Results

As we await the Biden administration's review and approval of the Lead and Copper Rule Revisions (LCRR) promulgated on December 22, 2020, it is time to start familiarizing yourself with the proposed revisions, which seek to better protect children and communities with more effective requirements. At a glance, the revisions will require water suppliers to identify the most impacted areas by conducting a Lead Service line (LSL) inventory; strengthen drinking water treatment and corrosion control practices; replace LSLs; increase sampling reliability; improve risk communication; and better protect children in schools and childcare facilities. Through exploring how three communities proactively addressed the risk of lead in drinking water, attendees will gain a better understanding of what to expect when the LCRR is in effect, what are federal mandates, and how to get a head start. New York City Parks and Recreation Department conducted a robust testing program to sample more than 3,500 interior and exterior drinking water fountains at its public spaces across the city's five boroughs, within 3 months. Existing asset data allowed the project team to leverage GIS and compatible mobile applications to identify fountain sites, track stagnation, and manage testing and results in real time. The extensive data management required for this project provides valuable insight for managing LSL inventories and workflows around the find and fix philosophy as proposed by the LCRR. In 2017, the Massachusetts Department of Environmental Protection (MassDEP) assisted the city of Lynn in mapping facilities and conducting baseline sampling for lead and copper at more than 600 fixture locations in 25 public school buildings. After receiving the baseline sampling results, a phased approach was developed to address fixtures with elevated lead levels on a priority basis. Beginning in late 2019, the city entered the second phase of their program addressing lead in school drinking water and began replacing more than 400 drinking water and non-drinking water fixtures throughout its schools. School closures due to COVID-19 proved beneficial to this project as it allowed for school-wide water shutoffs that resulted in an accelerated replacement program. Approaches to comply with LCRR in absence of readily flushable connections which is often the case within schools will be addressed. California's El Dorado Irrigation District (EID) conducted a bench study to proactively evaluate alternatives for their drinking water corrosion control treatment. The district added zinc orthophosphate (ZOP) at its three water treatment plants to reduce in-house plumbing lead corrosion. The study assessed the feasibility of converting to a phosphoric acid corrosion inhibitor in lieu of ZOP to reduce zinc loading to the distribution system and subsequently to wastewater. This included development and implementation of a distribution system monitoring plan designed to assess potential impacts to distribution system corrosion with a particular focus on areas with asbestos cement piping. The results of the study were utilized by EID, in collaboration with the California Department of Public Health, to improve the District's overall corrosion control strategy to specifically address the upcoming LCRR requirements. Participants in this session will learn how these three entities with different goals and limitations approached comprehensive investigations to reduce lead exposure to consumers and worked proactively to make changes that improve water quality in advance of the forthcoming LCRR. The presentation will also provide brief insight on the impact of 'potential revisions to the microbial and disinfection byproduct rules' from the LCRR, with emphasis on proposed minimum oxidant residuals and common measures to control lead, microbial levels and DBPs.

Introduction
The Harris County Flood Control District (District) initiated a comprehensive asset management (AM) program that is changing their approach to operating, maintaining, and investing in infrastructure assets that reduce the risk of flood damage to Harris County, Texas. The AM program requires business transformation throughout the District's organization that will drive operations and maintenance (O&M) and capital investment decision-based activities. The program is intended to be a living and actionable strategy that allows for continuous improvement as the organization grows and the program matures. The District is using a phased approach for the development of the AM program. The initial phase (Phase I) of the project, which was completed between March 2021 and August 2021, developed interim AM program components and demonstrated the AM program approach applied to concrete-lined channels (Figures 1 and 2) which are a subset of the District's overall asset portfolio. Phase I formulated and documented the District's AM Policy, formulated elements of a first-generation Strategic Asset Management Plan (SAMP) and developed preliminary long-term maintenance and capital renewal estimates for concrete-lined channels included in federal and non-federal Channels Inspection Reports. The project team documented the Phase I efforts and findings and outlined anticipated future efforts in an interim report. The second phase of the project (Phase II) is focused on further developing the AM program while approximating long-term maintenance requirements for as many District assets as possible to support the District's maintenance budget request for the upcoming two fiscal years. Phase II will be completed by September 2023. AM program development is following best practices established through the International Organization for Standardization (ISO) 55000 series of standards for AM. This presentation will provide a summary of the Phase I efforts and results. The presentation will also provide a detail the planned Phase II efforts and status to date which is anticipated to include a discussion of asset inventory, inspection methods, and the District's current approach to long term maintenance cost estimating. Phase I - Interim Development As an initial step to implementation, the project team developed interim policies and strategies, initiated cross-organizational buy-in, developed an improved asset hierarchy (Figure 3) and created an asset registry associated with concrete-lined channels (Figure 4). A cornerstone of AM program, the risk framework, was also developed. The risk framework is anticipated to be used in the District's decision criteria to prioritize major maintenance projects, where, with all other factors equal, assets with a higher risk will be first in line to be repaired or replaced. The interim framework was based on five risk criteria for promoting an equitable application of maintenance funding: social vulnerability, historic structural flooding, channel level of service, development age, and development intensity. These five criteria were used to measure risk and to apply a total risk score to assets associated with concrete-lined channels (Figure 5). Phase I - Results For the interim phase, program outcomes were demonstrated by performing life cycle cost modeling for the District's approximately 140 miles of concrete-lined channel. The estimated cost to replace these District-owned assets 'in-kind' was approximately $1.098 billion as determined by planning-level replacement costs using attributes from the asset registry and District pay items and unit costs. The life cycle cost modeling simulated the concrete-lined channel assets over a 100-year period with funding scenarios that included major maintenance, vegetation management, and end of life renewal. Four different funding scenarios were simulated to demonstrate funding requirements needed to achieve various average long-term performance levels (conditions) of the concrete-lined channel assets in the model. The interim results (Table 1) demonstrated that while an annual O&M budget of $14M will maintain the concrete-lined channel assets in a 'Very Poor' condition, an annual $34M O&M budget will maintain the concrete-lined channel assets in a 'Good' condition over the long-term. The interim results provide an example of life cycle cost modeling results that are anticipated to be used to both optimize available O&M funding and to routinely evaluate various O&M budget levels and their resulting long-term effects on the condition of the District's asset portfolio.

Phase II - Current Activities
The project team is currently evaluating District assets associated with their open channel network for three watersheds: Little Cypress Creek, Halls Bayou, and Vince Bayou (Figure 6). District assets associated with these open channel networks include channel, outfall, manhole, inlet, conduit, and control structure assets. For these watersheds and associated open channel assets, the project team is developing a detailed AM register of assets, preparing a condition assessment framework based on industry best practice, conducting field inspection/condition assessment activities, developing long-term maintenance estimates, and identifying maintenance projects for 2 fiscal years. The current effort will test and further define future approaches to the District's AM program. The presentation will provide a detail the planned Phase II efforts and status to date which is anticipated to include a discussion of asset inventory, inspection methods, and the District's current approach to long term maintenance cost estimating.

Results and Conclusions
The AM program is shifting the District's current approach of estimating future maintenance costs based on past expenditures to a forward-looking approach based on accurate and up-to-date District asset data. The approach allows the District to optimize application of available O&M funding to achieve the best long-term condition of District assets. The program also provides a method to routinely evaluate various O&M budget levels and their resulting long-term effects on the condition of the District's asset portfolio. The results of the program will allow decision makers to plan future O&M budgets based on desired asset condition and available funding.

Purpose: This is a case study of a sewer replacement that transformed into a strategic development initiative to enhance the image, character, and economic vitality of an urban center. Benefits of this Presentation: This presentation will benefit our industry by outlining the integrated approach to planning, building, and funding that made this complex project possible. It will present the challenges and the keys to success. Successful integrated infrastructure projects like this provide value to our industry by enhancing public perception of large-scale sewer work. Above-ground improvements offer citizens a solution they can see and touch while upgrading buried utilities they might not otherwise recognize as needing repair. Status of Completion: The construction was completed in 2018.

Abstract: The Downtown Renovation Phase 1 Project, aptly named 'ReNewark', began as an investment to replace aging sewers and meet EPA requirements in Newark, Ohio. The project was in the heart of a historic downtown square anchored by the Licking County Courthouse. This was a main trunk combined sewer - 48-inches in diameter and 15 feet deep. The primary goal was separation of this 130-year-old brick pipe to reduce overflows and reduce the risk of it collapsing. Since the sewer work was unavoidable, Newark leveraged the opportunity to also enhance the above-ground infrastructure. An integrated approach transformed this utility upgrade into a community redevelopment strategy. Multiple disciplines were engaged to separate the combined sewer, simplify the water piping, reconfigure traffic patterns, and add green infrastructure and pedestrian-friendly features. A multi-disciplinary funding solution was also devised which offset costs for each component of the project. One of the keys to getting this sewer project off the ground was leveraging a green infrastructure loan to pay for bioswales and a portion of the stormwater system. This ambitious sewer separation would not have happened without various entities collaborating to fund the work. Engagement with the public included extensive outreach to build consensus among citizens and the local business community. It happened informally while surveying the buildings as well as during structured events. Eight stakeholder meetings and three public meetings were held over a six-month period. They were attended by more than 500 residents who contributed their ideas to the future of Downtown Newark. The results were clear. The walkable character of the downtown was identified as a critical component for the ongoing viability of local businesses. The site investigations started with dye testing on more than 130 service laterals using remote-operated vehicle camera equipment. Arcadis also entered 90 businesses and residences to survey the existing utilities and perform a structural evaluation of the basements. A portion of the basement in many of the buildings extended beyond the exterior face of the building underneath the sidewalks. They were originally used as access points for coal or other supplies and some are still in use today. Other investigations included flow monitoring, hydraulic modeling, surveying, buried utility mapping with ground-penetrating radar, and geotechnical and archaeological investigations. Where possible, combined sewage inputs within the project area were separated. This diverts stormwater inputs away from the combined sewer and reduces overflows. The sewers were replaced with fiberglass-reinforced polymer mortar pipe with open-trench construction. The selection of this pipe material over a more traditional material like concrete allowed for faster construction in this busy downtown area. The water distribution system was simplified with dual pipes consolidated to a single 12-inch diameter ductile iron pipe. The design team set forth to improve the traffic pattern rather than replace roads in-kind after the sewer construction. The intersections surrounding the Courthouse Square were changed to mini roundabouts. The roundabouts achieved safer and easier pedestrian and vehicular traffic, improved urban aesthetic, and conversion of the traffic around the Courthouse Square from one-way to two-way streets. This provided easier access to downtown businesses. Roads were narrowed and sidewalks widened. More than twenty feet of total sidewalk width was added in some areas, creating outdoor space for events, dining, and retail. Green infrastructure improvements included 35,000 square feet of low-maintenance plantings, more than 130 shade trees, and 12,000 square feet of rain gardens and bioswales that flow into the new storm trunk sewer. The construction occurred in 13 phases over three years. Flexibility during construction was fundamental to maintaining utility and traffic continuity and keeping the downtown functioning. Bypasses of sewage flows and traffic maintenance plans were tailored for each phase to ensure minimal interruptions to the public. A project website www.wedignewark.com was created to keep the community in-the-know. Informational videos were created to promote key milestones, share progress updates, and educate the public on unique elements of the project including the benefits of bioswales and the efficiency of roundabouts. The public could see the results as the project progressed. This engagement during construction was key to getting public buy-in and cooperation. Since the construction commenced in 2014, Newark's urban center has experienced tremendous gains in population, jobs, downtown living, and economic growth. The $25M investment resulted in more than $60M in new private investment that transformed the Courthouse Square into a thriving district. The downtown was reborn with a pedestrian-oriented landscape and a safer, more efficient traffic pattern. It has become a source of community pride, energy, and revenue. The area has seen more than 100 built and planned downtown residential units, dozens of new businesses, and creation of the community-centric Canal Market District. Conclusion: An integrated approach to design and funding can move a large sewer project forward and yield economic benefits. Newark implemented this methodology and realized the benefits of enhanced traffic patterns, pedestrian safety, and stormwater quality. In addition to addressing an EPA mandate to reduce combined sewer overflows, the change to the aesthetic landscape has brought real value to the city and surrounding region.

A new development towards the first worldwide guideline on the assessment of odor exposure by using dispersion modeling is taking its first steps. At this stage, there are many initiatives around the world related to dispersion modeling but there is no specific guideline for odor modeling to our knowledge. Modeling odors is complex and many of the guidelines on modeling published around the world fall short in treating this vector. Odor modeling often requires forgetting traditional dispersion modeling operating modes and focusing on exposure. Odors are perceived in seconds or minutes, not hours, and this is key in calculating their impact on ambient air. Most odor incidents are generated during calm or very low wind speeds which do not facilitate the dispersion of an odor and that makes modeling challenging. There are also elements that need to be further investigated, such as the chemical mechanisms of odors to avoid conservative treatment of odors, perhaps grouping 'odor types' by their chemical nature, so that it will be possible in the future to treat odors emitted by a WWTP differently than those produced by a composting facility. Last, but not least, there is a need to investigate the role of Instrumental Odor Monitoring Systems (IOMS) on the evaluation of model performance. Development of this guideline is an initiative promoted by over 36 experts around the globe in the area of modeling odors. The group is led by Dr. Gunther Schauberger and Ms. Jennifer Barclay. The first meeting took place in August 2020, and there are planned monthly meetings. The aim of this paper is to report on the advances being made for this initiative.

Background:
Situated between the Kansas and Wakarusa rivers, Lawrence, Kansas has an area of nearly 35 square miles divided into 11 tributary watersheds and 59 sub-watersheds. The 2020 Census population of approximately 95,000 reside within city limits, which is primarily developed with single family residential being the primary use. A large portion of the city is occupied by the University of Kansas and its associated properties. The enclosed stormwater system is comprised of over 17,600 structures and approximately 265 miles of piping, including both public and private infrastructure. The City of Lawrence, KS, is required to comply with a National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Program as part of the federal Clean Water Act. Historically, the common practice was to hire a consultant to evaluate stormwater data, run pertinent calculations, publish a report of projects that the City will get to when budget allows or enough concerns are raised to address. The City of Lawrence challenged that process and looked to its consultants as partners to provide holistic and interactive stormwater solutions to find a balance for the stormwater system. Approach: Managing a stormwater system requires balancing financial resources and physical system needs based on available data. The Stormwater System ID, Assessment & Model Creation Project, undertaken by the City of Lawrence, KS is an innovative approach to identifying stormwater assets condition, criticality, and serviceability. This data, along with modernized stormwater modeling methods, is helping identify cost effective solutions to managing the stormwater system. The project team, consisting of engineering consultants and City Engineering Staff have learned several lessons during this comprehensive project. This session will highlight lessons learned from a private consultant and municipal engineer's prospective and help others become wise from our mistakes and help you find balance in stormwater management.

What makes this project unique?
The City of Lawrence wanted to better understand its entire stormwater system, which encompasses the entire City, all 59 subwatersheds across nearly 35 square miles. All the asset inventory and condition information will reside in one primary database, Utility Network by ESRI. This dataset is shared with other utilities within the City, helping level the informational knowledge. Additionally, every structure will have a 3D digital model allowing users to visually confirm condition and routing. What can be learned from this project? There are evolving technologies in managing a stormwater system, but they all come back to having a good map and a plan of action. The foundation of this project, which can be used on other projects is a solid repository for data, aka a map. From that foundation, project engineers and asset managers can start piling on information to make the map more detailed, especially in a digital environment. One of the first benefits to a digital, ESRI based map, was the ability query quantities and assign statuses to assets. The project team created live dashboards that recorded a host of statuses which helped track progress and identify a punch list of structures or lines that needed attention prior to being labeled 'Inspection Complete.' The second foundational piece of the project was a plan of action. The scope of assets to be identified and appraised, initially seems to be an endless list of letters and numbers. Using digital maps and isolating work to be done in a specific watershed at a time, helped make the task of collecting all the data attainable. A prioritization of tributary watersheds was created, and field crews worked across the basins systematically. Another foundational cornerstone is communication. The project team and sub-teams held regular status meetings and huddles. These interactions allowed the entire team to maintain visibility on progress, areas that needed attention and successes. Having an engaged team across the variety of individuals contributing was key to consistency. The field team included staff from one of the consultants and from the City, this required coordination and communication of procedures and standard language. The data team processing and performing QA/QC had to communicate with field teams and modelers to ensure field data was accurate and incorporated into the models.

Innovation and Technology at Work
The mapping technology and ability to see and find additional details on assets is a game changer. But investing in innovation was important to the City of Lawrence for several reasons. -Data collection was done without having to put City or contractors at risk during manned entry of a confined space. -Asset physical measurement information, as well as condition assessments can be done with one touch of the structure while in office. Saving time and reducing field data collection errors. -TREKK 360 scans and models provide a snapshot in time to the current conditions of structures to be compared to future scans. -Modeling experts have a variety of easily accessible data to tune their model. -The affordability and simplicity of deployment allowed multiple crews to collect data simultaneously and rapidly. Reducing the field time and negative impacts of weather delays. Better understanding the stormwater system from an asset identification standpoint, aided the ability to accurately model the system. These steps were critical to understanding the status quo and what improvements will be required to improve the level of service across the City of Lawrence. Balancing the financial resources and setting an acceptable level of service will be the second presentation by our team members of Burns & McDonnell.

The management of PFAS has been a topic of discussion among the water/wastewater industry for the last few years, which has led to the development of the EPA's interim guidance for PFAS management. Our current understanding of both the extent of PFAS contamination nationwide in drinking water supplies and the concentrations that produce adverse health effects in the human body are in their early stages. What is certain is that PFAS will become an issue of growing concern over the next several years, if not decades, with the advancement of contamination site and health testing. Recently drafted EPA interim guidance and its key focus areas. The current on-going USEPA's PFAS Action Plan intend to develop MCLs for PFOA and PFOS in drinking water and to take steps to classify PFAS as hazardous substances. These actions have the potential to affect wastewater utilities in two keyways: (1) By requiring higher levels of treatment to protect downstream public water supplies and/or expanded source water protection measures; and (2) By limiting disposal options for PFAS contaminated waste or biosolids. States are also developing their own standards for PFAS in surface waters. The standards could be drivers for new permit limits and/or additional monitoring requirements for WWTPs. In turn, these requirements could result in costly investments in new treatment technologies to achieve a higher level of PFAS removal. Following States have already developed MCLs ahead of EPAs action plan: -New York established MCLs for PFOA and PFOS of 10 ppt individually -New Jersey adopted MCLs for drinking water for PFOS (13 ppt), PFOA (14 ppt), PFNA (13 ppt), and groundwater quality standards for PFNA (13 ppt), PFOA (14 ppt), and PFOS (13 ppt) -Michigan adopted groundwater cleanup standards for PFNA (6 ppt), PFOA (8 ppt), and PFOS (16 ppt), and MCLs in drinking water for PFNA (6ppt), PFOA (8ppt), PFOS (16ppt), PFHxS (51ppt), GenX (370ppt), PFBS (420ppt), and PFHxA (400,000ppt) -New Hampshire adopted drinking water MCLs for PFOA (12 ppt), PFOS (15 ppt), PFHxS (18 ppt), and PFNA (11ppt) -Vermont adopted a drinking water MCL for PFHxS, PFHpA, PFNA, PFOS, and PFOA of 4ppt individually and 20 ppt combined. -Massachusetts adopted drinking water MCLs for PFOS (3.3 ppt), PFOA (3.3 ppt), PFNA (3.3 ppt), PFHpA (3.3 ppt), PFDA (3.3 ppt) and not to exceed 20 ppt combined. During this presentation the following topic areas will be also covered: 1.Removal mechanisms of the PFAS treatment technologies focused on destruction, concentrating, and sequestration 2.'Off-the-shelf' and innovative treatment technologies 3.PFAS minimization as a primary management strategy and the fate and transport of PFAS when these substances are used Although most municipal wastewater utilities have not yet had to deal with PFAS issues, a proactive approach, starting with an initial PFAS risk evaluation is recommended. This initial risk evaluation is intended to provide municipal decision-makers with some idea of where their PFAS risks lie, as well as give them recommendations for next steps to inform proactive planning for PFAS response.

Wastewater analysis for SARS-CoV-2 RNA has been underway in various locations across the world since early 2020 and is a rapidly expanding area of research. There is a limited understanding of the behaviour of viruses within the sewer network. However, it is likely that the virus is subject to a range of biotic and abiotic factors which may influence its persistence and transit time within the network . Understanding this behaviour is key in developing sampling strategies which underpin an effective Wastewater Based Epidemiology (WBE) health surveillance system. Developing this understanding requires answers to a number of core questions, namely:

•Does the virus follow conservative flow regimes?
•Does the virus degrade in the sewer environment?
• How long does the virus persist in the network?
•What are the impacts of re-entrainment after weather events?

A better knowledge of these factors would allow better interpretation sample results in the context of the environmental conditions, which will also create the foundation for being able to triangulate and track the sources of viral outbreaks.

In the UK over 90% of the water and wastewater networks are representing in hydraulic models. These models have been built over the past 10 – 15 years and have been subject to millions of pounds of investment to ensure they are fit for purpose and accurate. These models have the potential to be a key tool in an effective WBE program if used in the right way. To date, development has primarily been focused on flooding, which is the core driver in the UK, and less so on the representation of water quality parameters.

Method

Through this study we worked to assess how well these models could be used to represented viral transport in sewer network, as well as identify any potential limitations.

To do this we worked in two catchments, each with different properties to deploy an enveloped viral marker at known places into the sewer network and then tracking its appearance at various locations. This work was complemented with the conservative flow fluorescent dye tracer, rhodamine-WT. We followed these tracers through the use of an autosamplers in the network over 17 days. Using these results, we then calibrated a hydraulic model (with contaminant transport processes) to understand the key parameters which influence transport (degradation rate, flow rate, rainfall, pipe material and roughness).

The models use the Innovyze Infoworks ICM modelling platform. In all cities the models were 'cut down' to represent only the major network with inflow files at junctions, as in Figure 1. This was done to increase the speed of the models.

In order to ensure accuracy these cut down models are checked against the full model to make sure there are no differences. The conditions on the sampling days were then re-created by adding any rainfall and inputting the markers at the upstream manhole, representing it as coliform.

Results

The different catchments each highlighted different challenges and opportunities. In the first there was a pumping station in between the input location and the sampling point. This meant that initially the model under predicted the travel time by over 4 hours. To counter this the impact of the pump was derived by including its operational controls. After this was done the time of travel matched that of the experiments closely, as seen in Figure 2. In our simulations we ran a number of scenarios with different T90 decay times. In Figure 2 it can be seen that a T90 of 10 – 12 hours most accurately matches the experiments. This influences the design of a sampling strategy or interpretation of the result to incorporate this decay of the virus.

In the second catchment there was a single straight run of pipe, with no significant hydraulic structures. However, we were unable to recreate the travel time accurately, as shown in Figure 3.

The models use a standard Dry Weather Flow day based upon when they were originally verified. We compared velocity measurements taken on the day of the experiments to the validation day and there was a large differential. This may be explained by changing water usage during Covid altering the flow patterns in the sewer, as was suggested by the flow monitor at the outlet point, as shown in Figure 4.

Conclusion

The key conclusion from the work is that it is possible to represent an enveloped virus in the sewer network through the use of hydraulic models. Both in terms of travel time and decay rate. However, using the models 'off the shelf' can lead to large inaccuracies as the models may not be validated/ developed with the intention for use in water quality modelling or water usage has changed during Covid with home working to the point at which the models are no longer representative. In these conditions having flow measurements recorded at the same time as sample extraction can lead to more certainty around the outputs/ results and allow for the models to be adapted to match reality.

If the models are fully validated it is possible to use the water quality modules to represent the virus transport with a T90 decay rate of 10-14 hours. This means that sampler coverage needs to ensure that areas outside of this distance from a sampler need to be covered by additional in-network samplers to represent SARS-CoV-2 prevalence. Or include scaling factors to incorporate the likely decay of the virus.
The transport of the virus is conservative (via advection), as a result if the key parameter of interest is travel time this can be calculated based on only knowledge of the network configuration and the flow rates. However, the models are still required to explore the relationship with decay rates.

Future work

The opportunity to represent other health markers and chemicals is being explored as well as whether these models can be run in real time and integrate real time sample data to track the sources of infection in communities.

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.

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.

Project Background Located in the northeast corner of Cleveland (OH), Cleveland Water Pollution Control (WPC) achieved its largest project to date by designing, and constructing 5,200' of 48' sanitary relief sewer along a curved residential street (Marcella Rd.), and a heavily travelled local business corridor (East 185th St.). Despite some obstacles during the nearly $15 Million construction project, the relief sewer was a major step to mitigate area basement flooding while minimizing construction impacts to residents and businesses. This presentation will highlight the advantages, disadvantages, design considerations relative to curved microtunneling, and lessons learned. Project Objectives After decades of basement flooding complaints from property owners, modeling of the sewers confirmed capacity and high I/I issues within the Area sewer flow monitoring and modeling preceded the project design. While the service area is comprised of separate storm and sanitary sewers, high amounts of I/I exist within the common trench sanitary and storm system. Since I/I elimination impacts greatly vary on their impact to an existing system, a relief sewer was proposed. Fortunately, NEORSD had previously stubbed an appropriately sized pipe for this area that we could tie into. The relief sewer was designed to remove over 48 MGD (74 cfs) from the sanitary system during the design 5-year storm. Benefits of Presentation Microtunneling no longer is considered a new construction method. However, installing pipe along curved microtunnel alignments is a newer industry capability. This unique approach allowed the sewer alignment to follow the natural curve of the roadway. A more typical open-cut method would require a significant number of manholes due to multiple changes in direction, plus the costs associated with full depth roadway replacement, and sewer lateral replacement. This presentation will highlight current microtunneling methods and capabilities, construction area needed for launch shafts, receiving shafts, spoils processing equipment, and storage. Additional useful design information will be provided such as the importance of a thorough geotechnical report, and budgeting for unforeseen conditions. This presentation will highlight practical reasons to pursue microtunneling as an option, as well as cost comparisons to a typical open-cut installation. On East 185th Street specifically, open-cut construction would have exposed an old 72' brick storm sewer, and undermining the bedding/soils was not a risk the City was willing to take. The project also included acquisition of a small easement to accommodate microtunnel radius limitations. While land acquisition is not part of the City's typical design approach, the easement was easily acquired as the property owner got compensated without any disruption on their property. Proactive planning allowed for the necessary time for the City to obtain the required easement appraisals, and time to negotiate the acquisition before bidding and construction. Microtunneling was also a very attractive method for the City since East 185th Street is a heavily trafficked corridor with businesses, street parking, and walking traffic. Status Project construction occurred from August 2019 to November 2020. The microtunnel portion accounted for approximately 8 months of the 15 month project. As the COVID-19 pandemic emerged, the contractor was initially delayed, however once the proper safety procedures were setup, time was easily regained with the tunneling crews working night shifts. Since the night shifts were specifically for the tunneling process, worker safety due to visibility was not an issue. The tunneling equipment did have to be located in a suitable area due to the noise created, and the contractor obtained a waiver to vary from the City's noise ordinance. The microtunneling progress averaged around 34 feet per day (or shift) of progress with the tunnel. 4 months of post-construction monitoring was completed from mid-April through mid-August to compare the model's predictions to actual flows, and to demonstrate the need for additional sewer upsizing in the upstream area. The flow data did indicate that the sidestreets east of E. 185th need additional capacity. This was evident from the monitoring data as the main along E. 185th had capacity while the sidestreets were surcharged during an event near to, but less than a typical 1-year storm. Learning Outcomes - Microtunneling can reduce risk where open-cut construction would expose aging, expensive, or fragile utilities. - Budget time and money for unforeseen obstacles such as boulders and utility relocation. - Avoid or move overhead utilities before the project. Launch/receiving shafts for the manholes need to be accessed with large equipment/cranes, coordinate with utilities to mitigate construction delays. - Attendees will gain knowledge of what is possible with microtunneling, when to use or avoid microtunneling, and how to plan and budget for a microtunneling project. Conclusion This was a very important project for the City of Cleveland as the area has a long history of reported basement flooding, and action toward reducing the frequency of these events needed to be taken. The City was open to the bold approach of installing the sewer along a curved alignment via microtunnel to maintain vehicle, and pedestrian access, knowing the costs could be slightly higher than the open-cut method. The community was also very accepting of the approach, as though multiple community meetings we indicated the construction will help relieve future water-in-basement events with minimal disturbance. Home and business owners lying within the zone-of-influence of the tunnel had further confidence since the contractor offered to video inspect their basements before and after the project in addition to multiple ground points which were surveyed weekly to insure the tunneling was a safe method.

Municipalities, water agencies, and communities in Los Angeles County, California are working collaboratively to identify, fund, and implement regional multi-benefit stormwater capture projects that provide equitable benefits to the communities they serve. The City of Inglewood, a disadvantaged community in Los Angeles County, used funding provided through Los Angeles County's Safe, Clean Water Program, to develop a feasibility study for a regional stormwater capture project at its historically significant Edward Vincent Jr. Park. Building off the original stormwater improvements concept developed for the site, the study assessed an optimal selection of best management practices (BMPs) and enhanced park amenities to provide a range of benefits to regional partners and the surrounding local communities. The primary project components developed through the feasibility study include an infiltration gallery to maximize stormwater capture for the 895-acre contributing area, a dry creek channel that seeks to mimic a historic watershed feature, and a bioretention system that prioritizes nature-based solutions while conserving and enhancing park space. In considering the existing park infrastructure, the feasibility study identified opportunities to improve the baseball field, create a boardwalk over the bioretention area, build out the dry creek to add natural seating for park users, and provide educational signage to highlight the park's green infrastructure features and the importance of stormwater management. The overall project looks to incorporate green infrastructure while considering placemaking and education opportunities. The engineering solution becomes an opportunity to create a new circulation spine and organizing element that enhancements can be built around, defining an enhanced community space while leaving ample opportunity for the community to provide feedback on program and amenities design during future phases of the project. The presentation will focus on how the City of Inglewood is partnering with stakeholders to develop a multi-benefit project that will be implemented to meet stormwater compliance but with significant and expanded benefits to park users and the broader community. The presentation will provide the audience with examples of how to: Identify and incorporate park needs and community interests. Integrate planned projects into concept designs to enhance the connection with stormwater improvements. Improve site access, mobility, and safety for the community. Collaborate with stakeholders to understand project impacts and identify additional benefits

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.