AC25 Annual Conference Digital Bundle

CWEA Member: $295.00
Non-Member: $390.00

13.0 contact hours towards CWEA's certifications.
This series includes the following 50 minute sessions. 

Advancing Solids Thickening Through Suspended Air Application
In a recent project funded by California Energy Commission (CEC), an innovative thickening process -Suspended Air Flotation (SAF®)- was selected to be tested at demonstration scale. SAF® process presents a compelling alternative to traditional thickening methods considering its potential to reduce energy consumption and to separate emerging contaminants such as Per- and polyfluoroalkyl substances (PFAS).

The SAF technique employs a suspension of micron-sized air bubbles, ranging from 7 to 50 µm, in water to attain a volumetric air content of 40 to 50%. These bubbles are coated with a thin layer of soap film derived from an electrically charged anionic or cationic surfactant. The charged bubbles offer a substantial interfacial area for the adsorption of oppositely charged flocculated wastewater solids. In practice, suspensions of charged bubbles are introduced into the flotation tank to interact with wastewater solids. The solids then ascend to the surface and are skimmed off. The clarified effluent is recirculated to the headworks.
SAF enhances traditional thickening methods like Dissolved Air Flotation (DAF) by eliminating the need for dissolved air, thus obviating the requirement for pressurization systems, recirculation pumps, compressors, and airlines, leading to considerable energy savings. SAF's capability to manage high solids loads also results in substantial footprint and power savings, high solids recovery (up to 99%), and a high solids loading rate (up to 40 lb/ft2/hr). Moreover, no polymer is needed to thicken sludge to 4% solids. Owing to these benefits, adopting SAF technology can lead to an energy savings of up to 90% compared to its conventional counterparts, such as DAF.
This presentation will assess this novel technology, its performance, present results from case studies, and elaborate on the potential of this technology for PFAS separation.
Learning Objectives:
Define the suspended air flotation technology (SAF) and difference between dissolved air flotation (DAF) technology
Demonstrate the advancements of SAF technology for various case studies including thickening of Advanced primary treatment solids and secondary solids
List the important criteria for the design and operational challenges of the SAF technology

Anaerobic Digestion of Organics: Industry Drivers Overview of Two Case Studies for CHP and RNG
This presentation will discuss the diversion of organics, such as food waste and the co-digestion of these wastes with anaerobic digestion which generated biogas, a beneficial byproduct. Doing so allows reduction in landfill volumes and stabilization of the waste suitable for land application. The stabilization process, when accomplished with anaerobic digestion, generates biogas, a beneficial byproduct.

The presentation will include an overview of industry trends, including regional trends in State of California for organics diversion requirements. Other industry drivers that will be covered will include greenhouse gas emissions reductions, state and federal financial incentives, and drivers for renewable energy production.

When organic waste is diverted to a wastewater treatment facility, the organics can be co-mingled with municipally generated sludge in anaerobic digestion (i.e., co-digestion). This allows for existing infrastructure to be utilized for both wastewater treatment and landfill diversion while generating a biosolids product and digester gas. The produced biogas can be utilized as a fuel source for a process heating boiler or in a combined heat and power system or renewable natural gas.

Finally, the presentation will include case study overviews of two functioning wastewater treatment facilities with anaerobic digestion, both which are receiving significant quantities of organic wastes to generate biogas from co-digestion. One facility is utilizing biogas produced in a combined heat & power (CHP) for use at the facility and has achieved net zero operations beginning in 2022. The second facility facility has a very large high strength waste program with over 19,000 loads received annually. The biogas from this facility is processing the biogas into renewable natural gas (RNG) for pipeline injection which generates over $6M annually.
Learning Objectives:
1. Gain understanding of the industry drivers for organics diversion and resource recovery programs.
2. Learn about two functioning full-scale wastewater treatment facilities with anaerobic digestion, both which are receiving significant quantities of organic wastes to generate biogas from co-digestion.
3. Define the concept the organics diversion, such as food waste and the co-digestion of these wastes with anaerobic digestion which generated biogas and potential value of this renewable fuel.

Maximizing Biosolids Value: Post-Upgrade Optimization and Market Development
This presentation explores the optimization of new solids handling facilities and the creation of marketable biosolids products, drawing insights from two major utilities: Hampton Roads Sanitation District (HRSD) and JEA.

HRSD’s Atlantic Treatment Plant (ATP) transitioned from Class B to Class A biosolids production by commissioning a Cambi thermal hydrolysis process (THP) skid in mid-2020. This transition resulted in increased solids capacity and improved final dewatering performance. The presentation will delve into the startup and optimization process, highlighting lessons learned and how these upgrades have prepared HRSD to adapt to future regulatory changes.

Initial startup required ATP to disinfect digesters and all associated piping. The first digester was filled with heated disinfected non-potable water and seed from DC Water’s digesters. The approach to ramping up thermally hydrolyzed sludge feed started at 50% of DC Water’s loading rate and increased over several weeks.
Using existing dewatering centrifuges, the final dewatering cake solids improved from 14-16% total solids (TS) to 30% TS after THP implementation and optimization. Curing pilots using the 30% cake and a windrow turner determined the most efficient method for producing a low-odor, aerobically cured product. Lessons from 2023 pilot studies have been applied to full-scale curing operations initiated in early 2024.

JEA, one of Florida’s largest utilities, has proactively planned for the future of their biosolids program. In 2017, JEA’s master plan recommended decommissioning the old thermal drying system and outsourcing Class B dewatered cake processing to a third-party. However, this dependence led to uncertainties in costs and regulatory compliance.

In 2020, JEA revised their strategy, recommending a new regional biosolids handling facility at the Buckman Water Reclamation Facility (BWRF). This facility, designed to handle solids from all 12 JEA-owned water reclamation facilities, includes advanced thickening and dewatering equipment, two large thermal drum drying systems, and infrastructure for high-quality pellet production. These upgrades provide JEA with the flexibility to pivot as regulatory drivers change and new market opportunities arise.

The presentation will discuss innovative strategies employed by JEA, including a pilot of an in-line high-shear dynamic mixer to re-wet dewatered cake solids, reducing transportation costs and capital expenses.
Learning Objectives:
Describe the startup and optimization process of thermal hydrolysis and its impact on biosolids capacity and quality.
Explain approaches to evaluating and upgrading biosolids handling facilities, focusing on infrastructure, process reliability, and market development.
Identify key lessons learned in the production and market development for biosolids products."

Developing Engineering Design Criteria for Partial Denitrification Anammox (PdNA) Implementation for Multiple Biofilm Media
Partial denitrification anammox (PdNA) implementation can combat some of the most difficult challenges facing California’s water resource recovery facilities (WRRFs). PdNA can alleviate strains caused by population growth and nutrients, while offering long-term budgetary benefits. Rather than using traditional nitrification and denitrification, PdNA can be implemented which has lower energy requirements, carbon demands, and greenhouse gas emissions. In PdNA, nitrate is reduced to nitrite (partial denitrification), and the reduction of nitrite to nitrogen gas (full denitrification) is avoided. The nitrite produced from partial denitrification can then be reduced to nitrogen gas with influent ammonium via anammox. This process has been proven to be more stable than alternative methods (partial nitritation anammox [PNA]), making it an attractive option for mainstream wastewater treatment.

This presentation will provide an overview of a $4 million U.S. Department of Energy (DOE) PdNA study that will implement PdNA in six WRRFs nationwide. The study focuses on determining engineering design criteria as nitrogen loading and removal rates, mixing requirements, headloss, fill ratios, and retrofittability of different media (moving integrated fixed-film activated sludge [IFAS], fixed IFAS, and biological aerated filters [BAFs]) to enable widespread PdNA implementation.

Applicability to California Utilities:
PdNA implementation can be a beneficial solution for California utilities that are seeking to increase capacity or are considering the initiation of a water reuse program. The capacity enhancement holds particular significance for facilities with footprint limitations, as PdNA can be retrofit into existing facilities without significant construction. From the perspective of water reuse, tertiary PdNA in a BAF offers a solution for achieving effluent total inorganic nitrogen (TIN) and total suspended solids (TSS) limits while minimizing modifications to upstream infrastructure.

As a part of the DOE study, a pilot-scale tertiary BAF PdNA process will be evaluated at the Linda County Water District water resource recovery facility (WRRF) which should commence in Fall 2024. Startup and preliminary results from this pilot and other WRRFs will be shared at the conference.

Conclusion:
PdNA represents a cost-effective method for expanding capacity, reducing operation and maintenance costs, and transitioning to water reuse, making it a valuable solution for California utilities.
Learning Objectives:
Describe the overall benefits of PdNA, list several approaches to configure/implement PdNA, status of PdNA design criteria, and demonstrate innovative methods for overcoming headloss challenges associated with its implementation.
Identify the synergistic benefits of combining water reuse with PdNA and describe the tertiary BAF PdNA study at the Linda County WRRF.
Determine novel technologies that can potentially be integrated with PdNA to minimize the need for supplemental carbon."

A Flexible Future - How Split Flow BNR Opens Doors to Future Possibilities
Presentation Description: San Francisco Bay Area wastewater utilities are facing nutrient discharge regulations that impact near-term and long-term decision making. The City of Sunnyvale Water Pollution Control Plant (WPCP) balanced aging infrastructure needs with future nutrient to develop a phased approach for upgrading their treatment plant to remove nutrients.

The existing treatment facilities at the WPCP are aging assets and cannot meet anticipated future discharge regulations for nitrogen. The City decided to be an early adopter in nutrient reduction and to implement a two-phased secondary treatment upgrade to transition to a conventional activated sludge (CAS) BNR process. Carollo/Jacobs recently completed the design for the $300M Secondary Treatment and Dewatering Project. The construction of the Phase 1 secondary treatment facility and Demon deammonification sidestream treatment facility is in progress. The CAS facilities will operate in parallel with the existing oxidation pond treatment train and the Demon sidestream facility will treat return stream from a new dewatering process.

Dealing with aging infrastructure and a tight site, this phased approach allows the City lots of flexibility. Delaying the second phase of the project allows the City to:
• Defer costs and maintain financial flexibility
• Allow process intensification technology to mature
• Maximize site space and right size phase 2

This presentation will provide an overview of the project and review key factors that influenced the decision to implement split flow and sidestream treatment, and explore elements of the design that were implemented to successfully manage the split flow operation and flexibility for future expansion.
This presentation may be of interest to design engineers, decision makers, planners, or others charged with navigating future regulations and developing strategies to optimize performance and nutrient load management. The City of Sunnyvale is on their way towards implementing their Program that began in 2016. Key decisions on implementing split flow and optimizing the Phase 1 Secondary Treatment and Dewatering Project design have maintained flexibility for the City for what comes next.

Learning Objectives:
Understand how a phased approach to a process upgrade can delay capital investment and increase future flexibility.
Identify creative solutions that address multiple drivers such as aging infrastructure and new regulations.
Describe the benefits of planning ahead

Modifying a BNR Facility for Low DO Operation and Operating it to Get There
The Los Angeles County Sanitation Districts and Carollo Engineers, Inc. have participated in a Department of Energy project called “Transforming Aeration Energy in Resource Recovery Facilities through Suboxic Nitrogen Removal.” The project seeks to operate the activated sludge process at dissolved oxygen (DO) levels that are significantly below 1.0 mg/L while maintaining nitrification. The aeration process in a water recovery facility (WRF) typically consumes approximately 50% of the total energy of the plant. This project aims to reduce that energy consumption from 1500 to below 650 Kwh/MGD . This project involved pilot work as well as conducting full-scale modifications at the Pomona WRF to accommodate low DO operation.

The Pomona WRRF was built about 50 years ago and has not had any significant controls modifications since then. This may be typical of many WRF's in California. This presentation will cover in detail the significant modifications that were made to the facility and the costs. The old single speed centrifugal process air compressors were replaced with turboblowers. The old aeration control had one valve which controlled numerous aeration zones. New valves and flowmeters were installed to allow individual aeration zone control. A third-party control system was installed to allow precise DO control as well as ammonia-based aeration control. A solids retention time control system was also provided. To facilitate these control systems additional instrumentation, including sensors for ammonia, nitrate, DO, TSS, and sludge blankets, were installed. Details on the installation and maintenance of these sensors will be discussed.
The project team will also discuss the approach to reducing the DO while maintaining compliance. Results of low DO activated sludge transition will be presented. This project is due to be completed at the end of September 2024. Pomona WRF is currently operating an average daily DO of 0.85 mg/L. There is some disagreement about how low DO activated sludge works. It may be different organisms doing the nitrification or the existing population adapting to the low DO. The presentation will provide batch kinetic and nitrification test results as well as microbial analysis to try to provide an answer to that question.

Learning Objectives:
Upon completion, the participant will be able to understand the equipment and controls required to perform low DO operation.
Upon completion, the participant will be able to formulate a plan to transition a facility to low DO operation.
Upon completion, the participant will be able to understand the costs and benefits associated with low DO operation.

Addressing Future Uncertainties Through Adaptive Planning, Resulting in Intensification and Decarbonization of BNR
Adaptive planning serves as a valuable means to conceptualize and create designs for water resource recovery facilities (WRRFs) that accommodate various stages of growth, even those that are yet unknown. By offering flexible and high-performing technology options, intensification can assist in adaptive planning and effectively address the multiple challenges that WRRFs encounter today. This presentation will highlight the adaptable planning approach and intensification strategies implemented in the secondary treatment system design for the Town of Windsor Water District (Town) to:

• decarbonize their biological nutrient removal (BNR) system in line with net zero sustainability goals
• plan for uncertain growth in a space constrained site
• meet stringent nutrient limits, both nitrogen and phosphorus

The Town’s WRRF has a limit for effluent total nitrogen and phosphorus in their NPDES permit (set at 10.5 mg-N/L and below detection limit respectively). While the WRF has been consistently meeting their permit, these stringent limitations have become constricting when considering Town’s ability to meet growth requirements. Current average influent TSS and ammonia loadings have already exceeded the WRRF’s design capacity. In addition, the Town will be consolidating with an adjacent sanitation district whose growth comes with a substantial degree of uncertainty.

The Town conducted a nutrient removal study and conceptual design in 2020, and is now implementing the detailed design of the secondary treatment system. A roadmap will be presented of the adaptive planning design for this system, which considers multiple growth scenarios for each of the Town’s influent sources.

A variety of intensification options were considered in the design, including aerobic granular sludge (AGS), primary filters and hydrocyclones. Membrane aerated bioreactors (MABR) were ultimately selected for their modular nature, low footprint, and low energy requirement, which perfectly aligns with the Town’s drivers above. The roadmap will illustrate how intensification strategies such as MABR can facilitate adaptive planning by providing phased growth design options that don’t necessarily mean expansion at each step. This part of the presentation will also include an audience driven discussion about how intensification strategies can more broadly be tailored to specific drivers, just as it was in Town’s adaptive design.

Learning Objectives:
View a roadmap of how adaptive planning can be used for phased design under uncertain and unexpected growth for WRRF’s with a multitude of drivers
Understand an example of how a specific intensification option can facilitate adaptive phased design and help tailor the design to a specific client’s needs
Describe how a variety of intensification options can meet various drivers for WRRFs including but not limited to: meeting permits, decarbonizing, address site specific challenges such as space constraints, etc."

Benefits of Hydrocyclones for WRRF Performance: Better Settling, Improved Nitrification… and Reduced E. coli?!
The aerobic granular sludge activated sludge process using batch reactors has received attention for the potential it offers to intensify activated sludge. Intensification allows WRRFs to improve effluent quality with a smaller footprint. Alternate technologies like hydrocyclones have become commercially available, which help to retain faster settling particles while the slower-settling particles are wasted out of the system. This type of technology can be more easily incorporated into plug flow reactors. At some plug flow facilities that have both hydrocyclones and unaerated high food-to-microorganism (F/M) selector zones, a relatively high fraction of the activated sludge can become granules producing a “densified sludge”.

In 2020, the City of Wichita installed a four-cyclone skid (180 gpm of return activated sludge [RAS]) on one of six nitrifying activated sludge trains at the Plant 2 WRRF (rated 54 million gallons per day [mgd]). The benefits to settleability through reductions in the sludge volume index (SVI) of the mixed liquor and improved water clarity in the test basin was observed. The SVI in the main basins averaged 120 mL/g compared to 91 mL/g in the hydrocyclone pilot basin. The City has started sampling E. coli in its secondary effluent prior to ultraviolet (UV) disinfection. Initial sampling has indicated about a 0.5-log reduction in E. coli counts in the hydrocyclone train compared to the non-cyclone trains.

Current biological nutrient removal (BNR) improvements project at the Plant 2 will incorporate a full-scale hydrocyclone system. This presentation will present the design criteria and layout of the new hydrocyclone facility and BNR facilities, a 5-stage Bardenpho process with high F/M selector zones and 19 cyclones for sludge wasting. Design considerations for the ancillary support facilities will also be presented, including a cyclone feed sludge (RAS) pumping, discharge of the cyclone underflow into the selector zones of the BNR process, and overflow as waste activated sludge (WAS).

With many utilities in California facing addition of nutrient limits in their discharge permit, the approach provided in this presentation will help these utilities save capital dollars on their improvement projects.

Learning Objectives:
Upon completion, participants will have a good understanding of densified sludge and the benefits it provides for wastewater plant operations.
Upon completion, participants will learn the key elements to consider when designing a full-scale hydrocyclone based system to provide densification in a plug flow reactor.
Upon completion, participants will learn about the latest research associated with hydrocylones, which indicates that they can potentially reduce disinfection dose at WRRFs, in addition to process benefits ."

Registrants who view the live webinar to see the slides and hear the audio and then enter the correct attention check code (directions below) will receive 13.0.0 contact hours towards CWEA's certifications.

To receive your contact hours for viewing the recording, you will need to view each video in the series. Upon completion of the last video in the series, the system will automatically unlock the attention check code for you view. The two (2) different attention check codes that will be displayed, and you will need to enter these codes as 1st attention check code – 2nd attention check code (XXXX-XXXX) in the Attention Check Code component under the "Contents" tab.  

Please note, all user activity of CWEA certification holders on the Online Wastewater Education Network is subject to the CWEA Code of Ethics standards for professional conduct and ethics. Certification holders should receive credit for a training only once within the same contact hour period. Any attempt to undermine the certification process may be subject to ethics procedures and possible sanctions. It is not possible to receive contact hours for both attending the live webinar and viewing the recording.  

Once you have entered the correct attendance check codes, you will be able to create and download an electronic certificate of completion under the "Contents" tab.