Conference Papers

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

Our presentation will summarize the importance of incorporating resiliency and condition assessment into regional wastewater master planning to develop a balanced long-term capital improvement plan. The plan addresses traditional master planning considerations such as growth, hydraulic capacity and level of service, but also addresses asset condition, remaining useful life of critical assets, and system resiliency. Broward County Water and Wastewater Services provides drinking water for 59,000 customers while serving as a regional wastewater authority for over 600,000 residents in South Florida, with treatment at its North Regional Wastewater Treatment Plant. The plant and the regional transmission system are presented in Figure 1. The regional system is a pressurized transmission system receiving wastewater from both local systems and large wholesale customers, with eleven master pump stations that serve multiple gravity collection systems. The root need for the master plan is to address the aging infrastructure in the regional system and ensure reliable service for both the local and wholesale customers. While traditional master planning activity including hydraulic modeling and capacity assessment were performed, the traditional evaluation was augmented by the following modern master planning activities:
1. Condition assessment of the eleven master pump stations was performed for individual architectural, structural, building mechanical, process mechanical, and instrumentation and control assets. Figure 2 presents the asset score for one of the pump stations, with lower scores assigned to better asset conditions. As shown in the figure, the pump station was evaluated on nearly eighty individual assets to develop specific recommendations for each key asset in the station.
2. The hydraulic capacity assessment included a system resiliency evaluation to determine which branches of the transmission system have adequate redundancy in the event of a main break, and which branches can be more reliably served with a parallel relief main. In the example presented in Figure 3, a transmission main break downstream of four master pump stations can be mitigated by a regional relief main to the east. The evaluation determined that the majority of the central system has adequate redundancy to maintain service in the event of a break, following the installation of isolation valves to route the flow to the Northwest plant via one of the looped mains.
3. Transient modeling was performed to identify potential hydraulic issues from a sudden shutdown of a master pump station. In the example presented in Figure 4, the addition of a combination air and vacuum valve can mitigate the potential for vacuum conditions in the transmission mains following the sudden shutdown of the pump station.

From the elements of the planning process, a capital improvement plan that addresses hydraulic capacity, transient mitigation, asset condition, and resiliency was developed for the County's long-term implementation. By addressing each of these elements together, the plan is holistic and adaptable as the County moves forward. At the time of this abstract, the condition assessment, hydraulic modeling, transient modeling, resiliency analysis, and capital improvement plan development are final and complete. The overall master plan will be complete by November 2020. Our presentation will benefit any wastewater utility that is in the master planning process or considering developing or updating their master plan. While the case study is applicable to any wastewater utility, there will be additional benefits to any utility that operates regional transmission mains or manifold force mains with multiple pump station inputs.

Summary This paper and presentation will discuss the in-plant operating conditions leading to a late-in-the-design-process dewatering technology selection reevaluation for the Charleston Water System's (CWS) main wastewater treatment facility, the Plum Island Water Pollution Control Plant (PIWPCP). Specifically, the paper will discuss the steps taken to reevaluate the solids dewatering design after 90% design completion by transitioning the selected dewatering technology and making this change while minimizing impacts to the construction schedule already underway. The efficient and timely redesign around a new dewatering technology was achieved by leveraging onsite pilots, solids sampling and off-site assessments, as well as manufacturer presentations to assist CWS in reviewing the preferred technology vendor options. Ultimately, CWS selected centrifuges to replace the originally selected rotary fan press technology to ensure improved dewaterability across a wide range of influent characteristics. Furthermore, the paper will discuss the design challenges associated with accommodating a dewatering technology change while concurrently minimizing impacts to the building footprint and structural design in order to curtail construction sequencing design delays and allowing the Construction Manager At Risk (CMAR) contractor to begin pile driving and sub-surface foundation work as originally scheduled. Background The Plum Island Water Pollution Control Plant (PIWPCP) is the main wastewater treatment facility for Charleston Water System (CWS), providing wastewater treatment for the City of Charleston, Daniel Island, James Island, and several surrounding municipalities. The facility is positioned on a 22-acre island surrounded by salt marsh and discharges to the tidally influenced Charleston Harbor at a rated capacity of 36-MGD. This location causes significant constructability issues due to high ground water from tidal influences and local major rain events coupled with challenging subsurface issues and seismic codes requiring major structures to be built on pile supported foundations. Prior to design, a long-term facility master plan had been completed for the PIWPCP identifying facilities required to accommodate currently permitted flows of 36-MGD with expansion up to an ultimate facility capacity of 54-MGD on both the liquid and solids treatment trains. In accordance with the master plan recommended improvements, new solids handling facilities were included as part of the Phase 4 Capital Improvements Project. These capital improvements included the following new solids handling processes: - New Solids Handling and Dewatering Building with Rotary Fan Press dewatering technology - Three (3) Sludge Storage Tanks with Blending Pumps - Dewatered Cake Storage Sludge Hopper and Loadout Facility The existing dewatering unit process equipment at the facility includes three (3) rotary fan press dewatering units which dewater a blend of undigested primary and secondary solids resulting from the liquid treatment process. Secondary solids are gravity thickened prior to blending with the primary sludge solids immediately upstream of dewatering in a blending tank. CWS had many years of acceptable operating experience (See Figure 1, January 2017 through October 2021) with the existing rotary fan press technology entering the detailed design phase of the upgrade and had thus selected the same technology to utilize in the new dewatering facilities to be constructed during the Phase 4 Capital Improvements Project. The originally proposed Phase 4 Solids Handling Building was designed to hold up to seven (7) 8-channel rotary fan presses with ancillary feed, polymer makeup, and conveyance equipment to meet long-term buildout solids handling needs and accommodate facility expansion up to a 54-MGD ultimate treatment capacity. However, during the later stages of the facility design, CWS identified insurmountable issues with the existing rotary fan press technology used for dewatering (See Figure 1, After October 2021). Steep declines in dewatered cake solids content resulted in increased wet cake mass and volumes for transportation and disposal at a local landfill facility, significantly increasing downstream disposal costs. Concurrently, the local landfill was significantly increasing tipping fees for 'wet waste', further exacerbating solids disposal costs for CWS. In addition to reduced dewatered cake solids content, the rotary fan press solids and hydraulic loading rate performance declined which would require increased numbers of dewatering units to process the anticipated solids loadings under current and future operating conditions. This combination of impacts, decreased dewatered cake solids, increased downstream management costs, and reduced rotary fan press performance, caused CWS to investigate and reconsider the dewatering technology selection and basis of design for the new facility after the rotary fan press design had advanced to the 90% completion level. Upon further investigation, it was determined that influent characteristics at the plant had changed since the initial assessments, causing a detrimental impact on the proposed dewatering equipment performance. Some of the impacts were due to a new influent conveyance tunnel system and collection system behavior between wet and dry periods, new headworks facilities with increased grit removal capability, and new primary and secondary treatment facilities which were included with recently completed capital improvements projects (Phase 2 and Phase 3 projects). Following this initial investigation, CWS approved reconsideration of the dewatering technology selection to include other dewatering technologies (e.g., belt presses, centrifuges). Alternative Technology Selection Immediately following the decision to reconsider the dewatering technology selection, work began to conduct on-site pilot and demonstration testing of belt filter presses and centrifuges. Concurrent demonstration testing was conducted on the same feed sludge for the existing rotary fan presses, a trailer-mounted belt filter press, and a trailer-mounted centrifuge to assess dewatered cake performance and other design parameters for each technology. Table 1 and Figure 2 show the results of the concurrent dewatering technology testing. On-site testing was coupled with off-site and bench scale testing across a range of primary and secondary sludge blends to understand the impact of the primary to secondary sludge (PS/WAS) ratio on anticipated dewatering unit performance to inform operational decision making. Lastly, potential technology suppliers were invited to make presentations to CWS regarding their technology offerings. Ultimately, CWS selected high solids, horizontal decanting centrifuges to replace the rotary fan presses to ensure improved dewaterability across a wide range of influent characteristics and PS/WAS ratios. Following the updated technology selection, the planned dewatering facility had to be redesigned on an accelerated schedule for the new technology while staying within the same building envelope to retain as much of the prior design structural framing and layout as possible to expedite the design and permitting processes. This paper will share some of the design challenges associated with and overcome with the conversion from rotary fan press to centrifuge dewatering technology across the various engineering disciplines (e.g., process mechanical, structural / architectural, and electrical and control systems). Updated design of the new dewatering facility has since been completed with centrifuges (See Figure 3 for a rendering comparison) and construction is currently progressing on the facility.

Conceptualized in 2006 and completed in early 2021, the Lick Run Greenway in Cincinnati, OH, is a unique example of how a community and a wastewater utility can work together on a creative, green solution for sewer overflows. On the surface, the Lick Run Greenway looks like a park with a stream running through it, but this stormwater management/combined sewer overflows (CSO) reduction project eliminates 800 million gallons of CSOs annually into the Mill Creek, which in 1997 was named the most endangered urban waterway in America. In 2006, the Metropolitan Sewer District of Greater Cincinnati (MSD) began working on a Wet Weather Program with a focused solution for the Mill Creek. The original project was a purely gray concept: a CSO storage tunnel. MSD proposed a green alternative that would not only meet the same CSO reduction goals at a reduced cost but also help revitalize a disadvantaged community. MSD deliberately selected and brought the project to South Fairmount, a low-income, transient neighborhood that was once a thriving community. The basis of the project was could we fix an environmental problem while also reinvigorating a neighborhood. From the beginning, the project sought to not only to inform local residents, but to engage them in the decision-making process, including historic/cultural mitigation and a series of community design workshops that led to a Master Plan. During construction, MSD continued to engage through public meetings, tours, neighborhood briefings, social media, website, media coverage, and monthly drone flyover videos showing construction progress. MSD additionally developed a series of educational signs on the cultural history of South Fairmount and ecological benefits of the project. The signage was also converted into a virtual experience for visitors through the Lick Run Heritage Trail website. As the project neared completion, MSD turned its attention to how to make the park welcoming, clean, and safe for visitors and a resource for outdoor and environmental education. In early 2021, MSD rolled out the Lick Run Greenway Ambassador program, which includes an Adopt-A-Spot program, hiring local youths through a partnership with the Cincinnati Recreation Commission (CRC) and Groundwork Ohio River Valley to welcome visitors and help beautify the Greenway, and designing an anti-litter campaign. MSD also began working closely with the South Fairmount Community Council and Cincinnati Recreation Commission to help bring programming to the Greenway. In early summer 2021, MSD hired a college co-op to create and host weekly interactive, pop-up environmental education events geared toward children. The intern also created partnerships with the Queen City Pollinator Project and Cincinnati Red Bike. During the summer of 2021, MSD hosted a number of programs for the community at large, including an inaugural 5K run/walk, a Cincinnati Symphony Orchestra concert, a community-wide cleanup, and a Pumpkin Fest. Planning for 2022 is already underway, with the intent of bringing more programming and more environmental education to the South Fairmount community. The South Fairmount community has embraced the Lick Run Greenway, and MSD has embraced the challenge of helping revitalize this neighborhood.

Nature-based solutions offer a breakthough in addressing regional and local stormwater needs. The efficacy of these solutions, though recent in adaptation, are now well documented. The benefits are global across the stormwater and water resource spectrum. Across the United States as well as globally, larger regional projects with multi-disciplinary nature-based components are gaining acceptance and popularity in lieu of traditional project by project stormwater management or as a compliment to green infrastructure programs. The White House and National Climate Task Force recently developed and published a framework to accelerate nature-based solutions in November 2022. Clients across the US are actively developing these types of solutions for flooding, erosion, water quality, ecological uplift and habitat restoration, wetland mitigation and for compliance with impaired waterbody criteria. The strength of regional nature-based solutions is that a single project can provide multiple benefits rather than a single benefit such as flood reduction or stormwater capture that traditional approaches focus upon. This also opens up such projects to additional grant and partner funding as these projects may include resiliency, sustainability, mitigation or ecological benefits as well as the ability to address the needs of multiple projects and stakeholders rather than just one. In aggregate, these projects can be more cost-effective than traditional approaches. The Florida Department of Transportation (FDOT) completed a regional project in which an area of poor water quality in a stagnant bay was addressed with bridge cuts in a causeway to improve circulation and water quality and set up a water quality credit bank to address any project that drained to the bay that could be used instead of constructing traditional stormwater ponds and linear stormwater management. An internal FDOT audit concluded the project saved $100 Million over traditional construction and maintenance heavy approaches as well as resulting in much better receiving waterbody quality. In addition, nature-based solutions have a much lower carbon footprint than traditional approaches. In many cases they act as a carbon sink rather than a carbon producer. Based on the success and documented results of several nature-based solutions as well as non-traditional approaches to stormwater management in Florida that have run gamut from wetland restoration for ecological and floodplain mitigation as well as stormwater quality, utilizing stormwater for reclaimed water reuse, septic tank removal in impaired springsheds, tidal circulation improvement to address receiving water quality to seagrass restoration and ecological habitat uplift, FDOT developed a statewide manual to encourage nature-based, innovative stormwater solutions. One of the reasons traditional project-by-project stormwater solutions remain a strong option is the efficiency of a single stakeholder and project as well as a predictable design framework. To address these issues, the FDOT identified several strategies to improve adoption and success of multidisciplinary, multi-benefit nature-based and innovative stormwater solutions. These include: -Early identification of opportunities in planning stage -Early stakeholder engagement -Program wide approach so multiple projects can be tied to a regional solution\ -Early permit agency engagement to achieve buy in on novel stormwater management approaches -Exploration of grant and stakeholder funding -Development of a GIS-database to identify specific watershed issues and opportunities -Early identification of skillsets outside traditional stormwater approaches Regional nature-based approaches are likely to continue to increase. In addition to stormwater, they apply to water supply and infrastructure, environmental mitigation and restoration and coastal approaches such as living shorelines as opposed to traditional hardscape. It is often much easier to obtain public and environmental support and buy in for a regional stormwater facility that restores a natural hydrologic system, includes park or eco-tourism elements and serves multiple highways, developments or projects within a watershed than it would be for a traditional project and approach. As such, these projects are a win-win for a broad spectrum of clients and stakeholders. In addition, nature-based approaches are able to better accommodate and scale with climate change and hence are more sustainable and resilient.

Prince George's County, MD is located within the 80,000 square mile Chesapeake Bay watershed. EPA and the State of Maryland prepared the Chesapeake Bay Total Maximum Daily Load (Bay TMDL) for restoring the Chesapeake Bay's chemically, biologically and physically impaired waters. The Bay TMDL requires States, Counties and Cities within the watershed to limit the amount of Total Phosphorus, Total Nitrogen and Total Suspended Sediment that is discharged through point and non-point sources (urban stormwater runoff). Prince George's County combined meeting regulatory requirements with targeted local workforce and business development for this pioneering alternative delivery project. Prince George's County (County) and Corvias Infrastructure Solutions (CIS) developed the Clean Water Partnership (CWP) to design, build and maintain urban stormwater quality treatment best management practices (BMPs) to meet the County's Bay TMDL obligations. In addition to infrastructure improvements, the CWP balances risk, priorities, and social needs, through this Community Based Partnership (CBP). Bringing financing, engineering design firms, contractors, outreach and social/economic goals to this project, environmental compliance is being achieved with local economic growth and community involvement. This groundbreaking and innovative alternative delivery method is the first in the country and required a pioneering, dynamic and responsive team effort to meet the multiple program objectives. The two main CBP program elements include: 1) Environmental goals of design, permitting and construction of stormwater treatment devices, located throughout the 500-square mile County, to treat urban stormwater runoff. 2) Social and economic goals to meet aggressive target class utilization (40% for local, small and minority businesses) and local workforce (51% county resident utilization). Between 2016 and 2021, CWP has successfully implemented over 150 projects, certified over 300 BMP devices to help meet the County's MS4 stormwater permit requirements. In this process, CWP spent over $140 million in design and construction and reduced approximately 53,700 lb. of Total Nitrogen (TN), 7,300 lb. of Total Phosphorus (TP) and 4,405,100 lb. of Total Suspended Solids (TSS). In addition, more than 15,000 acres of drainage area is also treated to reduce pollutants to Chesapeake Bay. A key to the success of the CWP Program has been clear programmatic metrics including indicators and beneficiaries from day one. Primary program metrics focused on schedule/speed, scale economies and performance, community outreach, local disadvantaged subcontractor utilization, local subcontractor development, workforce utilization, and workforce development. Additional metrics were related to alternative compliance and partner programs, and project budget books and schedules. Moving forward, the CWP Team is focused on executing efficiencies to design and construct additional large pond retrofit projects and stream restoration projects based on their monitoring and tracking of BMP cost-effectiveness throughout earlier phases. In addition to complete data inventories on the number of BMPs built and drainage area managed, the CWP Team analyzed pollution removal and cost data of BMPs to determine Total Nitrogen, Total Phosphorus and Total Suspended Solids reduction for 10+ different types of BMPs. This performance summary information directly influenced the planning and siting of each subsequent phase of BMP design and construction. At the same time the Program Management team will continue to rely on performance data and think creatively to achieve its program goals and metrics in future phases. The CWP team has been focusing on asset management as the Program matures to its subsequent phases. This presentation will provide useful information for utility and public works department leaders, and stormwater management staff about creating or tailoring an existing program to meet large-scale targets for capital project delivery intended to meet water quality goals or other stormwater related objectives such as resiliency and flood risk reduction. Partnership goals, organizational structures and integrated delivery partners roles and responsibilities, and program metrics will be shared for discussion. Detailed information will also be presented related to specific program elements and BMP performance data that helped the CWP Team to achieve program milestones. As more communities face increasing regulation and climate-related threats to their stormwater infrastructure, bundling capital improvement projects for cost-effective and timely implementation may be necessary. The CWP Team will share lessons learned from their 6+ years of program execution, specific keys to success for other communities to consider and adaptive management strategies for future CWP success.

A post-treatment process is required to reduce the volume temperature-phased anaerobic digestate (TPAD), so that it can be more easily transported and disposed of. The digestate liquid fraction contains a lot of nutrients as well and biosolids might contain pathogen. Traditional dewatering process that uses expensive polymers, separates solid and liquid parts to produce condensed biosolids. Polymer conditioning focuses only on volume reduction. TPAD has a high solid content which makes dewatering difficult. Other challenges associated to digestate dewatering such as nutrient and resource recovery, odour control pathogen contamination in biosolids is not addressed in traditional polymer conditioning. It is hypothesised that metal salts as coagulant and oxidants are added along with polymer to enhance the post-treatment of TPAD that would enhance dewatering, nutrient and resource recovery and pathogen elimination in dewatered biosolids. Through the combination of chemicals, the current research seeks to increase TPAD post-treatment efficiency by improving the removal of P in the liquid fraction while producing a Phosphorus (P) rich and pathogen free class A biosolids. To compare the effects of polymer conditioning alone, conditioning with polymer with ferric chloride (FeCl3), polymer, FeCl3 along with hydrogen peroxide (H2O2) before centrifugal dewatering, cationic polymer alone, combined polymer with FeCl3, and cationic polymer with FeCl3, H2O2 in a pH-controlled environment. The best combination of chemicals was 2.5 kg/t DS polymer, 2.1 kg/t dry solids (DS) FeCl3 and 600 mg/l H2O2 at pH 8.0 with the lowest turbidity 11 NTU, specific resistance to filtration (SRF) 0.08 Tm/kg, capillary suction time (CST) 11.5s. The combined chemical dose shows a 94 to 99% improvement in dewatering indices such as CST, turbidity and SRF than raw TPAD. Around 88 to 90% decrease in centrate, TS2- and PN/PS ratio was also observed that contributed to odour causing potential and increased dewatering efficiency. 100 % P removal was achieved with no P in the centrate and P rich biosolids was produced with 40% cake solid content after combined chemical conditioning. However, the fecal coliform level of raw TPAD cake from the full-scale plant exceeds the regulatory limit. The dewatered cake turned into class A biosolids with just 57 MPN/g DS fecal coliform content after combined chemical conditioning in the lab scale study. In comparison with untreated TPAD cake, pathogens were reduced 100%. Combined chemical application reduces polymer dose by 40% as well as associated cost. The novel combined chemical treatment with cationic polymer, FeCl3, and H2O2 at adjusted pH are used to enhance digestate efficiency as well as reduce costs, storage requirements, and address nutrient imbalance, pathogens, and odors that offered more sustainable management. Wastewater treatment plants are thereby recommended to adopt the novel combined chemical conditioning the synergistic chemical combination of polymer, FeCl3 and H2O2, adjusting pH at 8.0 with Ca(OH)2 for TPAD post-treatment while assessing the full scale adaptability through pilot studies.

BACKGROUND The William E. Dunn Water Reclamation Facility (WEDWRF) is in Pinellas County, Florida and is operated by Pinellas County Utilities to treat wastewater collected from the County's northern service area, and to generate reclaimed water supply for the County's reuse distribution system. The WEDWRF is a 9.0 MGD capacity advanced 5-Stage Bardenpho process wastewater treatment facility that currently operates at an annual average flow of approximately 6.5 MGD. The existing solids management system for the WEDWRF includes two (2) rotary drum thickeners (RDT) for thickening waste activated sludge (WAS), two open top sludge holding tanks, two (2) belt filter presses (BFP) and truck loading bay. The existing BFP are old and require replacement. A pilot scale dewatering study was conducted with the following objectives: 1.Evaluate the dewatering performance of new belt filter press and centrifuge. 2.Optimize the polymer dosage to maximize cake solids and solids capture. 3.The efficacy of generating thickened waste activated sludge (TWAS) using RDT to thicken WAS prior to dewatering or bypass the RDT to directly dewater WAS as an operational, energy and polymer cost saving measure. 4.Analyze composite samples of centrate/filtrate stream for Chemical oxygen demand (COD), Ammonia and Phosphorous to determine the quality of the reject stream back to the headworks. 5.Perform life cycle cost analysis of dewatering operation and maintenance for BFP and Centrifuge. PILOT TESTING SCHEDULE The pilot testing was conducted between April 18, 2023 - June 6, 2023. Alfa Laval's BFP was tested between April 18 - April 20 for WAS, April 25 - April 27 for TWAS. Andritz centrifuge was tested between May 9 - May 11 for WAS, May 15 - May 17 for TWAS. Alfa Laval's centrifuge was tested between May 23 - May 25 for WAS, June 5 - June 6 for TWAS. A filtrate/centrate stream composite sample was collected on each day of pilot testing for both WAS and TWAS. RESULTS 1.Waste Activated Sludge The percent cake solids (%TS) obtained for WAS in Alfa Laval BFP ranged between 16.8-18.5% for the polymer dosage ranging between 10.0-16.8 lb/Ton. The solids capture for BFP was between 95 - 99%. Similarly, the percent cake solids (%) obtained for Andritz and Alfa Laval Centrifuge ranged between 20.0-24.5% for polymer dosage ranging between 14.5-62.9 lb/Ton for Andritz centrifuge and 13.2-35.7 lb/Ton for Alfa Laval centrifuge. The solids capture for Andritz centrifuge ranged between 89-96% and Alfa Laval centrifuge ranged between 94-99%. 2.Thickened Waste Activated Sludge The percent cake solids (%TS) obtained for TWAS in Alfa Laval BFP ranged between 15.8-17.7% for the polymer dosage ranging between 7.3-11.4 lb/Ton. The solids capture for BFP was between 96-99%. Similarly, the percent cake solids (%) obtained for Andritz and Alfa Laval Centrifuge ranged between 18.7-22.7% for polymer dosage ranging between 18.7-44.8 lb/Ton for Andritz centrifuge and 27.0-32.0 lb/Ton for Alfa Laval centrifuge. The solids capture for Andritz centrifuge was between 84-99% and Alfa Laval centrifuge ranged between 94-99%. 3.Centrate/Filtrate Analysis A composite sample of centrate/filtrate was collected on each day of pilot testing for both WAS and TWAS. For WAS centrate stream, the concentrations of COD ranged between 60 - 470 ppm, ammoniacal nitrogen between 0.1 - 0.3 ppm, total phosphorus between 2 - 48 ppm. For TWAS centrate stream, the concentrations of COD ranged between 102 - 2,440 ppm, ammoniacal nitrogen between 0 -150 ppm, and total phosphorus between 133 - 490 ppm. It is noteworthy to mention that the concentration of analytes reported here as received from the contracted laboratory. The key observations in the filtrate/centrate composite sample analysis are: 1.Concentration of the analytes appear to be lower during the belt filter press dewatering operation when compared to the centrifuge dewatering operation. 2.Concentration of analytes for TWAS filtrate/centrate stream appear to be significantly higher than for WAS. This indicates that there is release of nutrients in the holding tank. 3.The P concentration in the filtrate for TWAS appears to be in high enough concentrations that it could lead to the formation of struvite in the facility. This could decrease the dewaterability of the sludge and create maintenance issues, due to buildup in pipes and valves, at the facility. KEY TAKE-AWAYS The pilot testing results indicate that both BFP and centrifuge technology could be suitable for WEDWRF dewatering improvements. The BFP consistently achieved a cake solids concentration of 17.5 (%TS) for WAS. In the case of TWAS, the average percent cake solids were about 17.0 (%TS). Similarly, both the centrifuges performed better than BFP producing cake solids at an average of 22.0-23.0 (%TS) for WAS and 20.0 (%TS) for TWAS. However, the polymer consumption in the case of centrifuge was at least twice as much as BFP polymer consumption for both WAS and TWAS to achieve a 3-5% increase in percent cake solids. The centrate/filtrate composite analysis samples showed interesting observations with high concentrations of nutrients for TWAS. This could be attributed to the release of nutrients in the sludge holding tank. A determination of the exact duration and conditions that would cause this release of nutrients and soluble COD is something the pilot did not focus on. An understanding of the impacts of sludge degradation in sludge holding tanks especially in hot summer months is important for this and many other plants that use sludge holding tanks as buffers to limit plant dewatering operations schedules to only a few days a week. This could also impact the dewaterability of TWAS which was evident as the cake solids (%) obtained in TWAS was relatively lower than WAS. Furthermore, higher nutrient and COD loading in the centrate stream recycled to the headworks of the plant could lead to increase in aeration demands to treat the increased ammonia load . Similarly, there could be an impact in disinfection chlorine demand. To conclude, both BFP and centrifuge should be evaluated for both WAS and TWAS to have a complete understanding of overall life-cycle cost implications on each of those equipment. Life cycle cost analysis will be performed and presented by the time of Residuals and Biosolids Conference in 2024. This presentation will cover the pilot testing equipment operating parameters, feed characteristics, relationship between wastewater sludge cake solids and polymer consumption of dewatering WAS and TWAS, important parameters for plant operations decision making. Furthermore, the presentation touches upon nutrient and COD impacts of dewatering recycle streams and their potential impacts on plant effluent limits. ACKNOWLEDGEMENTS The presenters thank Pinellas County Utilities, Alfa Laval, and Andritz for providing pilot testing equipment trailers and for assisting during the pilot testing phase.

U.S. Army Corps of Engineers (USACE) accepted in 2019 post-construction monitoring as completed for the BNSF (Burlington Northern Santa Fe, LLC) Railway Company Intermodal Facility (IMF) mitigation conservation corridor located in the City of Edgerton in southwest Johnson County, Kansas. Presentation focuses on the successful design and implementation of nature-based (NB) stormwater management strategies associated with development of a complex industrial site as verified by annual monitoring. The purpose is to demonstrate that a carefully planned and designed ecological corridor can work in symbiosis with an adjoining industrial development to mitigate adverse impacts and enhance environmental benefits. Site is located approximately 35 miles southwest of downtown Kansas City, providing positive local context in support of the WEF SWI Stormwater Summit 2023 conference. The technologically advanced IMF enables efficient intermodal freight shipments within the BNSF rail network to the Kansas City region. Strategically siting the complex industrial development relative to key rail and highway transportation infrastructure required realigning approximately 2 miles of an unnamed Big Bull watershed tributary. Onsite mitigation was required to beneficially enhance, create, and restore the ecosystem functions and values of impacted wetlands and streams. The conservation corridor is excluded from future development or disturbance by perpetual easement, providing ecologically sustainable and long-term natural environmental benefits. Planning and design required considering watershed functions and values relative to stormwater management; water quality improvement; flood risk management; wetlands preservation; erosion control; and in-stream/riparian habitat conservation. The resulting ecological conservation corridor comprises approximately 59 acres; includes seven stormwater best management practice (BMP) areas; relocated stream with floodplain/floodway; and five restored wetland cells. Natural stream restoration techniques were used to realign the stream in a strategically sited and centrally located ecological corridor. Stream relocation included 31.23 acres of riparian buffer creation and 8.79 acres of riparian buffer enhancement. Development required realignment of 9,247 linear feet of a perennial stream to 7,747 linear feet of relocated channel with reference channel dimension, pattern, and profile. Riparian buffer areas included 16.75 acres of newly created shallow marsh and emergent/scrub-shrub zone wetlands for stormwater management. BMP treatment features manage site runoff from the IMF and surrounding areas prior to discharging into the relocated stream. At each stormwater outfall, a treatment train approach is used, including a forebay area (energy dissipation and sediment trap), constructed wetland area (water quality treatment), and vegetated outflow swale. A detailed water budget analysis evaluated the expected surface water runoff into the wetlands and modeled the hydrology of the wetlands to replicate natural conditions with the design. Onsite wetlands restoration included 7.18 acres not within riparian buffers, including a large emergent (herbaceous) wetland area in the center of the conservation corridor. Sustainable materials were primarily used to construct natural stormwater and erosion control features to provide water quality treatment for onsite drainage runoff before discharge to the relocated channel. Restored wetlands, riffles, pools, and ecologically designed drainage basins improve water quality, promote detention/infiltration, restore natural habitats, and mitigate indirect environmental impacts. Hard structures constructed with concrete and riprap were minimized. Where possible, onsite rock and vegetation were sourced for wetland and stream stabilization. Sustainable nature-based stormwater techniques and features utilized in design/construction will be presented. Relocation of the stream with detailed design of drainage features effectively reduced downstream peak flows and upstream base flood elevations (BFE). The realigned conservation corridor reduces the BFE at the upstream project limits by 3.63 feet. The first decade of operation has shown no evidence of channel instability (down-cutting, deposition, and bank erosion). Approximately 300-acre feet of annual runoff is routed through the wetlands. Monitored wetlands continue to demonstrate healthy and flourishing hydrophytic vegetation. The wetland detention ponds have successfully promoted nutrient reduction, sequestered carbon, recharged local water tables, and generally improved water quality. The naturally inspired conservation corridor and mapped floodway is a readily identifiable feature at Logistics Park Kansas City (LPKC). The corridor represents one of the largest local on-site mitigation efforts in Johnson County, providing habitat creation in conjunction with stormwater runoff treatment. Johnson County's Big Bull Creek Park is located immediately downstream of the conservation corridor, extending the corridor's environmental and water resource ecological conservation benefits into a 2,060-acre strategic prairie conservation and restoration area. The managed conservation corridor demonstrates the project team's commitment to minimize environmental impacts and contribute to long-term sustainability of communities served. The naturally landscaped floodway provides sustainable habitat for wildlife, waterfowl, and pollinators, while prioritizing stormwater and floodplain management. The presentation objective is to demonstrate how stormwater management functional requirements can be sustainably integrated with nature-based design features strategically sited within an ecological conservation corridor. The desired outcome is that the presentation will encourage participants to consider similar stormwater management strategies that are both environmentally beneficial and consistent with best management and design practices.

Wastewater based epidemiology (WBE) has drawn significant attention as an early warning tool to detect and predict the trajectory of COVID-19 cases in a community as it can provide evidence of both symptomatic and asymptomatic COVID-19 cases. However, precise and accurate viral copies quantification in wastewater is a prerequisite for making that tool successful. This ultimately is dependent on the effective and reliable virus concentration method prior to RNA extraction and quantification. Virus concentration is crucial in the wastewater especially when viral titers are very low, as is seen in building-based surveillance (Corchis-Scott et al., 2021; Gibas et al., 2021). Polyethylene glycol (PEG)-based precipitation, Electronegative Membrane Filtration (EMF), and Ultrafiltration are the popular methods that are being used to concentrate virus with successful signal detection (La Rosa et al., 2020; Wu et al., 2020; Kumar et al., 2020). However, in the context of congregate living facilities such as university residence halls, school rapid virus concentration method is necessary for faster data reporting. We previously reported outcomes of SARS-CoV-2 building level surveillance for a large urban college campus during Fall 2020 using EMF as the method of concentration (Gibas et al., 2021). However, to shorten the timeline from sample collection to reporting, we have tested an alternative concentration method using the InnovaPrep CP Select concentrator (https://www.innovaprep.com). We aimed to determine how the optimized CP Select protocol performs compared to the established EMF method in terms of filtration time, external control recovery, and sensitivity of SARS-CoV-2 detection and quantification. Method Wastewater samples was processed using the Innovaprep Cp Select method and EMF method side by side. Bovine Coronavirus or BCoV (BOVILIS® Coronavirus, Merck Animal Health, NE, USA), a surrogate of human coronavirus, was spiked into the wastewater as a process control prior to sample concentration. For sample processing with the CP Select concentrator, wastewater samples were centrifuged for 10 mins at 10000xg to remove solid debris. 10% Tween-20 was added to the supernatant in a ratio of 1:100 before concentration. 40 to 150 mL samples were then filtered through a single use 0.05 PS Hollow Fiber Filter Tips (InnovaPrep) using the automatic CP Select (InnovaPrep). Viral particles attached to the filter tips were recovered by eluting with 0.075% Tween-20/Tris elution fluid using Wet Foam Elution technology (InnovaPrep) into a final volume ranging from 250 uL to 500 uL. Conventional EMF or HA method was followed as previously described in Gibas et al., (2021). Following the EMF or CP Select concentration step, we then used the QIAamp viral mini kit (Qiagen, Valencia, CA, USA) for RNA extraction from 200 uL of concentrated sample. To determine whether a significant amount of virus remained in the pellets following centrifugation step, we quantified recovery of BCoV and natural SARS-CoV-2 from both the pellet and the supernatant of centrifuged samples. As part of the optimization of the Cp Select protocol we tested the sonication step addition prior to the centrifugation step and AVL lysis buffer (Qiagen) addition to the eluted concentrated sample to see the virus recovery performance. Quantitative reverse transcription PCR (RT-qPCR) was used to detect and quantify SARS-CoV-2 using CDC recommended N1 (Nucleocapsid) primer and probe set (Corman et al., 2020) and Bovine Coronavirus a primer/probe set published by Decaro et al., (2008). The detail of the RT-qPCR protocol was discussed in Gibas et al., (2021). Result The CP Select method resulted in a BCoV recovery rate of approximately 37%, which is higher than BCoV recovery from samples processed using an EMF protocol. The CP Select is capable of processing up to 150 mL of wastewater within 30 min, while the EMF method fails at larger volumes and operates optimally with 40 mL input. This allows for a higher effective volume of wastewater to be assayed with the CP Select relative to EMF, which in turn results in increased sensitivity for detection and quantification of SARS-CoV-2 from wastewater. About 25% of samples that tested negative when concentrated with the EMF method produced a positive signal with the CP Select protocol. Virus partitioning result indicated that a significantly smaller fraction of BCoV was recovered from the pellet than from the supernatant, with a P-value of 0.015 (P < 0.05). However, SARS-CoV-2 behaved differently from BCoV in centrifugation, with similar recovery fractions in the supernatant and the pellet (P value of 0.857). This difference may be due to the viral structure itself; the structure of the spike protein may result in SARS-CoV-2 attaching more strongly to a solid surface compared to BCoV. Ai et al. (2021). The optimization of the CP Select protocol by adding AVL lysis buffer significantly improved the virus recovery performance. Sonication step increased Bovine Coronavirus (BCoV) recovery by 19%, which seems to compensate for viral loss during centrifugation. Inhibition to RT-qPCR was not found for both of the method. Filtration time decreases by approximately 30% when using the CP Select protocol, making this an optimal choice for building surveillance applications where quick turnaround time is necessary. In general, the CP Select concentrator is advantageous for concentrating low viral titer wastewater samples, especially when rapid data reporting is necessary, and use of this protocol can also improve recovery and detection sensitivity.

The City of Richmond, Virginia, has been working on CSO improvements since before the enactment of the Clean Water Act and completed its first CSO Long Term Control Plan (LTCP) four years before US EPA finalized federal CSO policy in 1994. The most recent LTCP was completed in 2002 and included a list of projects that were incorporated in a state special order by consent (consent order). Since that time, the City had been continuing to implement these approved projects, while staying within specified consent order spending guidelines. In anticipation of needing to update the standing LTCP, the City finalized its RVA Clean Water Plan in 2017 (City of Richmond 2017), which provides a comprehensive understanding of the City's watersheds and associated water resources. The Plan identified the goals and objectives and associated metrics that would guide the City moving forward, and in particular identified the need to continue the implementation of Combined Sewer Overflow (CSO) control projects, as the most cost effective method of reducing bacteria in the receiving waters. In 2018, the City worked with the Virginia Department of Environmental Quality (DEQ) to develop a truly integrated discharge permit that included wastewater effluent, combined sewer overflows, and stormwater discharges. The integrated permit provides the City the opportunity to manage their water resources as one and provides the flexibility to implement projects necessary to achieve the goals and metrics identified in the RVA Clean Water Plan. In 2020, the City was swept up in a legislative effort to finalize CSO compliance across the state of Virginia. Ultimately, the City's consent order for CSOs was amended to conform with the new legislative action, that required the City to develop an Interim and Final Plan for CSO compliance with specific deadlines. The projects identified in the Interim CSO Plan, finalized and submitted to the state in June 2021, were focused on the use of real time controls and other methods to optimize the use of the City's existing infrastructure. These projects were found to be an extremely cost-effective method of reducing CSO volume. The Interim Plan has been submitted on schedule, the recommended projects are being implemented, and the Final Plan is under development and due by mid-2024. According to the amended consent order, implementation of the Interim Plan projects must be completed by 2027, and the Final Plan projects must be completed by 2035. Benefits of Presentation The audience will hear a case study of Integrated Planning, Integrated Permitting, water-quality-based CSO compliance planning, use of emerging technology to maximize use of existing infrastructure to cost-effectively control CSOs, and innovative stakeholder involvement throughout a pandemic.

ASTM Committee E64 on Stormwater Control Measures (SCMs) has published a series of new standards relating to specifications and performance protocols for manufactured water quality treatment devices (MTDs) including hydrodynamic separators (HDSs), media filters, and trash & debris capture technologies. These consensus-based ASTM standards have been developed to objectively measure the performance of these technologies to provide improved assurance on the efficacy of tested and verified technologies. This presentation will discuss the ASTM standards process and how it produces consistent quality procedures and products for the benefit of all stakeholders. An overview of these standards will be provided to gain insight into their rationale and essential elements. This presentation will also explore the potential benefits of using these standards as part of an SCM regulatory program; and what implementation of these standards within an authority having jurisdiction (AHJ) could look like. The prospect of a national validation process for ASTM standards via the Stormwater Testing and Evaluation of Products and Practices (STEPP) initiative will also be discussed. The overall intent of the ASTM standards process is to provide a high level of confidence to AHJs that the MTDs will provide long term and consistent treatment to meet water quality goals. Two E64 Subcommittees have been established to develop standards for both laboratory and field testing as E64.01 and E64.02, respectively. To date, laboratory standards include general specifications, standards applicable to HDSs, standards for media filtration, and a standard for trash & debris capture. General specifications address standard terminology for SCMs, silica-based test sediment and weighting factors for TSS removal on an annual basis. HDS standards and working items apply to TSS performance testing methods and data analysis, hydraulic characteristics and head loss, as well as scour testing to support online installations. Filtration standards and working items consider hydraulic characteristics, test sediment, performance testing and scour testing. The trash & debris capture standard is unique to laboratory protocols since it applies to manmade and natural materials >5 mm (5,000 microns) in two directions and uses a 'cafeteria style' approach for six testing elements. A standard for microplastics testing is also in progress. The first field-testing working standard addresses the use of autosamplers for the collection of paired influent and effluent flow-weighted composite samples. The development of new laboratory and field specifications and protocols is an ongoing effort with updates to existing standards occurring as the stormwater industry continues to advance MTD technologies and testing methodologies.