Results

Summary This paper will share the progressive evaluation and selection of a thermal drying technology for application at the Athens-Clarke County Public Utilities Department (ACCPUD) North Oconee Water Reclamation Facility (NOWRF). The progressive evaluation and selection process was conducted in multiple phases and included: - Confirmation of Sizing Criteria - Evaluation of the 'World of Options' for Thermal Dryers - Screened Technology Assessment Site Visits - Technology Type Selection and Competitive Pre-Procurement Process - Detailed Design and Bidding This paper and presentation will share the progressive process utilized by ACCPUD for the selection of a dryer technology and a technology provider using a combination of cost and non-cost evaluation factors in a multi-criteria procurement process. Confirmation of Sizing Criteria The current plant is permitted for a 14-MGD capacity and uses an advanced activated sludge process for treatment coupled with high solids centrifuge dewatering to produce a cake for landfill disposal. Future plans are to expand the plant by adding primary treatment and anaerobic digestion. Dryer sizing was confirmed against current and future residuals production rate scenarios and a design evaporation of of 4,500 lb-water per hour was selected. Evaluation of the 'World of Options' for Thermal Dryers The first phase assessment included a preliminary screening of the following thermal dryer technologies for possible application of at NOWRF: - Belt Dryers, - Rotary Drum Dryers, - Indirect Paddle Dryers; and - Fluid Bed Dryers Based on the preliminary screening of technologies the belt dryers and indirect paddle dryer technologies were selected for additional screening assessment. Screened Technology Assessment Site Visits Following the preliminary screening site visits were arranged for plant operating and maintenance staff to visit operating installations of the belt and paddle dryer technologies. Site visits were conducted in Pennsylvania, North Carolina and Tennessee to view operating installations and have discussions with facility operators. Results of these site visits will be summarized in the paper and presentation. Technology Type Selection and Competitive Pre-Procurement Process Following the site visits and discussions with facility operators of belt and paddle dryers ACCPUD operations and maintenance staff selected the indirect paddle dryer technology as the most appropriate technology for application at the NOWRF. Based on the preliminary screening of technology suppliers a competitive procurement process was designed that would consider both cost and non-cost factors in the final selection of a technology vendor. The competitive procurement was conducted between the Komline-Sanderson Paddle Dryer and the Andritz-Gouda Paddle Dryer systems based on development of a detailed technical specification describing the system and the minimum required system elements coupled with a preliminary general arrangement drawing for location of the facility on the plant site and integration with the existing dewatering system. The competitive procurement scoring allocated 25% of the scoring points to cost factors and 75% of the scoring points to non-cost factors. Cost based scoring criteria considered the following: (1) equipment capital costs, (2) estimated building costs to house the equipment, and (3) system operating and maintenance costs based on power consumption and thermal energy efficiency of the dryer system. The non-cost factors were allocated to the following major criteria: (1) manufacturer experience; (2) operability and maintainability; (3) air permitting and air emissions rates; and (4) process safety. The paper and presentation will share the results of the cost and non-cost scoring for the selection of the technology supplier. Detailed Design and Bidding Following selection of the technology supplier detailed design activities were initiated for the project. Preliminary design activities included sending a large sample (~ 15 cubic feet) of dewatered cake to the selected technology supplier to test in their pilot plant to confirm heat transfer coefficients and the minimum ignition temperature (MIT) for the paddle dryer. The sludge-specific heat transfer coefficient was utilized to confirm adequacy of the proposed heat transfer surface area. The minimum ignition temperature was used to confirm the paddle dryer thermal oil operating temperature. Results of the pilot testing will be shared in the paper and presentation. Detailed design has progressed through the 'bid ready' stage and the project has been bid and will begin construction in late 2021 / early 2022.

Challenge
The Village of Arlington Heights, Illinois (VAH), is a community of approximately 75,000 residents northwest of Chicago. The Village, located in the Des Plaines River watershed, has a mix of separate sanitary sewers (≈920,000 lf)and separate storm sewers (≈1,100,000 lf) as well as a combined sewer (≈350,000 lf) in the older downtown area. The sanitary and combined flow discharges to the Metropolitan Water Reclamation District of Greater Chicago (MWRD) for treatment while the separate storm sewer system discharges to area streams and waterways. In 2015, the Village's Utility Superintendent realized the Village did not have a robust storm sewer asset inventory and wanted to understand what infrastructure they had, where it was located, and what condition it was in. The Superintendent was planning to retire in four years, and wanted to prioritize building the storm sewer inventory before he retired. Solution/Approach The Village determined that a combination of storm sewer televising (CCTV) and select manhole and structure inspections and surveys would provide the information needed to update the Village GIS with accurate GPS locations, asset attributes, and condition data. RedZone Robotics (RZ), partnering with RJN Group, was selected to perform the CCTV work and the manhole inspections. RJN was responsible for the GIS data integration, manhole rim survey, and measurements at the manholes. The multi-phase project was initiated with a small pilot area and then expanded into four areas covering the rest of the separate storm sewer system, with the intent of completing the inventory in four years. Initially, RedZone's SOLO® pipeline inspection robot camera system was used to record conditions in the manholes and for the 8 to 12-inch sewers. Standard CCTV cameras inspected sewers larger than 12 inches, and multi-sensor inspections (MSI) were conducted in larger sewers with flows present. The primary Village goal for the program was to incorporate all captured findings-asset locations, details, and conditions, including NASSCO PACP ratings-in their in-house GIS to make it easily accessible to Village staff for operations and maintenance programming, and capital planning. This required conversion and integration of data from the standard RedZone ICOM® software deliverable. Work began in early 2016 in the pilot area and continued through the four phases shown in the exhibit above. -CCTV was performed using the SOLO camera, the standard CCTV camera, and the Profiler® (MSI). -Manhole inspections and locates were performed on selected structures designated by the Village. -Inspection data, including connectivity, diameters, materials, and NASSCO ratings, were updated in the GIS. Condition data was used to identify areas with issues and then plan sewer repairs. Challenges Developing a comprehensive storm sewer asset inventory presented unique challenges during data collection and management. -Data Collection Challenges --Dirty storm sewers required extra cleaning. The storm sewers were actually found to be dirtier than typical sanitary sewers. --The SOLO camera could not navigate past much of the debris, which required frequent communication between RZ and VAH. By the end of the project, RZ performed all the sewer televising with a standard CCTV camera instead of the SOLO. --Televising connections between catch basins, inlets, and manholes, proved to be difficult and time consuming; many of these were pulled out of the project. -Data Management Challenges --Coordination between RZ field staff, RZ coding staff, VAH GIS staff, VAH PW staff, RJN GIS staff, RJN field staff, and Village GIS consultant -Initially, three entities were involved in the data coordination: The Village of Arlington Heights (Owner) with two versions of the in-house GIS: one managed by the Public Works Department (PWD) and the other by the Engineering/GIS department. RedZone Robotics (Prime contractor)-CCTV and manhole inspections RJN Group (Sub-contractor)-Manhole survey and GIS -After the pilot phase, the Village GIS analyst retired, and the Village out-sourced their GIS, adding a fourth entity: Municipal GIS Partners (MGP-Village GIS consultant) --Poor initial maps, which are common in municipal storm sewer GIS layers --Map update volumes with complex, multi-party coordination -Incorporating updates involved extensive back-and-forth communications between all parties Updating AssetIDs for pipes, structures, updating connections, VAH field verifying questions, etc. -Making sure all parties are in sync after updates --Incorporation of data into Village GIS, not ICOM -- Staff turnover: VAH, RJN, RZ, MGP Because of the challenges, the program was not completed until December 2022. The Utility Superintendent driving the program did retire in Jan 2021, and the project continued. Only one team member that started the project in 2016 was still involved when the project was completed in 2022!

Conclusion/Recommendations
The asset survey, attribute, and condition data was collected and incorporated into the Village GIS at a slower rate than initially planned. The Arlington Heights storm asset inventory is much improved. The storm sewers were cleaned, and the Village has access to the video, inspection reports, pictures, and ratings provided by the PACP and MACP coding via a single GIS platform. Lessons Learned -Storm sewer CCTV has inherent challenges -Inspection technologies have operating limitations and should be selected with due diligence -Communicate, communicate, communicate -Map updates take time -Better to have the project engineer-led rather than contractor-led.

Following an EPA 308 Letter of Violation in 2014 citing high rates of SSOs within the collection system, Winston-Salem/Forsyth County (WSFC) Utilities identified system condition as a key driver of gravity sewer failures. A rehabilitation plan was quickly developed and implemented to assess and rehabilitate poor condition assets within the system. Five years later the plan has underwent significant changes. By understanding the basis of this program and using the results to date to improve the initial plan, a sustainable long-term collection system has been developed to achieve WSFC Utilities level of service goals. Initial rehabilitation needs were projected using a Statistically Significant Sample Survey (4S) which sampled the variety of pipes in the system to determine which features correlated with the poorest condition. Based on these findings, rehabilitation yield rates were developed for the system. Areas with assets most likely to yield high volume of rehabilitation work were prioritized for assessment and rehabilitation measures were developed based on these asset-specific inspections. This allowed WSFC Utilities to prioritize the inspection of assets most likely to be in poor condition, maximize the number of asset failures identified, and efficiently address these failures to improve overall system condition as quickly as possible. Five years later findings indicated changes from those initial assumptions. Pipes were yielding nearly double the rehabilitation requirements. Additionally, the cost of rehabilitation had begun to escalate quickly. Initial plans were no longer appropriate and needed to be modified to be sustainable over the long-term. Figure 1 shows where data has and has not been collected to date. Using the much larger data set that now included five years' worth of condition assessment data in addition to initial 4S findings, a variety of statistical and machine learning approached were used to update rehabilitation yield rates. The types of rehabilitation required for poor condition assets could now be projected as well. These improvements, combined with updated unit prices, were used to develop a update cost of bringing the system up to target service levels. Updated failure rate projections of initial asset classes can be seen below in Figure 2. Understanding the high levels of investment required to fully improve the condition of the collection system to target levels of service, WSFC Utilities elected to focus their rehabilitation program on the worst performing asset classes. By targeting condition assessment and rehabilitation activities on these poorest condition assets, overall system can be improved most efficiently. Challenges exist in collection of data on these assets only. Throughout the collection system these in-program assets are intermixed with non-critical assets. To assess condition and rehabilitate these in-program assets only would be inefficient. Even for sub-basins with the highest concentration of in-program asset classes non-critical asset data is captured. When accounting for this factor the total cost of condition assessment and rehabilitation for all in-program asset classes is approximately $158M in present value, as illustrated with Figure 3. This cost must be spread over multiple years. Resource constraints, including funding and workforce limitations, prevent the rapid deployment of these rehabilitation activities. However, as the timeline for this investment is extended the system continues to deteriorate. A sustainable long-term rehabilitation plan must invest enough resources to offset normal condition deterioration and improve conditions to target levels of service. By modeling condition deterioration and existing rehabilitation needs, WSFC Utilities can test funding scenarios to develop a plan that balances long-term service needs with financial limitations, as illustrated in Figure 4.

Introduction: Surface waters are challenged by a variety of conditions that may influence the persistence of microbial and viral species of concern. Water monitoring and management practices rely on indicator organisms, and thus it is important to understand how common stressors affect the persistence of indicators and pathogens comparatively. Persistence has traditionally been assumed to follow first-order decay kinetics, but this assumption is potentially over-simplifying a process that is known to be more dynamic than the assumed linear profile. Previous reviews and analyses have identified two and three-parameter models that have been shown to more frequently provide a good fit to persistence data than the exponential model (Mitchell & Akram, 2017; Dean et al., 2020). To explore the applicability of these models for targets persisting in natural surface waters, a systematic literature review and meta-analysis were conducted to assess the availability of datasets for modeling, and to explore the relationship between the observed persistence and the documented experimental conditions. The implications of the first-order decay kinetics assumptions were evaluated by completing factor analyses that relied on only the exponential model to describe persistence, and factor analyses informed by the best fitting models from the tested suite. Methods: A systematic literature review was conducted to identify all available datasets pertaining to indicators and pathogens in natural surface waters that documented the following factors: water type, water temperature, sunlight presence, predation presence, and method of detection. The targets fell into five main groups including fecal indicator bacteria (FIB), bacteriophages, pathogenic bacteria, viruses, and protozoa. Over 650 datasets were identified, extracted or digitized for the meta-analysis. Five models, the exponential (Chick 1908; Watson, 1908), exponential damped (Whiting & Buchanan, 2001), Juneja and Marks 1 (Little, 1968), Juneja and Marks 2 (Juneja, Marks, & Mohr, 2003), and double exponential (Shull et al., 1963), were fit to the datasets. Bayesian Information Criteria (BIC) values were used to identify the best fitting model(s), and goodness of fit was determined with normalized root mean square errors (nRMSE). If more than one model provided a good fit to the dataset, model-averaged metrics were calculated using the BIC value as a weighting value (Dean et al., 2020; Haas et al., 2014). To evaluate the effect of considering alternative persistence models, T90 and T99 values were calculated for each dataset with the exponential model (EP-calculated) and using the models determined to provide the best fit by the BIC and nRMSE values (BF-calculated). The EP-calculated and BF-calculated T90 and T99 values were then used as dependent variables in an exploratory factor analysis using correlation coefficients, Kruskal-Wallis tests, and basic linear models. The performance and predictive power of the linear model method were evaluated by fitting the models to training and testing datasets to calculate RMSE values. Results: The exponential model provided a good fit to only 15% of the tested datasets and the distributions of EP-calculated T90s and T99s had a higher variance than those of the BF-calculated distributions. In particular, the exponential model calculated a higher range of T90 values for FIB, bacteriophages, bacteria, and viruses, as shown in Figure 1. The exponential model also predicted higher average T99s for all target groups, suggesting that the impact of model selection becomes more pronounced after the first log-reduction. The discrepancy between T99s was greatest for the protozoa targets as shown in Figure 2. The T90 and T99s predicted by the different persistence modeling methods were treated as dependent variables in a variety of factor analyses. When only the exponential model was used to calculate the dependent variables, sunlight had inflated importance as indicated by the correlation and Kruskal-Wallis coefficients. Interestingly, the linear model fit to EP-calculated decay metrics had more significant interactions than the model fit to the BF-calculated decay metrics. Significant interactions were observed between sunlight and water type, sunlight and method, temperature and predation, and water type and method. The BF-calculated linear model only identified a significant interaction between sunlight and method. However it is important to note that the linear models fit to both the EP-calculated and BF-calculated decay metrics had relatively poor performance with RMSE values greater than 14 days. The predictive power was better for the T90 linear models (~ 11 days) than the T99 (~14 days). Conclusions: Traditionally applied first-order decay kinetics only provided a good fit to 15% of the tested datasets and there was greater variance in the calculated T90 and T99 distributions when the exponential model was fit to the data. These results indicate that fitting two-parameter and three-parameter persistence models can potentially reduce the uncertainty associated with target decay. The differences between the EP-calculated and BF-calculated metrics were greater for the T99 data than the T90 data, suggesting that the importance of using more accurate persistence models increases as later time points are considered. This is especially important when considering the reliance on natural decay in a number of surface water uses and applications. Notably, the differences between the persistence models fit were more prominent for target groups like viruses and protozoa, which are pathogen groups of high concern in surface waters. The factor analyses conducted herein indicate that the reliance on the exponential model may be potentially overestimating the effect of sunlight on decay in natural surface waters. The linear models fit in the factor analysis, however, were found to have poor performance on the datasets as a whole. This suggests that there may be factor-decay relationships that are nonlinear in nature and that other methods may be more appropriate to explore the dynamic behaviors of indicators and pathogens in diverse water quality and environmental conditions. The results of this analysis have implications for the fields of water management and risk assessment, as narrowing the uncertainty associated with indicator and pathogen decay in surface waters is a critical component of human health-related decision making for surface waters.

In Indianapolis, Indiana a developed neighborhood was seeing localized flooding during smaller rain events. When the neighborhood was built in the 1960's, almost no storm water infrastructure was built as the neighborhood was established. HNTB Corporation was selected to help the Indianapolis Department of Public Works(DPW) solve the neighborhood's drainage issues. At the start of the project, the goal was to improve the neighborhood drainage, introduce green infrastructure where feasible and provide a lasting solution. This presentation will focus on how the project came together, starting with the planning phases of the project. The presentation will focus on the collaborative effort to develop multiple alternatives and work with stakeholder groups to develop a preliminary solutions. As the presentation continues, we will discuss how we transitioned from planning to design. As we shift to the design portion, we will continue to focus on the collaborative process developed to ensure that all stakeholders were happy with the final product. As we start the design portion of the project, we will talk about the community involvement, design issues encountered, and schedule that resulted in the final product. While working through the design, the DPW reinforced its desire to include green infrastructure where feasible. We will step through the design process of including permeable pavers, rain gardens and other aspects of green infrastructure into the project along with the calculations involved to ensure that Indianapolis Standards were met. We will also discuss the areas where green infrastructure was not feasible and talk about why those options were not feasible. In the last phase of the presentation, we will discuss issues that came up during construction of the project and how those issues were resolved during construction. We will focus again on how the team worked collaboratively to ensure a final product. We will talk about some of the challenges faced and highlight how the project was finished. We will walk through how the project team was able to accomplish the initial goals of the project and provide a long-lasting, sustainable solution to the neighborhood's flooding problems.

Decentralized stormwater reuse is emerging as a sustainable approach to mitigate urban runoff issues while promoting resource efficiency. This abstract highlights the benefits of such a decentralized system, exemplified by the Arbor House Affordable Housing complex project in the Bronx. The Arbor House project successfully deployed a real-time stormwater management solution to address the challenge of combined sewer overflow (CSO) in New York City. By capturing and storing rainwater in cisterns, the system optimizes water use for rooftop urban agriculture and minimizes untreated wastewater discharges into local waterways. Key advantages of decentralized stormwater reuse, as demonstrated by this project, include: Reducing CSO Impact: Decentralized systems like the one at Arbor House significantly reduce CSO discharges by retaining and reusing rainwater. This proactive approach aligns with sustainability goals and helps protect aquatic ecosystems. Maximizing Resource Efficiency: The captured rainwater serves as a valuable resource for irrigation, reducing reliance on potable water sources and conserving this precious resource for essential needs. Environmental Compliance: The project's monitoring and reporting capabilities ensure compliance with environmental regulations, facilitating transparency and accountability in stormwater management. Community Benefits: Decentralized stormwater reuse projects often have the added benefit of enhancing community well-being. In Arbor House, the reclaimed water supports urban agriculture, contributing to local food production and quality of life. Scalability and Adaptability: Decentralized systems are versatile and can be scaled to suit the needs of various developments, making them a flexible solution for urban areas facing runoff challenges. Decentralized stormwater reuse, as demonstrated by this project, offers a sustainable solution to urban runoff challenges. It reduces CSO impact, optimizes resource efficiency, ensures environmental compliance, enhances community well-being with urban agriculture, and provides scalability for diverse urban environments. This approach sets a sustainable precedent for global urban water management. The Arbor House Affordable Housing complex project goes beyond stormwater management; it actively addresses equity and inclusion by providing affordable housing, supporting urban agriculture, creating jobs, mitigating environmental challenges, engaging the community, and promoting sustainable practices. These efforts contribute to a more equitable and inclusive urban environment. The Arbor House project exemplifies the transformative potential of decentralized stormwater reuse, offering a sustainable blueprint for urban water management. As cities worldwide grapple with stormwater issues and water scarcity, this approach showcases the feasibility and benefits of implementing decentralized systems to achieve water resilience and environmental stewardship. Learning Objectives: 1. Explore the concept of decentralized stormwater reuse and its significance in addressing urban runoff challenges and promoting resource efficiency. 2. Examine the project as a real-world example of successful stormwater reuse, focusing on its key benefits and impact on sustainability. Recognize the role of decentralized stormwater reuse in enhancing community well-being, promoting urban agriculture, and creating opportunities for local residents. 3. Assess the versatility of decentralized systems and their potential applicability in various urban settings, emphasizing their flexibility and adaptability. 4. Consider the broader implications of decentralized stormwater reuse as a sustainable solution with global relevance for urban water management and environmental stewardship.

In water-stressed regions around the world, a dearth of resilient water utilities is jeopardizing access to basic needs such as piped drinking and irrigation water. The availability of this water is heavily tied to utility management of wastewater as a resource to reverse growing supply pressure on freshwater sources, something which the American Southwest has dealt with head-on with its established aquifer and reservoir infrastructure. However, wastewater treatment and reuse infrastructure has become even more challenging for utilities in the region due to the growing impact of climate change-proliferated droughts. While technologies like MBR (Membrane Bio Reactors) and MABR (Membrane Aerated Biofilm Reactors) are being readily implemented as creative reuse solutions for the region, innovation in utility planning will be just as valuable. Further, the need for innovative infrastructure strategy applies to A) densely populated cities with limited space to add centralized utility infrastructure, B) new towns or suburban regions where utilities need to be quickly built and C) irrigation infrastructure that needs to be built or improved (i.e., 2021 Lake Mead crisis). Given these challenging scenarios, Modular Decentralized Wastewater Treatment (DWT) is a compelling new solution gaining traction globally. These systems are crucial for the Southwestern US and beyond in the fight against 'Day Zero' (including Cape Town itself) due to their associated affordability and speed of implementation. When implemented correctly, Modular DWT can also deliver the following benefits: - Augmented biological load removal capacity (depending on the technology used) o Can extend to nutrient removal in order to reduce coastal 'dead zones' - Minimized piping infrastructure and land usage based on accurate fulfillment of treatment requirement - Can be easily deployed in regions with Combined Sewer Overflow (CSO) issues as a standby unit -Simplified sludge handling and disposal due to point source treatment - Impacts of system downtime can be reduced due to distributed approach and standardized IoT Integration (rather than relying on one custom, centralized system) Our paper will identify hotspots for the next 'Day Zero' scenarios and how what a modular DWT program there might look like.

Introduction: In December of 2008, the City of Buffalo, MN began to beneficially use their biosolids as a fuel source at the Buffalo Wastewater Treatment Facility (WWTF). The biosolids treatment system at Buffalo consists of both thermal drying and thermal oxidation processes to reduce the amount of material leaving the site while minimizing overall fossil fuel consumption. The objective of this paper is to discuss the process, project background and to provide an update after more than a decade of operation. The Buffalo system is one of the only North American WWTFs that uses dried biosolids onsite for energy recovery and has a long successful operational track record. With ever increasing interest in reducing fossil fuel energy consumption and concerns related to emerging contaminants, particularly perflorinated compounds such as PFAS, there is a renewed interest in thermal destruction processes such as the one operated by the City of Buffalo. Project Background: Buffalo, MN is located about 30 miles west of Minneapolis and the City of Buffalo's WWTF consists of a conventional extended aeration activated sludge process designed for hydraulic capacity of 4.3 MGD. Prior to the biosolids system upgrade, the City had a combination of biosolids treatment processes using reed beds and liquid Class B land application. The municipality was receiving complaints associated with hauling biosolids out of the facility and it was increasingly difficult to locate farmers willing to accept the biosolids. Because of the difficulties with the Class B land application program, the city became interested in thermal drying to reduce volume of product and odors at the facility. However, the City was very sensitive to conserving energy, so the typical dryer system energy demand was considered unacceptable. After a review of available technologies including systems in operation in Europe, it was found that belt drying systems were being operated in combination with furnaces at similar capacities required by the City of Buffalo. Biosolids Process Description: The City of Buffalo produces only secondary sludge. The plant contains a large aerated sludge holding tank that provide enough capacity for several weeks of sludge storage. From the aerated sludge storage tanks, biosolids are dewatered to approximately 18-20% total solids (TS) via two belt filter presses. After dewatering, the biosolids are dried to greater than 90% TS in a BioCon belt dryer and then combusted in a reciprocating grate furnace where the fuel value of the dried biosolids is utilized to fuel the drying process by recovering energy from the hot flue gas exiting the furnace. The process is known as the BioCon® energy recovery system (ERS). This process combines a medium temperature belt dryer with a biomass furnace, which uses the dry biosolids as a fuel. The intent is to completely combust all organic material and recover process heat for the belt dryer. This integrated dryer and ERS is depicted in Figure 1. The thermal treatment process consists of several steps which are depicted in Figure 2. Dewatered biosolids are pumped from a storage silo, into the dryer cabinet through oscillating depositors, and onto a slowly moving belt located inside the dryer. Heat is transferred to the biosolids by circulating air between an air to air heat exchanger that recovers energy from the furnace flue gas and the dryer cabinet. Moisture is removed from the drying air by continuously extracting a portion of the air from the dryer, transferring it through a condenser and returning it back to the dryer. A portion of the air from the condenser is removed from the system to maintain a negative pressure on the drying system. The foul air is blended with fresh air and used as combustion air in the burners and furnace eliminating the need for separate odor control systems. Screw conveyers transport dried product from the dryer to a buffer silo that feeds a reciprocating grate furnace. The flue gas from the furnace passes through an air to air heat exchanger, where the energy is recovered for the drying process. From the air to air heat exchanger, the flue gas passes through a dry flue gas treatment system that consists of activated carbon and lime injection and a bag filter before being discharged out the stack. The ash from the furnace is transported via conveyors to a storage hopper. The residuals from the bag filter are transported via conveyors to a two bag packing station. Start-up and Performance Testing: During system start-up several issues were observed. The largest two issues were related to molten ash or clinker formation in the furnace and fouling of the air to air heat exchanger. Optimization of the furnace feed, cycling and temperature control were required to mitigate the clinker issue. The air to air heat exchanger initially had sonic horns meant to prevent ash fouling but this was found to be ineffective and heat transfer efficiency would drop after just a few days of operation. Ultimately, the sonic horns were replaced with pneumatic firetube soot blasters which prevented heat exchanger fouling allowing for long term reliable operation. Other issues that were noted during start-up included modifying the level sensor in the dried biosolids feed bin and replacing the packing on the progressing cavity pumps to a mechanical seal to reduce leakage. The performance testing was conducted in two parts. The first was related to energy consumption and natural gas savings by using the ERS system. The guarantee was based on dewatered total solids and that the natural gas consumption would be 574 British thermal unit per pound water evaporated (Btu/lb H2O evap) at 18% TS feed and 164 Btu/lb H2O evap at 22% TS feed. The energy consumption is compared to 1,400 to 1,600 Btu/lb H2O evap which is expected for a typical dryer system. The performance test which was conducted with 18% TS feed showed approximately 200 to 300 Btu/lb H2O evap was required during steady state operation as depicted in Figure 3. The second part of the performance test was the emission testing. The permit limits, summarized in Table 2, were based on volatile organic compounds (VOC's), particulate matter, and mercury. The performance during the stack testing exceeded minimum requirements and it should be noted that the mercury limits were lower than the limits required for new fluid bed incinerators as shown in Table 2. Operation and Lessons Learned: Since completing start-up, the system has now been in operation for more than a decade. Because of the large volume of storage available onsite and equipment capacity, the plant currently runs the system four to six times per year for extended periods of time which is desired for this process due to the high temperature in the furnace as numerous start and stops would reduce life off the equipment. During start-up, the furnace temperature increases at a rate of 80 degrees per hour up to 1,500 F to limit wear on the refractory. Operation temperatures higher than 1,600 F creates clinkers at the bottom of furnace, resulting in bottom conveyors having difficulties with both the size and hardness of ash chunks that need to be removed. The dryer starts on natural gas but at steady state operation it is supported by heat recovered from the furnace exhaust. Improvements to the system dewatering ultimately reduced fuel requirements as initially determined during system performance testing. The operational experience has shown the system is reliable, but several improvements have been made over the years. Some modifications to the system include: - Replacing mild steel conveyors and aluminum duct with stainless steel, - Replacing ERS grates that had worn air holes that allowed too much short circuiting. Additional modifications were made to have all grates moving in synchronization for better fuel agitation, - Adding a shredder after the rotary valve to improve uniformity of dry product from dryer which improved fuel use in the furnace, - Replaced sprinkler system inside the dryer with stainless steel and replaced solenoid valve with ball valve, - Added mixers to the sludge storage tanks to homogenize liquid sludge prior to dewatering, - Modified polymer system to improve dewatering performance. These improvements and lessons learned from the decade of operation will be discussed in the detail in this paper. Conclusion: The Buffalo ERS system is an example where dried biosolids have been successfully used as a fuel source for energy recovery for over a decade. The process provides many benefits and reduces future risks associated with fuel price volatility and biosolids beneficial use reliability. As the industry continues to focus on reduced fossil fuel consumption and concerns associated with emerging contaminants, particularly PFAS, interest in these types of thermal process is anticipated to increase.

INTRODUCTION Recently, the Western Branch (WB) Water Resource Recovery Facility (WRRF), one of the five major WRRFs of Washington Suburban Sanitary Commission (WSSC), has the immediate challenge with the biosolids odor produced during the processes of storage, dewatering, and transport of biosolids. The dewatered biosolid cake in WB-WRRF is disposed in landfills now, but the landfills have expressed concerns over excessive odors and in some instances stopped accepting the dewatered biosolid cake. This problem will be continued for the next 3 years. WSSC is looking for some solutions to reduce the biosolids odor issue. According to the processes operated in WB-WRRF, there are several possible reasons causing the odor emission issue. First of all, the blending of sludges with different characteristics may contribute to biosolids odor development. At WB-WRRF, three separate streams of waste sludge, namely high-rate activated sludge (HRAS), nitrification activated sludge (NAS), and denitrification activated sludge (DNAS) are combined in WAS Wet-Well and thickened using a dissolved air flotation (DAF) system. It is likely that the combination of these sludges has augmented the biosolids odor production. Second, the anaerobic condition created during the sludge holding time in the sludge holding tank may be another possible factor contributing to the biosolids odor emission issue. The dewatering centrifuges were shut down during the weekend, leading to 15 ft deep blended sludge accumulation in the two holding tanks for around 48 hours. The bottom of the holding tank may be considered anaerobic, and many offensive odor compounds could be produced during the holding time. It was reported that the major odor-causing compounds emitting from anaerobically digested sludge are mainly H2S, and volatile organic sulfur compounds (VOSCs) including methanethiol (MT) and dimethyl sulfide (DMS) (Novak et al., 2006). Therefore, it is our hypothesis that process such as aeration may maintain a relatively high oxidization reduction potential (ORP) in the sludge holding tanks and mitigate the odor generation. The objectives of this research include: 1. Measure ORP profiles throughout all treatment trains in WB-WRRF to infer the suspicious spots that have high odor generation potential. 2. Test various combinations of the blending of HRAS, NAS, and DNAS to study their effects on the odor emission following sludge dewatering. 3. Evaluate the effect of aeration in the sludge holding tank on odor emission from dewatered cake. METHODS Fresh HRAS, NAS, DNAS and blended sludge were collected from WB-WRRF and blended based on the actual blending ratios used in the WB-WRRF. A laboratory dewatering protocol was established to mimic the full-scale centrifuge dewatering processes following three key steps: (1) polymer conditioning under controlled mechanical shearing at G t value of 105, where G is the mean velocity gradient and t is the retention time taken for sludge to be exposed to shear force; (2) centrifugal sedimentation using a lab centrifuge; (3) cake compressing using a piston under controlled pressure to obtain a cake around 20% total solids which is similar to that in the full scale. The dewatered cake was stored in a glass jar with a septum stopper. The contents of odor compounds such as H2S, MT, DMS in the headspace of the jar were measured using a gas chromatograph (GC). Headspace gas samples were collected on a timely basis and manually injected into the GC. Meanwhile, the ORP profiles across the entire WB-WRRF were measured using two ORP probes. RESULTS ORP profiles along with the treatment trains of WB-WRRF. The three types of sludge in WB-WRRF, namely HRAS, NAS, and DNAS, were firstly combined in a WAS wet-well and then thickened in DAF prior to being stored in holding tanks in preparation for dewatering. As shown in Figure 1, we measured the ORP profiles along with these treatment tanks and found that the ORP quickly dropped from 113 mV in HRAS reaction tank to -81.55 mV in WAS wet-well. Thereafter, the ORP further dropped to -218.95 mV in the sludge holding tank, creating ideal conditions needed for formation of odorous compounds such as H2S, MT and DMS. High-rate activated sludge is the major source of odor generation The headspace peak concentrations of H2S, MT, and DMS measured during the storage time for seven combinations of the three types of sludge are shown in Figure 2. As can be seen, whenever HRAS was blended in, the peak concentrations of the sulfur-containing odorous gas were always prominently high. In contrast, only negligible peak concentrations of H2S, MT, and DMS were observed in NAS, DNAS, and NAS + DNAS. Since the blending ratios used in this study were based on the actual blending ratio in the WB-WRRF, it can be concluded that HRAS accounts for the odor generation during the dewatered cake storage, and NAS and DNAS appear to have little to do with odor generation. Aeration effect on the odor emission from dewatered cake (bench-scale). Aeration of thickened solids in the sludge holding tank was tested at bench-scale as an odor mitigation strategy. As can be seen in Figure 3, all control groups and the mechanical mixing groups demonstrated the higher peak concentrations of odorous compounds than corresponding aeration groups during the storage time (Figure 3). Particularly, the cake from the control group had the highest MT peak concentration, while the aeration group had the lowest one (Figure 3b). Likewise, the aerated sample gave the lowest DMS level (13.86 mg m-3 g-1) which is approximately 30% lower than those in the other two conditions (Figure 3c). Undoubtedly, the aeration in the simulated holding tanks substantially attenuated the extent of H2S, MT, and DMS emission from dewatered cake. Aeration effect on the odor emission from dewatered cake (full-scale). After obtaining the favorable result in the bench-scale SHTs aeration test, full-scale testing of aeration in SHTs as an odor mitigation strategy was conducted, as well. As shown in figure 4, the dewatered sludge with aeration pretreatment during the sludge holding time in the SHTs generated less H2S than the group without aeration pretreatment during the storage time (Figure 4a). There was not much difference between these two groups in terms of MT concentration (Figure 4b). Moreover, only minor levels of DMS were produced (Figure 4c), indicating that the major odorous compounds emitted from the full-scale dewatered cake were H2S and MT. We can conclude that aeration during the sludge holding time can reduce odorous compounds generated from the dewatered cake.

The City of Minneapolis established a Green Infrastructure (GI) Program in response to calls from the community to incorporate GI throughout the city. The community asked for practices that improve the environment and mitigate the impacts of climate change, largely in response to transportation project outreach. The resulting program supports a shift in design to integrate stormwater management and greening into transportation projects. The inevitable resistance to change 'how we've always built roads' without clearly defined requirements, guidelines, training, and funding came from expected and unexpected places. This resistance uses a variety of justifications, including questioning the motives and function of GI, imbalanced performance and aesthetic expectations, project deadlines, funding, a gap in the maintenance program, among others. This resistance uses a variety of tactics, including procrastination, the promise of the next project, budget constraints, feasibility challenges, among others. The resistance can be sophisticated or novel making it harder to recognize as a 'no', but it is often repeated, until a response can be crafted. Yet, the city has successfully installed hundreds of GI facilities in the three years since the program began, garnering major community support, and providing community, air and water quality benefits throughout the city. In this presentation, we will introduce the first in a series of challenges the program has had to endure and transcend: incorporating sustainable landscaping. Sustainable Landscaping is a term borrowed to help define the difference between GI practices such as native plantings that do not directly treat stormwater (SL) from green stormwater infrastructure (GSI) that captures and treats stormwater. We will walk through the motivations and goals around sustainable landscaping, introduce the forms of resistance we faced, and then present the various techniques we used to overcome individual and programmatic resistance to successfully implement sustainable landscaping in projects throughout the city.

Over the last 50 years, cured-in-place pipe (CIPP) has become the method of choice to rehabilitate old, crumbling, and leaking wastewater collection systems. Lower cost, speed of execution, reduced disruption, and long-term effectiveness of trenchless rehabilitation eroded support for the old 'dig and replace' approach. Today, CIPP is the most widely used trenchless method for pipe renovation. It is frequently specified by Utility Owners throughout North America, with Industry standards requiring minimum levels of quality, primarily flexural properties and chemical resistance. However, the question remains, 'is CIPP as good as new', and what steps are taken to protect residents from potentially harmful VOC emissions? Normally, sewer pipes and other pipes are manufactured in a factory under strict quality-control measures ensuring repeatability and consistent quality. CIPP, however, is manufactured in the field under less-than-ideal quality conditions producing less than ideal results. One CIPP might be tight fitting without blemishes or defects, while another has wrinkles, blisters, and delamination. CIPP can be installed and meet all requirements for physical and chemical resistance but might leak for the next 50 years. Significant opportunity remains to improve performance and overall quality of CIPP by simply changing the order of operations. The current trenchless model generally contemplates realizing comprehensive collection system rehabilitation meaning 'if you're going to control inflow and infiltration in a sewer collection system, you need to seal the entire system.' A number of issues can arise from sequencing events pursuant to current installation practices, whereby mainline rehabilitation occurs first and service pipes are lined thereafter. Clean outs are typically installed by the lateral lining contractor and are generally not in place when the mainline CIPP liner is installed. Some resulting issues involve public health and safety concerns, ranging from toilets blowing up during high velocity water jetting to homeowner complaints of headaches and paint smells during main liner curing operations. This can cause significant problems for the utility, the homeowner, and the contractor. Other issues arise when the main liner is cured but some or all service lines connected to it have not been temporarily plugged, which the author contends is a primary requirement if CIPP is produced with 'good as new' quality. In reality, under current CIPP practices, there are no substantive measures taken to ensure residents and businesses do not continue to discharge waste into the system while a resin-saturated liner is inserted and cured in the sewer pipe. Since the system is not taken out of service, not only is sewage allowed to flow and mix with the resin saturated liner, but VOC emissions amigrate up the service pipe, often contaminating air quality in a home or business. The adverse consequences of current municipal CIPP sewer rehabilitation projects include the following shortcomings where opportunities exist to improve quality, performance, and overall service life: - Sewage mixed with the resin-saturated liner may cause reduced physical properties and reduced chemical resistance. - Flow from service pipes can cause CIPP not to fully cure at service connections, leaving gooey resin that makes it difficult to reinstate the service properly. - Service pipes under head pressure can cause a 'lift' or bulge in the liner. - Main pipe sags collect condensation from steam curing, insulating the invert of the liner and preventing curing, resulting in a 'lift' The paper will argue that the solution is simple: change the order whereby segments of a collection system are rehabilitated by adhering to a specific Order of Operations with seven sequential steps: 1.Conduct a pipe survey including CCTV inspection, measuring pipe diameter, locating service pipes near private property lines, and marking exact locations for service cleanout installations; 2.Install a two-way clean out in each service line near the property line; 3.Divert system flow and take all service pipes out of service during CIPP; 4.Control groundwater influence on CIPP; 5.Install mainline CIPP after plugging service pipes and filtering emissions; 6.Install Lateral Lining after plugging service pipe and filtering emissions; and 7.Install Manhole Lining. The expanded role of the clean out drives the success of this new approach, providing the ability to plug the service pipe effectively taking the system out of service during CIPP rehabilitation. A two-way clean out allows for the inflatable plug to be positioned on the upstream side of the clean out. It also provides access to inspect, prepare, and rehabilitate the service pipe in the public right of way. An added benefit of the two-way cleanout is homeowners can have a contractor renew their private sewer from it. This more versatile clean out, adhering to ASTM F3097 and utilizing a minimally invasive installation method, is often used in conjunction with CIPP sewer system rehabilitation. A minimally invasive vacuum-excavated cleanout also answers sensitive homeowner concerns by eliminating conventional excavation, which often requires trench boxes and piles of dirt in the yard. Moreover, the minimally invasive cleanout provides for Same Day Restoration (SDR). SDR means the cleanout is installed by vacuum excavation, and landscaped areas, sidewalks and driveways are completely restored that same day, providing great benefit for all involved in the project. The first step of the Order of Operations is to conduct a comprehensive survey that measures, locates, and marks, ensuring solid knowledge of the system and its issues and the use of ASTM compliant components to tightly seal it 'good as new'. Installation of two-way clean outs on each lateral is next. They are thereafter used to improve main rehabilitation – using the cleanout to plug service pipes during main lining, together with bypass pumping of upstream basin flows, yields two improvements: 1.Removing all flows that might impair proper curing of the liner and its overall quality and performance; and 2.Bottling up VOC emissions so they do not enter structures which connect to the main through the adjoining service pipes. Moreover, it provides the capacity to filter emissions from curing operations, protecting workers and the public from potentially harmful fumes. Mainline lining then proceeds with the entire system taken out of service during insertion, inflation and curing of the new CIPP. Lateral lining then proceeds, with each service pipe plugged upstream of the cleanout during the CIPP lining process; the benefits described above are realized, ensuring CIPP is safe for residents and the public by filtering and monitoring all emissions. Finally, trenchless rehabilitation of manholes occurs. Though these changes are few and somewhat subtle, their impact is huge, yielding improved system rehabilitation, capturing and putting to good use advancements in trenchless technology, and improving the experience of those who live and work in a project area and of the utility as well.

Regional flooding has been controlled within the Coachella Valley in Southern California since 1915, with existing facilities built or improved in the 1970s following severe floods. The Coachella Valley Water District provides stormwater protection for a 590 square mile area within the valley by using approximately 135 miles of channels along with a number of dikes and retention basins that can convey approximately 80,000 cubic feet per second of flow from the surrounding mountains into the Whitewater River. In 2017, the District partnered with Black & Veatch to launch an extensive asset inventory and support implementation of their asset management system. This presentation will show how the rapid growth of CVWD's asset management system has benefited their stormwater management program by: 1) Showing the importance of data structuring and establishing a data collection protocol for a successful asset management program. 2) Engaging stakeholders across their business to create an expansive and robust registry which supports current and future programs. 3) Providing data to justify capital improvements and preventative maintenance decisions; shifting away from reactive maintenance and developing defendable investment prioritization. The Project has completed a field-based inventory, baseline full-system condition assessment, development of risk-based prioritization criteria, and mapping business processes. The stormwater assets were collected over a 4-week field effort with zero injuries. To execute these efforts, Black & Veatch leveraged an off-the-shelf ESRI product tailored so the final asset inventory seamlessly integrated with the District's CMMS software. CVWD staff were involved in each step of the project, helping structure data hierarchies and dictionaries, collecting field data, and incorporating institutional knowledge into business process mapping and prioritization criteria development. Data management was key as the final inventory contained over 80,000 data points including sub-meter accuracy GPS coordinates, field documented asset specifications, over 1,500 photographs, opinions of replacement costs, and baseline likelihood of failure and consequence of failure criteria. Post collection, the District's forces now have verified asset locations and attributes that provide reliability to day to day efforts. Scalability was built into the implementation to support on-going and future development of the asset management system.