Results

Summary:
The Metropolitan St. Louis Sewer District (the District) was concerned with odors from solids dewatering, cake hauling, and landfilling activities. Odors from sludge disposal at the landfill were threatening to close this outlet for District sludges, severely limiting options for solids management. To meet this need, the District conducted a comprehensive evaluation of liquid treatment for sludges at their facilities, beginning with bench scale testing for all three plants and culminating in a full-scale evaluation of the PRI-TECH® process at the Lower Meramec WWTP. USP Technologies' PRI-TECH process (iron salt dosing followed by downstream hydrogen peroxide dosing) was selected for full-scale evaluation based on the bench scale testing. The District has used ferrous chloride dosing into the sludge thickeners for hydrogen sulfide (H2S) control, providing a significant amount of total and soluble iron prior to dewatering. The PRI-TECH process was implemented with the addition of hydrogen peroxide into the conveyance lines just before the belt filter press. Odor control performance was measured using H2S meters, gas detection tubes, and the recorded descriptions and observations of the District's solids handling staff. Process Selection: Initial chemical control methods were qualified using USP's shake test methodology on samples of thickened solids treated with ferrous. Samples were dosed with oxidants, mixed, the headspaces were purged, and then the samples were shaken to volatize measurable H2S, methyl mercaptan, and ammonia. The next step of the bench scale testing assessed the durational odor control for dewatered sludge. This bench scale evaluation involved pretreating thickened solids with oxidants, dewatering with a Crown Press Belt Press Simulator, incubating samples, and then measuring purgeable odorants from the dewatered cake. Calcium nitrate addition was also evaluated before or after dewatering. While calcium nitrate was effective, the addition of iron upstream of the dewatering operations showed that the dosing of H2O2 at dewatering was both effective and offered a lower cost. Full-Scale Evaluation: Dosing of hydrogen peroxide and data collection at both belt filter presses began on 1/15/2019. The sludge prior to dewatering and filtrate was analyzed for iron, sulfide, pH, and phosphate. H2S at the belt filter presses was monitored. Dewatered cake samples were obtained from the press and analyzed for purgeable odorants at 0, 24, and 48 hours after dewatering. Ferrous chloride dosing rates were held constant throughout the evaluation. The goal of this phase of the evaluation was to determine the minimum dosage required to eliminate odorants present at the dewatering process. Since odorants continue to be generated in the dewatered cake, the dosage that eliminates odorants at this step may be considered the lowest dosage that will offer durational control. Dosages ranging from 125 500 mg/L of H2O2 eliminate ~90% or more of H2S at the belt filter press and from within cake immediately upon dewatering.. H2S Removal Dosage Rate Finding: A sample of sludge taken at the sample port at the active sludge pump was analyzed. It contained 11 mg/L of aqueous total sulfide, 300 mg/L of total iron, and 200 mg/L of soluble iron. The pH was 6.2. At the lowest H2O2 dosage tested, 15 mg/L, H2S under the belt was lowered from 32 to 17 ppmv, a 47% reduction. At dosages of 125 mg/L and higher H2S was reduced by at least 90%. Filtrate Analysis: With increasing dosages of hydrogen peroxide the total and soluble iron levels within the filtrate were reduced. This is likely due to PRI-TECH reactions whereby ferrous (Fe2+) state iron is oxidized to the ferric (Fe3+) state. A drop in phosphate concentrations was observed, with baseline filtrate containing 40 mg/L and the peroxide treated samples containing 20 mg/L. Cake Solids Improvement: Cake solids percentages displayed an apparent linear response to hydrogen peroxide dosing, increasing approximately 6% points from baseline to the 500 mg/L dosage. One mechanism likely contributing to this improvement is sulfide oxidation with hydrogen peroxide, allowing more of the iron present to bind with phosphorus bearing compounds rather than sulfides. Durational Odor Control Results: In dewatered cake samples ammonia and amines were not detected. It is likely that the low pH (6.2) of the feed sludge inhibits volatilization of nitrogenous compounds. H2S appeared to be generated on a linear basis within the 48 hour time frame, with lower overall H2S levels seen with increasing H2O2 dosages. Mercaptans were not detected at 24 hours but at all but the 500 mg/L dosage were detected at 48 hours. District staff trained in odor monitoring techniques recorded observations on odor characteristics, intensity, and prevalence throughout the solids handling and transport process. This feedback was considered to determine the hydrogen peroxide dosing rates ultimately necessary to meet durational odor control needs.

Conclusion:
The District decided to continue with the PRI-TECH application and awarded USP a five year full-service supply contract through a competitive RFP process. Through the full-scale evaluation period the H2O2 dosing rate range of 200 - 250 mg/L was selected as the most cost-effective treatment level that met odor control objectives.

The utility industry is changing at a rate that is faster than ever before. Increased regulatory pressure, higher level of service expectations from ratepayers, and an increased range of available technology and solutions to meet organizational missions are resulting in a need to continually develop and improve utility operations. For the most mature utilities there are often processes in place to facilitate this development organically. For less mature organizations, foundational processes need to be identified and created prior to addressing these new challenges. For utilities, understanding the current maturity of their organization is key to identifying a path to organizational development. Maturity assessments are he primary way to clearly understand the present in order to prepare for the future. In 2014 Winston-Salem/Forsyth County (WSFC) Utilities was facing a defining moment for their organization. The utility was experiencing historically low levels of service, facing USEPA regulatory action, and undergoing a change in leadership. New challenges were becoming more apparent and the institutional knowledge that the utility had historically relied on to make decisions was quickly disappearing. To understand a path to a successful future, the utility needed to develop a strategic plan to build the knowledge and skills to tackle these critical issues. Through the Collection System Improvement Program (CSIP), HDR collaborated with WSFC Utilities to develop this strategic plan. As a first step, a maturity assessment was performed with a diverse set of utility staff to provide a clear understanding of the organizations level of maturity around 12 core functions. The focus of the exercise included collection system operations. Functional areas of expertise were identified through a mix of utility input and industry benchmarking standards including the AWWA Utility Benchmarking Program. These functional areas include key areas of service delivery administered by the utility throughout the collection system: 1.Collection System Management 2.Condition Assessment 3.Capacity Assessment 4.Capital Delivery 5.First Response 6.FOG Management 7.Cleaning 8.Chemical Root Control 9.Easement Maintenance 10.Inspection — CCTV 11.Inspection — Force Mains 12.Construction & Repair These functions, and their associated maturity levels, were defined prior to maturity evaluation by the team. This was a critical step to allow for the objective assessment and goal setting for these functions by team members. Functions were assessed on a spectrum from Not Practiced — the least mature — to Continuous Improvement — the most mature. Maturity levels were defined under the following standards: - Level 5, Continuous Improvement — In addition to meeting the requirements of previous levels, new technology, processes, and approaches are regularly proposed and tested. - Level 4, Measured - In addition to meeting the requirements of previous levels, function is consistently delivered and performance is assessed against established performance goals. QA/QC occurs regularly. - Level 3, Defined & Standardized - In addition to meeting the requirements of previous levels, processes are defined and repeatable. Performance data may be collected but is not actively managed. - Level 2, Repeatable - In addition to meeting the requirements of previous levels processes are not formally defined, but informal standards exist. Limited QA/QC activity is performed. - Level 1, Reactive — Delivery of function is entirely reactive. Processes are established on a case-by-case basis. - Level 0, Not Practiced — The function is not performed by the utility. Target maturity levels were established by WSFC Utilities staff by reviewing level of service goals and connecting these goals to functional area maturity. This is a critical component of directing maturity assessment activities. By developing Target maturity levels, organizations are forced to make decisions about what they believe is achievable with available resources and required to optimize organizational outcomes. In the WSFC Utilities case, easement maintenance and inspection were determined to not require Level 5 maturity to meet the service goals of the utility. Once target maturity levels were established, an assessment of the maturity of the utility was assessed across all functional groups using a nested survey. This survey was administered to a combination of WSFC Utilities staff, members of the CSIP consultant team, and City of Winston-Salem employees from adjacent departments who work directly with the WSFC Utilities. Survey questions included qualitative assessments of the performance of utility functions that mapped directly to maturity levels, but not did not ask participants to specify a particular level. This allowed for a non-biased assessment of utility maturity without the implications of assigning a poor maturity rating. Understanding both target and current maturity levels allowed the team to understand what the gap between current performance and maturity goals were. Using this information, a strategic road map was developed to identify a path to increased organizational maturity through a series of operational initiatives. These initiatives included a range of strategies from implementing new processes and decision-making tools to improve utility performance to field training on the knowledge and skills needed to perform utility functions. Understanding the workload and path dependencies required to improve organizational maturity is key to managing expectations on the timeframe and level of investment required to reach target goals. After six years of assessing their own organization and working through the roadmap of initiatives, WSFC Utilities has made steady, lasting progress in advancing their organization. For all utilities, developing a clear vision and plan of action allows for the strategic investment in organizational development. By continually assessing organizational maturity, the effectiveness of these plans can be measured and adjusted to provide the most value to organizational staff and customers. For the most mature utilities this allows for the update of existing strategies and establishes a foundation for a consistent approach during mid and upper-level management changes. For less mature organizations, this process creates a path to targeted investment in most critical areas and a common vision of the future. Regardless of the position of any individual organization, maturity assessments are an effective way to understand and direct organizational development.

Background The Des Moines Wastewater Reclamation Authority (WRA) is made up of 17 metro-area municipalities, counties, and sewer districts in Central Iowa. They work together to protect public health and to enhance the environment by recycling wastewater and being the preferred treatment facilities for hauled liquid wastes. The Des Moines WRA has grown to be the largest wastewater treatment organization in Iowa and that has historically led to one major problem finding enough qualified employees to operate and maintain the treatment facility that serves half a million residents. In 2008, the Des Moines Wastewater Reclamation Authority (WRA) became one of the first municipalities in Iowa to take advantage of a Department of Labor (DOL) apprenticeship program by Iowa Association Municipalities (IAMU). The apprenticeship program was started because the WRA was struggling to find certified operators to hire. The job required that operators have an Iowa Grade 2 Wastewater Certification, and when a qualified candidate realized that they would be working overnights or evenings, they typically turned down the offer. With an apprenticeship, there are defined milestones that must be achieved in a timely manner, which allowed WRA managers to hire under-qualified candidates that would be required to complete the apprenticeship. Program Details The apprenticeship program is three years long in duration, it requires each apprentice to complete six thousand hours of on-the-job training and pass seven community college treatment and maintenance classes (with a C grade or better). Additionally, they must achieve their Iowa Grade 1 Wastewater Certification within the first year of employment, Class A CDL within two years and their Iowa Grade 2 Wastewater Certification by the third year. New hires that have pervious experience in the wastewater treatment field can receive previous experience credit for up to fifty percent of the on-the-job training hours. New employees that have already completed the any of the seven required classes will receive credit for them. With the acceptance of previous experience credit and classes previously taken, more experienced employees can be fast tracked while less experienced are allowed ample time to learn the ins and outs of working in the wastewater industry. When starting the apprenticeship program, WRA management created the position of Wastewater Training Specialist, in part to assist in the in the training of new Wastewater Operator Specialist employees. The first two apprenticeships classes (2009 & 2011) were held in conjunction with IAMU. The required classes were held at the facility with apprentices completing correspondence classes at Kirkwood Community College (Cedar Rapids, IA). After the 2011 apprenticeship class, the WRA brought the administration of the program internal and started to send apprentices to classes at Des Moines Area Community College (DMACC). DMACC just recently (2012) started to offer water and wastewater treatment classes in a traditional community college fashion with online, in-person or blended classes. According to Craig Hennager and Lori Card of DMACC, 'Apprenticeship students at times were 50% of the enrollment in the overall program. They kept the academic program viable as we grew and developed additional curriculum, establishing ourselves in Iowa as Water and Wastewater training leaders. Together we are making a difference.' Apprenticeship Success Since the inception of the apprenticeship program, there have been a total of thirty-seven apprentices. Of that total number, 30 have completed the program, with 23 still employed at the WRA. An additional five are currently in the program which leaves only two out of 37 that started and did not complete the program. As the program has continued, the WRA has discovered that the learning did not end at completion of the Apprenticeship Program. Out of the 30 to complete the apprenticeship, 19 have eventually achieved Iowa Wastewater Certifications 3 or 4 which is above and beyond the scope of the program. WRA's leadership in workforce development has helped staff advance their training and certification, DMACC to establish their Water Environmental Technology 2-year AA degree, and the local partner organizations like the Des Moines Water Works have followed suit to create an apprenticeship program for their water treatment operators. This program has been vital to the important job of providing qualified staff for the largest wastewater treatment facility in Iowa that is crucial to serves approximately 500,000 residents in Central Iowa.

One of the new requirements of the MS4 permits consists of a stormwater retrofit plan. This presentation will summarize the plan developed for the City of Minneapolis. We will also showcase one of the retrofit projects that was constructed, explaining how we took a different approach to incorporate environmental equity into the project through a jobs training learning lab without increasing the budget. The city has four flood surge ponds that are being evaluated for retrofit to provide water quality treatment. These ponds activate only when extreme weather events cause conveyance pipes to back up. This type of existing pond retrofit can be very cost effective and in some cases, may be one of the few options available in an already developed urban area. The first pond to undergo retrofit for water quality treatment was the Holland Basin, an existing flood surge pond that covers an entire city block. The basin is adjacent to a public high school and the neighborhood used the pond as a park space, adding to the complexity and outreach needs. The adjacency to a public high school in an over-burdened community presented an opportunity to use the project as a learning lab by employing youth to help with outreach, training material development, and restoration of the disturbed area using native plants. The project was successfully completed in the summer of 2021, and the learning lab contract continues for the warranty period to provide establishment maintenance. The learning lab paid 92 youth and installed more than 4,000 native plants for a project that provides water quality treatment for 20 acres. This presentation will explain the retrofit project and the approach to incorporate racial equity into an infrastructure project.

Understanding the human fecal concentration in a pooled wastewater sample is important for interpreting results of wastewater disease surveillance studies at different scales. Fecal indicator positive controls can be used for quantifying this concentration. Wastewater monitoring studies must also be designed to best incorporate knowledge of defecation frequency; while many studies rely on 24-hour composite samples, it is known that 60-70% of child-bearing age individuals do not have a regular 24-hour defecation cycle (Heaton et al., 1992). The aim of this work is to report on the variability of three commonly used fecal indicator targets (RNase P, PMMoV and CrAssphage) in 24-hour composite wastewater samples across 28 urban sewersheds of varying scales collected in four counties of Kentucky from August to December 2020. Results from the untransformed wastewater data indicate concentration ranges across five orders of magnitude: fecal indicator density of human RNase P ranged from 5.1 x 101 to 1.15 x 106 copies/ml; PMMoV ranged from 7.23 x 103 to 3.53 x 107 copies/ml; and CrAssphage ranged from 9.69 x 103 to 1.85 x 108 copies/ml. Despite stationary sample collection sites during COVID-19 lockdown, regional and temporal variability for fecal indicators was seen, with no clear relationship between fecal indicator concentrations and sewershed size or population income level. When used for public health, wastewater disease surveillance requires better regional and temporal baseline data on positive controls representing human contribution to a pooled wastewater sample.

ABSTRACT
Biogas generated from anaerobic digestion typically requires gas conditioning before it is used to generate energy. Elevated concentrations of hydrogen sulfide (H2S) in the biogas is often a limitation for downstream processing of biogas. Full-scale tests using micro-aeration technology was undertaken at several water resource recovery facilities and showed that this new process-integrated technology has potential using minimum plant upgrading while contributing to the sustainability and economic efficiency of the energy recovery process of waste sludge digestion at water resource recovery facilities (WRRFs). Keywords: anaerobic digestion, biogas, energy recovery, hydrogen sulfide, micro-aeration.

BACKGROUND
Biogas generated from anaerobic digestion of sludge typically requires gas conditioning before it is used to generate energy. The high concentration of H2S in biogas typically entails a limitation for downstream processing of the biogas as it creates maintenance related corrosion problems in combustion engines, and the release of SOx in ‚ue gases. Traditional physical/chemical end-of-the-pipe technologies (i.e. chemical scrubbing using caustic/hypochlorite or iron oxide-based adsorbents) are relatively expensive and can present relatively high environmental impacts. Biotechnologies (i.e. aerobic or anoxic biotrickling filtration) or physical-chemical combinations with biotechnology (i.e. caustic scrubbing followed by biological oxidation) have recently emerged as cost-effective and more environmentally friendly alternatives. Nevertheless, these biotechnologies are still limited by their high investment costs and their generated byproducts such as sulfuric acid and/or elemental sulfur slurry that need further processing or disposal. Micro-aeration, which involves the dosing of a small amount of air during the digestion process, is a process-integrated biochemical method of removing H2S from the biogas. Micro-aeration has been researched and used in industrial biogas plants, but rarely tested at municipal WRRFs. It has been applied in eastern-Europe in full-scale sludge digesters at WRRFs, with H2S removal efficiency of more than 90% in most cases. Moreover, micro-aeration improved the degradability of COD and volatile suspended solids in all cases. The studies discussed in this presentation are, as far as the authors know, the first full-scale tests in Spain and North-America that try to overcome the lack of full-scale experience with micro-aeration in digesters at WRRFs.

OBJECTIVE
The main objective of this presentation is to share information about micro-aeration and explain how it has potential as an effective digester biogas conditioning technology. The presentation will include research and full-scale testing data and information. These full-scale experiences may provide a stepping-stone for further development and wider implementation.

METHODOLOGY
Micro-aeration technology was tested over a period of several months in different full-scale digesters at different WRRFs. A small amount of air was injected in the sludge recirculation mixing pipe after the pump using fine bubble air injection nozzles or in the headspace of the digesters. The biogas H2S concentrations and sludge characteristics such as pH, alkalinity, total solids, volatile solids were measured daily, while the biogas production and sludge feed were measured continuously.

RESULTS
A comparison between the different types of digesters (i.e. digesters with mechanical mixing and digesters with internal biogas recirculation for mixing) are made to provide better understanding in how micro-aeration can best be applied. An example of the reduction of the H2S concentration in the biogas before and after introducing the micro-aeration process is illustrated in Figure 1. The H2S concentration in the produced biogas dropped by more than 80% from 5,000 ppmv to less than 1,000 ppmv when the micro-aeration was stopped. Directly after stopping the micro-aeration the H2S concentration increased back up to 5,000 ppmv. Figure 1: Reduction of H2S in the biogas during the initial phase 1 of one of micro-aeration tests. The presence of small amounts of oxygen in the anaerobic digestion process in the full-scale test did not significantly impact neither on organic matter removal nor on the biomethane productivity when the amount of air injected is limited. In fact, these full-scale tests (like other bench-scale studies) revealed that, besides efficiently desulfurizing biogas, micro-aeration can potentially improve organic matter degradation during municipal sludge digestion. The volatile solids content dropped in this full-scale test by a few percent from about 66.6% without to about 63.6% with the micro-aeration technology. This drop in volatile solids and a potential more stable digestion process was likely caused by the higher hydrolysis rates and/or alleviation of sulfide toxicity. The potential capital cost savings as well as operational cost savings that micro-aeration technology can provide is substantial. The cost saving on iron sponge media change-out are determined and will be presented. Some of the lessons learned from the full-scale tests include (1) the effectiveness of the air injection method using fine bubble air injection nozzles, (2) the identification of the locations where not to install the nozzles and (3) the quantification of the consequence of overdosing of the injected air amount. Multiple full-scale application of MA in digesters have been reported for different type of digesters (Table 1). The overview shows the different full-scale applications including digester size, organic feed material, biogas production, digester mixing method, biogas production and H2S reduction obtained in the biogas. In general, 80 to over 95% of H2S reduction have been achieved in multiple full-scale applications. Table 1: Example of Full-scale Digester Micro-Aeration Studies and Applications for Biogas Desulfurization.

CONCLUSION
From the full-scale tests and related research, it can be concluded that micro-aeration technology holds great potential for being an effective gas conditioning technology for different types of digesters along with requiring minimal capital investment and operating costs. Micro-aeration would also further contribute to the sustainability and economic efficiency of the energy recovery process during the waste sludge digestion at a WRRF.

We invite water utility managers and professionals to join us at the upcoming Utility Management Conference for a presentation that promises to impact the future of the water industry. In 2022-23, a monumental job analysis survey was conducted, involving over 15,000 dedicated industry personnel across water, wastewater, wastewater collection, and water distribution domains. This unprecedented participation underscores the collective commitment to advancing our industry and is the foundation for certification standards in North America and globally. The outcomes of these extensive job analysis surveys, coupled with rigorous psychometric analysis, will serve as the cornerstone for developing the water industry's only standardized certification exams. This pivotal development will transform operator training, industry resource materials, and the content of certification exams. Behind this groundbreaking initiative are more than five dozen dedicated volunteers, who have invested hundreds, if not thousands, of hours in meticulously analyzing survey findings and identifying emerging trends. Our presentation will unveil the draft Need-to-Know Criteria documents derived from these findings, providing an exclusive preview of the future certification landscape. But that's not all. We encourage active audience participation and critique during the presentation. Your invaluable insights will assist the Certification Commission for Environmental Professionals in shaping relevant, robust, and legally defensible certification exams. Remember, water environment operators are the bedrock of our public health systems, and these surveys form the foundation for determining the criteria for operator competence. The Utility Management Conference offers a unique opportunity for participants to contribute to the Commission's final reports before they are released to the public and adopted by state and provincial jurisdictions. Be part of this transformative journey, and help us secure a safer, more efficient, and sustainable future for the water industry. Together, we can ensure that our operators are equipped with the knowledge and skills needed to protect public health and preserve our precious water resources. Join us in shaping the future of water operator certification.

Purpose of the research and key message and knowledge transfer In summary, the key message from this work is two-fold: Close collaboration with industry enabled the design of a scientifically rigorous and highly focused experimental program in live sewers. The latter provided conclusive answers within four months and identified a way forward leading to technology implementation and identification of researchable gaps needed to make the technology more widely usable. The specific knowledge that this paper will transfer is that reliable humidity sensors to measure relative humidity >98% in gravity sewers can be achieved. This is a tool that will help the water industry to improve the management of its concrete gravity sewers and other infrastructure that is in contact with high concentrations of gaseous H2S in humid air. No commercially available technology can do this. In this work, the authors have demonstrated experimentally, building upon advanced design work, that optical fibre sensor systems represent an innovative, versatile and affordable technology that can be brought to bear very effectively on key monitoring problems in the water industry's infrastructure. Through the work reported and results demonstrated in this paper, the research has very successfully created a synergy of the skills of an academic group and a major water utility to identify, tackle and solve key problems in sewers -- problems that impact directly on consumers and are seen world-wide in the industry. In doing so, in an effective way like this, the paper demonstrates the benefits to be gained from a close collaboration between the two groups. Above all new knowledge has been transferred -- in both directions -- and through that new and more effective approaches to problem solving developed. Specifically, the project is based on new technology for humidity measurement -- this is an essential parameter that needs to be monitored to minimize corrosion of concrete gravity sewers. No humidity sensors that last longer than ~1 week in the aggressive gaseous atmosphere of gravity sewers and can reliably measure humidity above 98% relative humidity are available. Thus supporting better predictive maintenance, in situ monitoring of a sewer and an anaerobic digester is undertaken using innovative optical fiber-based sensor systems: these being chosen because of their inherent safety in the potentially methane rich environment, their ability to be protected against biofouling, their light weight, low power consumption (or battery powered), 4G compatible and ease of use over the long lengths (up to kilometers) needed for some applications. The multi-parameter sensors systems designed and evaluated are also well suited to use with the high levels of hydrogen sulfide, coupled with high humidity seen in sewers and biogas rich environments -- environments where conventional electronic-based sensor systems regularly fail due to acid attack. Benefits of Presentation and why this presentation should be selected and will provide a benefit to our industry Sydney Water's current management strategy relies on reducing gas phase H2S by the addition of chemicals (ferrous chloride, magnesium hydroxide and calcium nitrate) to the waste water. This strategy, implemented in a number of waste-water systems in Sydney, is costly (about $4M p.a.) and its effectiveness in reducing corrosion is unknown, due to an inability to directly measure concrete corrosion and deterioration of rehabilitation materials. No matter how effective this program is in slowing the corrosion rate, there will always be concrete corrosion and a method for prediction and detection of imminent pipe failure is needed because of the enormous costs of such failures. In particular, it is necessary to determine how much of the ubiquitous H2S and H2O can be left in the air in order to reduce corrosion rates to less than what Sydney Water defines as a sustainable 0.5 mm/year. Gravity sewers are buried infrastructures that undergo chemical deterioration because of microbiological induced corrosion (MIC). Microbiologically induced oxidation (MIC) of gaseous H2S into sulfuric acid results in concrete sewer corrosion. MIC costs billions of dollars annually to the water industry and has been identified as a main cause of global sewer deterioration. Sydney Water spends about A$60-80M annually repairing and protecting concrete gravity sewers and has a regular sewer inspection program. Currently, sewer condition is determined by man entry which is inconvenient and hazardous, has major safety issues and is expensive and so there is a need to minimize man entry by reducing damage from MIC, which can be reduced by controlling moisture in the gravity sewers to values approximately below 85% RH. No conventional humidity sensors that can last longer than one week exist under these aggressive conditions. Tackling this, this work describes the first and successful attempt to use optical fiber-based photonics sensors to monitor humidity in the range >98%RH in the overhead space in gravity sewers. This information is fundamental to develop reliable models that can predict the end-of-service life (EOSL) of concrete sewers. With the ageing of an asset, there is a point in its life, termed the End of Service Life (EOSL) and by doing so, it will be possible to save hundreds of millions of dollars that would have to be spent if collapses occur or premature repairs carried out to prevent a potential collapse. The approach developed together thus supports Sydney Water's corrosion management strategy, which has been created as an outcome of over $3M in research projects striving to better understand the processes that lead to the formation of H2S dissolved in the waste-water. Status of Completion The work done together by the authors has enabled the project to reach a high level of completion and results of the use of the systems in sewers and biodigesters have been reported in the major international media. Thus to date, three trials of tailor-made fiber optic-based sensor systems to monitor humidity in the range >98% RH in sewer air that contains high gaseous H2S concentrations of up to around 400 ppnv have been successfully completed. Based on this Sydney Water is implementing the photonic sensors technology in small catchments. For extensive implementation, Sydney Water is supporting extra research to develop 'low cost' interrogators that would make the technology more cost effective, well suited to long term, in-the-field research. Conclusion and take-away message The key 'take-away' message is that this is a significant innovation in optical fiber and photonic sensors that they can now be used in these 'dirty' environments. This has also allowed in-situ long-term monitoring under conditions where current technology fails. The major outcomes of the series of experiments carried out over the last five years is clear; fiber optic sensors systems can operate effectively, in the long term, in remote locations under battery power, saving of millions of dollars.

Background KC Water became involved in the Utility Analysis & Improvement Methodology (UAIM) Project in Year 2 of the initiative. Department staff charged with the planning and delivery utilized UAIM artifacts, resources and models to shape their program for the Fiscal Year 2022-2035 planning and project delivery cycle. About KC Water KC Water is a department of the City of Kansas City, Missouri's Municipal Government. Dating back to 1873, the department manages and operates the city's Water, Wastewater and Stormwater Utilities. With a service population of more than 600,000 the department has a combined $446 million operating budget and serves a population of 700,000 through direct delivery and multiple agreements with wholesale and inter-jurisdictional agreements. Clean Water is treated and distributed through 1 water treatment plant, 18 pump stations and 2,800 miles of water mains. Wastewater is treated and clean water is returned to the Missouri River and its tributaries by 6 wastewater treatment plants, 43 pump stations, and over 2,500 miles of sanitary sewer pipelines. Stormwater includes 600+ miles of sewer, 15 flood pump stations, 13 miles of levee and over 600 Green Infrastructure assets. Each year, KC Water spends approximately $200-$300 million on its combined capital program. The main drivers for its capital expense are rehabilitation of existing infrastructure, largely driven by the replacement of aging water and wastewater assets, including water mains, wastewater collection system pipeline, and treatment plant and pumping station assets. In addition, KC Water is in the middle of a program to reduce overflows in its combined and separate sewer systems in compliance with the federal Clean Water Act and policies of the EPA and the Missouri Department of Natural Resources ('MDNR') related to sewer infrastructure. The original cost for that program was estimated to be $4.5 billion (on an inflated adjusted basis) and was to be completed in 2035. By 2021, the department had spent approximately $800 million towards meeting the tenants of the decree. The decree was amended in 2021, and it is projected to cost almost $2 billion less than was originally anticipated. The department expects to spend over $700 million in its Water Utility and $1.8 billion in its Wastewater Utility on capital improvements through 2035. Case Study Description KC Water selected two initiatives as part of the Year 2 UAIM Project. Initiative #1 focused on documenting, improving, and implementing an updated CIP Planning and Business Case Evaluation process. Initiative #2 focuses on documenting and improving the CIP Project Delivery Processes and KC Water's efforts to implement a Project Delivery 'Roadmap' using the business process models developed as part of the Year 2 UAIM Project. Both initiatives were completed by the same project team at KC Water using the methodology, framework, and tools developed under the UAIM research project in Year 1. Goals Accomplished-- KC Water's goals for Initiative #1 were as follows: ---Documented the 'As Is' BCE/CIP Planning process --Compared our process to the model developed as part of the UAIM research project in Year 1 --Developed a robust 'Lessons Learned' list to share with other Utilities who may be interested in developing a more robust CIP Planning/BCE process. --Shared a list of new processes and tools that were developed and implemented as a result of the work done in the past year as part of the project. KC Water's goals for Initiative #2 were as follows: --Documented the CIP Delivery Process in a Business Process Model (BPMN) format. --Shared the KC Water CIP Delivery BPM flow charts and walk through the process models with key stakeholders (Engineer Management, Experience Project Managers, New Project Managers) to confirm the 'as-is' model is accurate and capture updates and detail missing and identify opportunities for improvement for the 'to-be' model. --Implemented and used the BPM flow charts for communication & training with KC Water Engineering and Project Management staff. --Made the BPM flow charts accessible to front line stakeholders responsible for Project Delivery to create greater clarity of the process, provide better access to resources needed to execute the project delivery process, and ultimately improve collaboration, decision making, and efficiency during project delivery to yield an optimal project outcome that improves levels of service and reduces risk at an optimal cost. Longer term goals and desired outcomes that were discovered and clarified as a result of collaborating with key stakeholders at KC Water were as follows and are currently being implemented: --Establish a 'road map' for our CIP Delivery Process that uses a 'common language' and standard to help frame conversations around the goal of understanding and improving existing CIP Delivery Processes. The intent of the 'roadmap' is to reduce confusion and the risk of people 'getting lost' trying to navigate their way through the project delivery life cycle at KC Water. -- Improve KC Water's execution of change management by using the 'roadmap' to make value added changes to the process and then implementing and communicating these changes using the BPM flow charts. These tools can help create greater consistency and allow for changes to be communicated more effectively to frontline stakeholders involved in the execution of the CIP Delivery Process.

In 2014 Winston-Salem/Forsyth County (WSFC) Utilities faced a defining moment for their organization. The utility was experiencing historically low levels of service and facing potential regulatory action from the United States Environmental Protection Agency (USEPA) relating to high rates of sanitary sewer overflows (SSOs). These events negatively impact public health, cause property damage, and harm local environments. Primarily caused by pipe blockages, the most efficient path to reducing WSFC Utilities SSOs was identified as more effective asset maintenance programs. By improving WSFC Utilities' approach to clearing and removing grease, roots, and debris from the collection system -- the primary cause of blockages leading to SSOs -- the utility had the opportunity to improve collection system performance and avoid regulatory action. As a part of this mission, WSFC Utilities established the Collection System Improvement Program (CSIP), a multi-year effort to relaunch the organization's Capacity, Management, Operation, and Maintenance (CMOM) program. HDR collaborated with WSFC Utilities to establish its vision and develop a strategic plan to achieve it. Program components included target initiatives to optimize utility operations -- including cleaning -- as well as condition assessment, capacity assessment, repair, rehabilitation, and replacement (3R) design and delivery, and staff augmentation to assist in implementation efforts. A key initiative established early in the program was to develop a methodology to optimize cleaning operations within the utility's 1,800-mile collection system and an associated tool to implement this methodology within the organization. The result of this effort is FreeFlowH20 (FFH20). FFH2O is a web-based application that simplifies systemwide collection system maintenance through the optimization of cleaning operations. Leveraging utility data such as GIS-based asset information, work order histories, maintenance observations, and condition assessment findings, FFH2O creates and manages a pipe cleaning schedule to promote right-time cleaning. By actively managing cleaning schedule within the collection system, FFH20 allows WSFC Utilities to focus cleaning resources on highest risk pipes and limit unnecessary maintenance on lower risk pipes. This results in cleaning activities taking place in pipes that have grease, roots, and debris that need to be removed and avoids unnecessary cleaning on pipes that are already clean. FFH2O implements this approach through a web-based interface that allows users to:

1.Visualize the pipe cleaning schedule
2.Select non-contiguous geographic groupings of pipe for maintenance
3.Manage individual pipe status
4.Directly interact with suggested schedule modifications
5.Review Asset History
6.Create manual recommendations in response to real-time field events
7.Manage active work

FFH2O has allowed WSFCU to transition from a reactive O&M approach to a proactive one. Since the implementation of the pipe cleaning schedule, WSFCU's SSO count has dropped from 124 in FY15 to 55 in FY22 -- a 55% reduction in 7 years. This has resulted in a more predictable operating environment that enables the utility to better plan for resource needs and maintenance operations within its system. In addition, SSO reductions resulted in the USEPA dropping the regulatory case against the utility and avoiding a consent order. By cleaning smarter, not harder, utilities have the opportunity to implement more effective maintenance strategies within their collection system. This enables organizations to positively impact collection system performance in the face of a range of challenges. Regulatory threats, staffing challenges, and budgetary constraints in collection system operations can all be mitigated by becoming more effective in day-to-day cleaning. FFH20 is one way to achieve this goal.

Liquid biosolids land application programs have successfully operated in North America for decades. Land application of biosolids is an economical way for farmers to improve crop production and soil health while reducing greenhouse gas emissions and the landfilling of biosolids. However, with growing populations and increasing wet weather events, some programs have more recently experienced operational challenges surrounding hauling, land application, and inadequate storage. This has encouraged some programs to explore alternatives to their traditional biosolids management practices. Lystek THP is a biosolids management solution that uses thermal hydrolysis to transform biosolids and residuals into a concentrated and pathogen free liquid fertilizer product. It is a cost-effective way to extend liquid storage and reduce management stresses in facilities with existing dilute liquid land application programs. The patented process produces a concentrated (13-16% solids) EPA Class A biosolids fertilizer, LysteGro. This concentrated liquid fertilizer is applied via sub-surface injection, ensuring cleanliness when compared to traditional surface methods. Injection application increases soil contact, ensuring efficient nutrient use, and mitigation of run-off potential. The liquid product also allows for efficient loading and off-loading, as well as odor mitigation at the plant and throughout transportation. Notably, the concentrated liquid biosolids fertilizer contains added potassium (K), a key nutrient that is present in only very low quantities in other biosolids. The addition of potassium ensures the product can be used as a full replacement for conventional mineral fertilizers - providing significant value to the farmer. Benefits of this biosolids fertilizer application are realized over multiple years due to the slow-release nature of the nutrients in the product and improvements in soil health. Micronutrients, including zinc and copper, as well as macronutrients, including calcium and sulfur, important for crop growth are inherent in biosolids. This provides farmers with an accessible and sustainable option for these nutrients that would typically be expensive to purchase in the mineral fertilizer form. The addition of organic matter to soils helps improve overall soil health - including improved water holding capacity, soil structure and tilth, increased microbial activity, as well as increased resilience to severe weather conditions. We will discuss two relevant case studies: St. Cloud, Minnesota, and the South Huron Valley Utility Authority (SHUVA) in Brownstown, Michigan and the operational improvements they have realized as a result of a reducing residual biosolids volumes by implementing a concentrated Class A liquid biosolids fertilizer program. The City of St. Cloud's Nutrient, Energy, and Water Recovery Facility was looking to pursue a Class A treatment technology as part of its Resource Recovery and Energy Efficiency master plan to prepare for possible future regulatory changes. Facing storage capacity issues with their previous dilute liquid Class B program, they were also looking for solutions that could reduce their biosolids volume. St. Cloud's Class B biosolids application program had been successfully managed and operated for many years by City staff, with a receptive farming community for biosolids. Lystek was selected by the City of St. Cloud to supply the Class A biosolids treatment technology. The system became operational in the plant by September 2018 and St. Cloud has continued to operate their successful land application program using their existing infrastructure and equipment, without the addition of any new buildings or biosolids storage. They have seen a dramatic 70% reduction in their biosolids volumes and associated trucking, correspondingly reducing their biosolids program's transport greenhouse gas emissions by 70%. The program itself has also become easier to manage as the City of St. Cloud saw decreases of 85% in their overtime hours associated with land application. The estimated cost savings of producing and managing a concentrated liquid fertilizer at St. Cloud are approximately $12 million over the 20-year life cycle when compared to alternative solutions. The South Huron Valley Utility Authority (SHVUA) was seeking a solution to manage their dilute liquid biosolids program at their wastewater treatment plant serving a population of 90,000. The existing low-solids, lime stabilized Class B biosolids program was severely limited by insufficient winter storage and the WWTP was required to implement a costly contingency option of dewatering and hauling to landfill. Switching to a concentrated liquid fertilizer program has provided the SHVUA WWTP with a solution to reduce biosolids volumes by over 50%, effectively doubling that plant's storage capacity, while also producing a Class A biosolids fertilizer for local agricultural use. This change has ensured operational security and eliminated the need to dispose of 'excess' biosolids in landfills, allowing the Authority's resource recovery program to advance. Additionally, the plant was able to eliminate the use of lime stabilization and the associated chemical costs, as well as necessary storage clean out activities. The Lystek THP module processing footprint was small enough that it could be installed in an existing building with unused space, maximizing the use of existing infrastructure. Concentrated liquid biosolids fertilizer programs allow for efficient biosolids management through integration with conventional wastewater treatment plant equipment and processes. This program can greatly reduce a WWTPs volume of biosolids and required storage infrastructure, remove the need for complex management systems and infrastructure, and decrease trucking costs, all while providing a desirable fertilizer product.

The intern program at South Platte Renew was formalized in 2019 to highlight the work of professional engineers in the water/wastewater field. Over the last four years, the program has evolved into a comprehensive experience for junior to senior level university and college engineering students to showcase the diverse engineering and problem-solving opportunities available within a professional setting. Experiences range from construction inspection, design and planning, budgeting, technical and process optimization, lab work, and piloting treatment technologies. In providing several resources and contacts, students can explore different facets of the wastewater field and experience the unique offerings from a public entity. Along with classic engineering technical skills, interns are shown the political drivers and challenges that must be considered when working as a government agency. Students are also given the opportunity to grow their professional networks, complete vital trainings, and build resumes with applicable experience. The main goal of the SPR Intern Program is to engage young engineers in the diverse work of wastewater in hopes to inspire them to join the workforce in the public sector. This presentation highlights the efforts and methods by SPR to build and maintain an intern program and how others can benefit from a university-to-organization pipeline. The framework and planning documents can be customized for the 3-month internship based on the organization's needs and focuses for that year.