Conference Papers

Our linear infrastructure requires regular maintenance, refurbishment, upgrades, and sometimes. replacement, for it to continue to effectively serve our communities. In order to properly care for this aging infrastructure, sewage bypass projects are frequently a critical component of many of these linear infrastructure projects. Temporary bypass systems is the typical solution to transfer water and sewage flow and maintain uninterrupted service during the necessary bypass of the existing infrastructure. The unfortunate side effect of this type of bypass project is frequently an increased release of hydrogen sulfide and other sewer gasses. These gases can cause a nuisance for the surrounding community via increased odor release. Also important, these gases can cause corrosion to concrete, metals and electrical components not intended to be exposed to sewer gases, potentially shortening the useful life of critical infrastructure. Most critically, however, Hydrogen Sulfide and other sewer gases are frequently found at concentrations toxic to human health, frequently reaching fatal concentrations in sewer systems. Open access points in sewer network, plus additional turbulence at the downstream discharge point all contribute to increased exposure to the environment of the gases that would otherwise be contained within the sewer system. Sulfide control at bypass pumping has traditionally involved a fan and undersized activated carbon canister that requires frequent replacement. There are a range of better suited solutions that can be implemented to effectively manage the sewer gas releases challenge. This paper will discuss the challenges of designing and implementing a sewage bypass pumping service and the merits of implementing effective sulfide control measures for any bypass operation including the use of liquid phase chemical treatment and foul air scrubbing technologies. The available technologies will be reviewed, and examples of best practice application will be discussed. There is no single perfect solution for sewer bypass sulfide control, and the appropriate technology combination is often project specific. The vapor phase technologies suitable for bypass pumping most commonly include appropriately sized activated carbon systems and packaged biofiltration technologies. Other vapor phase technologies such as chemical scrubbing may not be suitable due to the complexity of operation and project site requirements but may suit some specific bypass pumping sulfide challenges. In addition, either instead of or supplemental to the vapor phase technologies, a range of liquid phase technologies can be utilized to reduce the release of the sulfides into the gas phase, thereby improving the work environment for those involved in the upgrade project and making the management of sulfide gas release less challenging. These liquid phase technologies include sulfide capture, alternative biological oxygen sources, fast acting oxidants and pH adjustment technologies. The reader will learn that a comprehensive sulfide control strategy allows for the effective mitigation of hazardous, odorous and corrosive sewer gasses, minimizing the impact to our communities during maintenance or capital improvement activities both at the project site and at downstream discharge points.

Summary The pandemic hit Englewood at a time of dynamic change. Under new leadership, the City's Utility Department was in the midst of developing innovative solutions to address the aging water and wastewater infrastructure while maintaining customer affordability. Transformational change was necessary to establish a new baseline for level of service, and nothing was left untouched from the planning philosophy, prioritization of capital projects, financing alternatives and major adjustments to utility billing. Even the communication to City Council and the Water and Sewer Board was adapted to garner support for the City's new approach from the governing bodies and ultimately from customers. A series of informational presentations were made to City Council following the development of the master plans, and coupled with the financial evaluation, the case was made towards a defendable adjustment of rates and fees with a plan to invest over $140 million in the systems over the next five years. Addressing capital needs, taking advantage for new types of funding, implementing major changes to billing structure and procedures, and evaluating the impacts on customers, all hinge on a utility's ability to analyze the past and develop meaningful projections of the future. Englewood was able to accomplish its objectives in spite of the disruption introduced by the pandemic, and the results may be instructive to utility managers coping with similar disruptions in the future. Abstract The City of Englewood, Colorado serves about 11,000 water service connections and over 40,000 sewer service connections in areas just south of Denver. The City's water and sewer utilities survived for many years with little to no rate adjustments, but with significant capital investment needs uncovered by the City's master planning process, the City engaged in a financial planning and rate study process to meet its long-term financial obligations. The master plans resulted in a Capital Improvement Plan for the water and sewer systems that programmatically addresses the City's largest vulnerabilities. Prioritization of capital investment and optimizing operational strategies of the existing systems were important steps to develop a feasible and affordable plan. The City implemented a long-term financial plan incorporating debt and cash funding opportunities supported by modest, annual rate increases to maximize the Utility's financing capacity. The financial planning and rate studies (yes, multiple rate studies) included evaluation and implementation of a new water rate structure, tapping into all available financing tools, and transitioning from quarterly billing to monthly billing for many customers. This presentation will introduce each area of innovation the City considered in its financial overhaul. The master plan 'wish list' and the process City staff used to narrow down key desirable projects, such as lead service line replacements and water taste and odor improvements, will be described. The dynamic financial planning process will demonstrate how master planning and financial planning go hand-in-hand, especially in a time of disruption in customer demands. Further, financing decisions and the detailed process of applying for a WIFIA loan, will be described with a focus on data needs and on the management implications to the utility. Key decision points and lessons learned will be discussed and offered. Technical Content Through the use of dynamic financial tools, impacts of master plans, funding decisions including use of a Water Infrastructure Finance and Innovation Act (WIFIA) loan, converting flat rate water customers to volumetric billing, implementing a new billing system, and changing base billing practices from quarterly to a monthly schedule and customer bill impacts were evaluated. The City's consultants worked closely with City staff to customize financial forecast that minimized impacts on customers' bills. The Water and Sewer Board reviewed each step of the process prior to City Council consideration and acceptance. Project Status The Master Plans were developed in 2019 for the Water Fund and Sewer Fund, as well as for South Platte Renew, the water resource recovery facility co-owned with the City of Littleton and the third largest wastewater treatment facility in Colorado. Rate studies for South Platte Renew and the City's water and sewer funds were completed in 2020. The water rate structure was materially modified with a new monthly Capital Improvement Fee and increases to the variable charges. Moving into year three of implementing this change, budgets and rate increases for 2022 will be implemented, the WIFIA loan is expected to be closed in early 2022 and major components to the capital investment will be underway at the time of this presentation. Benefits and Significance Not every utility has access or the means to completely evaluate its financial sustainability. The City of Englewood proves a small to medium-sized system can thoughtfully change its approach to planning, structuring, and recovering costs. Further, the project demonstrates the ability of a focused process to achieve substantial change in the face of operational disruptions and uncertainty regarding changes in usage patterns. Finally, it demonstrates the ability of a project team to increase financial resilience while successfully maintaining a focus on affordability implications. Additional Co-Authors: Roger Austin, Vice President, Hazen and Sawyer Carol Malesky, Principal, Stantec Consulting Services Inc. Siyuan Rao, Senior Consultant, Stantec Consulting Services Inc.

NEW Water, the brand of the Green Bay Metropolitan Sewerage District, has completed a program, with initial planning starting in 2008, to replace its biosolids management system at the Green Bay Facility (GBF) in Green Bay, Wisconsin. The facility is permitted to treat 49 MGD of wastewater and process biosolids from the GBF and waste activated solids from their other wastewater facility, the DePere Facility (DPF). The GBF was constructed in 1975 and included a thermal conditioning system (TCS), belt filter press dewatering and two multiple hearth furnaces (MHFs) to process wastewater solids. This process train was chosen because agricultural land application in Wisconsin was deemed not to be practical. Subsequently, the TCS was shut down and in 2008, NEW Water took over operations of the DPF. The almost 40-year-old GBF did not have sufficient treatment capacity into the future and the equipment required replacement due to its age and increasing maintenance costs. In addition, the existing MHFs would not meet the pending federal Clean Air Act Maximum Achievable Control Technology (MACT) air pollution regulations for sewage sludge incinerators (SSIs) that became effective in 2016. Between 2008 and 2011, NEW Water and CH2M (now Jacobs) developed a Solids Management Facility Plan that evaluated numerous solids processing technologies and process trains to respond to these issues. Seventy-three solids unit processes were considered, some were eliminated and the remaining 52 unit processes were used to develop 17 process configurations. Of these 17 configurations, six alternative configurations were selected and evaluated in detail. The Digestion with Thermal Processing and Electrical Generation alternative was selected and later named the Resource Recovery and Electrical Energy Project, or R2E2. The R2E2 process flow configuration, shown in Figure 1, is an integrated solids processing system comprising mesophilic anaerobic digestion (MAD), dewatering and fluidized bed incineration with waste heat recovery (WHR). MAD was chosen as a first processing step to generate biogas for combined heat and power (CHP). High strength liquid organic wastes are co-digested in the MAD process to enhance biogas production and maximize power production and waste heat utilization. Dewatering using centrifuges, followed by fluidized bed incineration was selected as the most efficient method of managing the biosolids, given there is not land within economical distance of Green Bay for agricultural utilization. The fluidized bed reactor (FBR) is equipped with a partial scalping dryer, utilizing waste heat recovered from the FBR and using thermal oil to ensure autothermal combustion. Phosphorus is recovered from the dewatering centrate to produce a fertilizer product. In addition, beneficial uses of the residual ash are being pursued. The CHP, dewatering and FBR equipment trains were purchased and the balance of plant design completed in 2014. Construction commenced in August 2015 and commissioning and performance testing were completed by the end of 2018. Figure 2 shows operating data from the startup of the two digesters through August 2019. The system has been operating since November 2018, as an integrated system. Figure 3 shows a summary of the system energy distribution and usage at the design year of 2035 at annual average wastewater flow conditions. The R2E2 project is expected to generate more than 65% of the GBF projected electrical power requirements in 2035 using biogas only and up to 85% using supplemental natural gas to the full CHP loads. With the system thermal efficiency of about 60% based on heat recovered, the R2E2 project will meet NEW Water's goal of producing electricity in the most efficient way while maintaining autothermal combustion. The paper will discuss the energy recovery and production performance of the facility during the two years of full operation, including the Covid-19 period. Since operation of both digesters commenced, NEW Water has initiated its program of importing high strength organic waste (HSW) and has been increasing quantities to achieve design quantities. Biogas production has increased, with increased electricity production of green energy. The monthly biogas and natural gas electricity production, together with the monthly HSW imported quantities and generator run times in the first year are shown in Table 1. As part of the energy management system, SCADA options allow determining when is the optimum time to operate the CHP and the number of units to operate to reduce demand and other electrical charges. NEW Water continues to optimize energy production with waste heat recovery and matching plant heating requirements. The presentation will be of interest to municipal plant operators, wastewater utility managers, planners and design engineers who are considering integrated biosolids processing systems to maximize energy recovery and provide resource recovery opportunities.

Purpose: Lift stations and force mains are essential to any wastewater collection system. Lift stations and associated force mains operate in a highly corrosive environment, typically subjected to widely fluctuating flows and pressure surges that affect force main integrity. Lift station and force main design seeks to avoid common damage modes, including H2S-induced corrosion and solids accumulation, but rarely benefits from the physical assessment of the installed and operating system to evaluate design robustness. The current study outlines the design and operational enhancements of lift stations and force mains as identified during the condition assessment of Lift Station 43 (LS 43) in the City of Phoenix (City). The City owns and operates 28 lift stations and approximately 72 miles of force mains, including approximately 62 miles of 12-inch and larger force mains. A comprehensive condition assessment of the LS 43 force main was performed as part of the city's ongoing efforts to understand and minimize the risk associated with buried infrastructure. The LS 43 force main conveys wastewater approximately 1.5 miles from LS 43 on 75th Avenue south of Southern Avenue along 75th Avenue to Broadway. The force main has three barrels constructed of 24-inch diameter ductile iron pipe referred to as Barrels 1, 2, and 3 and experienced two breaks associated with air accumulation. A comprehensive assessment was completed, including hydraulic modeling, CCTV, and electromagnetic (EM) inspection. The study's results can be adopted to improve the service life of not just LS 43 but any future lift station and force main. Benefits: The LS 43 assessment identified best practices to improve lift station and force main hydraulics and service life. By utilizing hydraulic modeling with different pump states, the assessment identified the areas of negative pressure and gas buildup. The results of hydraulic modeling were confirmed via CCTV assessment, which showed the presence of a miscellaneous waterline in the force main. This revealed that incorrect ARV placement obstructed the efficient functioning of the lift station and force main. This presentation will benefit that industry by outlining the factors contributing to air accumulation and remedial measures to address the concern. The presentation will also discuss design modifications such as the location and elevation of air release valves (ARVs) and the type of ARVs the industry should adopt to improve the life of the force mains. Additionally, EM assessment determined internal corrosion below the springline caused by solids accumulation, an infrequently considered damage mode for ductile iron pipe in force main service. Suspended solids in wastewater can settle in the force main and develop areas of microbially induced concrete corrosion (MICC). Efforts to allow for maximum future capacity in the initial design had resulted in low velocities and solids accumulation. Cleaning tools are regularly employed to dislodge accumulated solids, but the lift station and force main designs rarely allow for easy launch and retrieval of a cleaning tool. Additionally, there is no clear guideline on the cleaning frequency to improve the system's service life and reduce operational costs. The study aims to discuss the velocities needed to prevent solid accumulation, as well as the frequency and essential design modifications necessary to support regular cleaning. The recommendations presented in this study can be applied universally to any lift station and help the industry develop designs with cleaning and maintenance requirements in mind. Status of Completion: The investigation work to address ongoing air accumulation and internal corrosion issues is 100% complete. Results indicated the flow velocities and cleaning methodologies the City should utilize to prevent further internal corrosion and location for ARVs installation to prevent air accumulation. The City is in the process of procuring a consultant to design the recommended improvements. Conclusion: The City will now be able to allocate necessary funds for regular force main cleaning, identify locations of concerns, conduct regular maintenance, improve lift station efficiency, and improve service life. In conclusion, the study has identified best practices to improve lift station and force main hydraulics and service life. These best practices can be used to improve future force main designs.

Since January 1999, Onondaga County, New York has been complying with an Amended Consent Judgment (ACJ) which includes control of combined sewer overflows (CSOs) to the tributaries of Onondaga Lake. In November 2009, the ACJ was again amended to incorporate green infrastructure (GI) strategies to further reduce wet weather from entering the combined sewer system (CSS) along with requiring other upgrades at the Metropolitan Wastewater Treatment Plant (Metro). This was the first court order in the country to require the use of GI, and the new program was named Save the Rain. Since 2009, Save the Rain has resulted in the construction of over 230 GI projects and more than 10 large-scale gray infrastructure projects and four small-scale, yet significant system optimization projects. Overall, the County has achieved the remarkable milestone of 98.1% CSO capture and elimination to date while also significantly improving water quality in Onondaga Lake and it's CSO-receiving tributaries and increasing resiliency in the combined sewer system. This presentation will highlight how utilizing both GI and gray infrastructure has provided the County with the opportunity to not only abate CSOs, but also increase conveyance capacity and resiliency in a combined sewer system that dates to as early as the 1850s. Discussion topics will include: - The County's standards for enhanced CSO abatement design including over-designing systems to ensure that they are designed for managing the storms of today and the future. In an ever-changing world due to the effects of climate change, the County's efforts to plan ahead to design for the storms of the future are an excellent example of building resilience into conveyance systems. - Stormwater quantity monitoring results of completed GI projects indicating greater than expected performance. Volumes into and out of several GI projects were metered to demonstrate GI's performance to the regulators. Findings from the metering period versus the original design intent will be provided along with a summary of the important conclusions that were made regarding the effectiveness of GI. - How the inclusion of GI allowed the County to decrease their total financial commitment without sacrificing CSO abatement goals. GI has been found to be more cost-effective than traditional gray infrastructure in the County's CSO abatement program. By constructing more GI, the overall program expenditures have been less than originally budgeted allowing the County to do more and go further with the program. The specific cost savings of GI vs. gray infrastructure will be provided allowing the attendees to takeaway information that will be extremely valuable for their own stormwater and CSO programs. - Oversized design of the Clinton and Lower Harbor Brook CSO Storage Facilities providing a total 11.4 MG of CSO storage. By oversizing these two facilities the County has planned for the future with larger facilities capable of managing larger storms. Examples will be provided for larger storms that have occurred since the facilities were operational showing the benefits of oversizing the facilities. - The financial impacts of oversized GI and gray infrastructure designs and how the County creatively managed available funding to the greatest extent possible. - Other methods developed by the County for resourcefully increasing capacity within the combined sewer system including required stormwater offsets for private development. Within the combined sewer system, the County requires a 2:1 offset. That is, for every 1 gallon of sanitary flow added to the system, 2 gallons of flow must be removed. Developers have been creative in meeting this requirement by installing GI, lining sewers, lining manholes, gray water usage. - Projections of system performance during extreme events and future climate change utilizing the County's combined sewer system SWMM model. The SWMM model has been an incredibly useful tool for planning projects and assessing system performance. The methods in which the model has been utilized along with results will be provided.

The City of Windsor (City) owns and operates two municipal wastewater treatment plants; the Lou Romano Water Reclamation Plant (LRWRP) and the Little River Pollution Control Plant (LRPCP). These facilities provide secondary level treatment for municipal and industrial wastewater from the City of Windsor, ON and the neighboring Municipalities of Tecumseh and LaSalle. The LRPCP and LRWRP produce approximately 2,400 and 8,500 dry tons per year of residual wastewater solids, respectively. Under the current management strategy, the residual solids at each facility are dewatered by centrifuge (to a dry solids content of ~ 28 %) and transferred to the City-owned Windsor Biosolids Processing Facility (WBPF). At the WBPF, the dewatered sludge cake is thermally dried and pelletized to produce a fertilizer product which is registered under the Canadian Federal Fertilizer Act and sold throughout Southwestern Ontario, Canada. The WBPF has multiple drawbacks including utilizing an energy intensive drying process, aging infrastructure and equipment, and is not expected to be capable of accommodating future wastewater residual projections. In recent years, there has been increasing attention paid to managing the organic fraction of municipal solid waste. In an effort to divert organic material from the landfill, many municipalities have integrated organics management programs, which involves co-processing wastewater residuals with the diverted municipal organic wastes. In addition to the environmental and cost benefits of diverting and combining these waste streams, this process maximizes the recovery of their remaining value in the form of electricity, thermal energy, and/or fuel. Environmental benefits of diverting organic materials from landfills include reduced methane emissions, decreased leachate discharges, and opportunity for energy recovery from waste. Similar to the California program, the Ontario Ministry of the Environment, Conservation and Parks requires 70 percent of organic waste to be diverted from Ontario landfills by 2025. The City of Windsor does not currently have an organic waste collection program in place; therefore, a program is in development. The source separated organic waste materials which may potentially be accepted through this program include municipal food and organic waste; institutional, commercial, and industrial food and organic waste; agricultural organic waste; and high strength waste (HSW) such as food processing waste, dairy waste, and fats, oils, and grease. To address future biosolids management needs and comply with regulatory requirements for organic waste diversion, the City of Windsor completed a comprehensive study to develop an Integrated Biosolids and Organics Management Strategy. This study presents the complete planning and evaluation process for the Integrated Management Plan including the identification of the opportunity and evaluation of alternatives as well as a review of biogas potential, energy savings, and GHG reductions through anaerobic digestion and biogas utilization. To select the recommended management strategy, the following three alternatives were compared: (1) improvements to the existing WBPF, (2) composting, and (3) anaerobic digestion. The evaluation included social and cultural environment criteria, natural environment criteria, technical / suitability criteria, and economic criteria. Anaerobic digestion was identified as the preferred alternative as it provides the ability to process wastewater residuals in a less energy intensive way for improved energy recovery from waste, biogas production, and reduced GHG emissions. Additional benefits of an anaerobic digestion facility includes: that it has smaller land area requirements; proven and reliable process operation; higher potential for federal and provincial grant programs; is consistent with the City of Windsor's Community Energy Plan and Climate Change Action Plan; and results in the production of a well stabilized finished product suitable for farmland application. Under this strategy, the wastewater residuals and organic waste would be processed at a centralized anaerobic digestion facility with biogas utilization via a combined heat and power (CHP) unit. Figure 1 outlines the proposed process schematic for this alternative. Table 1 shows the feedstock quantity, volatile solids (VS) loading, and biogas production for each feedstock material. Feedstock quantity for the LRPCP and LRWRP is presented based on historical mass of wet dewatered sludge cake measured from 2016 to 2020. It is estimated that an average of 10,300 wet tonnes of source separated organics (SSO) and 22.7 m3/day of HSW could be collected throughout the City of Windsor and processed at the proposed facility. The biogas production from digesting sludge is estimated to be 2,050 m3 biogas/day and 6,950 m3 biogas/day for LRPCP and LRWRP, respectively. Co-digestion would increase the total biogas production by approximately 50% with 1,350 m3 biogas/day from HSW and 3,600 m3 biogas/day from SSO. Table 2 shows the energy balance for the LRWRP and LRPCP with the projected energy production from anaerobic digestion and biogas utilization. The energy consumption presented incorporates the historic energy consumption at the LRWRP and LRPCP and projected energy consumption required for thickening, dewatering, and anaerobic digestion. The energy produced from anaerobic digestion of sludge would amount to 40% of the energy required to operate LRWRP and LRPCP. Co-digestion with HSW and SSO would increase this contribution to 62% of the total energy required to operate both plants. In addition, Table 2 shows the effect that anaerobic digestion and biogas utilization had on GHG emissions for LRWRP and LRPCP. Anaerobic digestion of sludge reduced GHG emissions by 1,400 tonnes CO2e/year and 400 tonnes CO2e/year at the LRWRP and LRPCP, respectively. Co-digestion would reduce GHG emissions further to 3,300 tonnes CO2e /year, which corresponds to approximately 36% reduction in GHG emissions. Based on this evaluation, significant energy savings and GHG reductions can be achieved through anaerobic co-digestion of wastewater residuals and organic waste. This solution would move the LRWRP and LRPCP towards a net-zero energy future, provide energy savings to the City of Windsor, and reduce GHG emissions via onsite energy generation and biogas utilization. This integrated management approach will allow the City to meet the regulatory organics diversion requirements and address biosolids management needs for the two wastewater treatment plants. The operation and maintenance cost for the facility would be approximately $1,400,000 CAD/year; however, this would be offset by fertilizer revenue (~ $1,400,000 CAD/year) and electricity savings ($3,000,000 CAD/year). The opinion of probable cost for such an anaerobic digestion facility is approximately $151,000,000 CAD (inclusive of contingency and engineering allowance; exclusive of taxes). There are several government rebate programs available which help to facilitate municipalities implementing waste diversion programs and adopting technologies that generate clean affordable energy.

PURPOSE City of Atlanta Department of Watershed Management (DWM), through its Clean Water Atlanta (CWA) Program, is required by the ongoing First Amended Consent Decree (FACD) to develop Remedial Measures Reports (RMRs). RMRs are planning and conceptual design documents providing the basis of design for detailed design and construction plans for capacity relief and sewer structural rehabilitation projects. In parallel, DWM developed Watershed Improvement Plans (WIPs) for major watersheds in the City. The WIPs identified stormwater projects to improve water quality and reduce the volume of stormwater discharged to the city's creeks. Custer Avenue, Clear Creek, and Intrenchment Creek are three of Atlanta's combined sewersheds that collectively are served by more than 707,000 linear feet (134 miles) of combined sewers. To reduce CSOs and minimize urban flood risk, the RMRs identified approximately 164,000 linear feet of sewer requiring either capacity relief or sewer rehabilitation with an estimated capital cost of $201.1 million. The RMR defined projects were collectively referred to as 'gray' infrastructure projects. Concurrently, approximately 1,100 stormwater water quality and control infrastructure projects were identified city-wide, through the WIP process, at a total estimated capital cost of approximately $600 million. Collectively WIP projects were termed 'green' infrastructure projects. Considering the significant capital costs of the identified green and gray projects, DWM requested that the Program Management Services Team (PMST), under the lead of Stantec Consulting Services, undertake a project to answer three simple questions: 1. Would it be possible to integrate green infrastructure with the planned gray infrastructure projects to address combined sewer overflow (CSO) and sewer flooding problems in three combined sewersheds? 2. Would it be possible to reduce the capital cost of current RMR plans without impacting future levels of service? 3. Would solution optimization modeling present an opportunity to increase environmental and community benefits in line with wider DWM 'One Water' objectives? METHODOLOGY To answer the questions all applicable green and gray projects to DWM's existing InfoWorks ICMTM hydraulic and hydrologic models. Green projects that would not directly influence combined sewer flows were omitted. Only green projects, if implemented strategically, that could have a beneficial outcome in reducing CSO activations and reducing urban flood risk were included. PMST and DWM have utilized the hydraulic and hydrologic models for a wide range of engineering planning and design activities for more than 20 years and, as a result, the models are well populated, reliable, detailed, and were able to provide an excellent level of detail to start the optimization. The updated InfoWorks ICMTM models were then imported into a cloud-based optimization software, OptimizerTM. OptimizerTM is a genetic algorithm software designed to solve complex multi-criteria problems faster and more efficiently favoring speed of process over absolute accuracy. For this project OptimizerTM was applied to analyze hundreds of thousands of green and gray project combinations to establish the 'best outcome'. After establishing a baseline plan, OptimizerTM varied the size, scale, and combination of all possible solutions to create new plans for comparison against the baseline using three metrics: capital cost, hydraulic performance, and non-cost benefit. Each metric was applied as detailed: Capital Cost. The incremental capital cost of each project was calculated and entered OptimizerTM as a lookup table. During optimization, as project scales and sizes adjust, so do the costs. For gray projects, the increments related to pipe diameter, pipe depth, storage tank volume, etc. and where applicable, construction technique. For green projects, the increments related to the relative size of the solution based on its ability to capture an amount of rainfall runoff volume using rainfall depth and contributing area. Hydraulic Performance. Hydraulic performance was measured by applying hydraulic penalty scores to threshold exceedances in the model's predicted hydraulic grade line (HGL) and flood volume. Penalties were proportional to the exceedances and applied to to every combination of gray and green projects, OptimizerTM tried to achieve the best hydraulic performance by converging on the lowest total hydraulic penalty score. Co-benefits. Infrastructure value is an important criterion for DWM, this metric was designed to evaluate the value of all gray and green infrastructure to ensure OptimizerTM decisions considered the value of all projects. Co-benefits ensured consideration of social, environmental, and economic indicators were included in determining the best outcome. The principles applied to all projects was consistent with DWM's Triple Bottom Line (TBL) categories across all watershed initiatives. With all project information, including metrics uploaded to OptimizerTM, the optimization process was repeated more than 100,000 times to continually seek convergence, each time attempting to find a 'better' green / gray plan based on the metrics. RESULTS Unlike many models, OptimizerTM creates several potential outcomes and there were many combinations of green and gray plans that offered a broad range of possibilities. Some plans performed hydraulically better, some less expensive, and some realized much greater co-benefits; however, no single plan was deemed to be 'optimal'. Results were presented in the form of a three-dimensional (3-D) Pareto graph from which a subset of potential plans were selected. The dimension axis representing capital cost, hydraulic performance, and co-benefits. The 3-D Pareto graph showing possible plans is depicted in Figure 1. DWM were able to select a preferred plan for each combined sewershed. The selected plans and their relative costs are summarized in Table 1. CONCLUSIONS In conclusion, the Green/Gray Optimization project was able to positively answer all three stated questions. 1. Would it be possible to integrate green infrastructure with the planned gray infrastructure projects to address CSO and sewer flooding problems in three combined sewersheds? Yes, it is possible. The project demonstrated there were effective green alternatives for all three combined sewersheds with WIP projects making up 4% of the total capital cost in Intrenchment Creek, 6% in Clear Creek and 31% of the total capital project cost in Custer Avenue. 2. Would it be possible to reduce the capital cost of current RMR plans without impacting future levels of service? Yes, in all three combined sewersheds, cost estimates were lower. Custer Avenue's selected plan was 39% less expensive; Clear Creek's was 16% less expensive; and Intrenchment Creek's was 52% less expensive. In all cases, the hydraulic performance of the selected plans was better than the original RMR plan. 3. Would solution optimization modeling present an opportunity to increase environmental and community benefits in line with wider DWM 'One Water' objectives? Without question, the inclusion of green projects adds enhanced environmental and community benefits to the overall outcomes for DWM and better aligns with City wide objectives to move to a 'One Water' approach that values all water. Further, these co-benefits are added without compromising sewer system performance.

The District of Columbia Water and Sewer Authority (DC Water) currently oversees over $7.5 billion in assets and manages a ten-year Capital Improvement Program (CIP) with a budget exceeding $5 billion. To that end, DC Water launched a District-wide inspection program in the Spring of 2022 that aimed to inspect 40 miles of sanitary and combined sewers between 12 and 60 inches in diameter each fiscal year. Findings from these inspections would be used to identify and prioritize assets for rehabilitation under the CIP. Performing inspection work in any major city is no easy feat. Performing inspection work in the District of Columbia, one of the most densely populated cities in the United States that also houses a plethora of federal agencies and military bases, presented a multitude of unique complications. Along with more typical road blocks such as aging infrastructure leading to emergency repairs and unmapped assets discovered in the field, the surrounding stakeholders and property owners affected by the inspection program included foreign embassies, government agencies, the US Secret Service, Joint Base Anacostia-Bolling, the National Park Service, the Smithsonian National Zoo, the DC Department of Transportation, a prison, and even disgruntled homeowner associations, to name just a few. The project team expertly handled an assortment of communications for permit acquisitions, access coordination, and stakeholder outreach. As if these circumstances were not challenging enough, the procurement timeline resulted in a tremendously accelerated inspection schedule during which 40 miles of inspection work had to be prioritized, performed, reviewed for quality, and invoiced all within the last five months of the fiscal year. Through an innovative use of new software tools, and copious amounts of coffee, this seemingly impossible feat was accomplished on time and on budget. The project team employed several programs and technologies to efficiently process inspection media and data in order to meet the ambitious deadline. T4 Spatial's inspection management platform, t4 Vault, allowed the inspection contractor to easily upload inspection submittals to the quality reviewer. The platform's user-friendly display showing the inspection media and reports side-by-side greatly facilitated quality assurance and quality control (QA/QC) reviews. Additionally, InfoAsset Manager (IAM) was deployed in conjunction with t4 Vault to perform corrections to the NASSCO PACP and MACP databases. IAM also possessed useful capabilities to export tracking sheets documenting the status of inspections and inspection reviews. In the field, the project team employed the use of the Fulcrum app for field inspectors to easily submit daily logs and field entries. Crews also collected GPS using Terraflex. Dashboards using ArcGIS Online were developed to convey the most up-to-date inspection data in an easy-to-understand quantitative and visual format to the utility owner. The inspection program is now wrapping up its second fiscal year of inspections and, to date, has completed over 100 miles of pipe inspections and 3,000 manhole inspections.

Introduction
As impacts of climate change intensify, changes in land development, weather patterns, and sea levels may result in communities having a greater risk of flooding. State, local, tribal, and territorial governments continue to face pressures as they determine how to address the needs of communities to respond to flood hazards. Furthermore, resources for flood risk and stormwater management are often inequitably distributed even though socially underserved populations experience the worst repercussions. The debilitating impacts of disasters on underserved communities have shifted discussions around how to prioritize equity and social justice considerations for stormwater management. Federal agencies such as FEMA and EPA are reassessing current policies, programs, and practices in the field of stormwater management to examine approaches that alleviate inequities. Recent initiatives from state and local governments to address the needs of underserved communities have also informed the development of federal equity initiatives highlighting the importance of planning for stormwater management. Other relevant national shifts such as the White House Justice40 Initiative which requires 40 percent of the overall benefits from federal investments in climate and clean energy to flow to underserved communities and includes programs such as FEMA's Building Resilient Infrastructure and Communities (BRIC), Flood Mitigation Assistance (FMA) and Risk Mapping Assessment and Planning (Risk MAP) programs. Furthermore, Executive Orders 14008 and 13950 address the need to build resilience against the impacts of climate change with a focus on advancing racial equity and support for underserved communities through the federal government. Based on existing federal funding and requirements prioritizing the needs of underserved communities, this paper explores opportunities for stormwater practitioners to advance equity by strengthening green stormwater infrastructure and planning.

Methods
This policy paper utilized two forms of data collection for this analysis--document review and interviews (n=5) with individuals working on stormwater management at the state, local and federal levels. The document review consisted of peer reviewed and grey literature (n=40) and a survey of existing equity tools (n=15) that can inform stormwater management practices. We also collated best practices from state, local and federal case studies (n=8), and recommendations on strengthening equity considerations for stormwater management. Further analysis included examination of community and stakeholder engagement by state, local and federal governments to address environmental justice and equity.

Discussion and Recommendations
This presentation will use examples from the aftermath of Hurricane Ian (Florida, September 2022) and Hurricane Fiona (Puerto Rico, September 2022) to demonstrate the importance of applying an equity lens before, during, and after disasters to address the needs of underserved communities. It will also provide an overview of current state, national and federal initiatives, such as the White House's National Initiative to Advance Building Codes, FEMA's Building Codes Strategy, Building Codes Adoption Tracking Portal and the Climate and Economic Screening Justice Tool to examine opportunities to enhance stormwater management that incorporate considerations for equity and environmental justice. There is limited analysis comparing cases studies across the state, local and federal government that are moving the needle on equity and environmental justice for stormwater management. By examining frameworks that are prioritizing historically underserved communities in all processes of stormwater management, stormwater practitioners can use these tools to strengthen community engagement and equity in planning.

Dynamic olfactometry (ES 137225) is the standard and well-established technique for odor intensity measurements, however it is not adapted for big industrial sites which need continuous monitoring and fast results. Additionally, these sites need to have odor sources identification solutions to ensure proper remediation actions. In the city of Ventspils, (Latvia), the harbour can welcome up to 20 petrol tankers, and the Baltic wind can push the gas and odors towards the city. The municipality does not have the tools neither to quantify nor to identify the sources of pollution and nuisances. In the experiment with the port authorities, an array of WT1 devices was deployed on different sites close to the sources and at the fence line. During the initial training period, the devices were trained with four different types of samples at different dilution levels (black fuel oil, solvent naphta, petrol, kerosene), and a successful correlation model was established following the 13725 standard between sensory measurements with dynamic olfactometry and the WT1 outputs, allowing the quantification of odors as well as the identification with an accuracy superior to a 0,85 R2. Additionally, a PCA (Principal Component Analysis) and a LDA (Linear Discriminant Analysis) were built and the WT1 modules proved to differentiate accurately the different sources of odor and pollution. The RUBIX WT1 gas and odors sensing modules allow not only on-line monitoring of Odor Unit and various gas emissions, but also allow odor fingerprint identification. The paper will present the methodology that combines a range of smart sensors with AI statistical data processing techniques, allowing for the odor sources identification. The experimental plan, including the training with dynamic olfactometry will be described.

The Interstate 579 'Cap' Urban Connector Project and creation of the new three-acre Frankie Pace Park provides a vital urban green space link and repairs broken community connections between Pittsburgh's historic Lower Hill District and the city's downtown business and cultural centers. Over 60 years ago, as part of 1950s and 60s national urban renewal initiatives and interstate highway expansion, over eight thousand Hill District residents were forcibly displaced by the construction of the new Crosstown Boulevard through Pittsburgh's Lower Hill District. The Lower Hill District was a vibrant and primarily Black neighborhood with a rich history of Pittsburgh born Jazz greats and the famous Pittsburgh Crawfords of the professional Negro League baseball. Access to the downtown area was significantly impacted for residents that remained adjacent to the eight-lane highway and its 40-ft deep concrete canyon. The construction of Frankie Pace park is a literal and metaphorical bridge, helping repair broken connections for the Hill District neighborhood residents and spur economic development. The $32 million park was opened to the public on November 22, 2021. The park is named in honor of longtime Hill District resident and community activist, Frankie Mae Pace. The park consists of over 250 newly planted trees, 4000 perennials and shrubs, 0.7 acres of pervious lawn, six (6) terraced rain gardens, 300 linear feet of artistic surface trench drains, and over 500 CY of topsoil placed on top of the cap structure. The 52,000 SF cap over the interstate serves as one of the largest public green roof projects in the region, if not the nation. The design of the cap structure was iterative process considering key design feature such as the weight of the engineered soil, landscaping plans, and potential event spaces on the structure. All these elements work together to capture, detain, and filter stormwater prior to entering the Pittsburgh Water and Sewer Authority's combined sewer system at the bottom of the site. Overall, an estimated 1.5 to 2.0 million gallons of stormwater is managed annually in the park and the lawns can store up to 6 inches of rain during a single rainfall event capturing a total of 2.1 acres of impervious area. In addition to the enhanced stormwater features, the park intertwines artistic and interpretive artwork from local artists allowing park users to learn the history of the Hill District and the importance of stormwater management. The presentation, if selected, will provide a brief history of the historical importance of Pittsburgh's Lower Hill District, an overview of how the project came to be, explain the design and construction of the cap and associated stormwater management features, and quantify the hydrologic and water quality performance of the site through design hydrologic and hydraulic modeling. The presentation will also highlight federal funding opportunities related to highway cap projects including USDOT's Reconnecting Communities Pilot Program. Attached are images of the before and after photos of the site and photos of the trench drain system and tiered rain gardens at the bottom entrance to the park..

Prevalent biosolids management practices treat wastewater treatment facilities as cost sinks, leaving them to pay ever increasing disposal costs for biosolids. Utilizing hydrothermal carbonization (HTC) to convert wastewater solids and organic wastes into valuable products turns wastewater treatment plants into sustainable, revenue producing assets. Hydrothermal Carbonization, or HTC for short, is the cornerstone technology in SoMax BioEnergy's suite of solutions for organic wastes. SoMax BioEnergy's HTC process is a continuous thermochemical process that utilizes moderate temperatures and pressures of ~350F & 430F (180C & 220C) and less than 580 psi (40 bar). The HTC reaction has variable retention times based on the feedstock from as short as thirty (30) minutes and up to four (4) hours. When considering biosolids processing, HTC's greatest advantage is that the reaction takes place in an aqueous environment, eliminating the expensive process of drying biosolids prior to processing. The HTC process + drying of the BioCoal product, uses less energy than drying the equivalent biosolids alone. In fact, HTC uses the water present in the biosolids as the primary reactant to perform chemical reactions. The key reactions that occur during the HTC process are dehydration, hydrolysis, decarboxylation, and condensation, all of which result in a product with higher C:O ratio than original feedstock. Hydrothermal carbonization of biomass generates a biochar-like solid product, known as hydrochar, and a nutrient rich process water. Comparing hydrochar to the original feedstock, it is more easily dewatered, has greater fuel characteristics, sorption capacity, and has added benefits when used as a soil amendment, such as increased fixed carbon and carbon sequestration potential. Research institutes across the globe are creating value added bioproducts from hydrochar ranging from concrete additives, to battery electrodes and activated carbon. Considering alternative methods of biosolids processing (land application, compost, and anaerobic digestion), HTC is the most carbon efficient, creates the lowest greenhouse gas emissions, and utilizes a much smaller footprint. The hydrothermal carbonization thermochemical process is also more robust as it is not subject to the same sensitivity issues biological processes encounter. The Borough of Phoenixville Wastewater Treatment Plant, in Pennsylvania, has partnered with SoMax BioEnergy to build the first commercial scale hydrothermal carbonization facility in North America. While European and Asian countries already utilize HTC to treat organic wastes including woody biomass, sewage sludge, digestate, food waste, and even municipal solid waste, North America has yet to implement this technology. This changes with the Borough of Phoenixville project, which at the time of writing this abstract, has over $1,000,000 in project funding has come from county and state grants and is under construction with commissioning set for Q1 of 2022. At capacity the Phoenixville HTC project will process ~15,000 tons of prepared 15-20% solids feedstock, generating over 1,500 tons (d.b.) of BioCoal (hydrochar). SoMax BioEnergy and the Borough of Phoenixville are implementing a two-stage approach to maximize the benefits of the HTC facility to align with the Borough's sustainability goals. The first stage of the project is utilizing HTC for treatment of sewage sludge within the plant and surrounding wastewater treatment plants to process biosolids. The second stage will expand the HTC feedstock to include food waste from the Borough and surrounding businesses. Stage two includes introducing gasification technology that utilizes the hydrochar as a solid fuel to power the wastewater treatment plant and put electricity back on the grid. The Borough Council and Management team sees electricity generation from waste they would have paid to dispose of as a win-win situation and steps in the right direction to accomplishing their 2035 goal of 100% clean and renewable energy. The Borough of Phoenixville HTC project, when fully realized will generate over 150% of the electrical demand of the WWTP, covering all electrical and thermal demands of the HTC process, while utilizing the excess electricity for other borough owned properties. Over the 20-year project lifespan, it is expected to generate over $35,000,000 in savings with a capital equipment payback period of around 7 years. In Spring of 2020, SoMax BioEnergy's hydrothermal carbonization solution received recognition from the U.S. Department of Energy as a Phase One winner in the Water Resource Recovery Prize and this fall was 1 of 6 Phase Two submissions. Unfortunately, the Phase two winners are to be announced the second week of November, just missing the deadline of the abstract submittal. In this presentation, SoMax BioEnergy will: 1) Introduce the Hydrothermal Carbonization (HTC) technology 2) Compare HTC to the status quo WWTP technologies 3) Share research developments and HTC product applications 4) Use plant data to discuss the impacts of HTC on effluents and overall mass and energy balances of the plant 5) Talk about DEP permitting and pathways forward for beneficial use 6)Discuss the experience that is commissioning a new technology