Results

Introduction Per- and Polyfluoroalkyl Substances (PFAS) have been an increasing focus of the public, legislative bodies, and the regulatory community, and recent EPA activities highlight this focus with respect to biosolids(1). In October 2021 the EPA released its PFAS Strategic Roadmap, outlining EPA actions with respect to PFAS for 2021-2024: these activities include a risk assessment of PFAS in biosolids to be completed by 2024(1). EPA also announced its intent to pursue the classification of PFAS under the Resource Conservation and Recovery Act (RCRA). While it is no means certain that federal PFAS regulations for biosolids are forthcoming, some utilities have faced - or might face - increasing pressure to consider either i) reducing PFAS and microconstituent loads in biosolids, or ii) processes that provide an alternative product for land application. Conventional treatment processes such as anaerobic digestion or composting do not mitigate PFAS concentrations(2). Pyrolysis is an alternative solids process that is gaining interest as a possible approach to mitigate PFAS and microconstituents. Current literature is contradictory on the impact of pyrolysis on PFAS, with removal(3) and no removal(4) being reported. Thus, new experiments were conducted to determine the fate of PFAS during pyrolysis of biosolids, and results will be presented at the conference. In addition to knowing the impacts of pyrolysis on the fate of PFAS, practical considerations of pyrolysis such as generation of difficult-to-handle byproducts and side streams, dryer operations and costs, and product management need to be evaluated holistically. To approach this topic of PFAS removal via pyrolysis holistically, this presentation has three main objectives: 1. Define pyrolysis and the pyrolysis products generated from municipal biosolids 2. Determine the impact of pyrolysis on microconstituents, including PFAS, using novel, unpublished pyrolysis batch studies that investigate the fate of PFAS in biochar, pyrolysis-liquid, and pyrolysis-gas 3. Understand practical considerations for implementation of pyrolysis Objective 1: Define pyrolysis and pyrolysis products Pyrolysis is a thermal decomposition process that occurs at high temperatures (normally over 450ºC) under limited or no oxygen. Pyrolysis of biosolids generates solid, liquid, and gaseous products. The solid product, called biochar, is a carbon-rich product similar to charcoal that can be used as a soil amendment because it retains moisture(5). It can also adsorb nutrients from thickening filtrate and be used to improve grass growth(6). The non-condensable gases produced, called py-gas, contain energy rich constituents such as methane and hydrogen(7). The pyrolysis liquid can be composed of two phases: light non aqueous phase called bio-oil and an aqueous phase known as aqueous pyrolysis liquid (APL). The bio-oil, which can be used as a renewable fuel upon upgrading, is corrosive during combustion and difficult to handle, whereas the APL also contains organic compounds and sometimes high concentrations of ammonia that can be toxic to biological processes such as anaerobic digestion(8). Objective 2: Determine the impact of pyrolysis on PFAS and microconstituents Novel Research Approach Experiments will be conducted in a lab-scale batch pyrolysis system as described elsewhere(9). Dried municipal biosolids will be used as the influent feed, and effluent biochar, pyrolysis-liquid, and pyrolysis gas samples will be collected for PFAS analysis. In total, 37 PFAS compounds will be analyzed by PACE Analytical® in the solid, liquid, and gas phases to determine the impact of pyrolysis on the removal of PFAS from biosolids. These experiments will be completed by the end of 2021 and the analysis will be completed by March 2022. This experiment will be the first study to investigate the presence of PFAS in all three product phases (solid, liquid, gas) following pyrolysis. Results from Previous Lab-Scale Studies These results will be presented in light of Dr. McNamara's previously published data that found 3 possible fates of microconstituents during pyrolysis of biosolids: a. No removal: microconstituents reside with solids (e.g. metals) b. Volatilization: microconstituents leave solids and reside with pyrolysis liquid c. Transformation: microconstituents are chemically transformed Batch pyrolysis experiments revealed that pyrolysis removed triclocarban (Figure 1), triclosan, and nonylphenol from biosolids(10). Triclosan and nonylphenol volatilized away from the biochar and into the pyrolysis liquid; triclocarban was chemically transformed during pyrolysis. These results indicate that, while pyrolysis might likely remove PFAS from the solid biochar phase, PFAS might still likely reside with pyrolysis liquid requiring further downstream processing. The experiments and analysis to be completed by March, 2022 will confirm this hypothesis. Objective 3: Practical considerations for implementation of pyrolysis Pyrolysis has been extensively used for non-biosolids feedstocks but is not yet mainstream for biosolids applications, partly because of the overall operational complexity of these systems and cost considerations. Compared to biosolids land application, pyrolysis technologies represent a significantly higher capital investment for utilities since feed to pyrolysis must contain only 5 to 15% moisture, requiring thermal drying as a pre-requisite for pyrolysis. The capital and operational costs for drying could be very high depending on the moisture content of the influent biosolids(7). Including drying within the system boundary also makes the overall energy balance of a pyrolysis system less favorable. The energy available in pyrolysis gas and liquid products is approximately equal to the energy required for drying and pyrolysis of biosolids that are 20% solids. Based on anecdotal evidence from some of the demonstration facilities, phase-separation, i.e., separating the various pyrolysis products, downstream from the pyrolysis reactor can also be a challenge that could impact the quality of pyrolysis products for downstream applications. The bio-oil that is produced can be difficult to handle and potentially hazardous. To address the handling concerns with bio-oil, pyrolysis systems either need to run hot enough to not produce bio-oil or utilities need other plans for handling bio-oil post production. In short, while a potentially promising method for biosolids treatment, long-term operational viability of these systems for biosolids applications, sidestream characteristics, and emissions control requirements for these systems are yet to be proven. The potential benefits of pyrolysis include solids destruction resulting in less hauling costs, generation of pyrolysis-gas that could be co-combusted with digester gas or landfill gas, and generation of biochar which has potential as a value-added product and the potential to reduce PFAS. Biochar improves the soil characteristics by not breaking down readily, providing carbon sequestration and improving moisture-holding capacity of soils. Utilities considering pyrolysis have to weigh the potential benefits of the technology alongside costs and other operational considerations to determine the overall feasibility of the technology for full-scale implementation. Any government subsidies or credits to support PFAS removal, that might make pyrolysis more affordable to utilities, will also be reviewed and presented in this paper.

Some of the more complex pipes that reside within the wastewater collections system are known as siphons/depressed sewers and are often referred to in the field as 'bellies' or 'sags.' Such systems typically navigate wastewater flow in pipelines that are near bodies of water, subways, tunnels, and other fixed utilities. These lines are constructed when traditional gravity design is not permissible, and a continuous grade cannot be maintained. Flow navigates the siphon pipe until it reaches pressurized flow and often creates foul odors which can be minimized by air lines. Siphon design allows for single barrel, double barrel or multi barrel and the number of barrels is typically related to the agency's requirements on hydraulic efficiency, maintenance, emergency events, and bypass requirements. Additionally, siphon design is critical for the future life span of the pipe due to its impact on operations. A poor design can lead to blockages, sediment build up and direct impacts on minimum velocities that are critical in siphons. For operations and maintenance this is critical because Siphon debris levels must be monitored closely to evaluate future needs for additional barrels, increased maintenance requirements and necessary repair work. In this abstract we concentrate on different operations and maintenance approaches on various siphons and the economic impact it can create for the utility owner and contractors. The first approach that will be discussed will be centered around cleaning siphons that have not been maintained and where minimal information is available. Secondly, the methodology of inspection and the various means that can be attempted dependent on the technology used. Lastly the combined approach of both inspection and cleaning will be discussed and evaluated. One of the most expensive approaches is often seen as is one in which the contractor blindly attempts to clean a sewer line (whether it be a siphon or not) without the known conditions of the pipeline. Not only is this a high-risk module but it is one where variables such as the structural integrity of the pipe, sediment levels, unknown debris types, and so much more are put into question. This approach will discuss a few siphons in San Bernardino that where maintained under a clean first approach. An inspect first approach can often be the least economically bearing approach because it is one that assumes it has minimal information from the start. This is because this method creates the information the owner can utilize to provide details about the siphon. Sonar and CCTV will be discussed and how the different technologies provide for varying deliverables and the limitations of each. Finally, one of the most comprehensive approaches is one in which the siphon is inspected, and the asset is assessed providing tangible details so that the line may be properly cleaned at a price that is well evaluated. This method will discuss the success of an inspect/clean siphon project in San Diego. This presentation will provide much needed information for a topic that has very limited information. This is because nationwide siphons are sometimes not maintained due to costs and or limited staff already strained by the primary collections system. The specialized work is one that is becoming more necessary and vital due to the aging assets and the imperative need to avoid emergencies on them.

Introduction Per- and polyfluoroalkyl substances (PFAS) encompass a wide range of compounds, numbering in the thousands. These compounds, because of their properties, have been used in a variety of consumer and industrial products and, consequently, are widely distributed in the environment (Buck et al., 2011). Research focused on understanding the sources of PFAS in drinking water and have identified municipal wastewater reclamation facilities (WRF) as an important pathway (Clara, Scheffknecht, Scharf, Weiss, & Gans, 2008). Because PFAS are concentrated in wastewater solids (Rainey, 2019), WRFs introduce these compounds to the environment through land application of biosolids, potentially allowing PFAS to enter surface water and groundwater (Lindstrom et al., 2011). What has not been well studied is the potential for sewage sludge incinerators (SSI) to introduce PFAS to the environment or destroy it. The extent of PFAS thermal destruction (i.e., thermal degradation by-product formation or complete mineralization) is poorly understood. No published data currently exist on the fate of PFAS through an SSI, although limited information from other industries can be referenced. This paper documents the current understanding on the fate of PFAS through SSIs and the research currently underway to further our understanding. PFAS Thermal Behavior For a combustion process to achieve complete PFAS thermal destruction (mineralization), PFAS compounds would have to be driven to their thermodynamic endpoints of CO2, H2O, HF, or sulfur compounds, if present. Residence time, turbulence (mixing), and stoichiometry (the relative mixture of waste to fuel, oxygen, and other gas-phase constituents) within the flame zone impact the completeness of combustion (Lewis, 2008; Niessen, 2002). Published research and industry guidance indicate that complete destruction of PFAS requires high temperatures (Table 1) which exceeds typical temperatures in SSIs. Notably, this guidance is based on limited conceptual or laboratory-scale experiments and precedence on previous guidance established for hazardous waste incineration. The baseline research for these recommendations stems from USEPA and other international environmental agency activities. Taylor & Yamada (2003) published results of a simulated hazardous waste incineration experiment with limited air to account for non-ideal combustion conditions. Experiments showed less than 0.4% and 0.05% of the PFOS fed to the reactor were detected in the exhaust at tests conducted at 600°C and 900°C, respectively. Yamada, et al., (2005) published a similar laboratory-scale study that considered combustion of PFAS-impregnated textiles. Neither PFOA nor PICs were detected under non-ideal combustion performance. Taylor et al. (2014) found no PFOA emissions after combustion of gasified fluorotelomer-based polymers. Full-Scale Incineration Studies A few full-scale studies have been published on the fate of PFAS through incineration systems with only two considering an SSI. Loganathan et al. (2007) investigated eight PFAS through a wastewater treatment facility. PFAS were measured in dewatered solids fed to the incinerator and in the ash. No mention was made on the operating conditions or whether the bottom or fly ash was sampled. Findings indicated a significant transformation of the measured compounds (26 & 97 percent); however, some PFAS were still detected in the ash. A second study is currently underway at an SSI facility employing an fluidized bed (MacGregor, 2020). Samples were taken at all inputs and outputs of the SSI system and analyzed quantitatively for 28 PFAS. Preliminary results show that mass flows were reduced through the SSI processes for all quantitated PFAS, with the exception of 6:2 fluorotelomer sulfonate. The authors also noted that the inorganic fluoride content of the wet scrubber discharge water was over 10,000 times that of the influent flow plus the measured PFAS fed to the furnace, assuming mineralization. No other studies have been published on SSIs, but limited information can be found in literature investigating incineration in other industries. Lemieux et al. (2007) reported on the USEPA's study of feeding carpet treated with fluorotelomer products into a pilot-scale rotary kiln furnace. The emitted PFAS detected, primarily PFOA and PFHxA, did not change when feeding PFAS contaminated carpet or not. Aleksandrov et al. (2019) investigated emissions from a pilot-scale rotary kiln incinerator. No significant PFAS emissions were detected. Thermal By-Products Bench- and pilot-studies have examined decomposition of specific PFAS congeners and by-product identification; several studies documented thermal PFAS degradation by-products (Table 2). These studies show that PFAS will decompose at temperatures relevant to operating conditions of SSIs although by-product formation will be a concern. Funded Research The USEPA (2021) has recently sampled an SSI as part of a broader sampling program at a WRRF. Samples were taken from all major input and output streams of the multiple hearth for PFAS characterization. The samples are currently being analyzed for targeted, non-targeted, and total organic fluorine. Winchell et al. (2021b) provide a detailed discussion on these analytical techniques. A separate study led by Brown and Caldwell with support from the Water Research Foundation's Tailored Collaboration program will sample two SSIs, one multiple hearth and one fluidized bed. This study mirrors the USEPA from a sampling and analytical standpoint. The full-scale sample will take place during the winter and spring. Initial work has included site selection and workplan development. Including, estimating PFAS emissions at various destruction and removal efficiencies (DREs) based on targeted PFAS measured in initial dewatered cake samples. Figure 1 shows the PFAS emissions from one of the test sites remain above the reporting limits for the analytical method at relatively high DREs. This suggests specific PFAS will be detectable unless achieving high DRE, a question highly sought after by the industry. Conclusions Thermal treatment of PFAS through SSIs represents a potential wastewater solids process for destroying PFAS; although, significant questions remain regarding both the destruction efficiency and potential formation of undesirable by-products. Temperature is only one of the three key operational parameters that should be considered when assessing destruction capacity in combustion systems. The other two important factors include residence time and turbulence. A well-functioning SSI will submit PFAS to greater residence times and mixing (or turbulence) than the laboratory-scale research performed to date, further promoting PFAS destruction.

Carbon and glass fiber reinforced polymers (FRP) have been used for infrastructure for more than three decades, and applications in pipeline rehabilitation has gained momentum in recent years. The advantages these systems can provide include high strength, light weight, and ability to be installed on essentially any type of pipe material, size, and geometry. The common practice for an FRP system design entails accounting for carbon layers only. While carbon fiber is extremely strong in tension (200,000 psi ultimate tensile strength and above), it is not as strong in compression (typically about 50 percent of tensile strength or less). As such, if the external loads on a pipe is significant, such as deeper gravity sewers, then a stand-alone design CFRP system will result in too many layers of carbon with a price greater than other alternatives by multiple folds. This has been the primary reason for FRP systems not being able to find many applications in the wastewater and stormwater infrastructure rehabilitation. This is changing with latest advents in the FRP industry. One such example is sandwich structure system developed by QuakeWrap based on one of the co-authors' (Dr. Mo Ehsani) idea of utilizing the I-beam concept for the FRP liner profile to increase ring stiffness without using excessive layers of carbon fiber laminae. This concept was developed into a pipe (StifPipe®) and has been used in a number of applications over the years. The first tier StifPipe® applications were made using a 'mini I-beam' fabric sandwiched between glass and carbon fiber polymer layers. Then after much testing and evaluation, the manufacturer (QuakeWrap) moved onto a proprietary 3D fabric that has the capability to absorb more epoxy resin, thereby giving it more ring stiffness without a significant increase in weight. The first installation of StifPipe® with the sliplining method dates back to 2012 for a 48-inch wastewater pump station discharge line in Avalon, California. The outside diameter (OD) of the StifPipe® segments used was 47-inches and the one-inch annular space was filled with non-shrink grout. This first installation was followed by multiple other sliplining applications mostly in stormwater lines and culverts up to 70-inches of diameter. In 2018, QuakeWrap started entertaining the idea of building a StifPipe® inside a pipe as cured-in-place installation. In other words, this would be applying the conventional FRP installation technique (wet layup) with the resin rich 3D core fabric. Upon a couple of successful mock installations at QuakeWrap's R&D facility, the first project with the wet layup was carried out in New Jersey (for Middlesex County) to repair a 66-inch storm sewer pipe. The installation went smoothly and QuakeWrap has completed several projects ever since with this method including a 12-ft diameter, 100-120 ft. deep stormwater tunnel under I-35 in Minneapolis, Minnesota (see the image below). The latter case required a 1.47-inch thick StifPipe™, which is designed to withstand the entire soil and groundwater pressure at that depth. FRP systems' high stiffness, hence low thickness along with their smooth surface (Manning's n between 0.009 and 0.010), often results in improved hydraulic capacity in a sewer line after lining. A typical StifPipe® has a pipe stiffness (PS) value of 75 and weighs about a tenth and fifth of concrete and centrifugally cast glass fiber reinforced pipe (CCGFRP) of equivalent strength, respectively. This enables installation of StifPipe® without any jacking equipment for diameters up to 72-inch. Design considerations include factoring in any excessive axial forces, which could require additional layers to prevent axial buckling in a pipe that is otherwise has a small wall thickness to withstand external and internal pressure (for force mains and surcharge conditions). The main installation challenge for the wet layup installation of StifPipe® is making sure the surface prep is done properly. This applies to all types of FRP installation; nevertheless, a unique challenge for StifPipe® is making sure the thick and heavy 3D core layer is saturated with epoxy completely and applied properly on the preceding layer. There is no saturating machine produced for this type of thick fabric; and therefore, the current practice is infusing the resin with ribbed rollers. Quality assurance is performed by weighing the saturated fabric. FRP systems are continuing to provide a viable alternative for pipeline rehabilitation, and the use of FRP systems for particularly large diameter pipelines is growing. Nevertheless, better design practices and education of the end users are needed to get the best out of these high-tech materials in achieving cost competitiveness. With such design practices it is fair to assume that the use of these materials will also grow in the gravity flow pipe systems (mainly storm and sanitary sewers) given the advantages they provide such as high strength, minimal thickness, smooth surface, and ability to accommodate any geometry. Right design and installation practices will enable engineers and owners to enjoy the great benefits of these materials to maximum extent. This presentation will present design and installation practices for composite, as well as proprietary, FRP systems used for sewer rehabilitation. The presenter will also provide insight into NASSCO's Guideline Specification for sewer rehabilitation with FRP, which was published recently. (https://www.nassco.org/resources/guideline-specs).

The Chagrin River-Lake Erie Direct Tributaries (CHALET) Stormwater Master Plan (SWMP) Study advanced the Northeast Ohio Regional Sewer District's efforts to protect Lake Erie, critical infrastructure, and over one million residents by addressing flooding, erosion, and water quality problems associated with stormwater runoff in the Cleveland Metropolitan area. Regional assets that receive and convey stormwater were evaluated throughout the 86-square-mile drainage area using a combination of field inspections and hydrologic and hydraulic (H&H) models. Field geomorphic inspections of waterways and stormwater basins were conducted through streamlined technology. Fifteen subwatershed models of the study area were also developed to identify flooding problems. Condition ratings for assets within the regional stormwater system (RSS) were then developed using standardized GIS data processing that integrated field inspection and modeled flooding results. Areas with poor ratings were grouped to define problem areas, and cloud-based GIS access facilitated the development and evaluation of alternative improvement projects. The resulting CHALET SWMP delivered a prioritized list of construction projects and operation and maintenance activities to reduce flooding and erosion risks and enhance stream health throughout the region. This presentation will focus on how inspection data and modeled flooding results were classified following the District's standards, integrated, and shared among the project consultant team to systematically compare risks across the study area and develop improvement plans. This process will be illustrated by focusing on one of the resulting 47 problem areas. This case study demonstrates how structural, hydraulic, and sedimentation and debris risks were flagged throughout the RSS and holistically considered when developing improvement projects. Key technologies that facilitated data collection, asset performance evaluation, and alternative development will also be highlighted. During the data collection process, culverted streams were inspected using closed circuit television, while stormwater basins and open channel streams were inspected through the ArcGIS Survey123 platform. These inspections produced numerous videos and photographs that were shared back with the District and hosted on their ArcGIS Online (AGO) platform. These inspections resulted in condition assessments with ratings for structural integrity and sedimentation and debris. These ratings for basins and streams were added into the GIS dataset used in the subsequent performance evaluation. In addition to the inspection data, open channel spherical imagery was collected throughout the study area. These 360-degree views of the streams were linked to a GIS dataset so that the consultant team could easily verify inspection results and develop improvement projects. This Google Street View-like tool proved invaluable for increasing the efficiency of desktop-based analysis, thus minimizing the need for return trips to the field. The CHALET SWMP team developed 15 H&H stormwater models using PCSWMM. These models drew on field inspections, flow monitoring, and spherical imagery. The PCSWMM models were used to predict flooding with the planning focus being, when feasible, to develop solutions that would avert flooding at the 100-year design storm event. Hydraulic condition ratings for RSS assets (culverted stream, basins, crossings, and streams) were based on the flooding depths of nearby buildings, roads, driveways, and other transportation assets. Using the District's standards, a condition rating related to flooding depth and a criticality rating related to asset importance were assigned to each building and transportation asset. More important buildings and roads, such as hospitals and highways, had higher criticalities than less important assets, such as residential garages or local streets. Condition ratings and criticalities of the RSS and associated buildings and transportation assets were combined to develop business risk exposure (BRE) scores in a comprehensive GIS dataset. Assets with high criticalities and poor condition ratings for structural integrity, hydraulic performance, and/or sediment and debris resulted in the highest BRE scores. Problem areas were delineated where multiple assets in close proximity had high BRE scores. Improvement alternatives were then developed for each area. Standardizing GIS data management of inspection results, generation of condition ratings, assignments of criticalities, and calculation of BRE scores supported data-driven performance evaluations and solution development. One problem area in the Euclid Creek East subwatershed serves as a case study for how comprehensive data management facilitated evaluating asset performance and improving regional stormwater management. Along this portion of Euclid Creek East Branch, inspections identified debris accumulation at a basin inlet, a failed crossing, and high criticality buildings near an eroding stream bank. Modeling predicted flooding of local roads. When considered together through the GIS database operational performance evaluation, this portion of the East Branch was flagged for problems stemming from hydraulic performance, structural integrity, and debris accumulation, and a problem area was defined. A set of baseline recommendations and two alternatives addressing flooding were created. The alternative that reduced the risk most effectively and efficiently was then recommended to the District in the SWMP. With standardized GIS data delivery, recommendations from this SWMP, in addition to the District's three previous SWMPs, can now be integrated and shared with internal District stakeholders, enabling the District to comprehensively present problem areas and recommendations across their entire service area. ArcGIS Online and the Enterprise Portal offer a dynamic and interactive method for effectively sharing SWMP recommendations. Results from this data-driven planning process now serve to prioritize nomination of improvement projects to the District's design and construction plan or for advanced stormwater planning.

The Detroit Water and Sewerage Department (DWSD) serves more than 230,000 accounts, including a residential population of nearly 650,000. DWSD's network consists of more than 2,700 miles of water main and nearly 3,000 miles of sewer collection piping within the city of Detroit. This presentation shall outline DWSD's Capital Improvement Program Management Organization (CIPMO) project. CIPMO's mission is to coordinate and execute capital project planning and project implementation across the City. CIPMO has taken a programmatic and collaborative approach to rehabilitate the water and sewer infrastructure with the goal of producing $500 MM worth of CIP projects over five years. In June of 2020, DWSD initiated a new, Geographic Information Systems (GIS) based procurement process intending to streamline procurement activities, increase the level of information provided to prospective bidders, and support the development of more accurate bids on capital projects. The newly implemented system is built on DWSD's existing enterprise GIS infrastructure, leveraging Esri's ArcGIS Online platform to publish and maintain a web mapping application that provides bidders with detailed GIS data on planned repairs, access to supporting documentation (including bid documents and plans), and base data that can be used to support the bid development process. This system provides bidders with the ability to interactively view data within the web mapping environment, query or filter data based on a variety of parameters, and export data and maps to support further analysis or assessment activities. This presentation will outline the previous procurement process, the development, implementation and management of the new platform, and detail DWSD's plans for future improvements to the procurement process. DWSD's Collection System includes lateral, connector/trunk, and interceptor sewers that collect and convey storm and sanitary flows throughout the service area through lift stations to the wastewater treatment plant. The sewers are generally a collection of clay, brick, concrete pipes ranging in size from 8 inch to 17 feet. The system has approximately 3,344 mile of sewers which includes 2,258 miles of lateral sewer, 559 miles of connector sewers, 483 miles of trunk sewers and 44 miles of interceptor sewers. The oldest of these sewers were constructed in the mid-1800s. The collection system services Detroit and 76 communities which include over 3 million people over approximately 904 square-miles in southeastern Michigan. DWSD's in-house crews perform routine maintenance of the collection system including open cut repairs to fix sewer collapses and sewer rodding/cleaning along with video inspection to identify areas/causes of flow obstructions and provide relief to customers. The Department utilizes contracts to carry out sewer assessments and construction for capital improvement and aid the in-house crews in performing emergency repairs. These contracts are also used by the Department to assist DWSD's crews in providing water-in-basement complaint investigations, sewer cleaning service and open cut repairs. These contracts are a good fit for the Department's short-term maintenance. Starting in the early 1980s, the DWSD began to use the Cured-In-Place (CIPP) method as an alternative to the open cut method in rehabilitation of the collection system. Segments of sewers determined to be structurally deficient were lined by the CIPP method. In the late 1990s, the Department initiated a larger scale CIP with the intention of rehabilitating up to 1% of the collection system annually. Prior to the inception of DWSD's current Capital Improvement Program Management Organization (CIPMO), the Department's Collection System CIP was managed and implemented through two sewer contracts divided between the east and west sides of the City. A quadrant of the collection system which represents approximately a quarter square mile in size was identified based on previous I/I study, water in basement complaints, cave-ins/collapse records and population density and assigned to the sewer contractor to assess, prepare and submit PACP reports, treatment strategies for DWSD's review and approval. Approved strategies for rehabilitation were also performed by the same contractor. The Department and its contractors utilized the open cut method, Cured-In-Place (CIPP) lining, Slip lining, Epoxy lining and Cementitious and Chemical Grouting methods in the Collection System CIP as the main methods of rehabilitation. The Department's annual renewal rate of the collection system was about ~150,000 linear feet of sewers per year, which was approximately 24% of what was recommended by the Department's Master Plan. DWSD's current CIPMO which was initiated in 2016 is taking a different approach to the capital renewal of the collection system. Instead of a single contract to perform sewer assessments, provide PACP reports, treatment strategies, design, and construction services; separate standalone contracts are procured to provide sewer assessment, data verification and acceptance, treatment strategies, design and construction. The details of DWSD's CIPMO process including emerging challenges, design & construction, resource management, procurement challenges, will be discussed in full at the conference. Beginning in June of 2020, DWSD initiated a new, GIS based procurement process that is intended to streamline procurement activities, increasing the level of information provided and supporting the development of more accurate bids on capital projects. The implemented web-based system provides prospective bidders with access to a contract-specific, interactive mapping application that details information on the planned repair, including needed replacement and rehabilitation work. This application also provides advanced functionality to support the export of data in tabular format, interactive toggling of map layers, and filtering or querying of data. As compared to the traditional approach of providing bidders with hard copy or static plans, the GIS-based procurement platform provides bidders with the following benefits to better prepare bids: Access to additional data on existing assets and proposed work. Access to a variety of basemaps (including aerial imagery, topographic, planimetric, and hybrid) to help provide better understanding of the construction activity areas. Ability to view geographic data interactively, at different map scales and/or combinations of layers. Flexibility to filter export data and maps to a variety of formats, including spreadsheet format, allowing for additional assessment and analysis to be performed Ability to 'bookmark' specific areas or locations, perform measurements, and make map markups that are specific to user logins This system also gives bidders the ability to access contract data on a variety of devices while maintaining data security through assigned, contractor-specific login credentials. Approved DWSD contractors are provided access to specific procurement sites on a contract-by-contract basis, minimizing the amount of effort required by DWSD to manage credentials and simplifying the login process for contractors.

Background and Project Goals: Material Matters supported the Applied Technologies Inc Team (Applied Technologies, Inc. GHD Group, and Veolia Water Milwaukee) in developing an Advanced Biosolids Facilities Plan for the Milwaukee Metropolitan Sewerage District (the District). The Advanced Biosolids Facilities Plan will identify and evaluate a variety of biosolids treatment alternatives that the District will consider, adopt, and implement. The project sought to answer the following three questions: 1. What is the best way to make Milorganite®? 2. What drivers influence the long-term viability of Milorganite®? 3. How can the District adapt to changing drivers? To answer the project questions, Material Matters developed an Operational Risk Register, with the support of the project team, to identify market risks most critical to maintaining the District's nationally acclaimed and distributed dried biosolids product - Milorganite®. Project Approach: The Operational Risk Register was developed to identify regulatory and market-based risk events associated with the Milorganite program. A risk register is a risk management tool that identifies potential risk events, assigns the probability of the risk event occurring (likelihood of failure [LOF]), and quantifies the resulting consequence if the risk event occurs (consequence of failure [COF]). Risk events include internal risk events (i.e., risk events that can be controlled by the operating entity), as well as external risk events (i.e., risk events that are outside of the control of the controlling entity). A risk register is a unique and innovative tool for evaluating a biosolids management program because it is dynamic and can be updated to match any changes in program goals or to reflect known changes in the market. Ultimately, over 60 potential risk events were identified and evaluated resulting from changes to District's biosolids processing (internal risks) or changes in the market or regulatory climate (external risks). The risk evaluation was based on existing customer purchase data, interviews with a representative sampling of Milorganite direct customers, and interviews with regulators from the top distribution states (Figure A-1). Information collected was summarized and used to evaluate the likelihood of the risk events occurring, and the corresponding level of consequence to the District should the risk occur. The scoring matrix and risk rating used for the risk register is shown in Table A-1 and based on scoring methods developed with the District as part of the 2050 Facilities Plan. Project Findings: Project findings revealed five key market-based risks critical to consider for the ongoing dominance of Milorganite® in the natural fertilizer market space, including: 1. Changing the physical characteristics of the Milorganite product (Figure A-2), 2. Reducing the production of Milorganite®, 3. Change in nutrient content or ratios, 4. Change in product odor, and 5. Regulatory changes related to contaminants of emerging concern (CEC) including per- and polyfluoroalkyl substances (PFAS). Mitigation measures and future consideration were provided to the District for operational risks identified as Medium or High overall risk. The risk register results will be used by MMSD to guide selection of process changes and technology choices for the remainder of the project. The outcome of the risk analysis concluded that technology decisions for wet-side treatment processes, digestion, thermal drying technology, and product diversification must be carefully considered in the next phase of the Advanced Biosolids Facilities Plan to avoid the highest rated operational risk. This paper will describe the risk register development process, including data gathering approach, scoring, and ranking process. The paper will also discuss the overall outcome, including mitigation measures to be used by the District to reduce risk impact on the program & and to preserve the Milorganite's unique position in the national fertilizer marketplace.

This paper will present a project in Novi, MI where 300 feet of 10-inch sanitary sewer was installed over a Peat and Marl Zone using a trenchless stabilization process and the pilot tube method of guided boring (PTM). The study is a comparison between the originally designed 'open excavation' project and the value engineered project using PTM and grout injection for the Grand River Road project (adjacent to two busy thoroughfares and a Cadillac Dealership). In 1996, the City of Novi, permitted development of a 10-acre parcel which included a sanitary sewer line that was added to their existing collection system. Located in Oakland County, this installation was originally constructed using PVC Truss Pipe at cover depths ranging from 10 to 12 feet. Below the pipe, the soil consistency was layers of peat and marl. In 2006, the site was redeveloped with an additional 10-foot of fill added to the area above the sanitary sewer line. This surcharge load affected the flexible pipe / soil structure as well as the peat / marl foundation below the pipe zone; the result was a failed pipeline. A new sanitary sewer line was proposed, designed, and bid as a conventional open trench excavation with 'over-excavation' of the marl zone. Soil borings indicated the existence of a peat/marl zone within the sewer elevation (on the west end) and below that, was a 5-foot layer peat zone above a 7-foot layer of marl. Moving to the east, the marl zone was just 2 foot below the sewer invert. The initial bid design required over-excavation of the peat and marl, the addition of a geotextile wrap, and 1-3 inches of backfill with crushed stone. This foundation improvement was required for pipeline support using conventional open-trench installation methods. This paper outlines the soil stabilization and installation method of PTM used to replace the sanitary sewer. The project was originally specified conventional open-excavation and the Contractor value engineered the project using grout injection and then used Pilot Tube Method of Guided Boring install the sanitary pipe.

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

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

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

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

Over the last ten years, several significant flooding events have occurred in the southeast Michigan. On August 12, 2014, 6 inches of rain fell over a 4-hour period and caused damage to 75,000 homes and businesses with an estimated $1.8 billion dollar loss (NOAA). In the last 4 years (June 22, 2017 and June 26, 2021) southeast Michigan has experienced two 1000-year events. The Southeast Michigan Council of Governments, SEMCOG, is leading an initiative to review and plan for changing rainfall patterns in the region. Model projections of future precipitation vary greatly, but the trends of increasing frequency and intensity of extreme precipitation events is anticipated to continue. Climate models project the Great Lakes region to experience a greater increase in total precipitation than most other regions. The amount of precipitation falling in the most intense 1 percent of precipitation events has increased significantly in the Midwest (42%) from 1958 to 2016. These numbers are projected to increase by another 40% or more by late century (GLISA). SEMCOG formed a working group comprised of local public works, state and county transportation departments, county drain commissions, local universities, and consultants to collaborate on design alternatives for resilient infrastructure into the future. The group evaluated use of current rainfall data, collected examples of national and international resilient infrastructure best practices, polled participants on comfort level of approaches and prepared a list of suggested alternatives. Ideas and approaches reviewed include: Using recent observed historical events as design storm for future projects. Changing the target level of service for the design criteria. Adding level of service design criteria to accommodate large cloudburst events. Incorporating the confident intervals in the existing rainfall statistics for future planning. Using a flat rate increase on the rainfall data to represent future predictions. Basing future rainfall projections on average annual projected temperature changes. Using detailed projected IDF statistics for mid- and end-of-century rainfall. Adopting a risk management approach for selecting design criteria based on potential hazards. Challenges and barriers to reaching consensus on best practices exist including: Interconnectedness of transportation stormwater systems with regional combined sewer systems. Varying design standards across different stormwater sectors. Funding priorities focused on GI and challenges addressing flooding through state programs. Varying CIP planning schedules that lack institutional frameworks to collaborate across infrastructure sectors. Uncertainty in economic impacts for infrastructure projects using the listed approaches. Lack of public understanding about declining levels of service in water infrastructure. The working group agrees on the need for consensus on best practices in the region. It's critical that the regulators support local efforts to address changing rainfall. Presently, transportation and water infrastructure sectors have varying design requirements. Current efforts include a guidance to the member communities on how to address the changing rainfall for infrastructure design purposes, economic impact analyses for selecting different rainfall conditions, and increasing the public's understanding on what the rainfall changes mean for their communities.

Municipal stormwater permittees in Orange County are implementing watershed management programs to meet MS4 Permit requirements. As part of these programs, Permittees are responsible for inventorying and inspecting private and public stormwater assets as well as reporting on progress toward watershed planning goals and regulatory requirements. To help address these requirements, the Permittees, Geosyntec Consultants, and Sitka Technology Group worked together over the last three years to develop an open-source web platform for stormwater asset management — OC Stormwater Tools (www.ocstormwatertools.org). This platform is intended to help manage and report on existing assets and plan for future assets (Figure 1). The tool caters to many user roles, from field crew to jurisdictional managers, across several modules. The Inventory Module maintains consistent BMP asset inventories across jurisdictions in the County. Geosyntec worked with early adopters to onboard their data and tailor the system to user needs. The Inventory Module supports mobile data entry, rapid condition assessment and maintenance tracking. It also allows users to inventory development sites and associated private BMPs. It now contains over 11,000 structural BMPs across 18 jurisdictions and is growing (Figure 2). The Trash Module supports Permittees in complying with statewide trash requirements. It also supports mobile visual surveys of the effectiveness of measures to reduce trash loading. Based on the inventoried trash BMPs, the tool calculates quantitative progress toward goals (Figures 3 and 4). The Modeling Module calculates the water balance and pollutant load reduction of inventoried BMPs for both dry and wet weather conditions (Figure 5). To do this, it runs algorithms in near-real-time as information about BMPs and their drainage areas is added. This is also supported by GIS resources and geoprocessing services provided by the OC GIS department. Although the network of BMPs in the County is complex, the algorithm recalculates the long-term stormwater capture efficiency, volume reduction, and treatment performance much faster than a continuous-simulation model. This presentation will provide an overview of the tool, key takeaways from the process, and a discussion of how this will support more streamlined reporting and planning in the future. We also hope to engage in an audience discussion about how this open-source code could benefit other stormwater and watershed managers.