by Clean Water Services in Oregon. The issue was temperature impacts and the cost of reducing temperatures at the wastewater treatment plant, a small point source, versus solar radiation impacts on the large land areas (nonpoint sources) ' see Cochran and Logue 2010. It has been shown over and over that focusing on point sources is not going to solve the problem. The solution is a watershed-based approach and that means point sources and nonpoint sources working collaboratively. A potential common thread between nonpoint sources, 402 permittees and 404 permittees are the use of green practices to achieve compliance. This is bolstered by the recent policy position of White House for the use of 'Nature-based' solutions ' see - https://www.whitehouse.gov/briefing-room/statements-releases/2022/11/08/fact-sheet-biden-%E2%81%A0harris-administration-announces-roadmap-for-nature-based-solutions-to-fight-climate-change-strengthen-communities-and-support-local-economies/ The White House position notes that, 'Few know that nature-based solutions can help address common problems, like coastal flooding or urban heat islands.' As noted earlier, controlling volume will also provide positive impacts regarding water quality by reducing the pollutant load. Similarly, addressing flooding addresses pollutant load, so the key is to look for opportunities to build projects with multiple benefits. The presentation and manuscript will include a discussion of similar but different approaches used for green approaches and the way quantity and quality can interact, specifically, controlling quantity controls mass of pollutants and leads to improved water quality. The presentation will include a number of examples where ecological restoration projects have addressed NPDES permit requirements as well as providing numerous ancillary benefits. The presentation will also include a discussion of the need to address both runoff and instream impacts that deliver pollutant loads into the downstream waters. It is also important to note that controlling quantity of water also provides opportunities to address flooding concerns which are not a driver associated with NPDES permits. While looking at the issues involved with needing to comply with permit limitations established to be consistent with assumptions of applicable TMDLs, the presentation will also consider the impact of CWA section 404 compensatory mitigation that arises as a result of projects that have potential to impact water resources. Compensatory mitigation may also be needed in order to address impacts due to stream restoration or other instream projects done to meet stormwater requirements and/or TMDL reductions. The presentation will also discuss how lessons learned in the compensatory mitigation program may be applied to make better watershed-based approaches more successful by including a specific set of options and practices similar to what is done to meet 404 permit requirements.

Facility Overview: South Platte Renew holds the distinction of being the third-largest Water Resource Recovery Facility (WRRF) in the state of Colorado. Serving as a vital lifeline, it caters to the needs of over 300,000 residents and consistently processes an average of 20 million gallons per day (MGD) of wastewater. SPR's asset registry is a testament to its complexity and scale, comprising nearly 6,000 assets across multiple disciplines, encompassing mechanical, electrical, instrumentation and controls, structural, and fleet components. The diversity within this asset portfolio is further underscored by the wide-ranging age of these components, stemming from the original plant construction in the 1970s, complemented by significant upgrades undertaken during the 1990s and the early 2000s. This intricate blend of assets has introduced a formidable challenge for SPR, as it endeavors to strike a balance between the renewal needs of variable aging infrastructure with other process and regulatory capital improvement needs. Asset Management Background: While SPR has been performing certain asset management activities since its original construction, SPR's formal programmatic asset management journey started in 2008 with the acquisition of an Enterprise Asset Management (EAM) system. Since then, SPR has advanced its asset management program by launching a series of initiatives designed to enhance overall asset lifecycle health. These initiatives encompass recurring asset-focused programs, such as equipment rebuilds, tank cleaning, HVAC maintenance, valve exercises, and concrete repair and rehabilitation projects. In addition, SPR has integrated asset management principles into its capital projects through standard development and data utilization. This ongoing commitment to enhancing asset management practices reflects SPR's dedication to continually evolve and improve its approach to ensure the sustained health and efficiency of its vital infrastructure. The Challenge: SPR has diligently worked across various departments to develop data management and maintenance strategies to support the ongoing advancement of its asset management program. However, one thing that became evident to SPR was the lack of a cohesive and organization-wide strategy amid the ongoing tactical endeavors. The lack of understanding and inconsistencies in asset management practices among SPR staff posed a notable challenge. It was not well understood among SPR staff what asset management meant and what the overall goals and objectives of the program were. It was also evident that there were inconsistencies in how asset management practices were being performed. The Solution: To address the challenges faced, SPR embarked on the development of a Strategic Asset Management Plan (SAMP) which had a dual purpose. Firstly, it formalized asset management strategies and policies. Secondly, it actively engaged key stakeholders and nurtured an asset management culture within the organization. The SAMP encompassed critical components such as: Identifying and recruiting key asset management stakeholders across operations, maintenance, engineering, data analysis, and senior leadership staff Developing a clear vision, goals, objectives, and policies around SPR's asset management program Establishing programmatic governance, roles, and responsibilities Defining levels of service and key performance indicators Implementing risk-based renewal planning methodologies in consideration of an asset's condition, criticality, and redundancy Optimizing maintenance strategies Benefits Realized: SPR has already realized several benefits from the development and implementation of the SAMP. There is overall a greater sense of understanding of asset management among staff, there is excitement and the realization of value from asset management activities, and there is consistency and clarification on many procedures and activities. Through the implementation of a SAMP, SPR will also gain an increased resiliency in financial planning through transparent and accurate reporting, as well as operations and maintenance practices, allowing SPR to better maintain high water quality and maximize value to customers. Lessons Learned: SPR's asset management journey offered valuable lessons, including the importance of starting with simplicity and gradually building complexity, eliminating silos, and the foundational importance of thoughtful and strategic data management. The SAMP emerged as a concise, repeatable document that can guide any utility in creating an asset management framework. Key Value Points for UMC Attendees: This presentation by SPR staff and its external consultant will provide attendees with insights into SPR's asset management journey, including: Step-by-step guidance for creating a SAMP and its associated benefits Strategies to avoid single points of failure by sharing institutional knowledge The significance of fostering an asset management culture across an organization Transitioning from fragmented and inconsistent initiatives to a formalized organizational strategy The advantages of self-performing SAMP development in collaboration with external consultants The importance of building upon past successes and discarding outdated approaches to meet current and future programmatic needs. SPR's asset management story serves as a valuable case study, offering practical guidance and inspiration for utilities seeking to enhance their asset management practices.

Question: In your opinion, what does OWASA do exceptionally well? Answer: 'Allows users to track water usage and see what they're being charged for; service is top-notch. You can always reach someone at the office if you need to. Even emergencies seem to be handled well (ie water main break a couple years back).' Answer: 'Community service. I love how easy it is to include a monthly contribution with my water bill and help out others.' Answer: 'I appreciate OWASA's communication. They communicate very clearly when bills are due (and exactly when they'll be paid if using autodraft). Recently they were testing systems in my neighborhood with smoke and gave lots of notice, including diagrams about what they were doing.' In 2021, having accomplished much of what was included in its most recent strategic plan, the Orange Water and Sewer Authority (OWASA) began a comprehensive process to update its plan for the next five to six years. OWASA has a 35 square-mile service area in Carrboro and Chapel Hill in North Carolina and provides water and sewer service for 22,000 accounts. Guiding principles for the strategic plan update included actively seeking to engage the Board, staff, the community, and other stakeholders, including proactive outreach to gather feedback to include and consider diverse perspectives. This engagement included an intensive environmental and organizational scan, with activities such as stakeholder work sessions, departmental strategic priority setting, peer reviews, industry publication reviews, and four separate surveys, which collectively garnered thousands of responses. While the overarching process of updating the strategic plan is still underway, considerable data analysis of the community survey has been completed and will be the subject of this presentation. Stakeholder input is invaluable in gauging the community's perception of the utility, as well as the community's priorities and preferences. To gather community feedback, and to be sensitive to COVID restrictions, OWASA created a tailored, 16-question online survey, available in both English and Spanish. The survey was hosted on the Zoho platform and was extensively promoted using a series of outreach strategies, including a direct email to all OWASA customers (for whom OWASA had email addresses), bus advertisements, tabling at the library, neighborhood kiosk flyers, and repeated social media posts on Twitter, Facebook, and Nextdoor. Respondents were asked what words come to mind when they think of OWASA ('water,' 'sewer,' 'clean,' 'reliable,' and 'expensive' were top choices) and to rate their satisfaction with OWASA's performance in a number of different areas. The highest levels of satisfaction were in drinking water quality, service reliability, and communications, while satisfaction levels were lower in cost of service. A significant percentage of respondents (more than 35% in each category) indicated that they didn't know how satisfied they were with regard to OWASA's environmental protection efforts, commitment to sustainability, and water/wastewater infrastructure construction, which suggests that there are areas where additional communication may be helpful. One of the other survey questions that will be invaluable for the organization as it works to clarify its priorities for the next five to six years was around responsibilities. OWASA asked, in addition to remaining committed to providing safe drinking water, protecting the environment through wastewater treatment, and meeting state and federal regulatory requirements, what responsibilities customers believed were most important for the utility to focus on. The most common responses included adapting to the effects of climate change, enhancing efforts to protect regional water quality, and preparing for emergencies and cyber threats. Most notably, when asked if respondents would be willing to pay more to address those responsibilities, more than two thirds of respondents indicated that they definitely or probably would be willing to pay more. This information, along with other community, stakeholder, and employee input will provide essential context for OWASA's Board and staff as they continue to work to update the strategic plan. As of the writing of this abstract, OWASA is still in the first phase of our strategic planning effort: the organizational and environmental scan. In addition to sharing the findings of the survey, our presentation will include what staff and Board did with that information in the development of the strategic plan.

There is a biosolids crisis occurring in New England, and one method for mitigating the effects of the crisis is to form an alliance to develop a regional biosolids solution. Such a solution is in progress amongst three utilities in New England who have committed to a study that evaluates the feasibility of a regional solution. The Study is especially timely, as the recent 2023 NACWA PFAS study on biosolids costs indicated: proactive biosolids management solutions lead to a more manageable cost when compared to a reactive approach to find a solution after regulatory drivers mandate action. These utilities seek to uphold their fiduciary responsibility to their customers and each bring distinct drivers to the New England Regional Biosolids Study (the Study). While one utility may be motivated purely by the economics, others may be driven based on Renewable Energy production goals that have been implemented by their State government. These drivers have an influence on how these analyses are framed and which data are most appealing for other stakeholders whose approval is essential for the Study to come to fruition as built infrastructure. The process for the Study includes activities such as a regulatory investigation, baseline costs, market and value chain study, siting alternatives, technology operating scenarios, cost evaluation, and non-financial evaluation. With this largely quantitative approach, the project team has grappled with the question of how to navigate through the complexities of different organizations that cross State lines to arrive at an agreeable solution that considers the quantitative and qualitative factors that drive this decision. Regulatory issues have become an increasingly difficult aspect of biosolids management in New England due the dynamic landscape. Many practitioners within this space around New England are aware of Maine's ban on biosolids application via LD1911 and proposed legislation in other states such as H.130 in Vermont which would place restrictions on biosolids end use due to microplastics pollution. This limits potential outlets and end uses for the processed biosolids product. This Study evaluated regulatory considerations not only in New England, but also neighboring territories such as Montreal who also imposed a ban on importing US-generated biosolids during the course of this project. Critical rules such as this further push utilities to find a solution, as they impose increased management costs for biosolids and residuals due to further restrictions on already strained outlets. With an understanding of the current state of regulatory issues documented, the team sought to establish baseline cases for each of the four facilities included within the Study. This task collected sludge loading for calendar years 2017 through 2021 to establish the current year, and projected expected sludge loading through year 2028 to determine future year conditions. The findings indicate the average and maximum month sludge loading are estimated to be 440,000 and 530,000 dry pounds per day, respectively. After the baseline costs were established, the project team completed a series of screening activities to evolve from the world of biosolids technology options to three proposed operating scenarios. The three operating scenarios that were proposed include the following technologies: THP, anaerobic digestion, incineration, and direct drying. Preliminary sizing was developed for the proposed operating scenarios to determine equipment sizing. From the equipment sizing, the preliminary site layouts and costs were established. The methodology and conclusions from this quantitative analysis will be shared during the presentation. The qualitative portion of the Study included non-financial evaluation of social, environmental, and technical aspects of the project. The decision criteria considered and debated amongst the project team which included the utilities, technical advisory committee, and consultants. The methodology for arriving at the final ranking included pair-wise ranking of the criteria as a group and ranking the criteria in order of importance by each utility. The pair-wise and order of importance rankings were averaged to arrive at an overall rankings that were used for developing scores for each alternative in an effort to quantify which operating scenarios allowed the utilities to satisfy more of the drivers that inspired the Study. The process utilized for this Study invited greater collaboration and allowed for consideration of all important aspects of the project, both financial and non-financial. Additionally, it covers not only the technical aspects of this Study, but also the qualitative criteria. This well-rounded approach provided learning opportunities about how consensus and collaboration were pivotal to progressing this project to the next phase. This presentation will cover the main milestones and deliberation amongst the project team to arrive at the recommendation for the main question: is regionalization the solution for biosolids in this area?

1. Context The recent focus for improving Anaerobic Digestion (AD) has been on the acceleration or preparation of sludges to improve gas yields through the process. In this context, Severn Trent developed its interest in Orege's application, SLG-F advanced sludge thickening / sludge conditioning technology for boosting AD performance. Severn Trent and Orege agreed to a 4-month, 2-stage trial over the spring and summer of 2023 at Worcester (Severn Trent Water) STW to better understand the application of the technology at a commercial scale in the UK. This paper presents the experience of STW including installation & commissioning, process performance data across the whole wastewater treatment plant and the increase in biogas production and CHP output recorded during the trial period. The innovative sludge thickening / conditioning package plant incorporates the SLGTM (Solid-Liquid-Gas) process developed by Orege and has already been installed as plug-and play containerised systems in the UK either to replace existing sludge thickening assets or where no mechanical sludge thickening was carried out. 2. Introduction Anaerobic digestion is a process commonly used on sewage treatment works throughout water and sewage companies (WASCs) in the UK. Many of these digesters were built in the 1960's. Since then, population increase means that many of these AD plants are now at maximum design capacity. There is a reluctance to build additional digesters to deal with future growth as technology progresses, therefore new solutions must be trialled. Worcester STW is a prime example of this; the site was expected to reach its built capacity by 2028, with new permits introduced by the Environment Agency additional dosing needed to be included producing additional sludge, this meant the digesters would be at full loading by 2025. Worcester is a sewage treatment facility just outside the city of Worcester; it serves a population circa 100k. It is also a reception centre for sludge imports from satellite sites in the local area. All imports are accepted into three reception tanks and manually transferred to a pre-digestion tank. All primary sludges are thickened in the primary sediment tanks (PSTs). Surplus activated sludge (SAS) is thickened using two gravity belt thickeners. All sludges are pumped into the mixed, pre-digestion tank, before being fed to the digesters. The digestion for the site consists of two conventional digesters, each 2900m3 in volume. They are operated following the site HACCP (Hazard Analysis and Critical Control Points) plan in order to ensure compliant cake for land application. The two CCPs for this HACCP plan are a minimum temperature of 34oC and a maximum feed volume of 161m3 per digester per day. As per Severn Trent standard, the digesters are mixed using biogas. 3. Methodology All onsite thickening during both phases of the trial was carried out by Orege SLG-Flosep technology (see figure6). SLGTM (Solid Liquid Gas) is a technology that has been developed and patented by Orege and is a sludge pre-treatment system which, using only air and polyelectrolyte, dramatically increases solid and water separation. The patented process is cost-effective and simple to operate. The Flosep is an optimised liquid/solids separation device that takes advantage of the unique characteristics of SLG conditioned sludge. Four thickening units were used onsite. Two of these units thickening a mixture of primary sludge and imported sludge. The other two units replaced the two belt thickeners that were being used for SAS thickening. All thickened sludge was pumped from these units into the pre-digestion tank before being fed to the digesters. Phase 1 consisted of analysing the impact of solely running SLG-F thickening units. Phase 2 consisted of phase 1, with the additional use of SLG-AD on the thickened SAS. SLG-AD consisted of an additional tank that recirculated the thickened SAS whilst injecting compressed air through two SLG units. The SLG conditioned sludge was then pumped into the pre-digestion tank. 4. Results & Discussion The impact of increased dry solids (%DS) on the digesters was analysed daily over the duration of phase 1. The analysis of the digesters can be separated into different blocks: digester control, biogas production and yield, and digester health. All results discussed are from phase 1 only. 4.1. Digester Control 4.1.1 TDS/day and OLR The %DS of the digester feed increased from 4.9% to 5.6% during phase 1. In the HACCP plan for Worcester, it states that the maximum feed volume is 161m3/day, the decision was made to continue to feed this volume despite the change in dry solids. This meant that the tonnes of dry solids (TDS) being fed increased. This took the TDS from 7.1TDS/d to 7.8TDS. (see figure 1) In parallel of the TDS, the Organic Loading rate was calculated and studied. The OLR baseline was 2.46kgVS/m3/d, this average increased to 2.78kgVS/m3/d. This increase is also due to the maintained volume feeding the digester at a higher DS%. Moreover, on some days the OLR was consistently above 3. With conventional digestion, the standard maximum OLR is 3kgVS/m3/d, as it was shown that a higher OLR can cause stress to the methanogens and therefore volatile solids destruction struggles to be done effectively. 4.1.2. Hydraulic Retention Time (HRT) As mentioned, the maximum feed per digester at Worcester is 161m3, which is an HRT of 16 days. As the volume remained the same the HRT was kept consistent at 16 days. 4.1.4 Temperature and other parameters A temperature increase in both digesters was observed over phase 1. Temperature went from 36.1oC to 38.3oC; or 6% increase (see figure 3). This is partially due to the increase in %DS. Less heat energy is required to heat sludge compared to water. This increase in temperature was also sustained, and the site was able to turn off the diesel-powered boiler and solely rely on heat from the CHP. Other parameters such as pH, alkalinity and Volatile Fatty Acids were monitored and showed a healthy digester. 4.2. Biogas Production and Yield 4.2.1. Biogas Production An increase in biogas produced was observed from 4760m3/day to 6586m3/day, corresponding to +38%. In addition, when stable and consistent feed volumes of 161m3 per day were achieved the biogas production increased to 7048m3/day over a two-week period - an increase of over 48% compared to the baseline (See figure 4). This increase was due to two reasons. The first, is the increase in OLR. The second, can be believed to be due to the use of SLG-F for thickening. The biogas yield increased from 338.8m3biogas/TDS to 404.3m3biogas/TDS. If the increase in biogas produced was solely down to the increase in OLR, the amount of biogas produced per TDS would have stayed approximately the same. This suggests that there has been a change in the sludge characteristics. Sludge could have changed due to the sludge ratio. However, even with an increase in sludge volumes, the mass ratio still stayed around 60:40, Primary:SAS. 4.2.2. Methane Content There was no difference in the percentage of methane content in the biogas. It can be difficult to obtain an increase in methane production as it depends on the colonies of methanogens. 4.2.3. CHP Output During Phase 1 the CHP output increased by over 34% from a baseline of 9.9MWh to 13.3MWh. The MWh/TDS produced increased from 0.73MWh/TDS to 0.92MWh/TDS during phase one. The data used for phase 1 however, does not include any flare data so this figure is likely to increase. 5.0 Conclusions Phase one of the trial was very successful. The use of SLG-F for all thickening onsite increased the overall digester feed %DS by 0.6%. This increase in the dry solids allowed greater utilisation of the digester capacity, but also a greater overall plant capacity and the daily import for the site was almost doubled. The OLR increase and the thickened sludge characteristic change correlated with an increase in biogas production of 38%. Another benefit was the reduction in the need to run the diesel boiler; this had a significant cost saving. 6.0 Phase 2 The aim of phase two was to determine if the addition of SLG-AD, which consisted of recirculating the thickened SAS to two SLG units, would increase the biogas yield further. Unfortunately, in the early stages of this phase, both digesters experienced blocking and spills due to RAG. These blockages meant that the digester feeds continuously stop-started. The data collected from this phase of the trial was inconclusive. However, the biogas yield showed a positive difference compared to baseline (see table 1). 6.1. Phase 2 at Monkmoor STW Phase two of the trial is due to be replicated at Monkmoor STW, Shrewsbury later this year. Key words:, Thickening, Biosolids, Innovative, Anaerobic Digestion, Biogas, Methane, Sludge, CHP, Package Plant, Severn Trent, Orege, SLG, SLG-F.

BACKGROUND DC Water is an independent water utility providing drinking water to 700,000 residents in the District of Columbia and wastewater collection and treatment services to 2.4 million residents in the greater Washington, DC area, including Virginia and Maryland. DC Water was created as an independent authority of the District of Columbia in 1996, previously operating as the Water and Sewer Utility Administration under the city's Department of Public Works. DC Water operates the world's largest advanced wastewater treatment plant, Blue Plains. This treatment plant is the largest point source discharge in the Chesapeake Bay watershed which stretches from New York state to southern Virginia. Blue Plains treats over 300 million gallons per day of wastewater to very low discharge standards and has incorporated approximately $1B in treatment infrastructure improvements to reduce nutrient loads to the Bay. Blue Plains is also the largest consumer of electricity in the District. As such, it has been important for DC Water to apply new and innovative approaches to meet our discharge permit; minimize adverse environmental impacts of our operations; and minimize rate increases to support the infrastructure improvements and other regulatory and legal mandates. In 2013, DC Water created a new position, Innovation Chief, perhaps the first such role in the municipal water sector. This position grew out of DC Water's Research and Development (R&D) program to support process upgrades at Blue Plains. The role expanded DC Water's innovation program and led to the generation of multiple patents, mostly for wastewater treatment processes and technologies. It also expanded DC Water's innovation ecosystem with academics, manufacturers, and consulting partners on local, national, and international scales. This R&D program continues today with a focus on continually evolving treatment challenges. DRIVERS FOR CHANGE DC Water's emergence as an independent authority in 1996, and the associated cultural transitions, continues to this day. The Authority continues to evolve with organizational and leadership changes. The majority of the recently established Senior Executive Team importantly brings experience from outside the water sector to their leadership roles. This reflects leadership's interest in shifting the organizational mindset from a municipal department to one that brings the best practices of the corporate world to address the challenges of an independent water utility. Part of this shift includes the ongoing need to break down organizational silos and cross-pollinate ideas and concepts across the enterprise. There are approximately 1100 employees at DC Water at facilities spread across the District. Leadership recognized that while innovation was thriving at Blue Plains via the R&D program, there was not an embedded culture of innovation that existed across the enterprise. A culture that cultivated and encouraged innovative ideas up through the organization was needed. Innovation in every department, whether it be wastewater treatment, water distribution, finance, customer service, human resources, fleet, or pumping operations, was needed. A governing structure that applied a consistent approach to innovative ideas was needed. A program that highlighted innovators and sparked diverse input was needed. With this understanding of a need for change, against a backdrop of increasing rates; affordability challenges; aging infrastructure; Consent Decree and regulatory compliance needs; and a rapidly changing workforce; DC Water embarked on an Innovation 'refresh' in 2020 to: 1.Redefine and strengthen the innovation process for added benefit to its ratepayers 2.Provide superior service to our workforce and communities 3.Position the Innovation Program as a key enabler 4.Inspire a culture of innovation across the enterprise THE INNOVATION 'REFRESH' Over a ten-week period in fall 2020, DC Water staff worked with two external consultants to provide leading-edge perspectives on innovation from outside the water sector and best practices from global water sector leaders. The process included a 'current state' analysis with a dozen design thinking workshops with participants including DC Water's Senior Executive Team, an Innovation Working Group with representatives from every department in the utility, input from the Board of Directors, and key external stakeholders. This analysis resulted in ten key opportunities for DC Water in our innovation refresh: 1.Achieve vision and value clarity for innovation 2.Present sustainability in three key forms 3.Create an inclusive and equitable culture 4.Foster innovative mindsets and engage employees 5.Utilize innovation to tackle the basics 6.Break down silos to leverage existing talent and resources 7.Leverage human-centered design 8.Make data-driven decisions to drive innovation 9.Build structured methodology and governance 10.Engage partners across the innovation ecosystem Building on these opportunities, the Working Group continued to engage to co-create a new operating model for innovation at DC Water. This included an Innovation Hub operating structure, governance, KPIs, and an innovation process for 'use cases,' or innovative ideas. The Innovation Hub (Fig. 1) was designed to first focus on two key capabilities to support innovation at DC Water: data analytics (data engineers, analytics, visualization, etc.) and design (service design, visual design, user interface/user experience), etc.) The innovation process builds on traditional stage-gate approaches with five steps in the process: idea intake, staffing, project planning, project execution, and scaling. The output from this ten-week engagement was the innovation strategy and operating model, including a timeline and budget for mobilization, program launch, and scaling up both the Innovation Hub and a culture of innovation across DC Water. This process started with the hiring of a dedicated Innovation Director in July 2021 and initiating efforts to mobilize, launch, and implement DC Water's new innovation strategy. THE PATH FORWARD Efforts are underway to bring DC Water's enterprise-wide innovation program to life. Preliminary milestones include: 1)A cross-functional team of internal Innovation Champions. As a functioning team that spans across DC Water, these Champions engage with employees, encourage participation, and communicate innovation activities so that everyone is included 2)A functional Senior Executive Team (SET) comprised of the CEO and direct reports as executive sponsors to both the overall innovation program and projects that get authorized for development 3)An automated idea capture tool to allow for crowdsourcing of ideas to key problem areas across DC Water's organizational siloes and beyond to include business partners, universities, and industry vendors. Plans are to implement and use this new capability to engage employees in idea sharing tied to innovation challenges. The aim is to increase employee engagement in innovation activity through 'gamifying' the idea capture process. 4)A quick win of our first innovation 'use case' to go through the five-step innovation process referenced above. We were able to swiftly go from problem to idea to proposed pitch to the SET for approval. This was a highly visible solar project aligned to two DC Water's strategic imperatives, sustainability and equity 5)An innovation pipeline of 40+ ideas, where new ways of applying technology to work activities can generate greater effectiveness, efficiency, and overall value to DC Water's ratepayers 6)A communications strategy across the workforce to give added visibility to and substance for DC Water's innovation program. This will be an ongoing effort designed to build momentum; encourage and recognize participation; and showcase success stories of what gets accomplished 7)An evolving ecosystem of external partners to collaborate in sharing ideas, building solutions, and learning from each other. The aim is to coordinate and work across the organization to benefit from these two-way partnerships with industry and academia Significant program progress is anticipated before UMC conference in February 2022 and the co-authors will update the audience on the lessons learned, recent accomplishments, and planned activities. The overall aim of DC Water's innovation program is to formulate and implement strategy for the entire organization-one that leads to innovative solutions consistent with its vision, mission, and core values. As DC Water continues move toward a more mature model from which to innovate, what gets done, how, and by whom will lead to a sustainable process of steady achievement, a process whereby key problems continue to get solved through a pipeline of ideas that can be prototyped, validated, and implemented with positive impact.

Today's water sector operates in a complex and dynamic environment. While water utilities have been successful for generations, utility leaders have begun exploring new approaches to water services that will help them navigate these challenges. In a global survey, over 90 percent of utility executives believed that innovation was critical to the future of their organization, however only half believed that they were effectively leveraging it (WRF 4642). As a result, some utilities have formalized innovation management as a business function, including the development of innovation leadership roles that are responsible for accelerating the exploration and adoption of new services, processes, and technologies available to the water sector. While the role of innovation leader is a crucial ingredient for success, utilities must also have an executive innovation champion that works in collaboration with the innovation leader. Their role is to embed innovation management as an effective business function by providing direction and ensuring innovation remains an organizational priority. When these two roles work effectively together the benefits of innovation can reach the entire organization as well as customers. Based on a series of utility executive interviews and workshops, conducted as part of The Water Research Foundation's (WRF) Project 4907 Leading Water and Wastewater Innovation, a coalition of 76 utility partners from the United States, Canada, United Kingdom, Brazil and Australia as well as AWWA, AMWA, WEF, WSAA and NACWA found five fundamental tactics that are practiced by successful executive innovation champions to frame and sustain innovation at their organizations. In addition, two specific opportunities for collaboration with their innovation leader that are pivotal to the success of the innovation program were identified. Below you will find a summary of these five critical tactics along with utility examples and a summary of the critical action areas for collaboration. These tactics include: - Defining organizational need and expectations for innovation. Clarity is critical. Less than 40% of utilities have described the urgency or vision for innovation. Additionally, only 30% have identified key challenges or opportunities that need to be explored (WRF 4642). Without alignment with organizational priorities, innovation activities are unsustainable and fail to support a culture of exploration. Leadership must frame the priorities and expectations for innovation investments. Establishing strategic alignment between innovation program priorities, organization philosophy and critical success factors can be done by explicitly addressing innovation in the Strategic Business Plan (SBP). At Louisville MSD, innovation is linked to one of the critical success factors (CSF) in their SBP ( Blueprint 2025). This CSF states, 'Realize operational efficiencies and revenue generation through strategic partnerships and innovation.' Their organizational performance measures and transformational initiatives are tied to each critical success factor. They use these measures throughout the organization to determine organizational performance incentives and support staff evaluations. - Providing resources for exploration, development, and adoption of new concepts. An innovation program without resources will fail to achieve expectations. Only 44% of utilities have established a process or dedicated resources to support innovation (WRF 4642). The top resource needs for innovation include funding for idea development, staff time to explore concepts, physical space for experimentation, and tools for evaluation and cross functional collaboration. Executive champions should focus on identifying available resources to support these processes. At Central Arkansas Water, they found their GIS department was the most requested partner to engage when exploring a new idea. Therefore, they knew it was vital to increase the resources in the GIS department to ensure they were available to others for idea development and deployment. - Establishing measures that are aligned with expectations. Measures are just part of the story. According to WRF 4642, only 35% of utilities have established innovation-related performance measures. However, there is a wide array of performance measures used to evaluate the impact of innovation programs. These measures can include program impact indicators that assess organizational efficiency, quality, resiliency as well as revenue. While the innovation leader should be responsible for maintaining leading and lagging measures that communicate the impact of the program, the executive champion should work to ensure that quantitative and qualitative measures selected align with organizational philosophy, priorities, and desired narrative. At Urban Utilities, they started without metrics and focused on improving the culture. As their program matured, they began to focus on the return on investment for their entire innovation portfolio. Currently, they are experiencing a 10% return including both capital and operating expenditures. They also measure employee engagement in the innovation program. 40 percent of their employees are engaged in the program either through idea generation or participating in idea development sessions. - Rewarding and recognizing innovation activities - successes and failures. Reinforcement builds culture and culture is the key to sustainable innovation. Only 17% of utilities reported innovation-specific reward and recognition measures. Innovation programs track progress and recognize the contributions and the employees that generated them. Recognition can range from a simple 'thank you' to innovation activities recognized in a formal appraisal process. The executive innovation champion should work to provide a diverse range of measures to reward and recognize as well as foster collaboration with the responsible parties for communications and human resources. At the Louisville Water Company (LWC), they make it a point for their staff to be aware of LWC successes so they can be advocates and share it with their family, friends, and the community. These stories can be shared not only through employees but also through annual reports, education programs, social media, and involving the community in innovation projects. - Demonstrating continued support by example and participation. An open-door policy is not enough. The Executive Champion is the chief advocate and plays a key role in nurturing and supporting organizational behavior by participating in it. There are simple steps an executive innovation champion can perform to demonstrate a commitment to innovation including submitting an idea, participating as a judge or mentor for idea submitters, or hosting innovation meetings. At the City of Atlanta's Department of Watershed Management, they hired a Chief of Innovation to ensure time was dedicated to engaging the entire organization and developing an innovation strategy that established goals and actions aligned with the overall organizational strategy. Additionally, two specific opportunities for collaboration with the innovation leader that are pivotal to the success of the innovation program include: 1: Creating a meaningful innovation strategy. To help manage the tensions created by change, an organization can create an innovation strategy. An innovation strategy is a succinct guiding document that provides direction, pathways, and progress tracking. Strategy development provides a simple and collaborative process to align program leadership, process and culture including commitments and roles for the executive champion and innovation leader. Executive champions should ensure that the strategy uses the language of the organization and aligns with utility priorities. 2: Launching and sustaining an innovation program. Once the innovation strategy is developed, executive champions should help find a sustainable pace for the program by working with the innovation leader to align launch and management activities based on available resources, organizational priorities, and cultural change-readiness. Executive champions should also commit to regular progress and redirect meetings that may be held frequently following the launch of the program until the program has become established. Water utilities are adopting innovation management as a core practice to maximize the benefit of new technologies, services and process emerging across the water industry. A key to success is the engagement of the executive champion. This session will unpack the tactics summarized above to equip executive champions to work effectively with their innovation leaders as well as effectively leverage innovation management practices to build agile and fit for future organizations.

The Intergovernmental Panel on Climate Change (IPCC) found that anthropogenic methane emissions are responsible for 45 percent of current net warming (IPCC, 2023). The EPA estimates that centralized WWTPs in the United States are responsible for 14 percent of waste methane emissions. At WWTPs, methane emissions are most prevalent in the solids handling areas, as methane is produced as a byproduct from the microbial breakdown of organic waste during anaerobic treatment of wastewater and sludge. Reducing WWTP methane emissions plays a vital role in reducing our near-term greenhouse gas emissions, which is necessary to avoid climatic tipping points and reduce environmental impacts. This manuscript will summarize: 1.Why utilities should care about fugitive methane emissions at their WWTPs. 2.Approaches to identify and quantify sources of fugitive methane emissions at WWTPs. 3.Strategies for mitigating these fugitive methane emissions, and 4.How to fund these mitigation strategies. In addition to the summary, the manuscript will dive into the details on mitigation strategies, specifically: 1.Describing fugitive methane emission pathways around solids handling processes, primarily anaerobic digestion, biogas handling, and digestate processing and storage. 2.How to update our designs and O&M practices to mitigate these emissions. The City of Columbus's (Ohio) is at the forefront of identifying, quantifying, and mitigating fugitive methane emissions. This manuscript will use the work around their Southerly WWTP Bioenergy Project as a case study that other utilities with anaerobic digestion can learn from. The goal is for our industry to design better digestion systems to do our part in mitigating the worst impacts of climate change and provide the best value for our communities. City of Columbus's Southerly WWTP Bioenergy Project The City of Columbus (Ohio) has embarked on a Bioenergy program to transform the solids handling process at the Southerly WWTP (SWWTP). The project includes a 60,000 gallon per day organics receiving facility (ORF) to prepare waste organics for co-digestion, a 6 MG digestion process expansion to increase solids capacity and convert organics and sludge into biogas, and a 8MW cogeneration facility to make renewable electricity and recover heat from the biogas. Further, to expand on the City's cutting-edge work to identify and quantify fugitive methane emissions at the SWWTP, the project includes upgrades to the existing digestion system and redirecting foul air from the solids handling processes to the new waste gas burner facility. These improvements are projected to reduce identified fugitive methane by 91 percent and captures additional biogas for use within the cogeneration facility. Why Care About Fugitive Methane Emissions The capture and utilization of the fugitive methane identified at Columbus' SWWTP is equivalent to taking 18,000 cars off the road and saving the city $350,000 annually in combined heat and power savings that otherwise would have been lost to the atmosphere. Reducing methane emissions also: - Helps meet climate goals -As part of its Climate Action Plan, the City of Columbus (City) has set ambitious goals for the Columbus community to be carbon neutral by 2050, in alignment with the Paris Climate Agreement. An interim goal to reduce GHG emissions by 45 percent by 2030 was set to help meet the 2050 target. - Protects against Future Regulations-The U.S. Environmental Protection Agency (EPA) has moved to include GHGs, particularly methane, as regulated air pollutants under the Clean Air Act. This has led to the development of GHG reduction standards for the power, and oil and gas industries. For example, the Inflation Reduction Act includes provisions that indicate designated petroleum and natural gas facilities must calculate baseline methane emissions and be subject to a fee on excess methane emissions (Murphy, 2022). Similar regulations may eventually be adopted in the municipal wastewater sector. - Improves Public Perception - Methane emissions are gaining additional scrutiny from the public and climate activists. There is currently publicly available satellite imagery that can pinpoint large emitters of methane (including WWTPs) with many more satellites coming online in the next 12-24 months. Proactively identifying and mitigating fugitive methane transforms a negative publicity risk into a positive story of how the city is reducing emissions, improving health, and recovering resources. - Maximizes biogas beneficial use-To ensure the cogeneration facility is sized properly and biogas use, and related renewable energy production is maximized, it is critical to identify locations where fugitive methane can be captured. - Maximizes EPA GHG reduction grants-For the City to position for GHG reduction grants through the Inflation Reduction Act for future improvements, the City needs to justify and demonstrate the need to reduce GHG emissions at SWWTP. - Identify methane leaks posing safety risks-Leaking methane, along with associated constituents in biogas (i.e. hydrogen sulfide), pose a health and safety risk for plant staff. Identifying and mitigating these emissions will reduce the risks of potentially fatal accidents. How to Identify and Quantify Fugitive Methane Emissions Multiple measurement technologies were researched and deployed to identify and quantify fugitive methane emissions at the SWWTP; this included drone flux measurement (DFM), an optical gas imaging (OGI) camera, a gas analyzer, and a biogas capture box. A comparative analysis of the resulting data from these approaches was used to produce the emissions for the SWWTP. As expected, most of the methane emissions were associated with the solids handling parts of the facility, as outlined in Figure 1. How to Mitigate Fugitive Methane Emissions The field investigation helped to identify sources of fugitive methane in the solids handling and treatment processes that are associated with biological activity under anaerobic conditions, entrained biogas in the sludge, and dissolved methane in the sludge. Sources of fugitive methane identified at SWWTP are summarized in Figure 2, and include: - Annular space between floating covers and digester wall - Digester Pressure relief valves - Gaskets of digester cover hatches and manways - Flanges of digester gas piping - Leaks through concrete digester walls - Gas handling equipment - Exhaust stacks of odor control systems serving solids handling processes - Waste gas burners The manuscript will summarize evaluation of different mitigation strategies. The selected improvements share a common theme, which is to: 1.Maximize production and extraction of biogas in the anaerobic digesters, which reduces the potential for biogas to be emitted in downstream solids handling processes. 2.Improve biogas capture of the digestion and biogas systems. Some of the improvements include in the Bioenergy project are: - Improve digester feeding, mixing and withdrawal to maximize biogas production and extraction within the digesters. - Replace floating covers with fixed concrete covers rated for 60-inch water column gas pressure and embedded liner for corrosion protection and gas imperviousness. - Overhaul the biogas handling system to provide a larger delta between the operating pressure range and the safety pressure setpoints (waste gas burner backpressure control valves, pressure relief valves, emergency relief hatches, etc.). - Capturing the solids handling foul gas and combusting it in a vapor combustion unit (VCU), which is uniquely capable of combusting low percent methane gases. - Other miscellaneous advancements (liner penetration details, gasket specifications, instrumentation and control strategies, O&M practices). Most of these improvements have already been implemented and proven effective separately on previous digestion projects. Case studies of some of these examples will be highlighted to make the case that combining these improvements can provide an example of a new standard of care for designing and operating digestion facilities. How to Fund Fugitive Methane Mitigation Improvements A summary of how the Bioenergy project was structured to maximize the potential funding available from the Inflation Reduction Act (IRA); it is estimated that this project will receive over $50M from this program alone. Closing The City of Columbus's (Ohio) is at the forefront of identifying, quantifying, and mitigating fugitive methane emissions. This manuscript will use the work around their SWWTP Bioenergy Project as a case study that other utilities with anaerobic digestion can learn from. The goal is for our industry to design better digestion systems to do our part in mitigating the worst impacts of climate change and provide the best value for our communities.

Introduction The current era is challenging to plan for long-term biosolids infrastructure upgrades. Over the past decade, many of the traditional solids management outlets have dwindled, with incinerators shutting down due to increasingly strict air regulations, and many landfills starting to limit biosolids loads. Land application is one of the strongest remaining pillars of traditional biosolids management, with its relatively low costs and effective nutrient recycling making it a favorable option. As of 2021, 43% of all biosolids in the USA were land-applied. Given the uncertainty around future regulations restricting land application due to PFAS and other emerging contaminants, this outlet is also facing its existential crisis. While confidence in traditional biosolids outlets waver, at the same time many utilities across the country are grappling with their fast-approaching need for renewal of solids infrastructure. Many of these solid systems built in the 1970s have needed capital upgrades repeatedly deferred to the point that major investment is now needed as these systems reach the end of their service life. Additionally, there has been attrition in O&M staffing across the country due to Covid and other global forces. With limited experienced O&M staff, it becomes difficult to embrace advanced technology, especially purported to destroy PFAS which are very early in their development phase and whose efficacy is as unclear as the future regulations they intend to address. Waiting for these regulatory and technology questions to be answered would be ideal but not feasible for many utilities whose time to act is now. The case study for the City of Toledo, OH forms the basis of this paper. Toledo is planning and procuring funding for one of the largest upgrades in its Bay View WWTPs history. This impending solids system upgrade is viewed as an opportunity to enhance sustainability and reduce GHG emissions by recovering more renewable energy from biosolids. There is also trepidation, however, over pouring major investments into digesters with the looming uncertainty around land application due to future federal PFAS regulations. Existing Conditions This paper presents an overview of the recent solids planning effort for the Bay View WWTP (ADF - 68 MGD). In 2022 the City developed a facility plan that included demolishing plant digesters (built in the 1930s) to clear space for new liquid stream process. The plan included constructing a new solids facility on new plant land created by filling part of the bay on which the WWTP sits. This WWTP currently produces ~ 40,000 wet tons of Class B biosolids annually, which consists of combined thickened primary and WAS that is anaerobically digested and dewatered to Class B cake. These biosolids are land-applied using a 3rd party cake management partner, while occasional loads are sent to landfills during seasonal outlet restrictions. The biogas generated is utilized on-site for digester heating with boilers. Toledo had previously shown advanced thinking and ambition in energy recovery as it constructed a combined cycle turbine CHP plant at the WWTP designed to run of digester gas and landfill gas piped in via a trans-city pipeline. This facility was sitting currently unused due to lack of sufficient fuel, as landfill gas volumes were less than half of the anticipated design values. The City engaged the engineering team to explore various solids processing alternatives and recommend a path forward for their new solids processing facility. The team focused on maximizing energy recovery and enhancing sustainability while recognizing that the City was staff-limited without capacity to take on new advanced technology adding considerable O&M effort. Another driver was to reduce final solids volume and develop alternatives centered around Pyrolysis and Gasification addressing PFAS concerns. Since the City was capital and staff limited, these alternatives were developed with the leading technology manufacturers as 3rd party turnkey projects to be owned and operated by a 3rd party commercial entity. Methods A comprehensive and holistic solids and energy modeling effort was developed to understand complex and interacting impacts of implementing various solids and energy processes in one framework (Figure 1). Each potential combination of processes was quantitatively analyzed for annualized cost, greenhouse gas (GHG) reductions, net power generation, and initial capital cost. Along with determining an operationally sound and cost-effective treatment facility, processes were also examined to meet the goals of generating Class A biosolids, maximizing energy recovery, and utilizing technology that shows promise for reducing PFAS contained in residuals. The technologies investigated under this framework include: Pre-digestion - Gravity Thickening of Primary Sludge - Mechanical Thickening of WAS - Thermal Hydrolysis - Thermal-Alkaline Hydrolysis Digestion - Single Stage Mesophilic Digestion Post Digestion - Dewatering - Thermal Drying Biogas Utilization - Digester heating via boilers - Existing Combined Cycle Turbine CHP - New Combine Heat and Power Engine - Renewable Natural Gas -On-site and 3rd Party - Thermal Drying Biochar Processes - Pyrolysis - Gasification Leading technology manufacturers were consulted to develop 3rd party proposals for Biochar Processes. The proposals included the technology provider and a solids management contractor that would serve as O&M staff and manage all residuals. Two different project delivery methods were considered for biochar technology - turnkey contracting and city finance. Under turnkey contracting, the 3rd party would finance and construct the facility, operate, maintain, and charge Toledo a tipping fee for cake delivered. For the city finance option, the City would pay to build the facility and engage in a long-term O&M and residuals management contract with the 3rd party entity. Results The quantitative results (Table 1) from the energy flow modeling were used as a guide to provide recommendations to the stakeholders, some of which are described below. - Reusing digester biogas for generating renewable natural gas results (RNG) in the increased monetary value of the gas. Current solids loading would generate about $1,700,000 gross RIN revenue annually. Adding the RNG system alone to the existing facility did not meet the project goals since there was no final solids volume reduction. - Addition of a pre-digestion hydrolysis process for WAS changed the overall outlook from a solids volume and energy endeavor. Hydrolysis allowed additional solids to be digested, greater biogas generation and increased the dewaterability of sludge. This alternative reduces GHG emissions more than others while reducing dewatered solids by 33% compared to the baseline. This alternative retain the same solids management program, optimizing the cost and sustainability of the existing solids facility; however, does not create a Class A product or destroy PFAS. - Adding a thermal dryer to the digestion system with enhanced WAS lysis system is recommended to create Class A granules eliminating the export of Class B biosolids. It was still financially advantageous to send biogas to RNG and fuel the dryer with NG. This scenario reduces the amount of solids transported out of the facility by 78% but increases the annualized cost of solids management while increasing GHG emissions. - For mitigation against future PFAS regulations as an end goal, a 3rd Party turnkey solution with either pyrolysis or gasification would need to be considered as the only viable option. Pyrolysis systems appeared to have better financials but did not include as much redundancy as the Gasification system proposed. The syngas produced helped the energy balance of these processes, but both were net energy consumers, driving increased GHG emissions. The turnkey project delivery would reduce the capital spent over the baseline scenario by about $100 million by digesters and eliminating cake storage. The case study findings provided a need to stay flexible while investing capital in upgrading the biosolids facilities. While federal regulatory action is not imminent, using a phased project delivery approach for the solid's upgrade project will be prudent while re-investing in digestion. The initial phase would include the installation of a single WAS-lysis treatment train as a large-scale pilot treating ~50% of the WAS load. Biogas will be utilized to produce RNG, thus increasing the value of the energy resources. Adding a thermal dryer or biochar processes will increase the solids handling systems' cost, complexity, and GHG emissions. These options need to be planned for both budgeting and space allocation, but should be phased for implementation when there is evidence that the market for land-applied cake is reduced or eliminated due to regulatory concerns.

Introduction Water Resource Recovery Facilities (WRRFs) have increasingly been investigating and implementing co-digestion of food waste to generate revenue and maximize biogas production. In California, an additional regulatory driver is Senate Bill (SB) 1383, which requires organics diversion from landfills to mitigate short-term greenhouse gas emissions. To meet these goals, the City of Oxnard applied for and obtained an EPA grant to study food waste pre-processing and co-digestion implementation at the Oxnard Wastewater Treatment Plant (OWTP). Carollo developed a feasibility study for co-digestion implementation, and Dr. Matt Higgins (Bucknell University) conducted a bench-scale study involving co-digestion, dewatering, and odor testing of the City's sludge and source-separated food waste from the City's Del Norte Materials Recovery Facility (MRF). The results of the bench-scale study were then used to refine the design criteria and operational assumptions used in the feasibility study. This session will cover the approach and key findings of the bench-scale and feasibility studies. The City and the Carollo/Bucknell team hope that this study can serve as an example to other WRRFs interested in implementing food waste co-digestion. Bench Scale Study Three months of samples of primary and waste activated sludge from the OWTP and source separated food waste from the Del Norte MRF were sent to the Bucknell Anaerobic Digestion Laboratory (see photo in Figure 1) at Bucknell University. The food waste was diluted and blended before delivery. Four anaerobic digesters were operated, Digester 1 as a control with no food waste addition, and Digesters 2- 4 at increasing food waste loading rates. The target food waste VS loading rates to each digester expressed as the mass of VS from food waste divided by the total mass of VS in the digester feed (food waste plus feed sludges) were: Digester 2: 25%, Digester 3: 35%, Digester 4: 50%. In addition to evaluating digestion performance, this study also evaluated the impacts of food waste co-digestion on foaming potential, dewatering, and cake odor production. A summary of the findings from the bench-scale study is provided below: -Food waste characteristics: --The food waste slurry TS and VS content averaged 5.8 %TS and 81 %VS, respectively. -Digester performance: --The food waste did not impact the digesters pH, alkalinity, and nitrogen and phosphorus concentrations in any appreciable way at the loading rates in this study, except for the digester upset. --As expected, food waste co-digestion increased the volatile solids reduction (VSR), biogas yield (see Figure 2 for a graph of biogas production for the 4 Digesters), and methane content of the biogas. The overall VSR for the control digester averaged 45.9%, while the VSR for the test digesters was 52.4-59.5%. From this, the VSR for the food waste itself was estimated as 72-77%. --A digester upset in Digester 4 occurred when it was fed a food waste VS loading of 60% relative to the total VS loading. Based on this, a conservative maximum food waste loading for stable digestion of 45% was selected for the feasibility study. This limit allows for significant food waste addition while maintaining digester stability. -Foaming potential: --The viscosity and foaming potential increased as food waste loading increased. --No clear pattern was observed for volume expansion. The lower two loading rates of food waste (Digesters 2 and 3) had a greater volume expansion than the control, while at the highest food waste loading (Digester 4), the volume expansion was less than the control. -Dewaterability: oAs the food waste load increased, the polymer demand increased and the cake solids concentration decreased. The lower TS concentration could have been due to a lower concentration of divalent cations, which was observed in the higher food waste loading digesters. -Cake odor potential: oFood waste addition did not negatively impact cake odor potential. As a result of these bench scale results, the design team was able to refine site specific design and operational criteria for the full-scale co-digestion cost and energy feasibility study, including identifying the maximum design food waste VS ratios for stable digestion and quantifying anticipated changes in biogas production and revenue, polymer demand and costs, dewaterability and biosolids production post co-digestion. These criteria were adopted for the following desktop feasibility study. Feasibility Study The purpose of the feasibility study was to determine the required facilities, costs, and other impacts of food waste co-digestion and whether the benefits from increased biogas production and cogeneration power generation are sufficient to cover the implementation costs of a co-digestion program. A summary of the findings from the feasibility study is provided below: The capacity assessment determined that the OWTP has sufficient capacity in all their processes to handle the increased loads, except when one digester is out of service. In that instance, the City could divert a portion of the food waste to the Agromin composting facility rather than building an additional digester. The capacity assessment also found that, with food waste co-digestion, the OWTP would approximately double its biogas production. -The condition assessment found that the City has already made or plans to make many of the improvements identified in the condition assessment. Most notably, the City plans to refurbish a digester which is currently out of service. -This feasibility study evaluated a wide range of technologies for pre-treatment of source separated food waste to produce a bioslurry suitable for co-digestion. Three alternatives were selected for a more detailed life-cycle cost, site layout, and non-financial evaluation. A hammer-mill at the Del Norte MRF with additional polishing with a sludge screen at the OWTP was the preferred technology selected for this study (see Figure 3 for a process schematic). -The co-digestion program alternative was evaluated against a baseline alternative, whereby the City continues their current operations. The City's food waste is currently managed by a third party which composts it at the Agromin composting facility. -The hourly energy analysis allowed the City to accurately estimate energy savings from increased biogas production from food waste co-digestion by taking into account fluctuations in biogas production as well as varying electricity usage charges during the winter and summer and during on-peak and off-peak hours. -The energy analysis found that food waste co-digestion would increase cogeneration power generation by 79 percent compared to the baseline alternative. However, the net plant power usage for the co-digestion alternative is only 23 percent lower than the baseline when accounting for additional power loads for food waste processing. -The results from the energy analysis were fed into the cost/benefit analysis which consisted of a 20-year life-cycle cost analysis including capital and O&M costs to compare the baseline and co-digestion alternatives (see Figure 4 for cost results). The analyses found that based on the unit cost assumptions made, the co-digestion alternative is more costly both in capital and O&M costs compared to the baseline, even when accounting for the increased biogas production and cogeneration power generation of the co-digestion alternative. -The analysis identified that one of the major O&M costs is the cost for food waste slurry hauling from the MRF to the OWTP. A sensitivity analysis indicated that the hauling cost can greatly impact the affordability of food waste co-digestion compared to the baseline scenario. In conclusion, this bench scale study and feasibility study found that, while the City of Oxnard has sufficient capacity for food waste co-digestion, the co-digestion alternative is more costly compared to the status quo of continued composting of the City's food waste. These results are likely due to the fact that the biogas is used for cogeneration and to the high hauling costs assumed in this study. While the results are specific to the City of Oxnard, the approach taken in this project of combining feasibility studies with bench-scale studies can serve as an example for other WRRFs. This project demonstrated how WRRFs interested in implementing food waste co-digestion can use cost-effective bench scale studies to gain confidence in the techno-economic evaluation of full-scale food waste co-digestion.

Purpose: The purpose of this presentation is to provide the attendees with planning and design criteria and solutions when dealing with the design of a sewer lift station within a tsunami and sea level rise impact zone. Background: The City of Bellingham is located approximately 100 miles north of the City of Seattle in Washington State, 20 miles from the Canadian border. The city's Roeder Lift Station is located near the industrial area along Bellingham Bay and serves much of the northern part of the city. The existing lift station was suspected to be operating under reduced reliability conditions during peak storm events. The city contracted with Carollo Engineers to complete an alternatives analysis and design to increase the existing lift station's pumping capacity from approximately 8 million gallons per day (mgd) to 18 mgd. The existing dry-pit/wet-pit station is located on a small city-owned parcel of land surrounded by Port of Bellingham (Port) and Burlington Northern Santa Fe (BNSF) railroad properties. The station's existing 18-inch diameter force main is routed through a city utility easement on Port and BNSF properties including crossing under a BNSF spur track to reach the discharge manhole location. Two lift station retrofit alternatives and one new submersible lift station alternative were evaluated, including installation of a parallel force main alternative. The selected alternative included a new submersible lift station 1,100 feet north of its current location. The lift station design included a combination of variable speed driven non-clog submersible pumps and screw centrifugal pumps in self-cleaning pre-rotation basins with a pumping range of 1 to 18 mgd. Other improvements included 2,500 lineal feet of parallel 14-inch and 28-inch diameter HDPE force mains with trenchless installation beneath the railroad, installation of a 36-inch diameter PVC gravity sewer main and manholes, and miscellaneous 24-inch diameter HDPE water main replacement. Design Challenges: During the planning and design of the sewer lift station replacement, several design challenges came to light. These included the limited property owned by the city and the lack of a viable location near the existing station, the presence of a creek just west of the proposed station location, and issues related to the stations location near Bellingham Bay including tsunami and seal level rise impacts. The first challenge encountered by the design team was the lack of city-owned property near the existing station. Two of the replacement alternatives included retrofitting the existing station infrastructure while a third alternative included constructing a new adjacent station. The lack of property available to the city required relocating the proposed lift station. Further validating the need to relocate the station was the presence of Squalicum Creek approximately 2,000 feet upstream of the proposed station location. The existing gravity sewer crosses the creek before entering the station and the top of the pipe is exposed in the creek bed. The city has future plans to improve the creek which would require lowering the sewer line. An analysis was completed to look at installation of a deeper gravity sewer or installation of an inverted siphon. The two challenges having the greatest impact on the design of the new sewer lift station were sea level rise and tsunami impacts. Based on FEMA mapping, the location of the new lift station is within the 100-year flood plain. The potential impact of flooding became painfully apparent during November 2021 when a major rain event caused significant flooding at the proposed lift station site. Adding to the challenge, the FEMA flood maps do not take into consideration future long-term change due to climate change and the rising sea level. Sea level rise predictions for our project area ranged from 1.1 to 11.7 feet above the base flood elevation. Through multiple modeling efforts the design team settled on a sea level rise impact of 1.5 meters and a 100-year storm event to set the initial water surface elevation used for design. The final challenge impacting the design of the replacement lift station was the fact that the new site was located within the Tsunami Design Zone. With the State's adoption of the International Building Code, we were required to use the Washington Tsunami Design Zone Map to determine whether Risk Category III or IV structures needed to be designed for tsunamis. The tsunami inundation elevation at the project site was identified as 21 feet based on mapping. Ultimately, the impacts related to tsunami inundation controlled the site design and the new station was elevated 9 feet above the existing grade. Status and Conclusions The project was bid for construction in April of 2023 with an engineer's estimate of $18 million including tax. The city received four bids ranging from a low bid of $17.5 million to $21 million. The project is currently under construction with an estimated completion date of Spring 2026. The design of the replacement sewer lift station was impacted by multiple surrounding water bodies which lead to many lessons learned throughout the design. Scour within Squalicum Creek caused exposure of the existing gravity sewer line. Future improvements to the creek impacted the depth of the future sewer upgrade requiring a deeper lift station wet well. This factor required construction of a new lift station and would not allow retrofit of the existing station. The location of the new lift station site and its proximity to Bellingham Bay caused the need to design for sea level and tsunami impact zones. Lessons that were learned during the design included understanding that FEMA flood plain mapping does not take sea level rise into account and that tsunami inundation can have a more significant impact on the final grade of the proposed site. Additionally, the design of the on-site structures themselves relative to the thickness and strength of the structure walls can be affected by the potential for tsunami impact loads. Finally, construction in a historically intertidal zone overlaid by fill required ground improvement design to stabilize the soils before construction could begin.

Executive Summary: The GLWA (Detroit) and NEORSD (Cleveland) are two large regional wastewater utilities that face similar challenges (e.g. funding/rates, aging infrastructure, CSOs, employee turnover) and have recently initiated innovation programs to help address these issues. Innovation is critical to current and future operations within their organizations. Both organizations have 'formal' innovation programs, but they are different stages of maturity. This paper (and presentation) will compare the GLWA Innovation Programs and the NEORSD Innovation Program — from inception through launch through current day to day operations. The goal of this paper is to provide some key insights to other water and wastewater utilities that may be considering implementing an innovation program or those that may need to take a 'step back' and look at their current innovation program frameworks. Innovation Programs — 2 Different Utilities - 2 Different Approaches Based on recent Water Research Foundation studies, a vast majority (>90%) of utilities surveyed believe that innovation is critical to their future. Additionally, 70% of the utilities participating in the research have developed formal innovation programs within the last 10 years. The GLWA and NEORSD have formal innovation programs in their organizations — but the journey they have taken has been different and they are at differing stages of maturity and have different approaches to various innovation program components. GLWA Launch — The GLWA 'Innovation Program' launch was initiated to help motivate and retain staff engagement, track ideas related to efficiency and operational improvements, and to help provide an assessment point for reviewing and screening external technologies. The GLWA launch benefitted from already having a successful research program, due to existing relationships and collaborations, but also experienced challenges from those same relationships due to the differences between research (narrow focus on a small subject) and innovation (broad focus on many subjects). GLWA initiated it's innovation program with two primary components: a quarterly workshop which focused on assessing external technologies via a series of vender presentations and developing an internal GLWA idea management software platform. This paper focuses on the idea management aspect of the GLWA innovation program. NEORSD Launch — NEORSD launched their initial Innovation Program framework in 2018 — utilizing a fairly 'informal/voluntary' administrative approach with a 'Big Bang' communication mode (1 organization wide email announcing idea submission form is available). As time passed, it was quickly realized that this approach did not achieve the desired goal of 'develop, encourage and sustain a culture of innovation' with NEORSD. Subsequently, NEORSD changed its approach to innovation program management, dedicating resources and designing a new innovation program framework — with the original program goal continuing to be a driving principle. In February 2020, NEORSD started the evolution of their innovation program framework — with a comprehensive relaunch strategy developed. Many challenges have been encountered and many lessons have been learned on this journey. See Figure 1 for a visual summary of the NEORSD Innovation Program framework - detailing the three primary components - communication, process and administration. Idea Management - 2 Different Approaches Ideas (like water lines, pumps, sewers and manholes and other equipment we use) should be considered as assets — and managed accordingly. Not all ideas will get implemented, and not all implemented ideas will be implemented right away. Sometimes an idea must be postponed, or slowly grown, until the timing is right, and resources are allocated for implementation. A key component of an innovation program is idea management and GLWA and NEORSD have taken different approaches in managing their ideas. GLWA Approach — GLWA approaches idea management as somewhat of a 'free for all' of good ideas and community engagement. However, those ideas must be managed within a structure of submission, commentary, review, and engagement with potential implementers. Idea management must have three specific components: 1) idea tracking, 2) feedback to the ideator, and 3) database of idea submissions, as shown in Figure 2. GLWA chose to implement a third party vendor software provide this structure. NEORSD Approach — The NEORSD idea management approach is less formal and structured when compared to GLWA and it has been recognized as a key area as part the NEORSD innovation program relaunch activities. Ideas that are managed by paper lists/post-its, emails and spreadsheets are not conducive to being able to be accessed, analyzed, reported or managed. A comprehensive idea management approach is being developed at NEORSD in 2021-2022. Steps that NEORSD is taking to develop this approach will be shared in the paper/presentation. Summary — Lessons Learned The GLWA and NEORSD have taken different approaches in their development and administration of their innovation programs. Many challenges and successes have been achieved along the way for both organizations — and there are lessons learned to share with other water and wastewater utilities that may be considering developing or revamping an innovation program. Innovation at a water or wastewater utility are not typically encouraged. The water sector must produce via a series of specific tasks to meet a set of specific requirements. Novelty is not beneficial or necessarily even useful. As a result, when trying to engage and develop your workforce innovation, there are often roadblocks preventing clear discussion, and clear understanding, of what might be gained. As each of us have developed our utility's respective innovation programs, we have encountered different aspects of institutional resistance or indifference. At the same time, we have also encountered various pockets of unexpected creativity. Some of these issues are listed below. 1.Communication differences 2.Rigid thinking versus 'free form' innovation 3.Team engagement and marketing the program 4.Differences of opinions 5.Differences in expectations We summarize our presentation and paper with the discussion of these challenges and some of the remedies we have used to circumvent them.