Results

Purpose: The purpose of this presentation is to walk the audience through the process of increasing the capacity of a wet weather collection system and how this affects the sustainability of the system. The presentation will present the concepts of sustainability as defined in the ASCE MOP 151 Sustainable Design of Pipelines. Benefits of Presentation: There are several benefits to the industry that this presentation will provide. This presentation will provide a real-world project where the San Antonio Water System had to work through the process of increasing the capacity of a major interceptor through the historic and congested downtown area. This presentation will describe the options available and the deciding factors used for the ultimate solution. When faced with the requirement to increase capacity of a centralized gravity wastewater collection system, utilities have numerous options that can span the full range of costs, schedule, impacts to resources, customers, the environment, and to the public. The recently issued ASCE MOP 151 Sustainable Design of Pipelines publication provides an abundance of ideas for engineers and utilities to consider when designing and constructing a pipeline project to increase its sustainability and minimize its adverse impacts. As the San Antonio Water System (SAWS) Broadway Corridor Interceptor Improvement Project was recently placed into service, this provides an opportunity to compare the project to the precepts presented in ASCE MOP 151. There are multiple solutions available for designing an interceptor to handle both dry flows and wet weather flows. These solutions include inline and offline storage, upsizing, pumping, and parallel pipes (typically with one being the relief sewer). Each of these have their own unique hydraulic properties and requirements and influence the final design. This presentation will review the hydraulic characteristic of each solution and how this can affect the ultimate sustainability of the project. The hydraulics of a gravity sanitary sewer are of utmost importance to ensuring the proper operation of the system and long-term longevity and unimpeded service to the public. However, it is imperative that proper hydraulics is not the only or even the top-ranked factor used in determining the final solution. Status of Completion: Completed, operational since 2020 Conclusion: Many projects use a matrix to help consider other influences that could steer the decision-makers toward one solution or another. This is exactly the approach that SAWS and the design team used in determining the final solution for the Broadway Corridor Interceptor. ASCE MOP 151 provides a well-documented and step-by-step guide for scoring those influences that affect the sustainability and resiliency of pipeline projects. As laid out in the MOP, the areas that should be considered include pipeline materials, owner best practices, planning and design best practices, construction, operations and maintenance, and life-cycle analysis. This presentation will evaluate each of these areas and how the Broadway Corridor project measures up against each of these sustainability goals. With the updated Broadway Corridor Interceptor operational since 2020, this presentation will provide the audience with a real-world example of how projects can be designed more sustainably by applying the principles of MOP 151 during the planning and design phase and how important it is to continue the application of those principles through construction and operation to benefit the owner and community.

CSO 032 and Third Street Consolidation Sewer -- River Crossing Under the river, and through the levee, to the siphon headbox we go Statement of Purpose: Design evaluated trenchless techonologies, creative construction methods, but ultimately settled on open cut installation with innovative specification language to allow for contractor flexibility in order to construct the 107 MGD siphon under the St. Mary's River due to cost, risk, and schedule. Project Summary: As part of Fort Wayne's CSO Long-Term Control Plan, consolidations sewers are proposed to convey CSOs to the City's new CSO Conveyance Tunnel. Arcadis designed the consolidation sewer to convey flow from CSO 32 and the Third Street Lift Station. The CSO 32 and Third Street Pump Station Consolidation Sewer project entails 1200 LF of 66-inch pipe, 40 LF of 54-inch pipe, 140 LF of 84-inch pipe, a diversion structure that will intercept combined sewage flow from the Third Street Pump Station and convey it to Drop Shaft 09 (DS-09) located in Headwaters Park, modifications to CSO 032 to add a slide gate, and modifications to the Third Street Pump Station to add floatables control to the CSO outfall. Project was designed to convey 107 mgd of combined sewage into Fort Wayne's new CSO tunnel to reduce CSO overflows. Project challenges include open cut installation of the pipe through the St. Marys River and Army Corp of Engineering floodwall, deep installation, adjacent properties and utility conflicts, constructability concerns, and permitting. Status of Completion: Construction was complete in 1st half of 2022. Contractor Feedback Early in the design, Arcadis obtained feedback from contractors to discuss the Project and get their thoughts regarding trenchless and open cut installation methods based on their experience. Installation methods evaluated included open cut, jack and bore, horizontal directional drill, and microtunnel. River Crossing Coordination A challenging part of design was incorporating specification requirements for the river crossing to allow the contractor time and installation freedom for the crossing to ensure a low bid price. Work items were included for River Crossing, River Crossing Delay, River Crossing Event Cleaning, and Local River Measurement Gauge. The intent of the pay items were to share risk with the contractor during typical low river times and provide flexibility to the contractor during construction. Design Lessons Learned - Identification that a 100-foot working area across the St. Mary's River would be pursued to allow for flexibility in open cut construction. Contractor had the freedom to do an earthen cofferdam, portadam, sheet piling, or other method to install the three siphon pipes across the river. - Identification that the St. Marys River levels are different year to year and an extended construction period would allow for construction flexibility. - Need to plan for floatation and protection of pipes under the St. Mary's River. - Coordination with other projects in the area and the Hosey Dam downstream to adjust the river level to aid in construction, but limit impact to community. Construction Lessons Learned - Contractor will use all the allowable time in the Contract. - Contractor willing to work at risk to meet the project schedule. - Define material removed from the river. Material pulled form the river was uncompactable. Contractor brought in clay fill. - Multiple Stakeholders impacted by river lowering (directly after labor day) - Sheeting is not watertight. Up to 4 pumps operating (8 inch + 2/3 inch pumps) Conclusion: Due to thorough design evaluation, working directly with contractors, and creative design thinking, innovative specification language was added to the Contract to allow contractor freedom to factilitate the construction of the siphon under the St. Mary's River. The project was successfully completed on time and on budget. Other utilities will learn how trenchless options are evaluated and why ruling out open cut could be a mistake, the value of engaging contractors early in the design process, how specifications can be used to share risk with the contractor, and the value of understanding your assets.

INTRODUCTION The Saddle Creek Retention Treatment Basin (RTB) is a significant project as part of the City of Omaha's water quality program 'Clean Solutions for Omaha' to address compliance with their Long Term Control Plan to address combined sewer overflows. Prior to the construction of the facility, over 65 times per year, untreated combined sewage overflowed into the Little Papillion Creek (LPC) from the City's CSO 205 outfall structure. With the new facility in place, combined sewage will be diverted to the RTB to receive grit and screenings removal, disinfection, solids settling, and dechlorination before being discharged back to LPC. The Saddle Creek RTB project began planning and design activities in April of 2011. Construction commenced in Spring 2019 and is anticipated to start operations in the summer of 2023. This facility will provide storage and equivalent to primary treatment of combined sewage flows up to the permitted design flow rate of 160 million gallons per day (MGD) with the ability to screen, remove grit, and disinfect flows up to 320 MGD. Lower volume flows will be captured within the basin and will be pumped into the Little Papillion Creek Interceptor (LPCI) and conveyed to the Papillion Creek Water Resource Reclamation Facility (PCWRRF) for full secondary treatment. Larger volume flows will receive grit and screenings removal, disinfection, solids settling, and dechlorination before being discharged to the LPC. The facility will result in a significant reduction in the volume of untreated CSO, total suspended solids (TSS), and E coli bacteria entering the LPC. This presentation will describe how the Saddle Creek RTB will effectively and reliably capture and treat untreated combined sewage in compliance with regulatory requirements. FACILITY OVERVIEW The Saddle Creek RTB facility consists of a 3.3 million gallon (MG) underground concrete storage basin, with grit removal, mechanical screening, chemical disinfection, gravity effluent discharge, a dewatering pump station, as well as Headworks, Operations, and Chemical Buildings. The facility also includes a diversion structure, sewers, odor control, stormwater BMPs, driveways, and other appurtenances. Refer to Figure 1 for a Process Flow Diagram illustrating the various features of the RTB facility below ground. The facility operates during wet weather events. Prior to the completion of the Saddle Creek RTB project, an existing dry weather diversion weir directed dry weather and a portion of wet weather flow, up to 40 million gallons per day (MGD), was sent to the existing Dupont Grit Facility and ultimately to the LPCI. Prior to this project, any excess flow was discharged untreated to the CSO 205 Channel and eventually the LPC. The existing dry weather diversion pipes will be abandoned as part of this project and replaced with a new 60-inch sewer which will pass through a grit pit within the new facility's Headworks Building. The diversion weir will send flows using real time control and smart sewer technology to provide gate control of up to approximately 60 MGD to the LPCI before overflowing into the RTB influent sewer. This new diversion chamber will divert wet weather flow up to the peak treatment design flow of 160 MGD to the RTB. This diversion chamber configuration ensures that flow rates up to the design flow can pass through the RTB and does not increase the risk of upstream flooding during larger events. Captured volume in the tank will be pumped into the LPCI and conveyed to the Papillion Creek Water Resource Recovery Facility (PCWRRF) for full secondary treatment. Flows more than the facility capacity will be routed around the RTB and discharged into the LPC. Dry weather flow and some wet weather flows up to approximately 60 MGD will pass into a new grit pit, the diversion flow grit pit, constructed in the proposed Headworks Building. For flows passing through the RTB, large grit and other heavy materials will drop out via gravity into a second, larger grit pit, the RTB grit pit, prior to entering the screen channels. Downstream of the RTB grit pit, mechanically cleaned screens will provide for the removal of objectionable solids with the intent of protecting downstream equipment and controlling floatables. The facility includes three (3) continuous duty multi-rake screens with a clear opening size of ¾-inch. Disinfection must result in an effluent that meets E. coli and total residual chlorine (TRC) permit limits. Liquid sodium hypochlorite and sodium bisulfite will be used for disinfection and dechlorination. Above ground improvements include a building to house controls, grit and screening equipment, and chemicals. Refer to Figure 2 for a rendering of the finished facility. PROJECT COMPLETION STATUS In December 2018, the City received bids within the budget for the project and in February 2019, a contract valued at approximately $90 million was approved to build the Saddle Creek Retention Treatment Basin facility. Construction began in April 2019. Wade Trim performed design engineering on the project and is currently providing construction management services. The project is scheduled for Substantial Completion in Spring 2023. Refer to Figures 3 and 4 for construction progress photos. CONCLUSIONS The project's innovative use of a 'gravity in, gravity out' design for the RTB facility allowed for a reduction in pumping of significant flows. The use of real time controls and smart sewer technology will allow this facility to operate efficiently and effectively over a wide range of conditions, which have been evaluated through extensive hydraulic modeling and development of process control strategies. The use of instrumentation for flow and level measurement used in process control must incorporate redundancy and be flexible to allow for changes in available technology and must be compatible with other technologies being used at the facility and within the collection and treatment system.

An iteration of this abstract was accepted at the previous WEF Odors and Air Pollutants conference and was eventually presented as a video presentation. However, due to very limited audience exposure as well as the desire to include additional good neighbor 'hot button' items into the paper (permit requirement and food waste impacts), I feel that the conference audience could benefit from 're-presenting' this paper in an expanded and updated form. As population densities increase and expanding residential areas encroach closer to water resource recovery facility (WRRF) property boundaries, less tolerant communities are steadily placing more pressure on facilities to implement 'good neighbor' policies. The term 'good neighbor' can apply to multiple criteria including odors, noise, or even safety. In the context of this paper the term pertains exclusively to odor and toxic emissions control. A benchmarking study was conducted in 2016 by the Air Quality and Odor Control Committee of the Water Environment Federation (WEF). In that study, top drivers urging odor control/management decisions were identified including external customers, regulatory, and internal goals. The study found that almost 50 percent of the agencies who participated in the study implemented odor control strategies that went beyond strictly regulatory requirements. The study also quantified costs associated with odor control for conveyance system and WRRF components which included both vapor phase and liquid phase treatment. Since costs are a function of population and system scale, all costs were normalized by dividing by population served and system scale (defined as millions of gallons per day [MGD] x miles of pipeline). Both Operation and Maintenance (O&M) costs and capital costs (5-year capital improvement costs) were included. This paper focuses on five top odor performing utilities in the United States and what they spend to maintain good neighbor status. These top performers were chosen based on the following criteria: Reputation: Recognized as good neighbors by the community. Top performers don't stop at regulatory requirements for preventing nuisances. They maintain a program of continuous improvement. Diversity: All four agencies utilize unique approaches to odor control; from greater emphasis on conveyance system mitigation to greater emphasis on WRRF vapor phase systems to somewhere in the middle. This swath of approaches provides excellent comparison and allows for broader representation. Sensitivity: All four agencies are located in relatively sensitive urban locations and therefore must comply with strict regulatory as well as local requirements Costs related to odor control management for each agency were quantified and broken down into the following categories: Infrastructure capital costs (CAPEX) (based on today's dollars) for both conveyance and WRRF Direct O&M costs (OPEX) pertaining to maintenance, chemical dosing, and utility costs including electrical and water for both conveyance and WRRF Indirect OPEX Some differences between this study and the previous study include the following: OPEX in this study include indirect costs such as chemical sludge processing and hauling, chemical dosing to accommodate settling problems associated with volatile fatty acids (VFAs), additional scum pumping, and various maintenance process related maintenance activities CAPEX in this study were calculated based on existing odor control infrastructure converted to today's dollars versus 5-year capital improvement costs Cost metrics for this study were developed based on per capita (i.e.; population) and MGD versus per capita and system scale (i.e.; MGD mile) Data from the WEF study relied on numerous survey responses. This study is based on a limited number of performers and therefore takes on a more case study approach for supplementing the benchmarking study. Understanding the relative costs, cost metrics, and individual cost proportions can assist utilities in understanding where they stand and areas where there may be room for improvement or optimization. This paper discusses how the approaches of the best agency programs differ from more typical agencies as well as lessons learned from these top performers. Results of this study will prompt other agencies to ask the following key questions. How much do you spend to prevent and remedy the offsite environmental impact of your operations? Is it enough? Is the money being spent in the places where it can have the most benefit? Do you think you can do better? No two WRRFs are alike and what works for one facility might not work for another. There are differences in flow, population served, population density, climate/temperature, age and condition of infrastructure, characterization of the influent, community sensitivity, offsite odor goals, and other factors. However, there are best practices, approaches, and decisions that are common among the best performing utilities in how they minimize their off-site odor impact. This study examines holistic approaches used by top performing agencies for balancing CAPEX and OPEX for conveyance systems with those of downstream WRRFs to reduce overall odor impact. Consequences of offsite odor goal selection have a direct impact on CAPEX and OPEX related to implementation of an odor management program. More stringent odor standards result in higher present-worth costs because more stringent standards typically require larger, more expensive odor control systems that consume greater amounts of labor and energy and other consumables (e.g., chemicals, media, etc.). A representative graph of offsite odor complaints versus present-worth costs is provided in Exhibit A that shows that reducing complaints to near zero becomes exponentially more costly. Similarly, other Agency-unique and regional/localized issues can also have a direct impact on CAPEX and OPEX including permitting requirements, extent and configuration of collection system, plant processes, and high odor emitting sources including food waste receiving. Knowing where to spend odor control dollars must begin with understanding the sources of odor at a WRRF or in the conveyance network. In part, this comes from process knowledge, but measurement, monitoring, and even modeling play a critical role in informing these decisions. What may be considered 'hidden' costs are presented in this study. For example, septic plant influent can exhibit high levels of volatile fatty acids (VFAs) which can lead to problematic filamentous sludge bulking at primaries. This can in turn require additional polymer usage at downstream biosolids processes impacting costs. Certain liquid phase chemical treatment technologies can prevent septicity while others simply treat the septic sewage by removing dissolved sulfides. Understanding these hidden costs can help in implementing the best options as part of one's odor control program. A breakdown of per capita annual costs for all five agencies are provided in Exhibit B. Agency names remain anonymous while locations and specific characteristics are provided. Agencies are described as follows: PNW: Pacific Northwest agency NV: Nevada agency NoCal: Northern California agency SoCal: Southern California agency EAS: South-Eastern agency

INTRODUCTION Anaerobic digestion is utilized by water resource recovery facilities (WRRFs) to stabilize wastewater residuals and recover renewable energy in the form of biogas. Recently, anaerobic co-digestion of wastewater residuals with high strength organic waste has gained much popularity in the wastewater industry due to it's potential to improve methane yield. Fats, oils and grease (FOG) is one of the desirable co-substrates due to its higher methane production potential and degradability (compared to wastewater residuals) (Salama et al., 2019). However, some studies (Amha et al., 2017; Wu et al., 2018) have shown that higher FOG loadings can be inhibitory to the digestion process or the complex consortium of microorganisms involved. Therefore, it is critical to explore and understand how FOG impacts the co-digestion process and evaluate methods to avoid inhibition. One of such methods examined in this work was to evaluate if microbial acclimation through stepwise introduction of the co-substrate can avoid inhibition during FOG co-digestion. The goal of this study was 1) to determine the impact of co-digestion of waste activated sludge (WAS) with FOG on methane yield and microbial communities using short term Biomethane Potential (BMP) tests and long-term bench-scale reactors; and 2) to determine if microbial acclimation through stepwise introduction of FOG can be implemented to avert inhibition by comparing step-load and shock-load conditions in bench-scale reactors. METHODOLOGY Substrate and inoculum collection: Anaerobic inoculum was obtained from the Nashville Metro Biosolids WRRF's anaerobic digester which treats primary sludge and secondary scum. The WAS was obtained from City of Cookeville WRRF. The FOG used in this study was pure fats and grease obtained directly from a pork roasting grill at a local restaurant. BMP tests design and operation: Three experimental phases were carried out in 160 mL serum bottles at 35 °C. Phase 1 involved mono-digestion of WAS, as well as the co-digestion of WAS with FOG fractions of 25%, 50% and 75% (volatile solids basis). Phase 2 involved the co-digestion of 50% FOG with the 25% FOG digestate from Phase 1 as inoculum, while Phase 3 involved the co-digestion of 75% FOG with digestate from Phase 2 as inoculum. Phase 1 lasted for 20 days, while the phase 2 and 3 lasted for 13 days each. Bench-scale experimental design and operation: The experiments were conducted using two identical 10 L bench-scale reactors with a working volume of 6 L and operated at 35 °C. During the startup phase, all the reactors were fed with 100% WAS until they reached steady state. The designated control reactor was fed with WAS throughout all experimental phases, while the test reactor received various fractions of FOG. Phases 1 to 3 were conducted at volatile solids loading rate (VSLR) of 2 g-VS/L/d, and involved co-digestion of 25%, 50% and 75% (VS basis) of the co-substrates, respectively. Due to digester failure in Phase 3, Phase 4 was experimented as a recovery phase by feeding the test digester with only WAS. Phase 5 involved the co-digestion of 75% co-substrate at higher VSLR of 4 g-VS/L/d without prior exposure to the co-substrate, and therefore without prior microbial acclimation. Reactors were operated at 20 days SRT and each experimental phase was run for 3 SRTs. The digesters were monitored weekly by measuring parameters such as biogas volume and methane content, pH, and VS removal. The methanogenic community present within the different experimental phases were also examined through 16s rRNA gene sequencing to understand the impact of the FOG fractions on the methanogenic communities. RESULTS & DISCUSSION Results from the study revealed that compared to the mono-digestion of WAS, co-digestion with FOG can improve specific methane yield (i.e the total methane volume per gram VS added) up to 16.5-fold. The specific methane yields of all the tested FOG fractions were higher at the BMP level than the ones observed in the bench-scale as shown in Table 1. In the BMP study, inhibition was not observed even at the 75% FOG fraction; however, 75% FOG was found to be inhibitory in the bench-scale experiment as seen in the decline in weekly average biogas production rate in Figure 2. The BMP tests were loaded only once, which made it less likely to cause inhibition as compared to the continuous loading in the bench-scale experiment which resulted in organic overload and subsequent inhibition. At the microbial scale, the overall methanogenic community was dominated by Methanolinea, a hydrogenotrophic methanogen, and its abundance remained similar across all the tested FOG fractions at the BMP level. However, significant reduction of methanogenic population was observed during the inhibitory conditions at 75% FOG fractions in the bench-scale experiment, as shown in Figure 3. The results suggest that bench-scale experiments provide more realistic methane yields with detectability of inhibitory thresholds of FOG as well as reveal methanogenic community response to different FOG fractions under stable and unstable conditions. The bench-scale experiment also showed that step-wise increment of the FOG could not achieve microbial acclimation to avert inhibition in this study. Further, FOG co-digestion was only viable with up to 50% FOG addition at the 2gVS/L/d loading rate. At the higher loading rates, inhibition occurred due to accumulation of volatile fatty acids above 2,000 mg/L and decline in pH. It should be noted that the 50% FOG threshold observed in this study may have been influenced by the inoculum, the FOG characteristics or lack of continuous pH adjustments within the experimental phases. CONCLUSION The study shows that FOG can be used as a co-substrate to improve methane yield when up to 50% FOG fraction is used at an organic loading of 2gVS/L/d. The study also provides insights about the influence of operational modes and stepwise acclimation strategy on FOG co-digestion and highlights the need for other strategies to avoid inhibition in FOG co-digestion systems.

This presentation is intended to convey the design concepts, efficacy of rehabilitation methods, and construction challenges for the Guam Waterworks Authority (GWA) Interceptor Sewer Refurbishment Project. The project included the rehabilitation of a large diameter interceptor sewer by UV cured-in-place pipe (UV CIPP). Design of the UV CIPP was based on ASTM F2019 - Rehabilitation of Existing Pipelines and Conduits by the Pulled in Place Installation of Glass Reinforced Plastic (GRP) Cured-in-Place Thermosetting Resin Pipe (CIPP). Design criteria for the project included the calculation of dead loads based on the actual depths of cover above the top of the existing pipes as well as live loads based on AASHTO HS25 for sewers both inside and outside of the roadways. Guam is a U.S. Territory in the Western Pacific with a population of almost 170,000. The island is approximately 10 miles wide by 32 miles long. It is located about a quarter of the way between the Philippines and Hawaii, approximately 900 miles north of the equator, and it sits atop the western rim of the Marianas Trench. The island is strategically important to U.S. military operations because of its location, its land areas suitable for major airports, and its naturally deep harbor is a safe port for ships and submarines. U.S. military bases, including Naval Base Guam and Andersen Air Force Base cover approximately 39,000 acres or 29% of Guam's total land area. To accommodate the increased wastewater flows expected with the transfer of 5,000 or more U.S. Marine Corps families from Okinawa to Guam in late 2024, the Guam Water Authority assessed the condition of about 8.4 miles of 18-inch through 42-inch diameter interceptor sewer to reliably carry wastewater. The interceptor sewer extends from Andersen Air Force Base on the north end of the island along Guam Route 9 and thence along Guam Route 3 to the Northern District Wastewater Treatment Plant. The existing interceptor sewer was constructed in the 1970s. An assessment of the condition of the sewer was conducted in 2010, and a report of the findings was completed in 2015. The report noted significant corrosion of the inner walls of the sewer and recommended rehabilitation of its entire length. Additional assessment in 2017 noted that most of the sewer was constructed using Techite Reinforced Polymer Mortar Pipe and Asbestos Cement Pipe. Both materials can be problematic. Techite pipe is a thin-walled fiberglass composite pipe that was manufactured in the 1970s. It was removed from the market in about 1980, because it was found to be subject to catastrophic failures. Because of the concerns to health caused by the handling of AC pipe- especially the risks of inhaling asbestos dust when cutting the pipes - it is no longer produced or allowed in many countries, including the United States. Guam Waterworks Authority utilized a progressive design-build delivery process to procure a contractor (design-builder) for the project and contracted with our design-build team in September 2019. The design-build team included Core Tech-Hawaiian Dredging (CT-HD), as the general contractor; Michels for the UV CIPP lining; Mocon Construction for manhole rehabilitation; Dueñas, Camacho and Associates for bypass pumping and civil design; and Gresham Smith for rehabilitation design. The project was funded by the Department of Defense (DoD) for the U.S. Marine Corps redeployment of families from Okinawa to Guam. GWA and CT-HD determined that UV CIPP was the best solution for the pipeline rehabilitation. Previous attempts to install conventional CIPP on Guam USA had achieved mixed results at best. This was partially due to the remote location of the island, which makes the installation of conventional CIPP logistically difficult. Essentially, the conventional liner manufacturer must either build a wet-out facility on the island, or the installation crews must wet out the liner on the job site. On-site wet-out is difficult for even small pipe diameters. It is impractical if not impossible for larger diameter liners. Therefore, UV CIPP was selected because the liners could be impregnated at the manufacturer's wet-out facility, then properly stored and transported by container ship to the island. The obvious conclusion is that UV CIPP is ideally suited for sewer rehabilitation in a remote location such as the island of Guam. Almost all the existing manholes on the interceptor were PVC lined precast concrete. Significant portions of the PVC manhole liners were defective and in need of repair. In lieu of repairing the PVC liners with similar products, our Design-Build team proposed rehabilitating the defective manholes using an epoxy lining system. The $23 million project, which included the rehabilitation of approximately 44,350 LF of 18-inch through 42-inch diameter sewers, necessary pre-lining point repairs, and the refurbishment of approximately 100 manholes, was successfully completed in July 2020. Although the project was completed on schedule and with minimal change order costs, our team had to overcome significant challenges. These challenges included: - Scheduling of all phases of the work, including long delivery times for the liners from the manufacturer. - Numerous bypass pumping setups, which were complicated by required minimum cure times for cementitious repairs before lining the existing manholes with Raven epoxy. - Detailed traffic control plans and coordination with highway construction along Guam Route 3. - Scheduling and permitting work on Federal Lands. - Protection of Endangered Species such as the Common Mariana Moorhen. - Archeological Review. - Constructability issues such as:
a manhole and sewer segment that were partially under a multistory apartment building.
removal of jagged edges of failed
Techite pipe without a robotic cutter, which was not available on the island. It is felt that the information provided in this presentation will be of value to the engineering community, especially for future projects with large diameter sewers, extensive bypass pumping, remote installations, and stringent design requirements.

Our cities are built over thousands of miles of hidden stormwater infrastructure. Stormwater performance data is infrequently and informally collected, meaning we often do not know what is going on in pipes until something goes wrong. Flow datasets are typically collected from monitoring projects that are temporary, limited, and sparse. Stormwater utilities are at the cusp of the same data revolution that electric, gas, and water utilities undertook: system-wide metering. Technology advances have made dense, real-time flow sensor networks possible and affordable. Moving beyond traditional flow monitoring, real-time flow metering gives rise to new data-driven BMPs and insights to help cities to understand their systems. Two case studies will be presented from Jersey City, NJ, and Norfolk, VA, demonstrating the broad applicability of flow metering as a stormwater BMP. Jersey City Municipal Utilities Authority installed a real-time flow sensor network to track and quantify combined sewage overflows as they occurred. The network featured multiple sensors at different locations in each outfall to determine the timing and volume of CSOs. Over a six-month study, direct measurements found 42 CSO days with a total discharge of 16 MG, compared to a SWMM model prediction of 21 CSO days and 10 MG of discharge (Fig 1). The differences detected in modeled and measured volumes are notable because JCMUA is required to report release volumes, and their Long Term Control Plan is developed for a specific volume. Flow metering in Jersey City is ongoing with a third network expansion planned for 2021. The City of Norfolk uses a real-time network to track tidal backflow in the storm system and separate contributions from tailwater and stormwater. Dense sensor networks were deployed in two flood-prone sewersheds. One objective was to evaluate overall capacity trends. Fig 2 shows the 30-day average capacity in one sewershed, which was over 50% full. The network delineated the exact inland extent of tailwater here. An algorithm was developed to separate stormwater from tidal flows in real-time. Fig 3 shows measured depth at a location with tidal influence, and Fig 4 shows the stormwater flows separated by algorithm. Findings from Jersey City and Norfolk show that using flow sensor networks to capture real-time data is critical to assessing system performance, is applicable to variable settings and objectives, and that real-time data itself can be considered a stormwater BMP.

Charlotte Water is the largest sewer utility in the Carolinas with approximately 4,500 miles of gravity sewer. Charlotte has been implementing a substantial and aggressive long-term sanitary sewer rehabilitation program to reduce sewer system overflows (SSOs), correct historic maintenance problems, and reduce infiltration and inflow (I/I) into aging sewers. Charlotte's rehabilitation program has a current annual budget of about $25.5 million, including an annual budget of approximately $10 million for small diameter sewer rehabilitation and approximately $6 million for large diameter sewer rehabilitation. Charlotte has been systematically rehabilitating their large diameter sewers over the last 10 years. Charlotte's main trunk sewer entering their largest treatment plant (McAlpine Creek Wastewater Management Facilities) is a 78' concrete sewer installed in the 1960s. The sewer has deteriorated over the years, including significant structural defects/cracks, heavy infiltration into the sewer, and severe hydrogen sulfide corrosion. Failure of this large sewer would cause a major sewer system overflow and be extremely difficult to repair. Charlotte prioritized this 78-inch sewer as their most critical sewer asset in need of rehabilitation. This presentation will discuss the first phase of the 78-inch sewer rehabilitation work that was completed in 2022 for $6.5 million. The 78' sewer is routed through the Carolina Place Mall and big-box store parking lots and crosses two major 4-lane roads. The sewer is 64 feet deep at its midpoint and 32 feet deep at each manhole. The total length of 78' sewer rehabilitated was 2,700 feet, with one section of sewer being 2,200 feet long with no intermediate manholes. Cured-in-place pipe lining (CIPP) was installed in the 78-inch sewer via an 'over-the-hole' wetout installation, meaning the CIPP was wetout (manufactured) right on site and immediately inverted into the 78' sewer. Special CIPP thickness design was required due to the 64-foot depth. The bypass pumping system had a capacity of 57 mgd and included ten 12' pumps manifolded into three 24' force mains over 5,000 feet long each. The bypass piping was routed across two major roads utilizing portable steel truss bridges over the roads -- the first time this was ever approved for such use by NCDOT. This was a major project with many difficult obstacles and challenges. The design issues, construction techniques, and bypass pumping system were very unique and definitely not an everyday type of rehabilitation project. The complex design issues that were encountered that will be presented to the attendees include determining the accurate inside pipe diameter using specialized LIDAR CCTV inspections to profile the pipe (this pipe was severely corroded so the inside diameter was larger than the original pipe diameter), modifying the CIPP thickness design parameters to achieve a design that could be successfully installed (including the soil modulus, short-term flexural modulus and safety factor), utilizing a fiberglass reinforced liner to reduce the CIPP thickness and allow the 2,200-foot section of CIPP to be transported to the jobsite and installed in a single installation (including shipment via a special 94-foot-long trailer with 44 wheels that could be steered independently), and designing a temporary steel truss bridge over a 5-lane and 3-lane road to allow the bypass force main piping to cross the roads (the first time NCDOT ever approved a bridge installation for this purpose). The primary purpose of this presentation will be to thoroughly describe the unique challenges with this project and transfer our lessons learned and unique solutions to the attendees. Large diameter sewers are the most critical sewers in the sewer system as they convey large amounts of flow. Failures can lead to major sanitary sewer overflows (SSOs) and significant environmental impacts. Rehabilitating large diameter sewers is extremely complex and difficult, and the design challenges often seem insurmountable, just like was the case for this project when Charlotte prioritized this sewer for rehabilitation. Sharing our lessons learned, out-of-the box thinking, and unique solutions to difficult design issues will be invaluable to the attendees as they return home to tackle their own difficult, large diameter rehabilitation projects. In addition, several of our design and construction solutions will impact the rehabilitation industry as a whole, in particular in the Southeast where this project was performed. We have demonstrated that substantial CIPP material can be shipped to the jobsite using a special 94-foot-long trailer, whereas shipments were previously limited to a much smaller quantity of CIPP on a much smaller trailer. Understanding that a trailer this large is available will impact how other parts of the country start planning their CIPP designs and installations. Further, we have convinced NCDOT to allow temporary truss bridges over their roads for bypass pumping which will significantly change how rehabilitation projects can be performed. We now have another method to address the difficulty of how to cross DOT roads with bypass piping, and we are already seeing that solution being utilized in other parts of North Carolina. Sharing this solution at a national conference may have wide-ranging impacts across the country.

Water utilities are at the forefront of providing clean, reliable drinking water to communities. To bolster the region's water supply, Portland Water Bureau (PWB) is making a significant investment in the construction of a state-of-the-art Filtration Facility. This endeavor harmonizes with PWB's broader Strategic Plan and Smart Utility Plan, serving as a technological roadmap for optimizing PWB operations. A pivotal component of the Smart Utility Plan is the implementation of an Enterprise SCADA (Supervisory Control and Data Acquisition) system, unifying control and oversight across PWB's water distribution and filtration facilities. This abstract delves into the strategic planning and meticulous execution of this crucial SCADA system integration. Key Planning and Execution Phases: 1. Strategic Planning: The foundation of PWB's SCADA journey lies in understanding the existing SCADA system conditions and evolving standards. This phase also entails identifying user requirements for the SCADA system, envisioning a conceptual SCADA system that harmonizes these requirements, and conducting a rigorous technology evaluation and selection process. Lessons learned from interviews with peer utilities shape the technology choices. 2. Public Procurement: A vital milestone is the initiation of a public procurement process. PWB explores avenues for securing long-term SCADA software and system integration services, positioning a sole source supplier for future construction endeavors. This strategic move streamlines procurement and reinforces the stability of the SCADA infrastructure. 3. Roadmap Updates: The pinnacle of PWB's planning phase culminates in the creation of a comprehensive roadmap report. This document encapsulates design and implementation strategies, meticulous risk assessment, consideration of installation alternatives, planning-level cost estimates, and the formulation of a project schedule for seamless SCADA system implementation. The roadmap report is continuously updated as PWB progresses its Smart Utility Plan. Introduction: PWB's SCADA systems have been the backbone of real-time data monitoring, remote control, and data archival, spanning both water distribution and treatment facilities. With the impending addition of the Filtration Facility in 2027, the opportunity to unify PWB's SCADA systems presents itself. A critical aspect of this transformation is the evaluation of the Human-Machine Interface (HMI) platform and associated technologies to meet the evolving needs of the Smart Utility program. Objectives: The primary objective of our SCADA System Roadmap is to navigate the modernization of PWB's automation systems, ensuring alignment with the Smart Utility program's requirements. Furthermore, this roadmap aims to provide a unified platform for managing both distribution and filtration seamlessly. It identifies gaps between PWB's current-state and desired future-state automation systems, offering invaluable planning-level cost estimates and a well-structured implementation schedule. The roadmap serves as a repository for essential planning elements, including technical memorandums, drawings, conditions surveys, concept designs, and technology selections. This cohesive package establishes the foundation for standards development and project design. In summary, PWB's pursuit of a unified SCADA system represents a seminal step in safeguarding a sustainable supply of clean drinking water for the community. The strategic planning and execution detailed in this abstract underscore the significance of meticulous preparation in the integration of complex technologies and systems.

The purpose of this paper will be to present recent advances and techniques along with proper application of proven methodology to rehabilitate two structurally compromised reaches of the Northwest Interceptor Sewer (NWI) in the City of Detroit, Michigan. The NWI is one of the major interceptor sewers in the Great Lakes Water Authority (GLWA) system and serves hundreds of thousands of residents and businesses in Detroit, Redford, Livonia, and Westland, Michigan. As part of the asset management initiative GLWA inspected the NWI using remote operated vehicle (ROV) video techniques in absence of flow control, preventing the lower half of the NWI to be inspected or observed. The ROV inspection revealed several reaches of the NWI along Trinity Avenue and Pierson Street at Warren Avenue that appeared significantly distressed and required emergency rehabilitation. Further investigation, evaluations, and designs were required to perform the required rehabilitation. Manned inspections of these NWI reaches were attempted but were extremely limited due to the high flow conditions. At that time, GLWA activated their Emergency Repair Contract CON-149 with Inland Waters Pollution Control (IWPC) to implement flow control devices and perform the required rehabilitation under a design build approach. An extensive flow control plan was developed and implemented to gain entry. This plan included new flow control gate construction, diversions to other nearby interceptors, and wet weather flow-through designs. Coordination with environmental agencies and knowledge of the GLWA system were important aspects to develop this plan. A geotechnical investigation conducted as part of the initial effort revealed silts and sands surrounding the pipe, with a static groundwater level high enough to drive soil material into the pipe through major cracking, causing concern for further degradation of the pipe. Following implementation of flow control, a manned entry was performed, which revealed more extensive deterioration than was initially apparent, including several sections on the verge of collapse. Immediately following the inspection, rehabilitation options were developed and reviewed based on the variable condition of each reach. Cured-in-Place rehabilitation was not selected due to requirements for long term wet weather flow control that would have been extremely expensive and that would have presented unacceptable risk to the environment. Slip lining methods were not selected due to the large entrance shafts that would be required and the unacceptable reduced lining diameter that would have resulted. Ultimately, a rehabilitation system was selected consisting of: 1) Stabilizing the existing host pipe by emergency support, followed by 2) restoring ground support around the host pipe, and then 3) Installing a reinforced sprayed geopolymer liner to restore the structural lining. This approach allowed for restoration resulting in maximum pipe diameter, with the least risk to the environment. Initial emergency stabilization consisted of first installing steel ribs in the most degraded reaches, followed by groundwater dewatering to minimize further loss of ground through the lining into the sewer. Geotechnical instrumentation consisting of piezometers and surface settlement points were installed to monitor the ground surface above the interceptor, followed by cement and chemical grouting to stabilize the ground around the pipe and further minimize loss of ground into the pipe. Major cracking was repaired in some reaches by installing reinforcing steel rods and anchors followed by over-patching with Eco-Cast lining materials. Following stabilization of the host pipe, the interceptor reaches considered compromised were re-lined with a steel reinforced Eco-Cast lining system. The system consisted of installing horizontal and circumferential steel to limit future cracking of the Eco-Cast liner. This presentation will discuss the emergency approach to the inspection, design, flow control, and rehabilitation methods of the NWI, during which time continuous sanitary sewer service was maintained without interruption, and no sanitary overflow occurred to the environment as a result of the project. Unique and creative methods for accomplishing this repair will be discussed, including the use of a dry weather diversions and bypass; and developing a fully structural finished and crack resistant spray-on lining with thickness of only 3 inches. The rehabilitation of the Trinity and Pierson reaches are complete and flow has been restored to the NWI in this area, with minimal surface disruption and no negative impacts to the environment. The project leaves behind a permanent flow diversion structure that will allow inspections and maintenance for years to come. As a side note, ongoing follow-on tasks for this project will provide two additional permanent flow control structures. This rehabilitation project illustrates several conclusive lessons to the industry described as follows:
Full dewatered inspection of Interceptor sewers is essential, as the initial ROV inspection of this sewer was not adequate due to high flows. Where practical, sewer owners should preemptively install flow controls within their major interceptors that will facilitate regular full-diameter inspections.
Repair methods must be balanced against available and feasible flow control options.
Distressed Interceptor reaches are often distressed due to poor soil conditions such as wet silt/fine sand conditions.
Grouting these reaches to re-establish host pipe confinement is essential usually requiring an exterior dewatering system.
Use of a reinforced sprayed liner system is an effective method to be employed for limited flow control conditions while providing a structural and flexible complete repair, with minimal diameter reduction. Reinforcing is essential for spray-lining systems where future movement or reflective cracking of the host pipe is a possibility.

In order to prevent sewer overflows, it is imperative to ensure waste water containing fats, oils, & grease discharged by commercial restaurants do not reach the sewer system. This presentation will provide a complete overview of how municipal inspectors can manage and conduct onsite fats, oils and grease inspections within commercial food service establishments. Every aspect of inspections will be addressed from managing an inspection program to conducting the actual onsite inspections. Videos of inspections being conducted and actual case studies from inspections will be referenced. The presentation is broken down into five parts listed below. Part 1: Why Conduct FOG Inspections? We will first show the value and reasoning behind conducting inspections. Ensuring facilities within the jurisdiction are adhering to local regulations is a crucial aspect of managing a FOG program. By conducting onsite inspections, regulators can verify that the grease separation device(s) are adequately operating, educate the facility's staff of the importance to keep FOG out of the sewers, and issue needed warnings/fines. Part 2: Scheduling & Resource Allocation A municipal inspector is challenged with ensuring that all facilities are within the compliance guidelines of the local jurisdiction. Often times these professionals are faced with a lack of staffing in comparison to the number of facilities and need to allocate available resources accordingly. We will explore scheduling methods used by inspectors for both inspections being conducted on a regular frequency and emergency inspections. Part 3: Step by Step Onsite Inspection Process This portion of the presentation will focus on a clear step by step process of conducting an onsite FOG inspection. We will explore how to communicate with onsite facility staff and inform them of the inspection process. We will go into detail in terms of what items an inspector should be looking for during a walkthrough. There will be particular focus on examining a grease removal device in terms of physical condition, capacity, and operating efficiency. Part 4: Issuing Warnings & Notices of Violations We will explore different methods used throughout the USA in terms of issuing warnings, notices of violations, and fines. There is a high variability in this area depending on how much enforcement leverage the department conducting the inspection has. Actual case study examples of what has worked and what has not worked for different municipalities will be used to demonstrate the effectiveness of various approaches. Part 5: Follow up & Enforcement Depending on the outcome of an inspection, some kind of follow up may be required. Different methods of follow up procedure examples will be shown and we will discuss the effectiveness of each. Verifying that violations were corrected and providing facilities the resources and education to ensure compliance going forward will be reviewed. . Attendee Outcomes or Learning Objectives. 1.The attendees will learn the relationship of FOG and sewer overflows 2.The attendees will be able to put together an inspection scheduling program 3.The attendees will be able to troubleshoot a grease separating device 4.The attendees will know how to execute thorough onsite FOG inspections

In the past two decades, wastewater treatment plants (WWTP) have been undergoing a dramatic transformation from solely focusing on wastewater treatment to resource recovery of valuable byproducts from waste. Utilities are increasingly realizing the benefits of biofertilizer production, nutrient recovery, energy production, and water conservation and the value it brings to the overall bottom-line for the end user. Wastewater utilities are also uniquely positioned to bridge the demands of renewable energy production as well as reducing organic solid waste from ending up in landfill, both regulated in many states in the US. The US EPA has identified more than 1,300 facilities in the US that rely on anaerobic digestion to reduce organics from wastewater, however, per the American Biogas Council, an estimated 40% of all anaerobic digesters in the US are being underutilized. Digesters with excess capacity are energy sinks, requiring just as much heat and electricity when operated at under capacity as they do while fully optimized, but with very little return in the form of energy production (as biogas). This unused digester capacity can be utilized to anaerobically codigest landfill diverted organics to produce biogas, which in turn can be converted to biomethane or heat and electricity using a combined heat and power system. Increased biogas production is just one of the many benefits of introducing high strength biodegradable wastes from commercial and industrial establishments into municipal anaerobic digestion systems. Digestion systems can also be designed to produce Class A or exceptional value (EQ) biosolids that is returned to the market as biofertilizer or soil amendment. In anticipation of an upgrade from 5.0 to 7.7 MGD, Hermitage Municipal Authority in Pennsylvania undertook a major upgrade of their solids handling facility to increase treatment capacity. The facility only has secondary treatment, meaning there is no easy-to-digest, high calorific value primary sludge as a feed to the new anaerobic digesters. As part of the upgrade, one of the goals was to boost biogas generation and use it as the primary fuel in a combined heat and power (CHP) cogeneration system to offset process heat and generate renewable electricity. This lead to a solids management plan specifically design to address high strength codigestion of source separated organic (SSO) wastes imported to the facility, mostly focused on pre-consumer expired or contaminated food waste, all while still able to produce a US EPA approved Class A biofertilizer. A new two phased digestion system was built using two existing anaerobic concrete tanks on site and one new steel tank. This system includes a first stage thermophilic hydrolysis reactor to acidify high strength waste, followed by high rate mesophilic digesters. A new biogas collection and treatment system and a combined heat and power unit was installed. Subsequently, a second CHP system was installed to maximize biogas utilization with minimal downtime. A new depackaging system, capable of handling dairy/liquid waste was included as part of this initial upgrade. This limited use process justified the needs of the time since only one regional dairy had agreed to divert their pre-packaged, expired dairy waste to the wastewater plant for organics recovery. Subsequently, a second depackaging system was installed to widen the imported source separated organics profile, specifically to include the capabilities to extract organics from various packaged solid food waste. The design of the facility also include a staging area to receive imported packaged organic waste from grocers, large food manufacturers, dairy and other organic waste generators. More recently, a new innovative depackaging process was installed to improve organics removal efficiencies, reduce contaminant level in extracted organic slurry, and manage increased throughput of imported waste at the facility. The three depackaging units are now capable of handling both solids and liquid waste effectively. Since January of 2013, the facility has grown from having just one dedicated organics waste supplier to now receiving food waste from over a dozen major sources. The facility has since processed over 8,000 dry tons of solid waste and over 12 million gallons of high strength liquid waste. The facility utilizes a custom organics feed staging strategy in the advanced anaerobic digestion system, that allows an applied organics loading rate (OLR) in excess of 12 kg/m3 (0.75 lb/ft3) in the first stage thermophilic acid digester. The second stage mesophilic gas digester is fed at a rate of 3 kg/m3 (0.19 lb/ft3), which is typical of conventional digesters, but is capable of higher OLR input. The phased digester feed is a combination of secondary municipal sludge and depackaged organic high strength slurry, in some instances pre-heated prior to introducing it to the thermophilic digesters. The organics loading ratio on a mass basis for municipal sludge to imported waste ranges between 1 to 0.6 and 1 to 1, with 20 tons of municipal sludge for every 12 to 20 tons of organic slurry. The phased digestion system is a US EPA's Process to Further Reduce Pathogens (PFRP) equivalent process, designed to achieve Class A biofertilizers as the final product. The current bioenergy system is capable of treating over 125,000 cubic feet of biogas and generates up to 13,400 kilowatts hour of power. The goal is to convert the biogas into compressed natural gas (CNG) to capitalize on the renewable energy credits to improve the cities renewable energy portfolio. In addition to increasing the bioenergy and biofertilizer production, the authority collects tipping fees from food waste generators that offsets ratepayer contributions. Renewable bioenergy production using landfill diverted organics all occurs within this resource recovery facility. This synergistic approach will benefit the solid waste industry from having to find new ways to manage organic food waste, the energy industry from having to build new renewable energy facilities, and most critically the wastewater industry in maximizing existing infrastructure to produce biofertilizer, recovery nutrients, produce bioenergy, and conserve water all while generating revenue from tipping fees. The paper offers a concise methodology that illustrates this synergetic approach to a growing problem. The paper aims to cover the nuances of source separated organics pretreatment, anaerobic codigestion and related processes.