Stoughton, Ryan

Ryan Stoughton, PE is the Assistant City Engineer Wastewater Division for the City of Kalamazoo. Ryan received his bachelors in civil engineering from Western Michigan University. He has worked as an Operator at the Kalamazoo Water Reclamation Plant, an engineer at Jones Henry, and now in engineering leadership for the City. He has a wonderful wife and two great kids and has recently jumped into the recreation of RVing.

Titles from this speaker

Description: Building for the Future: A Commonsense Approach for Kalamazoo Water Reclamation...

Building for the Future: A Commonsense Approach for Kalamazoo Water Reclamation Plants' Dewatering Facility Upgrade

Abstract

Rising chemical and sludge disposal costs, an uncertain future for biosolids disposal, and operator shortages; are some issues shared by many wastewater utilities today. The Kalamazoo Water Reclamation Plant (KWRP) dewatering upgrade case study presents a road map for other utilities on how to address the pressing issues many utilities face today by incorporating pilot testing, and utilizing operations and maintenance staff input in the equipment selection and design process, selecting the equipment to produce the driest cake, configuring equipment in a way to minimize odor and maximize the potential for future expansions, and by visualizing data to fast track the operator training process. This presentation presents a history of the plant, its past and present concerns related to biosolids, and an overview of its dewatering facility commissioned in 2022. KWRP, located in western Michigan, serves approximately 190,000 people. KWRP previously used sludge incineration, but the incinerator was abandoned in 1999 due to the implementation Title V EPA, a stringent air quality regulation for flue gas from incinerators. Until the most recent upgrade discussed here, the gravity-thickened primary sludge and waste-activated sludge from the biological nutrient removal (BNR) process were combined and dewatered together using four belt filter presses. Because a sizable pharmaceutical production plant is in the service area, activated carbon is added to the BNR process to absorb micropollutants. In 2001, because of the closure of the incinerator, KWRP started to produce Class A biosolids using the RDP lime addition and pasteurization process. This class A sludge production process did not last long. The plant experienced too many difficulties with operating and controlling the installed RDP process for the required sludge production throughput. Michigan's rising costs for land application fees were another factor for discontinuing that process. In 2008, the utility moved to 100% landfilling sludge, taking advantage of relatively low disposal cost: $17.5/wet ton. From 2008 to the present, the plant has faced a steady rise in disposal costs, on average 13.0% /year; cake dryness requirements (%TS) have also tightened. Maximizing the dryness of the dewatered cake and reduction of disposal volume became a priority for the Dewatering Facility Upgrade. Additional objectives for the upgrade included minimizing the odor source and improving the operational environment in the sludge dewatering facility, designing a flexible set up to adapt future changes in post-dewatering solids-handling, and to ensure the selected equipment is intuitive for operators to dial-in and maintain. KWRP believes pilot testing provides the most accurate data for decision-making and solidifying the facility design. The city opened an invitation for paid pilot testing to all interested manufacturers in 2014. Eleven manufacturers and six technology alternatives participated. After testing was completed, centrifuges were selected as the equipment of choice, for being the lowest annualized cost option in present-worth with the possibility for simple future expansion. (Figure 1). Figure 1: Annualized Total Cost for Kalamazoo Sludge Dewatering Options After receiving proposals from vendors, the city organized operators' visits to other water reclamation facilities and equipment manufacturing and equipment service facilities to gather KWRP staff input during the selection process. Among the equipment evaluated, Centrisys was selected for several reasons: The central location for repairs was fundamental for the centrifuge manufacturer choice, along with access to their top technical and optimization leaders in the company. Simple operation and maintenance of the hydraulic scroll drive, in comparison to a gearbox drive, was also a critical factor for the equipment selection. The hydraulic scroll drive was also preferred for its ability to generates higher torque than gear box to maximize the cake dryness. Three Centrisys CS26-4 units were installed in 2021 and successfully started up in 2022 (Figure 2). The project design includes the necessary infrastructure to support the current installation along with the possibility of an additional fourth Centrisys CS26-4 if needed. The upgrade resulted in the immediate improvement in sludge dewaterability: before the upgrade a 2-meter Andritz belt filter press was generating 16-17% cake; after the upgrade, the centrifuges now generate cake in the range of 21-24%, which translates to a disposal sludge volume reduction of 20-30%. The timing was just right: When pilot testing began, disposal costs were $30.90 per ton. In 2022, it was raised by 44% over the previous year to $92.71/wet ton, making it one of the highest in the region. Figure 2: Centrisys CS26-4 Installation at Kalamazoo Water Reclamation Plant Working through the volatility of disposal costs and uncertainties in the regulatory climate, KWRP has selected ancillary equipment to accommodate future changes better. Instead of open-top conveyors, cake piston cake pumps are now used to move the dewatered biosolids. The piston pumps can generate operating pressures up to 1,500 psi. In the case of either future regulations of emerging contaminants like PFAS, or increasing disposal costs, where further processing of the dewatered cake by means of sludge drying are required, facility additions can be accommodated by a simple reconfiguring of the pipes. The selection of the cake pumps over open conveyors minimizes the source of odor. The small amount of odorous gas generated from the decanter centrifuges and the cake pumps is now treated through activated carbon filters to improve the operator environment. Another design consideration for ease of operation is the addition of Valmet total solid meters to the centrifuge feed lines (Figure 3). The centrifuges have forward control of the polymer dosing systems: taking the measurements from the TS meter and the flow meter and pacing the polymer rate by specifying the polymer dose in lb/dry ton, rather than just a pump speed, in the control panel. This setup makes training new operators easier by giving real-time trends for the operators to learn about the plant and specifically dewatering operations. Additionally, having the polymer dose input (lb./ton) at the centrifuge which resembles what the operators learned for the operator training exam aids staff in being able to visualize the data. This in turns helps KWRP to shorten the initial training period for dewatering operations and more quickly move operators to the next level of training: tuning the centrifuges and to take on tasks such as selecting better polymers to get more out of their new equipment. Figure 3: Installed Valmet Meter KWRP addressed these challenges via a data-driven, and operator-centric approach for their biosolids dewatering facility upgrade. The primary pieces of the KWRP story are: the support from the community in funding the pilot testing piece of the dewatering equipment evaluation, the operator site visits to learn about the equipment, and the inclusion of innovative technologies such as real time solids measurement and visualization. In close collaboration with the equipment suppliers, KWRP found the winning ticket for navigating uncertain regulatory market conditions and preparing the plant for the future.

This paper was presented at the WEF/IWA Residuals and Biosolids Conference, May 16-19, 2023.

SpeakerStoughton, Ryan

Presentation time

11:15:00

11:45:00

Session time

10:45:00

11:45:00

SessionSession 04: Process Case Studies in Dewatering

Session number04

Session locationCharlotte Convention Center, Charlotte, North Carolina, USA

TopicThickening & Dewatering

Author(s)

R. Stoughton

Author(s)R. Stoughton1, J. Gable2, 3, 4,

Author affiliation(s)City of Kalamazoo1; Centrisys/CNP2

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date May 2023

DOI10.2175/193864718825158822

Volume / Issue

Content sourceResiduals and Biosolids

Word count16

Description: Digitalization of odor, corrosion and safety management in sewer networks - The City...

Digitalization of odor, corrosion and safety management in sewer networks - The City of Kalamazoo

Abstract

The City of Kalamazoo has, over several years, been implementing a programme of works to improve odor management performance. This programme has included upgrades to the design of the sewer network, the establishment of an Odor Task Force with representatives of the City, local industry, elected officials, regulators and community groups, and the implementation of continuous monitoring focused on odor impacts. To complement this programme, the City piloted the creation of a digital twin of the network to support the identification and mitigation strategies for odor (in addition to corrosion and safety risks associated with hydrogen sulfide and methane). This case study explores the application of the SeweX product at the Davis Creek catchment in the City of Kalamazoo. SeweX was undergoing transformation from a deterministic model usually applied through a consulting approach, to a commercial software product. This case study reviews the process of collaboration between vendor and the City and the progress towards implementation of its digital strategy. The project included: - Configuration of a sulfide and methane model. - Calibration of the model with wastewater quality and gas measurements. - Visualisation of high risk areas across the network. - Assessment of alternative operating scenarios including chemical dosing and ventilation. - Training. - Review by key project stakeholders for suitability as a tool for ongoing use. Assessment of value of the product for wider rollout. ...Critical Success Factors The critical success factors for this project were: - Model accuracy to a level of accuracy that could be used for decision making across the network. - Ease of use — Model setup should be possible by non-subject matter experts. Results should be accessible and understood by the key users of the information for making decisions regarding capital allocation. - Scaleability — The solution should be able to be used in other networks with similar levels of available information and be able to be integrated into current work practices. ...Lessons Learned Initial results showed good agreement between measured and modelled results for H2S gas at Davis Creek in both the range of concentrations and variation of concentration across the day. The key lessons learned included: - Engaging with a complex modelling product of this nature at its stage of maturity provided an opportunity to positively influence product design and rapid product improvement. Flexibility from both vendor and customer was needed. - Organisational champions are critical to both develop and deliver the strategy in a large and diverse organisation with many stakeholders in the management of odor, corrosion and safety. - As an organisation-wide, accessible model for sewer network corrosion, odor and safety was a very new concept, intensive internal stakeholder engagement was needed identify the best approaches for integrating the solution for the longer term. Adapting to feedback throughout the process, especially monitoring requirements, was important. Taking time to understand the needs of different functions and individuals within the business and how this initiative best supported those needs was a valuable exercise. ...Outcomes This case study shares the key results and outcomes from the analysis of potential improvements to odor, corrosion and safety managements at the two catchments, which considered changes to chemical dosing strategy, ventilation and/or hydraulic properties in the network. Progress towards organisational objectives of improved decision making related to odor, corrosion and safety management in sewer networks was also reviewed.

This paper was presented at the WEF Collection Systems and Stormwater Conference, April 9-12, 2024.

SpeakerKolominskas, Chaim

Presentation time

09:30:00

10:00:00

Session time

08:30:00

10:00:00

SessionSmart Collection System Programs

Session number13

Session locationConnecticut Convention Center, Hartford, Connecticut