Kraemer, Jeremy

Jeremy Kraemer is a Wastewater Technical Director in GHDs Waterloo, Ontario office. He is motivated by our global climate emergency to help clients mitigate GHG emissions and implement more resilient wastewater solutions. Jeremy is past chair of the joint Water Environment Association of Ontario / Ontario Water Works Association climate change committee, member of WEFs GHG Focus Group, and the National Advisory Committee for the Canadian Water Networks net zero water roadmap. He is a registered professional engineer in Ontario and obtained his Ph.D. from the University of Toronto.

Titles from this speaker

Dynamic Process Modelling for Aeration Blower Design at the Humber Treatment Plant

Abstract

The City of Toronto initiated a design and construction project in 2022 to replace the existing secondary treatment aeration blowers at the Humber Treatment Plant. A comprehensive review of historical flow and plant operating data was conducted to derive a design-year hourly diurnal flow and load profile (8,760 discrete data points) for input into a commercial wastewater process simulation tool. The output oxygen demands were used to generate process airflows considering varying wastewater temperatures, standard oxygen transfer efficiency based on net airflow per diffuser and diffuser depth, and dynamic alpha based on aeration basin oxygen uptake rates at each time step in the flow and load profile. Statistical and seasonal analyses were applied to the resulting airflow data sets to determine performance guarantee points at varying inlet air conditions for blower equipment preselection

The City of Toronto initiated a capital project in 2022 to replace the existing secondary treatment aeration blowers at the Humber Treatment Plant. A comprehensive approach was implemented to develop the process design basis for the new aeration blowers using dynamic wastewater treatment process modelling to derive process airflows for a one-year hourly diurnal flow and load profile. Resulting airflows were used to determine performance guarantee points at varying inlet air conditions.

SpeakerRizzuti, Daniel

Presentation time

08:30:00

09:00:00

Session time

08:30:00

10:00:00

SessionThe Big Bad Blower: Huffing and Puffing Air Through Your Aeration Basins

Session locationRoom S401d - Level 4

TopicEnergy Production, Conservation, and Management, Facility Operations and Maintenance, Intermediate Level, Municipal Wastewater Treatment Design

Author(s)

Rizzuti, Daniel

Author(s)D. Rizzuti 1; J. Kraemer 2 ; Pretorius 3; T. Young 4; T. Gretarsson 5; D. Pease 6; T. Shen 7; E. Eini 8; V. Szonda 6; D. Rizzuti 1;

Author affiliation(s)GHD Ltd., Waterloo, ON 1; GHD Ltd., Waterloo, ON 2 ; GHD 3; GHD 4; GHD 5; City of Toronto, ON 6; City of Toronto, ON 7; City of Toronto, ON 8; City of Toronto, ON 6; GHD 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159068

Volume / Issue

Content sourceWEFTEC

Word count13

MBRs Are More Cost-effective Than Ever Before

Abstract

A cost model was developed to compare the capital and 20-year lifecycle cost of MBR vs. CAS treatment technology for a greenfield WRRF. Concept designs and cost estimates were developed for six treatment performance scenarios at two design flow capacities: 20 ML/d and 200 ML/d. Compared with a prior version of this model developed in 2012, MBR has become more cost effective compared to CAS in general, most notably for less stringent treatment requirements, while the cost savings of MBR for more stringent treatment requirements has improved, but more modestly. A primary driver of this is the advancements in membrane design, primarily the reduction in air scour energy for membrane cleaning due to new diffuser technology, greater membrane packing density reducing membrane equipment costs and further reducing air scour requirements, decreased membrane cleaning requirements and longer membrane life, and increased use of gravity permeation from membranes under average day operation.

SpeakerYoung, Thor

Presentation time

16:30:00

16:50:00

Session time

15:30:00

17:00:00

SessionAlternative Approaches to Intensify Secondary Treatment

Session locationRoom S404a - Level 4

TopicIntermediate Level, Municipal Wastewater Treatment Design, Nutrients

Author(s)

Young, Thor

Author(s)T. Young 1; J. Kraemer 2 ; D. Rizzuti 3; S. Malatches 4; J. Lim 5; C. Thiemig 5; T. Young 1;

Author affiliation(s)GHD Inc 1; GHD Inc, Waterloo, ON 2 ; GHD Inc, Waterloo, ON 3; GHD Inc, Toronto, ON 4; Veolia Water Technologies & Solutions, Oakville, ON 5; Veolia Water Technologies & Solutions, Oakville, ON 5; GHD Inc, Bowie, MD 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159019

Volume / Issue

Content sourceWEFTEC

Word count8

Description: Real-world Reliability and O&M of High-speed Turbo and Integrally-geared...

Real-world Reliability and O&M of High-speed Turbo and Integrally-geared Blowers

Abstract

Aeration blowers consume around half of all electricity used at a water resource recovery facility (WRRF). Choosing the most efficient blowers can save money, electricity, and greenhouse gas emissions. High-speed turbo blowers and single-stage integrally-geared (SSIG) blowers offer some of the highest efficiencies for process aeration, but operations and maintenance (O&M) staff may not have experience with these technologies. This paper documents comparative O&M experiences between turbo and SSIG blowers compiled from interviews with thirteen (13) North American water utilities with medium to large size blower installations as well as the authors’ own experience and past projects. In addition, turbo blower reliability and failure data and maintenance contract information were solicited from turbo blower manufacturers and summarized. This information was used to support one water utility’s blower technology decision and the authors hope this information will be useful to other utilities as well.

This paper compares O&M experiences with turbo blowers and single-stage integrally-geared blowers from interviews with 13 North American water utilities with medium to large blower installations and the authors' experience and projects. Turbo blower reliability data and maintenance contract information from manufacturers is summarized. This information was used to support one utility's blower technology decision and the hope is this information will be useful to other utilities as well.

SpeakerKraemer, Jeremy

Presentation time

09:30:00

10:00:00

Session time

08:30:00

10:00:00

SessionThe Big Bad Blower: Huffing and Puffing Air Through Your Aeration Basins

Session locationRoom S401d - Level 4

TopicEnergy Production, Conservation, and Management, Facility Operations and Maintenance, Intermediate Level, Municipal Wastewater Treatment Design

Author(s)

Kraemer, Jeremy

Author(s)J. Kraemer 1; J. Kraemer 1 ; T. Jenkins 2; T. Young 3; C. Pretorius 4;

Author affiliation(s)GHD 1; GHD 1 ; JenTech Inc 2; GHD 3; GHD 4;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159070

Volume / Issue

Content sourceWEFTEC

Word count11

Tacking Fugitive Methane Emissions at WRRFs - Global Lessons

Abstract

Fugitive methane emissions from sludge treatment and biogas handling processes are a significant source of GHG emissions, particularly critical for WRRFs with anaerobic digestion. Sewer methane production can also contribute to significant GHG emissions for the entire wastewater systems. There is lack of consistent methodologies for quantifying and monitoring these emissions in North America, which could lead to over- or (more likely) underestimation of their contributions to the overall GHG footprint. Ongoing work in Europe show the criticality of direct methane emissions monitoring, and operational approaches to mitigate methane emissions through regular survey, proactive leak detection and repair and independent certification. This session will present an overview of the sources of fugitive methane emissions in collection systems and at WRRFs, available methodologies in monitoring and quantifying fugitive methane emissions (including challenges and issues), and practical tips for reducing methane emissions based on global case studies.

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

SpeakerLake, Amanda

Presentation time

13:30:00

15:00:00

Session time

13:30:00

15:00:00

SessionGlobal Approaches to Tackling Fugitive Methane Emissions

Session locationRoom S402a - Level 4

TopicIntermediate Level, Sustainability and Climate Change, Water Reuse and Reclamation

Author(s)

Lake, Amanda

Author(s)A. Lake 1; C. Scheutz 2 ; B. Beelen 3; E. Shen 4; P. Nielsen 5; A. Vellacot 6; A. Fredenslund 7; K. Kraemer 8;

Author affiliation(s)Jacobs 1; Technical University of Denmark 2 ; GHD 3; Jacobs 4; VCS Denmark 5; Jacobs 6; Technical University of Denmark 7; GHD 8;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825158977

Volume / Issue

Content sourceWEFTEC

Word count10

Description: Technical Brief 1: Pursuing Low-Cost Operational Changes to Mitigate Nitrous Oxide...

Technical Brief 1: Pursuing Low-Cost Operational Changes to Mitigate Nitrous Oxide at Two Halton Region WRRFs

Abstract

INTRODUCTION Nitrous oxide (N2O) is a potent greenhouse gas (GHG) with a global warming potential of nearly 300 times that of carbon dioxide. It is a major contributor to Scope 1 direct process emissions from wastewater treatment plants. In Ontario, Canada, the provincial electrical grid is already decarbonized, with a grid intensity <40 g-CO2-e/kWh, compared to the global average around 480 g-CO2-e/kWh (Ritchie and Rosado, 2020). Owing to low GHG emissions from electricity consumption, the Regional Municipality of Halton (Halton Region or Region) has estimated that N2O from treatment contributes a majority portion of Scope 1 GHG emissions at their wastewater treatment plants (WWTP). The Region's plant operations staff understand that N2O emissions may be an indicator of 'unhappiness' of the biomass and sub-optimal environmental conditions for treatment. Optimizing these conditions and removing stressors can reduce N2O emissions which is why operational optimization can be an effective mitigation approach. However, N2O generation mechanisms are complex due to multiple production and consumption pathways covering high dissolved oxygen (DO), low DO, and anoxic conditions (Figure 1; readers are referred to Ye et al. (2022) for a comprehensive explanation of N2O generation). Owing to variability of N2O production across space (i.e. different areas of a bioreactor) and time (daily, seasonally, yearly), Halton Region determined N2O needs to be measured to know what is happening. Therefore, the Region has undertaken a 2-year project with the goal of pursuing 'low hanging fruit' N2O mitigation strategies through operational optimization which is achievable based on current global experience. The objectives of the work include: (1) Measuring N2O emission factors (EFs) for Mid-Halton and Skyway WWTPs; (2) Identifying the operating parameters influencing N2O emissions & identifying low-cost operational optimization mitigation techniques; (3) Verifying the effectiveness of operational changes to reduce N2O emissions. METHODS In early 2024 Halton Region installed online dissolved nitrous oxide sensors (Unisense Environment, Aarhus, Denmark) at their two largest WWTPs, Skyway and Mid-Halton, with sensor data recorded starting early February 2024. The Skyway WWTP is rated 140 ML/d average day flow, with liquid treatment comprised of primary clarification, nitrifying activated sludge configured as long single pass tanks operated fully aerobic, dual-point ferric addition for phosphorus removal, deep bed tertiary sand filters, and sludge treatment comprised of thickening, anaerobic digestion, and dewatering. The Mid-Halton WWTP is rated 125 ML/d average day flow, with liquid treatment comprised of primary clarification, nitrifying activated sludge configured as 5-pass serpentine tanks operated with a year-round anoxic zone plus a seasonal anoxic swing zone, ferric addition for phosphorus removal, and sludge treatment comprised of thickening, anaerobic digestion, and dewatering. Figure 2 illustrates the bioreactors of both plants along with locations of dissolved oxygen and N2O sensors. Halton Region will conduct quarterly nitrogen profiling along the length of the bioreactors containing N2O sensors to understand where nitrogen conversion and N2O generation risk is highest. The Region created a standard operating procedure (SOP) and field data collection sheet for operations staff. The first bioreactor profiling was conducted at both plants on July 8, 2024 and the second one on October 28, 2024. Three sources of data are used: online SCADA data, lab data from the Region's laboratory information management system (LIMS), and a plant operations spreadsheet with daily summary data and operating information. A 'data lake' is generated by aggregating all data sources together through data merging and processing and calculating derived data (e.g. N2O mass emission rate, ammonia turn-over rate). Data analytics were performed including correlation 'heat maps' and other data synthesis. Artificial intelligence (AI) and machine learning (ML) methods are being applied through Cobalt Water Global's N2ORisk DSS which helps understand risk conditions for N2O, and is creating site- and location-specific ML models that will be used as soft-sensors later in the project when mitigations are tested. RESULTS Figures 3 and 4 illustrate the first 3 months of dissolved N2O concentrations measured at sensor location #1 at the Skyway and Mid-Halton WWTPs. As of writing this abstract, the second batch of data (months 4 through 8) are being analyzed. Four operational factors anticipated to relate to N2O generation are discussed. Dissolved Oxygen Both plants have high DO concentrations, routinely >4 mg/L, whereas the Cobalt Water N2O DSS recommends DO of 1-2.2 mg/L (Figure 5). There are periods of time when N2O generation is well aligned with DO changes (Figure 6). Optimizing aeration is the most common N2O mitigation technique owing to energy savings often being a co-benefit. Several European plants such as Eindhoven (Netherlands) have realized N2O reduction through DO adjustment (Porro et al., 2017) and this operational change is applicable to both Mid-Halton and Skyway WWTPs. Ammonia Turn-Over Rate Ammonia turn-over rate influences N2O generation at Mid-Halton and Skyway WWTPs. Figure 4 illustrates the Mid-Halton bioreactor MLSS compared to N2O concentration. The drop in both concentrations around March 14, 2024 was related to bringing the neighboring bioreactor online after a maintenance period. Operations staff built up the mass inventory prior to that time. With another bioreactor online the ammonia concentration and loading rate dropped resulting in less N2O. Bioreactor profiling was useful for understanding the nitrogen turnover rate along the length of the bioreactors, illustrated in Figure 7 for Mid-Halton and Figure 8 for Skyway. Although there is uncertainty in the nitrogen values at Mid-Halton (total nitrogen balance drops and then rises again), the highest ammonia turn-over rate was at positions 3, 4, and 5 at Mid-Halton (Figure 7) while it was positions 1 and 2 at Skyway (Figure 8). N2O production at a given sampling location was correlated with ammonia conversion in the upstream location (Figure 9). Skyway's profile was unexpected, and on investigation it was determined the ferric dosing prior to aerated grit tanks was resulting in extremely high primary clarifier performance with 80% TSS and 68% BOD removals. This extreme performance resulted in low organic loading to the Skyway bioreactors allowing immediate nitrification at the front of the tanks. These observations suggest a potential operational change to increase the MLSS so the biomass-specific ammonia turn-over rate will decrease. This mitigation was observed to reduce N2O emissions by 74% at the AvedÃ¸re WRRF (Andersen et al., 2022). Similarly, increasing the return activated sludge rate to dilute nitrogen concentrations and shorten hydraulic retention to push activity further down the train may also be useful. Diurnal Centrate Loadings At Skyway, the Region dewaters biosolids using a centrifuge about 6 hours per day for 5 or 6 days per week. The centrate is stored and then returned to the headworks over a four-hour period around 4-8pm. This slug load of ammonia reaches the aeration tanks in the late evening around midnight. The impact of this time-varying ammonia loading is observable in the N2O concentrations of Figure 10. Each day when there is dewatering there is a corresponding spike in N2O generation around midnight, while on the weekend when there is no dewatering there is no midnight N2O spike. At Skyway, extending the duration of centrate return would decrease the slug load ammonia. Rodriquez-Caballero et al. (2015) lowered N2O in a full-scale SBR with this technique. This approach is not applicable at Mid-Halton since dewatering centrate is already fully equalized and returned over a 24-hour period. pH There was also an observed correlation between N2O and pH at both plants (Table 1). This relationship could also be observed in the data (Figure 11). DISCUSSION/CONCLUSIONS Based on the first 3 months of data, Halton Region has observed N2O generation at the Skyway and Mid-Halton WWTPs is correlated as expected with DO levels, ammonia loadings, mass inventory levels, and pH. It is already clear there will be several operational changes that can be tested during year 2 to assess low-cost N2O mitigation. Interestingly, the N2O emission factors are quite different between the two WWTPs and differ from the IPCC default (Table 2). These results confirm the site-specific nature of N2O emissions and reaffirms the need for WRRFs to measure N2O to know their actual emission rate. At time of writing data from June to September is being analyzed. The conference presentation will include all data available and the Region will have decided which operational changes to test.

This paper was presented at the WEF Residuals & Biosolids and Innovations in Treatment Technology Joint Conference, May 6-9, 2025.

SpeakerKraemer, Jeremy

Presentation time

14:15:00

14:20:00

Session time

13:30:00

15:00:00

SessionHow DO Setpoints and Control Impacts Performance and Emissions

Session numberITT Session 04

Session locationBaltimore Convention Center, Baltimore, Maryland, USA

TopicAdvanced Biological Nutrient Removal (ABNR), Aeration Control, Full-scale Optimization, Greenhouse Gases, Microbial communities, Modeling, Nitrogen, Nitrous oxide, Simultaneous Nitrification-Denitrification (SND)

Author(s)

Kraemer, Jeremy, Duong, John, Baker, Chandra, Oberoi, Sanjeev, Pharand, Lizanne, Porro, Jose, Andersen, Mikkel, Ye, Liu, de Haas, David, Bhayani, Bhavin, Beelen, Benjamin, Sabzwari, Aby

Author(s)J. Kraemer1, J. Duong C. Baker2, S. Oberoi2, L. Pharand2, J. Porro3, M. Andersen L. Ye4, D. de Haas1, B. Bhayani1, B. Beelen1, A. Sabzwari1

Author affiliation(s)GHD, 1The Regional Municipality of Halton, 2Halton Regional Laboratory, 2Cobalt Water Global, Inc., 3

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date May 2025

DOI10.2175/193864718825159750

Volume / Issue

Content sourceResiduals and Biosolids Conference

Word count17