As more stringent requirements to eliminate Sanitary Sewer Overflows (SSOs) are enforced, peak flow management becomes a more challenging task for wastewater treatment managers. The simplest approach to peak wet weather flow management, from a regulatory point of view, is onsite storage, where excess influent flows are diverted to side-stream storage basins to prevent the washout and long-term effects on biological processes. In the past, methods of sizing peak flow storage ranged from using a 5-year 24-hour storm hydrograph, to developing longer periods of wet weather events and calculating the resulting flows due to back-to-back storm events. This new methodology is intended to identify a storage volume that balances construction costs with the level of risk for potential storm events. It allows a utility to evaluate storm event coverage against the cost to build storage.

This paper was presented at WEFTEC 2023 in Chicago, IL.

Blue Plains Advanced wastewater treatment plant (AWWTP) was the first utility in the USA to install Cambi thermal hydrolysis process (THP) together with anaerobic digester (AD) to reduce solids production, increase energy resource recovery and produce class A biosolids. The new facilities were commissioned at the Blue Plains Advanced Wastewater Treatment Plant (AWTP) in 2015. The technology choice provided a major benefit on dewatering process by improving the cake TS, which has a large economic impact on treatment operations by decreasing the hauling costs, and by improving the quality of the "Bloom” biosolids product that is regionally marketed (Li, 2021). Dynamic changes in operational condition of the THP and AD process, sludge characteristics, and seasonal impacts (Li, 2021) result in high variety of cake TS (%) from 24 to 38% TS and filtrate TSS from 50 to 1530 mg TSS/L at the final dewatering belt filter presses. Poor cake TS causes higher hauling costs, while unreliable filtrate TSS significantly impacts the filtrate treatment facility. In addition, the polymer cost also may increase year by year depending on the market price, so picking the right optimal polymer dose range can optimize operational cost. In practice, the polymer dose is set manually by the operator and requires constant attention to minimize polymer dose while maintaining good operational throughput. Polymer dose decision making is thus mainly driven by human factors. Therefore, this study focused on investigating if the polymer dosing decision made by operators is adequate or if there is room to improve dewatering performance, which helps to define research development needs for helping optimizing polymer costs at the plant.

Wastewater collection and treatment system plays a critical role in facilitating sustainable urban environment. Maintaining complex wastewater infrastructure, with varied range of assets and functionalities, is extremely challenging. For the City of Houston (COH), providing quality service in the wastewater sector is even more demanding due to rapidly increasing population and diverse industrial and commercial growth. To confront the challenge with modern technology, COH envisioned an intelligent planning tool to prioritize and optimize rehabilitation of its gravity pipe network by integrating asset inventory, field inspections and machine-learning models into a data-driven predictive analytics platform. This paper illustrates the underlying modules of the tool with their analytical framework. It also explains application of the tool to analyze future risk levels in different scenarios and optimize rehabilitation strategies.

This manuscript summarizes the past 18 months of deploying a predictive operational dashboard leveraging machine learning (ML) to forecast inflow into Citizens Energy Group’s DigIndy Tunnel system. We will present our lessons learned in the deployment of the ML tool in the cloud, managing the ML tool, and the integration of meter data to evaluate the accuracy of the forecast. Citizens Energy Group is the combined water, wastewater, natural gas, steam, and chilled water utility in Indianapolis. Citizens is presently implementing a 20-year CSO consent decree with required completion in 2025. Consent decree compliance is primarily achieved through the DigIndy Tunnel system, a 28-mile long, 18-foot diameter tunnel network. Citizens is also implementing a pair of storage facilities in the Upper White River and Upper Pogues Run watersheds. Our ML tool consists of an artificial neural network fit to long-term datasets to predict inflows to the DigIndy Tunnel using the 72-hour NOAA radar rainfall forecast (Sutton et. al, 2022). The neural network and automated tools to obtain actual gauged rainfall and metered tunnel inflow are fully contained within Citizens’ Azure Synapse enterprise cloud environment, with data storage in Azure Data Lake. The forecasted rainfall and tunnel inflow and actual data is presented in an online Power BI dashboard hosted in Citizens’ enterprise architecture that is accessible to all engineering and operations staff.

The Mobile-Organic Biofilm (MOB) process includes mobile biofilms and their retention screens with a bioreactor and liquid and solids separation. The MOB process is inexpensive, easy-tointegrate with wastewater treatment (WWT) processes, and provides for high-rate WWT in biofilm or hybrid bioreactors. This paper describes mathematical modeling of the MOB process presented by Boltz and Daigger (2022). This paper describes MOB process (1) modes of operation, (2) design and analysis methodology, and (3) mathematical modeling. The mathematical model was applied to simulate a fixed bioreactor volume and secondary-clarifier area as MOB process Modes I, II, and III. Simulated differences between MOB process modes of operation are described.

Solids thickening is an indispensable unit process for process intensification of biosolid s treatment. The fluctuations of feed sludge characteristics often impact the stability of the thickening process, reduce process capability, and increase operation and maintenance costs. Often, the optimization of sludge thickening is focused on meeting performance requirements as detailed in specifications. This study expands the assessment of sludge thickening by including both thickening equipment and its up- and downstream infrastructure from a process capability perspective. The presentation will benefit engineers and utility operators in better design and troubleshooting of sludge thickening processes with designed thickened sludge solids total equal to or higher than 6%. The presentation will provide practical suggestions for improving the process capabilities of sludge thickening, including pumping improvement, pipe flushing using digested sludge, and improvements on sensors.

With the proliferation of artificial intelligence, machine learning, and other advanced computing solutions, utilities are looking to take advantage of the massive amounts of data at their disposal by using it to make real-time decisions that improve operational reliability and performance. But when is an organization ready to adopt a data-centered culture? This paper will discuss what’s needed for the successful adoption of advanced data analytics tools and share the results of a pilot project with the goal to transform a wastewater utility’s maintenance strategies from reactive to proactive using a predictive analytics software that leveraged the data collected by an existing process control system. The objectives of the pilot were: 1) to determine whether operational deviations could be detected ahead of conventional process control system alarms, and 2) to provide actionable intelligence prior to equipment/operational failure.

The utility industry is faced with the challenge of providing reliable treatment, distribution, and collection of water/wastewater services to a large infrastructure of customers, while being good environmental stewards. Thousands of assets comprise the treatment, distribution, and collection system across multiple facilities. Standard equipment operation is critical to providing customers with high quality water/wastewater services that meet regulatory requirements. To ensure proper operation of critical equipment, a PM strategy is utilized at KUB. Multiple resources are utilized when executing preventive maintenance, such as labor, materials, and equipment, among others. Aligning resources in an optimized manner can be challenging. A common method for solving optimization problems such as scheduling is linear programming. This paper discusses the utilization of a linear program to define an optimized PM schedule for the water and wastewater treatment plants, and the sustainment of the gains through tracking KPIs.

In wastewater practice, there is an immense lack of knowledge in understanding the precise kinetic role of distinct bacterial populations in the overall kinetic rate of biological processes including denitrification. There is a growing need for more in-depth research to identify the functionalities of denitrifiers, especially under different operational conditions. Additionally, little effort has been devoted to developing a model that simulates all mechanisms of partial denitrification. This gap needs to be filled so that further research and engineering design could be conducted to achieve a systematic perception and optimization of partial denitrification anammox (PDNA) systems. Therefore, this study demonstrates the need for developing a mathematical model that could project all the major potential mechanisms of partial denitrification. This study discusses the development of a comprehensive and novel model that describes nitrite accumulation considering microbial ecological shifts, alternative carbon sources, feast-famine and carbon internalization, COD/N effects in kinetics, etc.

Renewable Water Resources (ReWa) in Greenville, SC, initiated a dewatering evaluation in 2021 to explore alternatives for dewatering anaerobically digested biosolids from three of their Water Resource Recovery Facilities, Mauldin Road, Pelham and Lower Reedy. The objective of this project was to provide engineering services for evaluation of the remaining useful life or replacement of existing belt filter press (BFP) sludge dewatering equipment with new BFP, centrifuge, or screw press dewatering equipment. Bench Scale testing was conducted considering several technologies and onsite pilot testing of a centrifuge was conducted and compared to the existing BFP. A unique part of the study included comparing the fecal coliform regrowth and odor potential from both the centrifuge cake and BFP biosolids. All facilities showed fecal coliform regrowth and increased total volatile organic sulfur compounds with centrifuge dewatering, as expected, but one facility also showed regrowth with belt filter press dewatering.

Clay County Utility Authority (CCUA) is a regional utility provider of water, sewer, and reclaimed water to over 49,000 residential and 3,000 commercial/industrial customers in northeastern Florida. Over the next 25 years, CCUA will face a number of significant water resources challenges such as a doubling of water demands due to significant planned growth in the region, existing groundwater supply that is reaching sustainable limits, environmental regulations on minimum flows and levels for sensitive surface waters that are influenced by groundwater withdrawals, and newly passed Florida legislation calling for elimination of all liquid wastewater discharges into surface waters. To meet these challenges, CCUA developed an Integrated Water Resources Plan using a One Water approach to develop a roadmap for nearand long-term water resources investments.