Conference Papers

The City of Richardson is eyeing the finish line for an eight-year, comprehensive capacity and condition assessment of its entire collection system. This presentation will focus on the City's nearly $10 million investment to develop a data-driven asset management plan. Assessment results will provide an accurate, consistently developed baseline for future master planning and asset management programs, as well as for the implementation of a more efficient, collaborative program of street and pipeline repairs. The assessment results were used to group and prioritize capacity and renewal recommendations to form a capital improvement plan (CIP) for the overall collection system. Intentional Focus on Holistic Goals Richardson City staff was intentional in maintaining a holistic approach to the assessment program to fully understand the impact of improvements on the overall system. It approached the program with five goals: - Prioritize its CIP to address system capacity deficiencies - Prioritize its rehabilitation program for aging infrastructure - Develop sizeable projects for cost and schedule efficiencies - Consider other infrastructure improvements, such as street rehabilitation - Determine funding levels needed to create a sustainable system Flow Monitoring to Determine Baseline The City installed six long-term flow meters to monitor their respective locations for two years and 34 temporary meters to develop the 2017 Master Plan. This data identified the I/I rate of each major basin and was used to establish the basin order for subsequent fieldwork. The City recently deployed 60 temporary flow meters throughout the City as part of the 2022 Master Plan Update to evaluate the impact of the City's ongoing rehabilitation effort and recalibrate the hydraulic model. Hydraulic Modeling to Understand Impact of Alternatives The City built and calibrated an all-pipes hydraulic model using the InfoWorks ICM software as part of the 2017 Master Plan. By developing the model to this level of detail, the City was able to identify existing and future capacity constraints and develop the capacity-driven CIP recommendations in the Master Plan. The City is actively recalibrating the hydraulic model using the data provided by the 2022 temporary flow monitoring. The additional 26 meters deployed in 2022 provide a more detailed picture of the hydraulic conditions, providing a better calibration and system analysis. Model results incorporate combinations of key factors, including projected growth rates, design storm selection, and its impact on I/I and operations alternatives. Asset Condition Assessments The City developed an ambitious plan to determine the condition of all its wastewater assets within eight years. The plan involved staggering the fieldwork within a basin so that the pipe, manhole, and cleanout inspections would occur in one year and be followed by the smoke testing inspections the following year. After the CCTV and smoke testing inspections are completed, a Sanitary Sewer Evaluation Study for the basin is finalized, and that data is then incorporated into the long-term rehabilitation and capital plans. The City has completed CCTV inspections for all 6 basins and smoke testing for 5 basins. CCTV for an Up-Close Look NASSCO's Pipeline Assessment Certification Program (PACP) standards shaped the program team's assessment of the pipelines using CCTV information to identify pipe defects and determine pipe-condition scores, as well as to update the City's GIS for the collection system. The CCTV inspections facilitated the cleaning of clogged pipelines, identified areas for priority re-inspection, supported the development of rehabilitation and replacement recommendations, and allowed the City to fast-track repairs of critical pipelines that needed priority attention. To date, the City has inspected nearly all 410 miles of the collection system. Digital Manhole Inspections The program team used NASSCO Manhole Assessment Certification Program (MACP) Level 2 standards for digital inspection of manholes that could be possible sources of I/I. Visual inspections covered manhole surface components -- frame, ring, cover, and frame seal -- while 360-degree scanning equipment that created 3D videos and point clouds for each manhole were used for the subsurface structure. The digital inspections fulfilled MACP Level 2 inspection criteria that traditionally have required time-consuming manned entry into the manholes. To date, the City has inspected nearly all 4,800 manholes in the system. Smoke Testing to Identify I/I Sources The program team began smoke testing during the dry summer months starting in year three of the program. Blowers and smoke candles are used to fill the wastewater lines with low-pressure smoke which escapes through defects in the system indicating possible sources of I/I. The team flagged, photographed, and collected GPS coordinates of any smoke observed leaving the system. An assessment was made to rate the intensity (high, medium, low) of the smoke observed, which is used to quantify the potential I/I rate of the observation. To date, the City has smoke tested approximately 345 miles (85%) of the collection system. GIS Updates using Field Data The data for both the City's PACP and MACP inspections are being integrated into a single repository in the City's GraniteNet data management system. The City utilizes the unique asset identifiers within the GIS system to link GraniteNet, the City's asset management system (Cityworks) and GIS database to provide a comprehensive picture of every inspected asset. This data is incorporated into the hydraulic and risk-based assessment models to provide the most up-to-date pictures of the collection system. Risk-Based Assessment to Prioritize CIP Hydraulic modeling capacity data, CCTV, MACP, and smoke-testing inspection data were entered into InfoAsset Planner software to shape a risk-based assessment (RBA) prioritization process. The program team incorporated condition data into a renewal-planning decision matrix to shape a system-wide CIP that identified and prioritized areas for rehabilitation and replacements. An automated decision tree process was developed to identify an action plan for each asset based on its observed condition and estimated risk. Lessons Learned Communication is critical to the success of the City's program. The program extends beyond Engineering and Public Works and included the GIS, Fire, Parks, and Communications departments. - Public notification while testing was underway included door-to-door notifications to business owners, door hangers at residential addresses, and road-side signs. - Having an outside vendor QA/QC the inspection data helps to validate the data's quality. - Including IT in the program plan is crucial due to the data storage size needs and the numerous software and databases that each contain a different piece of the asset management puzzle. - Through the cleaning and inspection efforts, capacity has been restored in the collection system, potentially deferring or eliminating CIP projects. - Since FY2017 through FY2021, the annual trend in SSOs has decreased. - Through the comprehensive process, the City now has updated GIS, a more holistic picture of the collection system, and can make proactive, data-driven decisions.

The Milwaukee Metropolitan Sewerage District (MMSD) recently embarked on a digital transformation journey to develop a culture that embraces and actively seeks advanced data solutions to support real-time decision-making that improves outcomes and generates value for its stakeholders. This is the first project of its kind for MMSD and requires a strategic approach that evaluates not only the technical aspects of digital transformation but also the human aspect of digital transformation. From the moment the discussions of advanced data solutions began at MMSD, it was apparent that the concept of digital transformation and advanced data solutions meant something different to just about everyone, and that the level of understanding and perceptions of advanced data solutions such as machine learning (ML) and artificial intelligence (AI) warranted a strategic pause to define what digital transformation means to MMSD. During the process, it was clear that there were and still are some stakeholders that are skeptical and that buy-in won't be sold but rather must be earned. The discussions were challenging and required careful navigation to get MMSD to the point of getting comfortable being uncomfortable. For MMSD, that meant collaboratively working together to take their first steps forward on something they've never done before: developing a digital transformation framework. This presentation shares MMSD's process to build internal consensus around digital transformation and provides insights into the early phases of the project, to inspire and support peer agencies in building momentum for digital transformation in their organizations. It covers all aspects of pre-launch, including finding an executive champion, finding allies within the organization, developing a cross-functional steering committee consisting of both allies and skeptics, internal outreach, external engagement, and how we scoped a project to develop a digital transformation framework for our organization rooted in education, technology, process, people, and culture. MMSD initially did an RFI to clarify its thinking about digital transformation and to validate and improve the RFP content. They strategically waived some standard RFP requirements to cast a wide net and ensure that all qualified firms would respond, and leaned on the prospective consultants to define the approach that would lead us to success. This resulted in a large pool of strong responses and engaged new prospective project collaborators. The sixteen responses were put through several rounds of evaluation before the final selection was made. This paper also shares progress to date. In July 2023, MMSD and a consultant team led by Brown and Caldwell kicked off the 78-week Digital Transformation Framework Development project focusing on digital transformation within the water reclamation facilities and conveyance system. We will discuss the structured analytical approach that underpins the project, how we organized and managed the project team for success, the kickoff meeting agenda and findings, how the pre-launch work enabled stakeholders to get comfortable with unexpected changes in the core consultant team, how MMSD provided initial data to the consultant team, the best practices workshop agenda and outcomes, and the agenda and outcomes of a series of small group meetings focused on the business risks associated with digital transformation. About MMSD MMSD is a regional government agency that provides water reclamation and flood management services for about 1.1 million people in 28 communities in the Greater Milwaukee Area. The MMSD service area is 423 square miles and covers all, or segments of, six watersheds. Established by state law, MMSD is governed by 11 commissioners with taxing authority. MMSD is most proud of its track record of capturing and treating 98.5% of all wastewater collected since 1994. MMSD has a contract operator, Veolia Water North America, for the operations and maintenance of the conveyance system and water reclamation facilities. Learning Objectives After attending the session, attendees should be able to: 1.Explain, interpret, and practice the approach MMSD used to align itself around a shared understanding of digital transformation, to scope the project, and to participate in initial project work 2.Paraphrase and generalize the analytical framework and methodology 3.Examine the outcomes of the initial work and hypothesize the outcomes of similar work within their own organizations.

Introduction After four decades of operating a cogeneration facility to produce electricity and heat, Metro Water Recovery (Metro) commissioned a Biogas Utilization Study in 2021 to consider historical and new beneficial uses of biogas at their Robert W. Hite Treatment Facility (RHWTF) that serves Colorado's Denver metropolitan area. While cogeneration has been the industry standard for biogas utilization at water resource recovery facilities (WRRFs) for decades, biogas upgrading to renewable natural gas (RNG) has become more prevalent due to federal incentives available under the Renewable Fuel Standard (RFS) program created under the Energy Policy Act of 2005. And while the RFS program has been the historic driving force behind the shift to RNG, a drive by major companies to reduce the carbon footprint of their operations are leading to further incentives for biogas, potentially mitigating the risk of relying on a single revenue stream. This study investigated two alternatives for beneficial reuse of the biogas resource at Metro's RWHTF: - Upgrade and continue to operate the Cogeneration Facility to generate electricity and heat using biogas. - Construct a new facility that converts biogas into RNG for direct injection into a natural gas pipeline owned by Xcel Energy (Xcel) and monetize the RNG. While WRRFs across the country have embarked on similar evaluations; this project was unique in that it included an in-depth evaluation of the long-term viability of financial incentive markets, sustainability impacts, future natural gas demand, and the potential impact from current and future state policies. This evaluation was then used to inform sensitivity evaluations of the two alternatives to facilitate decision making. Monetizing RNG The study evaluated four pathways for Metro to generate a revenue source from their RNG. These revenue sources included: 1. Sale of brown gas, 2. Participation in the Renewable Fuel Standard (RFS) program, 3. Participation in state-specific Low Carbon Fuel Standard (LCFS) programs, and 4. Participation in the voluntary market. The sale of brown gas is typically tied to regional natural gas indices, with revenue calculated based on the amount of gas injected into the natural gas utilities' pipeline. The sale of brown gas can be paired with renewable credits as shown in Figure 1. The study evaluated the long-term viability of the RFS program, considered the potential for an LCFS program in the State of Colorado, state legislature geared towards the reduction of the carbon footprint of building heat, and reviewed the strength of voluntary markets. The renewable volume obligations (RVO) under the RFS are set to expire at the end of 2022, and members of Congress have voiced support for the replacement of the RFS with a national LCFS program (similar to California) that provides incentives for a wider range of low carbon fuels. To date, there remains a significant gap in RNG supply to meet the originally planned renewable volume obligations. Whether the RFS program is continued or replaced by an LCFS program, it is anticipated that a system of federal renewable credits will remain in place for the foreseeable future for RNG. The viability of an electric renewable identification number (e-RIN) pathway was also considered; however, the EPA has not approved any such project, despite receiving approval requests. The Colorado Energy Office recently evaluated the viability of an LCFS program for the State of Colorado. This report (Low Carbon Fuel Standard Feasibility Study, September 2020, ICF Resources, L.L.C.) stated that, 'Experience in California, Oregon and British Columbia has shown that LCFS programs can deliver on the above policy objectives, and that LCFS programs are a cost-effective mechanism to reduce GHG emissions and increase the share of lower carbon fuels in the transportation sector, while having a smaller cost impact on retail fuel prices relative to other decarbonization policies.' No movement has been made to date by the State legislature to introduce such a program. Many corporations and utilities have established 'carbon-free' energy goals, which has created a voluntary market for RNG. Due to the higher RIN pricing, increasing RNG demands in the voluntary markets have resulted in increasing value and revenue potential. Table 1 shows the pricing variability for the voluntary markets and illustrates the increases in the market based on current conditions and drivers towards RNG sustainability goals. Long-term Natural Gas Demand As the energy sector transitions to meet renewable energy goals, there is increasing demand for natural gas that is anticipated to continue through 2050. The U.S. Energy Information Administration (EIA) projects increasing demand for compressed natural gas (CNG) over the next 30 years at 1 percent compounded annually. CNG demand is also expected to remain strong in the transportation sector, despite the focus on electrification of light-duty vehicles. CNG continues to be the major fuel source for heavy-duty vehicles. Figure 2 expands on the uses of CNG in the transportation sector and demonstrates there is a steady increase in CNG consumption through 2050. As Xcel, the local electric and natural gas utility, further develops their renewable energy portfolio to meet their 2050 carbon-free electricity goals, natural gas is anticipated to remain the backbone of reliable energy sources and backup emergency power for the next 20 years. State of Colorado Policy Impacts The State of Colorado is targeting a reduction of greenhouse gas emissions by 90 percent of the 2005 values by the year 2050. Legislation approved in 2021 requires natural gas and electric utilities (i.e. Xcel) to reduce the use of natural gas by consumers. Xcel could purchase RNG from Metro to decrease the reliance on natural gas. While a cap-and-trade program introduced this year was vetoed by the Governor, the Public Utility Council is currently reviewing a means of implementation for the legislation which could include an avenue for RNG. Alternatively, Metro could decide to pursue this type of program on a voluntary basis with other states or utilities that have existing programs. While the State has evaluated different types of RNG legislation and potentially creating their own LCFS program, nothing has materialized that would influence Metro's decision on which biogas alternative to move forward with. Variability of Utility Costs Electricity and natural gas costs are large operating expenses for Metro's annual budget. Pricing volatility for electricity and natural gas could impact either of the biogas alternatives. The EIA forecasts that increasing renewable energy capacity will result in a slight decrease of electrical rates through 2050. However, regional differences will occur based on the level of renewable energy in the regional electric utility's portfolio. According to the EIA, natural gas pricing fluctuates based on weather, economic growth, market competition, gasoline prices, and availability. Figure 3 illustrates the yearly average Henry Hub natural gas spot pricing. Sensitivity Evaluations Sensitivity analyses were developed to capture the financial viability of both alternatives based on the changing future conditions described above. Figure 4 presents the range of life cycle costs for the cogeneration alternative, with consideration of changing electricity prices and renewable electricity credit value. Figure 5 presents the range of life cycle costs for the pipeline injection alternative, with consideration of RIN pricing, voluntary market, and natural gas market volatility. Based on the sensitivity evaluations, the pipeline injection alternative in almost all cases provides a positive financial return to Metro when compared to the cogeneration alternative. The pipeline injection alternative has a simple payback of 3 to 10 years depending on the revenue model. When comparing the base case alternatives, pipeline injection has a 20-year net present value that is $205 million higher than the cogeneration alternative. Based on the recommendations of this study, Metro is planning to proceed with preliminary design and development of a biogas upgrading and pipeline injection system.

BACKGROUND The United States Environmental Protection Agency (USEPA) and Massachusetts Department of Environmental Protection (MassDEP) have recently implemented non-point-source, watershed-based nitrogen Total Maximum Daily Load (TMDL) limits for multiple small coastal estuaries around Cape Cod Massachusetts. The TMDLs for the four (4) estuarine systems around the Town of Chatham, Massachusetts, a town with a population of approximately 6500, are very stringent and require removal of much of the wastewater nitrogen coming from the many individual septic systems, as well as nitrogen from the stormwater and lawn fertilizers, at the many developed properties (see Figure 1). Nutrients have been overloading the local estuaries for years causing highly visible eutrophication issues as well as impacts to the groundwater-source drinking water supply. Based on these nitrogen TMDLs, the Town developed a Comprehensive Wastewater Management Plan (CWMP) which utilizes sewer extensions, a wastewater treatment facility upgrade, growth neutral land use controls, stormwater management, and fertilizer reduction research and management to meet the limits. THE PROBLEM AND ITS SOLUTION The Town has historically relied almost exclusively on individual septic systems for wastewater management. Once nitrogen was determined to be the nutrient of concern with respect to the local estuaries, sources of nitrogen were investigated. Almost 70% of the total nitrogen was identified as coming from wastewater and a full 85% of nitrogen from all controllable sources (fertilizers, stormwater, wastewater/septic system) was wastewater related (see Figures 1 and 2). Although many treatment systems were investigated including traditional and enhanced septic systems, cluster and decentralized systems and large-scale municipal wastewater facilities, it was the centralized treatment facility with its 93% removal of nitrogen that was needed to meet the strict TMDLs which required overall effluent levels to be at the limit of technology for nitrogen. In order to remove nitrogen to the extent shown in Figure 3, the Town has begun an extensive sewering project which will sewer two thirds of the Town in Phase 1 (which is expected to be complete within twenty years) and the balance of the town would be sewered in an additional ten years during Phase 2 as shown in Figure 4. In order to accommodate this additional wastewater, the water pollution control facility was upgraded significantly including nitrogen removal to 3 mg/L and accommodations for future phosphorus removal. The total cost of the extensive sewering and treatment upgrade project is projected to be approximately $300 million dollars with more than two thirds of those costs ($210 million) being for the Phase 1. THE APPROACH The Town-wide approval of the plan was the result of a focus on outreach and public participation. This consisted of the creation of a citizens advisory committee (CAC) which contributed to the development of the CWMP. A key component of the plan that maintained the public's support was a 'Growth Neutral' bylaw which allowed for controlled 'wastewater related' growth within the Town. The involvement of the public through the CAC, public meetings, and other means was a primary reason why this CWMP gained approval where other town plans failed. In addition, the cost of the Plan was made affordable by spreading costs to all property owners, and by capturing scarce federal grants and taking full advantage of state and federal loan programs. IMPLEMENTATION As part of the Planning stage, an extensive Sewer CADD model of the entire Town was developed (results shown in Figure 4). This model included Phase 1 and Phase 2 of the CWMP implementation. The flat terrain in this coastal community resulted in the projection of over eighty pumping stations being needed for this small Town with a year-round population of only 6500. This model provided the roadmap needed to commence the Town-wide sewering project. In 2009, the initial implementation phase of this plan commenced with the 'backbone' of the collection system being designed and constructed. This 'backbone' consisted of the main gravity sewer lines and forcemains installed across the Town that will serve the vast majority of the expanded system. With both the backbone of the system and the wastewater treatment facility upgrade completed in 2012, a series of smaller collection system offshoots will commence in the ensuing years with the Town committing to a continuous sequence of small sewer extensions over the next few decades. As shown in Figure 5, the newly upgraded wastewater treatment facility has been removing nitrogen to the limit of technology since the initial startup was complete in the summer of 2012. SOCIAL, ECOMONIC, AND SUSTAINABLE DESIGN COMPONENTS This Project provided a roadmap for the Town to follow to solve problems created mostly by wastewater and provides the following social and economic benefits in Chatham: -A planning document outlining a wastewater solution -Remediation and protection of drinking, pond, and estuarine water quality -Preservation of the Town's fishing economy -Preservation of the Town's vacation economy -Land use growth protection (Flow Neutral) to apply to all properties connected to the sewer -Costs being distributed in an affordable manner. The historic use of septic systems as the primary type of wastewater management in Chatham was not sustainable because it was causing eutrophication of its coastal estuaries and freshwater ponds, and threatening its groundwater drinking water supplies. The CWMP recommendations of wastewater collection, advanced treatment, and treated-water recharge to the groundwater system provided a sustainable and holistic method for water resource management. Through the Town's efforts in completing their CWMP and growth neutral policy, they were also able to secure 0% SRF loans for this and their next phase of sewer extensions, over the 2% loans normally available. CURRENT STATUS The CWMP outlines a phased implementation of the Phase I sewering. With the initial implementation phase complete, the planning documents and SewerCADD models are now in use as the expansion of the collection system continues with annual sewering projects. The long-term plan to remediate the impaired waters is well underway as the Town has implemented its plan to gain complete control of their wastewater.

Learning objective: Attendees will learn how workforce development is a continuous cycle of assessment, planning, application, measurement, and learning and be able to take actionable steps to enhance workforce development initiatives. Public water utilities face particular challenges to building and developing the talented and committed workforce needed to ensure successful operations. A convergence of challenges makes this especially difficult as we approach the middle of the 21st century. Increasing demands of environmental regulations and economic forces impacting the ability to deliver services cost-effectively are coupled with the loss of experienced professionals and fewer people entering public service. Add to this changing expectations of the employer-employee relationship and competing demands for funding, and the water utility sector is facing an unprecedented challenge. While most utility leaders recognize these workforce challenges, few are able to independently overcome the barriers to tackle the issue and make significant headway. The water utility sector can build a strategic, holistic, compelling vision for its workforce and thrive in today's work environment by adopting a practice of continuous improvement by implementing a Cycle of Successful Workforce Development. This cycle includes five stages: assessment, planning, application, measurement, and learning. In each stage, utility leadership can take tangible, actionable steps to enhance workforce development. This presentation will (1) explore the barriers to significant investment in workforce development in the water industry, (2) introduce the Cycle of Successful Workforce Development, and (3) share examples of several utilities where elements of this cycle were applied for enhancing workforce development. Industry guidance, former utility leadership experience and case studies will be used to walk attendees through the cycle. The cycle begins by performing a comprehensive organizational assessment that considers what skillsets and positions are needed and where gaps exist in the current workforce. Benchmarking, span of control, and matrix of authority reviews are integral parts of this 'on ramp' to the cycle. The results are then utilized for planning business process improvements and assembling the desired organizational structure. Recruiting and hiring are crucial to identifying and securing candidates, and will be guided by competency assessments and job descriptions improvements informed by strategies grounded in the realities of the current workforce supply/demand environment. Onboarding and training are crucial application steps to set up employees for success, whether they are new to the organization or established staffers assuming new and more challenging roles. Well-planned training programs will ensure all know the organization's goals and objectives and have the opportunity to succeed. Training should be coupled with business process improvements. Career ladders, succession planning and leadership training provide flexible pathways for professional growth, improve organizational continuity and resiliency, and help retain talented employees. Measurement of achievement against defined goals helps achieve success through both organizational and individual performance monitoring. Competitive salary, mentorship programs and incentive programs foster a culture of continuous improvement. Reassessment of the organization at budget preparation time each year will identify opportunities to adapt the plan to changing circumstances and external influences. Learning from regular review of both organizational and individual achievement against goals provides opportunity to refine processes and will help employees identify and achieve their career goals.

Microplastics is an important class of contaminants of emerging concerns. In scientific literature, microplastics typically refer to plastics particles, fibers, and fragments between 1 µm and 5 mm. Water Resource Reclamation Facilities (WRRFs) are conduits between the waste sources and the environment. WRRFs collect a large quantity of microplastics from various sources, including municipal waste, roadway run off, industrial discharge. Conventional wastewater treatment processes have been effective in separating microplastics driven by physical-chemical properties of microplastics, and consequently, microplastics accumulate in solids stream and biosolids (Blair et al., 2019; Bui et al., 2020). Treated biosolids have a range of disposal pathways, among which agricultural land application accounts for approximately 50% of annual total biosolids disposed. Land application of biosolids presents avenues for microplastics in biosolids to enter and accumulate in agricultural soil. The accumulation of microplastics in agricultural soils can lead to various adverse implications for soil quality by impacting soil structure, water dynamics, and soil biota. Microplastics that enter the terrestrial environment through biosolids can further mobilize to different environments, through storm runoff and aerosolization. Understanding microplastics' occurrence, fate, and transformation in biosolids treatment is crucial to mitigate the above-mentioned adverse effects of microplastics in biosolids and to promote the beneficial and sustainable use of biosolids. Information on microplastics cross the solids treatment steam is yet to be summarized or synthesized to assist stakeholders understand risks associated with microplastics on a high level. To this end, a comprehensive critical review was conducted to inform the state of knowledge of microplastics studies regarding sludge and biosolids and synthesizes data from those studies, to address the lack of understanding of microplastics in those unit processes. This study captures data and knowledge from 51 studies including peer-reviewed journals articles, reports, and conference proceedings. The proposed presentation will cover the abundance, fate and characteristics of microplastics in solids stream and biosolids, as well as methodologies for analyzing microplastics in sludge and biosolids samples. This study is part of a Water Research Foundation funded project (WRF 5221). Abundance and Fate of Microplastics in Solids Stream and Biosolids Wastewater sludge can be a sink of microplastics as a large portion of microplastics in wastewater can be separated during skimming and sedimentation. The abundance of microplastics in each type of sludge varies over multiple orders of magnitude (Fig. 1). The lack of consistent sampling across the entire solid treatment train poses challenges in developing an understanding of how different sludge treatment processes affect microplastics and quantifying the transformation of microplastics. Based on the intra-facility variation of microplastics in solids treatment stream, the level of microplastics does not significantly change from sludge generation, thickening to stabilization, but reduces after dewatering, showcasing potential accumulation of microplastics in sidestreams. Innovative biosolids treatment technologies, such as pyrolysis and hydrothermal liquefaction, provide opportunities to remove microplastics along with other persistent contaminants of emerging concerns. On average, 14,900 pieces of microplastics can be deposited into soil per dry kilogram of biosolids applied, revealing biosolids as a pathway for microplastics to enter the terrestrial environment. Furthermore, maximum sludge values are significantly higher than the average at 169,000,000 particles per kg. Sources in literature indicate microplastics increasing '280 items/kg and 430 items/kg' with sludge application (Yang et al., 2021). Soil concentrations are observed to range from single digits per kg to approximately 40,000 pieces per kilogram. The average concentration of microplastics in soil is approximately within 100 particles per kg to 1,000 particles per kg for a rough order of magnitude comparison. Approximately half of the microplastics found in sludge and biosolids are in the shape of fibers, which indicates laundry discharge is an important source of microplastics in wastewater and biosolids. Microplastics of Different Characteristics: Polymer Types and Morphology A total number of 31 types of polymers were reported in literature. Polyester, polypropylene, polystyrene, polyethylene, polyamide, polyethylene teraphatalate are the most frequently reported and abundant types of polymers. Polyester and polyamide are commonly used for making synthetic fabric (Sun et al., 2019). Thus, they often appear as microplastics fibers in wastewater and biosolids and their prevalence is in line with the abundance of fibers in various types of sludge. The polymer types abundant in biosolids align with the ones in wastewater reported in previous studies (Bui et al., 2020; El Hayany et al., 2022), showing that laundry discharge and storm runoff are major sources of microplastics in wastewater as well as biosolids. Source control to reduce microplastics load in raw sewage could be an effective measure for microplastics reduction in solids stream. Additionally, the similar abundance of polymer types in liquid and solids stream processes also reveals that the accumulation of microplastics in solids stream is not polymer type specific. Methodologies for Microplastics Quantification in Biosolids Sampling and analytical methods used in literature are summarized to inform future analysis of microplastics in sludge and biosolids. The sampling of low solids content samples, e.g. secondary sludge, digested sludge, can utilize automated sampling system and pumps, whereas high solids content samples are manually taken using containers or shovels. The sample processing procedure typically follows: density separation, chemical digestion, and vacuum filtration (Fig. 2). The quantification of microplastics in literature is count-based and relies on vibrational spectroscopy. Mass-based quantification should also be adopted for future studies due to the potential fragmentation of microplastics. Conclusion The literature review conducted by the Project Team showcases the state of knowledge on microplastics in solids treatment stream. It informs utilities of the abundance, fate of microplastics in different process units and in relation to facility characteristics and location, providing information that utilities can use to assess potential risks. It also provides insights into the origins of microplastics in biosolids, which help utilities identify potential entry points into the water treatment and wastewater systems. Currently there is no standard method for microplastics analysis in sludge and biosolids. The summary of reported methods in literature will provide the utilities valuable references and guidance on producing reliable, reproducible data.

A passionate and consistent workforce is critical to ensuring a successful water/wastewater industry for years to come. The high-level goals of this presentation is: -Understand what employees value in their careers. -Hear how they are feeling on a wide range of topics including flexibility, mentorship, workload, and team support. -Learn what changes they desire to increase their motivation and contentment. The objective of this presentation is help create a better workplace for employee retention. This presentation will offer perspectives on workforce development from two sides of the workforce. Kathleen Mannion is considered a 'rising professional' with 7 years of experience all in the consulting industry. Molly Nause-McCord is considered a 'seasoned professional' with 13 years of experience all in the public sector working for the City of Portland Bureau of Environmental Services. In addition to their own perspectives, this presentation will offer the insight that Molly and Kathleen learned from a survey they sent out to other members of the industry. The survey was anonymous, consisting of 25 short answer questions on a wide variety of topics including experience level and duration, motivations for joining the field, employee engagement, and professional development. Kathleen and Molly widely distributed the survey to get a diverse set of respondents. The distribution included via email list serves sent by the Pacific Northwest Clean Water Association, as well as distribution through Kathleen and Molly's networks. There was a lot of interest in the survey and 159 responses were received while the survey was open in July and August 2023. There was good representation amongst the respondents across sectors (52% public sector, 43% consulting, and 5% other), years of experience (22% 0-5 years of experience, 20% 5-10 years of experience, 20% 5-10 years of experience, and 28% of 20+ years of experience), and gender (53% female, 41% male, and 6% all others). After reading through the thoughtful responses and survey results, the information was categorized into four categories: -Individual to Industry: how individuals view the water/wastewater industry including their motivations for joining, motivations for staying, confidence that they will remain in the industry, and greatest challenges they see for the industry moving forward. -Employee Contentment: evaluated how content employees are, how that compared across different demographics and groups, and what is contributing to employee contentment. -Mentorship and Growth: assessed how employees are feeling about themselves as a mentor, relationships they have with their own mentors, and obstacles that are preventing further mentorship. -Airing of Grievances: understanding the top contributors to employee dissatisfaction at work including amount of workload, lack of recognition, monotonous tasks, and personal work/life balance. We also evaluated how this varied across different groups, races, and demographics. This presentation will present the results of the survey, as well as the personal input from Kathleen and Molly and their differing backgrounds. Overall, the results from the survey were very positive with 73% of respondents listing themselves as content and engaged. A Gallup poll from the first half of 2021 stated that 36% of workers in the United States were engaged. Therefore, this shows that the water/wastewater work force is significantly more engaged and content than the rest of society. However, there were helpful takeaways from this presentation highlighting areas for improvement to further progress the workplace. This presentation was given at the Pacific Northwest Clean Water Association (PNCWA) annual conference in September 2023 and received lots of positive feedback. The attendees had several questions and stayed after the presentation to discuss more. The presentation was given a 30-minute time slot at the PNCWA conference, but attendees recommended a longer time slot in the future to dive further into the survey results. If the Conference Planning Committee has any specific areas of the survey results that they would like the presentation to focus on we would be happy to tailor our presentation as requested.

Introduction The Coronavirus Disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2), has exposed modern society's vulnerability to infectious diseases. Reliance on clinical testing of symptomatic individuals has proven challenging due to the inability to identify asymptomatic cases and time lags between disease onset and clinical reporting to public health agencies. Wastewater surveillance is a disease-tracking tool that supports early response, such as public health decision making and vaccination efforts. Public health agencies have partnered with local officials, wastewater utilities, research institutions, and consultants to implement practical wastewater surveillance programs. CDM Smith has focused on building these partnerships to facilitate SARS-CoV-2 wastewater testing programs around the globe. Our work aims to support the use of wastewater data to inform specific public health interventions. This presentation highlights wastewater surveillance case studies at facility, neighborhood, and city scales to illustrate best practices for developing wastewater surveillance programs. Wastewater Surveillance Program Development A successful wastewater surveillance program requires collaboration between community leaders, wastewater utilities, epidemiologists, public health officials, engineers, doctors, and other scientists. Our approach to building programs relies on early engagement of these stakeholders. The team defines program objectives, devises a cost-efficient approach to wastewater sampling and analysis, develops communication plans, establishes data presentation techniques, and informs on potential public health interventions. The collaborative approach improves consensus building. Program execution focuses on gathering and presenting reliable wastewater data in a timely and effective manner. Wastewater Surveillance Case Studies CDM Smith has helped develop wastewater surveillance programs at the facility-, neighborhood-, and city-scales in the United States and Middle East with varying goals and objectives. The United States Department of Veterans Affairs developed a program to monitor eight conjugate living centers (CLCs) throughout the U.S (CA, NC, PA(2), TN, TX, WA (2)). The goal of the program was to provide an early warning system to prevent outbreaks in CLCs. From January to June 2021, CDM Smith assisted in grab sample coordination, collection, and delivery to the VA analytical laboratories in Temple Texas. The VA project showed that initial planning of sampling and shipping logistics was critical to rapid turnaround of wastewater surveillance data. The VA labs indicated the SARS-CoV-2 wastewater data was used to target testing resources and mitigate outbreaks in CLCs. In collaboration with CDM Smith, the Massachusetts Department of Health implemented facility and neighborhood programs with the objectives of identifying COVID-19 cases sooner than clinical testing and confirming absence of disease. 24-hour composite wastewater samples were collected three days per week and analyzed for SARS-CoV-2 and other sewage markers. Results are communicated via email to state and city officials, and COVID-19 case data are evaluated for correlation with wastewater virus concentrations. Local-level surveillance provided public health officials an early-warning of an outbreak in a community in eastern Massachusetts. Public health measures included mask distribution, deployment of mobile testing units, and education campaigns. A city-scale surveillance program was established in April 2020 in Detroit, Michigan, and is still ongoing. The program objective is to develop a model to predict spatial and temporal variation in COVID-19 cases based on wastewater concentrations, demographic data, and sewer conditions. Grab samples are collected weekly at 12 locations, including at the wastewater treatment plant, and analyzed for SARS-CoV-2 and other sewage markers. Results are discussed weekly with public health officials, and data are analyzed using principal components analysis. Collaborating with the United States Agency for International Development (USAID), CDM Smith helped develop city-scale surveillance programs in Amman, Jordan and Cairo, Egypt. These program building projects focused on analyzing existing research infrastructure to support sampling campaigns and analytical testing, implementing wastewater monitoring and action plans, training seminars, and data visualization dashboards. Insights from U.S. case studies were used to establish recommendations that allow international partners to manage their wastewater surveillance programs. Conclusions and Recommendations Wastewater surveillance is an effective tool to measure aggregated community-level biomarker data. The approach is being used effectively at many scales during the COVID-19 pandemic. CDM Smith's wastewater surveillance work revealed several important findings including: A successful program starts with collaboration between public health agencies, local officials, research agencies, and their partners. SARS-Cov-2 wastewater concentrations are strongly correlated with COVID-19 cases. Normalizing viral concentration data to other wastewater data is helpful to mitigate competing influences in the sewer system. Wastewater surveillance data was used to inform specific public health actions such as awareness campaigns. Development of wastewater surveillance programs can provide a proactive tool to respond to disease outbreaks, understand drug use, and measure other indicators of community health and wellbeing. Future applications of the approach include early identification and understanding of disease outbreaks, understanding antibiotic resistance, and addressing health disparities Widespread development of programs could provide public health officials a proactive tool to respond to disease outbreaks. The Centers for Disease Control and Prevention (CDC) established the National Wastewater Surveillance System (NWSS) to improve acceptance of the approach. Wastewater surveillance is being funded through a combination of federal, state, and local support.

Background The United States Environmental Protection Agency (USEPA) and Massachusetts Department of Environmental Protection (MassDEP) have implemented non-point-source, watershed-based nitrogen Total Maximum Daily Load (TMDL) limits for multiple small coastal estuaries in southeastern Massachusetts. Southeastern Massachusetts towns have approached this nitrogen contamination problem — primarily caused by overuse of septic systems as populations grew - in very different ways. Methodology Although almost all communities in the Study Area have explored growth neutral land use controls and solutions such as stormwater management and fertilizer reduction, some towns have taken a primarily traditional approach to solving the problem while others have explored alternative technologies. Some towns place an emphasis on traditional solutions such as sewering with an enhanced nitrogen removal process centralized wastewater treatment facility. Others have explored innovative non-traditional technologies such as shellfish aquaculture, permeable reactive barriers, inlet widening to improve tidal flushing, decentralized treatment facilities, and nitrogen reducing onsite septic systems. Many communities are developing a hybrid approach where traditional sewering is targeted for the highest density neighborhoods with non-traditional strategies being implemented in more less densely developed areas. Results Communities with TMDLs have initiated comprehensive wastewater management plans (CWMP) to develop methodologies to reduce nitrogen impacts. Representative case studies illustrate the unique solutions adopted by two of these communities; these both provide lessons learned to any community facing similar challenges. The communities of Oak Bluffs, MA and Chatham, MA each approached the CWMP process differently. Although the solutions were different, both communities faced a significant challenge- as a result of significant long term project costs — which has resulted in a robust public education effort. Case Study #1: Chatham's Septic to Sewer Strategy The Town of Chatham, MA has a severe nitrogen contamination problem. As shown in Figure 1, one third of the watersheds within the Town require 100% removal of wastewater nitrogen and almost three quarters require more than 50% removal of wastewater nitrogen to meet the Town's TMDL goals. The solution to this problem was estimated to cost over $300 million for a community with a year round population of just over 6000. In order to solve this problem, the Town developed a phased implementation approach. This approach primarily consists of planned implementation of traditional sewering technologies with limited non-traditional technologies for targeted areas. In the first phase of the plan the Town's existing Water Pollution Control Facility was upgraded to a limit of technology nitrogen removal process and its flow capacity was increased (Figure 3). The Town has been implementing septic to sewer conversion projects that account for approximately 15-20% of its TMDL compliance requirements every three years (Figure 2). Now almost 40% complete with its TMDL compliance plan, over 700 properties have been removed to date from septic systems, providing a potential future nitrogen load reduction of about 3,000 kg/y for this initial part of a larger long-term implementation program. In addition, the Town has completed an inlet widening project (Figure 4) as well as implemented a fertilizer management plan, the only two non-traditional nitrogen reduction options that were feasible to help address the significant contamination issues in this town. Overall, the Town plans to achieve its nitrogen TMDL goals within a 20-year timeframe. Case Study #2: Oak Bluffs Hybrid Nitrogen Management Approach The Town of Oak Bluffs is a small community with a year-round population of less than 5,000 people. The majority of the Town lies within one of four nitrogen sensitive coastal watersheds (Figure 5). Every summer, the Town sees a substantial population increase from tourism, which has contributed to the nutrient impacts observed in the Town's water resources. The Town has a small centralized wastewater treatment system, with limited options for treated effluent recharge expansion, which drove the Town to evaluate multiple non-traditional nitrogen management technologies as part of its comprehensive wastewater management plan (CWMP). In order to meet its nitrogen Total Maximum Daily Load limit goals, the Town has developed a hybrid Recommended Plan, which integrates multiple nitrogen management strategies for each watershed including centralized sewering, an enhanced nitrogen removal on-site septic system program, and permeable reactive barriers. The Recommended Plan includes the implementation of an adaptive management process to incorporate cost-effective pilot technologies into the plan once they demonstrate feasibility. The adaptive management process will involve ongoing water quality monitoring to monitor and respond to the results of the implementation. This adaptive management approach will enable the Recommended Plan to be adjusted based on the monitoring results of the environmental and economic impacts associated with the construction of sewers and implementation of pilot projects in Oak Bluffs. Benefits and Next Steps The complex wastewater nitrogen contamination challenges in southeastern Massachusetts require significant investments to reverse years of environmental degradation. This problem is being addressed by the small communities in Southeastern Massachusetts with innovative solutions that seek to manage high costs by balancing traditional and non-traditional wastewater management solutions. The solutions outlined above are allowing for the recovery of degraded coastal waterways using fiscal sustainable approaches. However, as the problem took many years to develop, so will the solutions with many of these comprehensive wastewater management plans having a schedule of 20, 30 and even 40 years to implement, making the results more of a long term goal.

Treatment of odors from municipal sewage collection systems and wastewater treatment plants often proves challenging in harsh middle east climate conditions. Some of the main challenges include underestimation of the odor concentrations in the municipal collection systems and wastewater treatment plants, and the selection of inappropriate odor treatment technologies for these applications. Odor concentrations are often orders of magnitudes higher than what is experienced in the USA and other Western climates, which is mostly attributed to the very high summer ambient temperatures and often long residence times of the sewage in the collection systems. This paper provides an overview of a comprehensive odor study that was performed at the headworks of the Al Filaya WWTP in Ras Al Khaimah (WWTP), UAE to determine the design criteria for the odor control system. It also reports on the successful implementation of biotrickling filter technology to treat the odors at the headworks. In 2021 Ras Al Khaimah Wastewater Agency (RAKWA) contracted with BioAir Solutions to perform a comprehensive odor study at the newly constructed headworks at the WWTP to determine suitable design criteria for the odor control system. The study included the measurement of both liquid phase pH, temperature, and dissolved sulfide, as well as vapor phase H2S, methyl mercaptan, ammonia and ammine concentrations. It also included the estimation of suitable air ventilations rates from the various odor sources at the headworks, including the inlet chamber, screen channels, vortex grit removal system and others. The odor study revealed that the sewage at the headworks is very septic, and the dissolved sulfide concentrations vary between 12 mg/L and 32 mg/L. Henry's law equilibrium calculations, which incorporated sewage pH, dissolved sulfide, and temperature, resulted in an equilibrium vapor phase H2S concentration of between 580 and 3,200 ppmv. The final design basis for the odor control system was 3,500 Am3/hr of airflow at design average and peak H2S concentrations of 2,350 ppmv and 3,525 ppmv, respectively. The required H2S concentration in the air after treatment was < 0.25 ppmv, which equites to 99.99% H2S removal efficiency. Biotrickling filter technology was selected as the most suitable technology for the application. RAKWA decided to upgrade the existing biotrickling filter and add a second reactor to treat the odors at the headworks. BioAir Solutions supplied and installed two EcoFilter biotrickling filters which were put in operation in December 2021 (see Figure 1). Once the system was fully acclimated, its performance was tested to validate that it achieved < 0.25 ppmv H2S concentration in the discharge stacks of the two reactors. Figure 2 provides the performance data for the two EcoFilter reactors. This case study demonstrates the importance of performing odor studies to verify the odor concentrations and ventilation rates for existing WWTP applications in harsh climate environments. If new greenfield WWTPs are developed, it is important to use data from similar other plants in the region to develop a suitable design basis for the odor control system. The study further demonstrates the suitability of biotrickling filter technology for successful odor removal in hot middle east environments, without the need for secondary carbon polishing. It is, however, very important that the system be design for the appropriate H2S concentrations to avoid media failures that may occur if the actual H2S concentration is much higher than the design H2S concentration.

We are in the midst of a generational shift taking place right before our eyes. With this shift, America's workforce is changing, and rapidly. According to the Pew Research Center, Millennials have surpassed Baby Boomers as the nation's largest living adult generation. This trend is expected to continue through the 2030s as the millennial generation continues to grow and join the workforce while Boomers continue to age and retire. The impact of this ongoing transition is felt in nearly all segments of the economy, including the utility industry. Vast amounts of knowledge and experience are walking out the door as retiring employees look to start new chapters of their lives. In too many cases, this is happening without that valuable knowledge and insight being imparted to the next generation of utility professionals. As a critical component of the utility management infrastructure, especially during and after the COVID-19 public health crisis, water utility leaders need to be thinking proactively and strategically about ways to effectively leverage aging employees as a valuable resource and develop a succession plan to ensure future continuity within the organization. This session will provide historical and projected labor force data and emphasize the importance of growth, development and learning for employees from onboarding through retirement. We will demonstrate what a strategic talent management process looks like in today's environment and review the stages of developing and implementing an effective plan. The speakers will highlight the benefits of strategic talent management for both current success and future sustainability. Key learning objective: Discuss and demonstrate the importance of an effective talent management program for water utilities, including an understanding of the full talent management lifecycle from talent acquisition (workforce planning, recruitment, selection), through talent development (onboarding, training, performance management), talent retention (leadership development, employee engagement, rewards and recognition) and talent sustainment (succession planning, knowledge transfer). Participants will learn about the critical stages of talent management and understand the essential components of a strategic talent management program, along with leading industry practices to help utilities successfully manage changing workforce challenges.

Abstract: Introduction: The San José-Santa Clara Regional Wastewater Facility (RWF) provides secondary and advanced tertiary wastewater treatment for the cities of San José and Santa Clara, California and multiple tributaries. The RWF is co-owned by the cities of San Jose and Santa Clara, and is operated by the City of San Jose (City). The RWF has a rated capacity of 167 million gallons per day (MGD) and processes wastewater solids using anaerobic digestion. The RWF has used cogeneration engines for over 30 years to provide heat and power for the facility. However, the existing cogeneration system reached the end of its useful life. The City decided to replace the existing cogeneration engines with an updated system to continue providing the RWF's heat and power demands as part of its commitment to sustainability. The San Jose Cogeneration Facility Project was designed and constructed through a progressive design-build process. The design was centered around four 3.5 MW internal-combustion, engine-driven generator units. The Cogeneration Facility is shown in Figure 1 and the engine room in Figure 2. Table 1 is a project fact sheet with key specifications. The 14 MW system has the capacity to meet the projected RWF electrical demand of 13 MW in 2040. Space for a fifth 3.5 MW unit is provided to have a firm capacity of 14 MW in the future with one unit out of service. Experience throughout the planning, design, construction, and commissioning of the project is shared. Insights discussed: -Early selection and procurement of cogeneration units -Integration of cogeneration with standby power systems -Biogas treatment and management -Fuel blending of biogas with natural gas (and provisions for future landfill gas) -Emission requirements met with post-combustion treatment -Heat recovery and management -Business-case decision making throughout the project -Startup considerations Discussion: The project included early selection of the cogeneration and gas treatment systems in the initial design stage. By selecting the equipment early in the design, subsequent design stages were tailored to known specifications. The cogeneration units were selected through an evaluated bid process that quantified the value of electrical efficiency, fuel blending capability, gas compression requirements, cost of parts, and maintenance requirements (triple bottom line analysis). The cogeneration facility is integrated with two separate utility power feeds and standby generators. This integrated power system provides a reliable power supply for the RWF. Protective relays were included to meet the electric utility interconnection agreement and allow for excess power to be supplied to the utility grid if necessary. The design provides for supplemental natural gas to be replaced with landfill gas in the future. Because of the significant amount of natural gas required (as much as 50 percent of the fuel energy content), prior to landfill gas availability, to meet the plant power demand, these cogeneration units need to meet the stringent Bay Area Air Quality Management District (BAAQMD) emission requirements of a natural gas fueled cogeneration system. Digester gas treatment protects both the engines and the engine exhaust gas treatment equipment. The biogas treatment system is shown in Figure 3. Biogas treatment includes hydrogen sulfide removal (initially iron sponge, now a proprietary media), moisture reduction, siloxane removal via activated carbon, and particulate removal. In this case, gas treatment followed gas compression and moisture removal. Consequently, the gas treatment occurs at a relatively high pressure of 50 psig. Provisions for the incorporation of future landfill gas were also included in the piping design. Each engine is equipped with a dedicated gas blending system to allow operation using any blend of biogas and natural gas. The gas blending system responds to changes in digester gas production (via gas holder level) to achieve a power output setpoint without requiring a system shutdown, though the peak power output of a cogeneration unit reduces as the natural gas quantity increases. Exhaust gas treatment was provided to meet BAAQMD emission limits. Exhaust gas treatment consisted of selective catalytic reduction (SCR) for nitrogen oxide (NOx) reduction and an oxidative catalysis for carbon monoxide (CO) and volatile organic carbon (VOC) reduction. The most difficult contaminant to treat was NOx. The BAAQMD requirements limited the facility to 0.124 g/bhp-hr, compared to federal requirements of 1.0 and 2.0 g/bhp-hr for natural gas and biogas fueled engines respectively. Heat generated by the cogeneration units is recovered from the engine and exhaust gas to provide process heating demands as well as selected building heating. New dual-fuel auxiliary boilers provide supplemental and backup heating for the RWF. Rejection of low temperature heat that can't be beneficially used is provided by cooling towers. The anaerobic digestion system at the RWF is being converted from mesophilic anaerobic digestion to a temperature-phased anaerobic digestion (TPAD) system. The heat supply system was designed to accommodate the higher temperatures and heat requirements for the TPAD system. The heat recovery and hydronic heat supply system was coordinated with the TPAD project team to meet the heating demands both in terms of temperature and amount of heat while maximizing heat recovery from the engines. Using the progressive design-build delivery method enabled collaboration between the Owner and the Design-Builder, particularly during the early design stages. Approximately halfway through preliminary design, it became clear that the project required value engineering to reduce costs within the City's budget. Approximately 20 percent of the project cost was reduced through a value engineering effort with the City and the Design-Builder. Business case evaluations were conducted throughout the project for decision-making based on meeting multiple objectives of economic, environmental, social, and operational categories. Life cycle cost to benefit ratios were compared for different options to guide selecting the best option. There were several startup procedures that could be followed on other projects. The biogas treatment system was tested and commissioned using the boilers prior to sending treated gas to the engines. The engines were started on natural gas first to test ancillaries prior to running on biogas. Lessons Learned: -Early selection of cogeneration units and gas treatment system enables an efficient design process -Integrating the utility power feeds with the cogeneration units and standby generators results in a reliable plant power supply -Additional exhaust gas treatment (such as oxidation catalysts and selective catalytic reduction) can be used with comprehensive biogas treatment to meet strict air quality management districts. -A fuel blending system for biogas and natural gas, provides operating flexibility -Heat recovery from the engines can be designed to be compatible with a higher temperature thermophilic digestion process. -Costs can be controlled during design with a progressive design build procurement and value engineering.