Berry, Melissa

Melissa is a Mechanical Engineer with a range of experience over a 18 year career. She started her career in oil and gas consulting, developing...

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About Berry, Melissa

Melissa is a Mechanical Engineer with a range of experience over a 18 year career. She started her career in oil and gas consulting, developing fundamental design engineer skills; then transitioned to working for a start up piloting municpal waste gasification technology. Her work was focused on gas cleaning and recovered water treatment. The last 7 years she has now found a niche working on waste water odour control projects with a focus on sewer and ventilation modelling.

Berry, Melissa

Titles from this speaker

Studying Odor And Corrosion For 168 Kilometers of Large-Diameter Interceptor

Abstract

Background Oakland and Macomb Counties, located north of Detroit, Michigan, USA, are largely served by three connected yet separate interceptor systems. These include the Clinton Oakland Sewage Disposal System (COSDS), Oakland-Macomb Interceptor Drain (OMID), and the Macomb Interceptor Drain (MID). These systems serve the Oakland County Water Resources Commissioner (OCWRC), the Oakland-Macomb Interceptor Drain Drainage District (OMIDDD), and the Macomb Interceptor Drain Drainage District (MIDDD), respectively. Together, these three systems total about 168 km (104 miles) of deep interceptor sewer. Maps of the systems are provided in Figure 1; system design profiles are provided in Table 1. Persistent corrosion issues since the 1970s have led to the deterioration and at times catastrophic failure of portions of the interceptors. At certain venting locations, fugitive H2S emissions result in recurring odor complaints. Objectives Since about 2011, actions have been taken to study these issues in a system-wide approach and to initiate mitigative improvements with three principal objectives in mind:

*Identify options to reduce the rates of corrosion

*Cost-effectively extend interceptor operating life

*Minimize odor complaints Together, they are working toward complete odor and corrosion control coverage of their combined systems. The Districts currently have active condition assessment, grouting, and lining operations; however, the size of the interceptors makes Contractor mobilization, access, and liner installation complicated and costly. Odor and corrosion control could potentially limit lining to specific problematic segments and result in significant cost savings. Methodology Characterizing the impact of sulfide generation, H2S release, and sewer corrosion required a comprehensive approach, including reviewing past studies and completing field sampling, developing sewer process models using the commercially available Wastewater Aerobic/Anaerobic Transformations in Sewers (WATS) modeling platform (The WATS Guys), air dispersion modeling, and fan testing. The extensive data collection program included wastewater characterization and continuous sewer differential pressure and vapor-phase H2S concentration monitoring using Acrulog (Clontarf, Queensland, AUS) digital monitors. Sampling was completed at 57 locations in total across all three systems. This information was used to develop and calibrate system sewer process models. For the OMID and MID systems, multiple unique conditions were modeled. Critical scenarios included (1) dry weather (low flow), (2) wet weather from inflow and infiltration (high flow), and (3) 'storage and release' operations. For the COSDS, the impact of the Elizabeth Lake Pumping Station (ELPS) on the downstream sewer and areas that were concurrently undergoing condition assessment inspections were most critical. Results From sewer process modeling, the factors leading to the most severe odor/corrosion conditions included:

*'Storage and release' operation of flow control (gate) structures in the OMID and MID — This operation, which is used either for flow management or downstream maintenance access, increases detention time and generates sulfide. When released — either by raising the low-flow sluice gates or overtopping the divider walls in the flow control structures — turbulence results in H2S stripping (Figure 2), sewer pressurization, and fugitive odorous emissions at ground-level.

*H2S stripping at MID and OMID drop manholes — Hydrogen sulfide is released at turbulent vertical drop manholes where community sewers that flow through metering facilities at higher elevations discharge into the deeper MID and OMID.

*Force mains and pump station operations within the COSDS and MID — Anaerobic conditions occurring in the force mains exacerbate sulfide generation, particularly for long or low-velocity force mains. For example, the ELPS in the COSDS switches between two 1.3-km (0.8-mile) long force mains every 12 hours, increasing H2S and modeled rates of corrosion (Figure 3). Jacobs worked collaboratively with another consulting team that was hired by OCWRC to assess through field inspection and in situ testing specific areas of the COSDS that may require rehabilitation. The extent of corrosion was independently confirmed by corrosion rates calculated by the sewer process model. Conclusions This comprehensive approach to evaluating specific operating conditions enabled the design team to identify the most effective locations and methods (to address odor and corrosion. Activated carbon treatment systems were proposed for the MID, as well as process improvements to the existing Fraser Biofilter (designed/constructed by others). As of January 2024, the design of the OMID systems (by Jacobs) is complete, which presented unique challenges related to aesthetics, visibility, and site constraints requiring unique solutions — e.g., concealing one system to reflect the surrounding neighborhood (Figure 4). Additionally, the sewer process model of the COSDS system has been completed, and the basis of design is under development, which will include odor and corrosion management recommendations. One recommendation will be to pilot a force main flushing protocol at the ELPS in early 2024 as a potentially cost-effective alternative to treatment.

Oakland and Macomb Counties, located north of Detroit USA, are largely served by three connected, yet separately managed interceptor systems. Since their construction, these systems have experienced odor and corrosion issues. This paper will review the methodology and tools used to study these issues, the study results, and the recommendations for achieving system-wide mitigation that will reduce the rates of corrosion, economically extend interceptor operating life, and minimize odor complaints.

SpeakerGraziano, Steve

Presentation time

08:30:00

08:50:00

Session time

08:30:00

10:00:00

SessionIntercepting Odors and Corrosion: Modeling, Mitigation, and Monitoring

Session number304

Session locationRoom 244

TopicAir Quality and Odor Management, Collection Systems, Facility Operations and Maintenance, Intermediate Level, Public Communication and Outreach

Author(s)

Graziano, Steve, Desing, William, Berry, Melissa, Matteo, Jason, Brown, Joel, Schultz, Scott, Downing, Stephen

Author(s)S. Graziano1, W. Desing2, M. Berry3, J. Matteo4, J. Brown5, S. Schultz6, S. Downing7

Author affiliation(s)1Jacobs 2Jacobs, 3Jacobs,4Jacobs, 4Oakland County Water Resources Commissioner, 5Macomb County Public Works

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159692

Volume / Issue

Content sourceWEFTEC

Word count11

Description: Odors and Air Pollutants 2023 cover

Using Advanced Sewer Ventilation Modeling to Size Vapor Phase Controls

Abstract

Learning Objectives 1.Summarize the developments that have led to creation of sewer ventilation models. 2.Explain the steps required to build and calibrate a sewer ventilation model. 3.Show an application for using the ventilation model to size an odour control unit. Introduction Sizing air extraction for vapor phase odour control is a difficult task often leading to large safety factors and oversized equipment. Fan testing can be used to determine flow rates more accurately; however, it is a costly exercise that often only captures a limited range of wastewater flow conditions. Sewer ventilation modeling has evolved to accurately predict air extraction rates and optimum locations for installing odour control. This paper discusses the history of sewer ventilation modelling and presents case studies demonstrating applications of ventilation modeling for odour control in sewers. Development of Ventilation Modelling In 2007 the Water Environment Research Foundation undertook a review of all published literature on sewer odours and corrosion. Sewer ventilation was found to be the subject in most need of further research (Apgar et al, 2007). Field tests using tracer gas were used to measure air flows in large sewers leading to a proposed conservation of momentum approach to natural ventilation with the air/water interface modelled as flat plate with a drag coefficient. However, the drag coefficient value was unknown. (Witherspoon, 2009) In 2011 the Australian research Council initiated a project to determine the interface drag coefficient. This work culminated in a model for calculating air pressure and flow in a linear sewer network (Ward, 2011), subsequently, flat plate drag coefficients were measured in laboratory-scale studies at the University of Aalborg (Bentzen,2016) for use in the conservation of momentum method. In 2020 a software tool was developed capable of solving air pressure and ventilation in large, branched sewer networks, including representation of air extraction fans, and then overlay the ventilation results in sewer process models (Ward, 2022). Work is continuing to better represent how drop structures impact ventilation rates. The ability to overlay this ventilation model with the sewer process model allows for more accurate estimation of headspace H2S concentration and the required airflow rates to maintain sewer headspaces under negative pressure. Two case studies are presented where this methodology is applied. In one, the client was able to make changes to the sewer network prior to completion of design, and in the second, odour control systems were sized without the need for costly fan testing. Case Studies Region of Vaughan New Trunk Sewer Construction: The region of Vaughan, part of the Greater Toronto Metropolitan Area (GTA) is constructing a new major truck sewer, Jane St Trunk, and twinning portions of existing trunk sewers, Keele Langstaff. The trunk sewers will provide sufficient capacity to service the projected growth in Northeast Vaughan to the year 2051. Sewer process models and overlaid ventilation models were developed for 2024 (completion of the Keele-Langstaff segments) and 2028 (completion of the Jane St segments) growth scenarios. These time frames represent the lowest flow scenarios, i.e. highest sewer detention time, which are the conditions most susceptible to sulphide generation and potential odour release. Sampling took place to allow calibration of the models. A comparison measured versus modelled data will be detailed and as well as assumptions that were made during calibration. The major finding of the study was that the planned dropped structures along the Jane St Trunk caused sulphides to be stripped from the water into the gas phase, leading to elevated levels of H2S, see Figure 1. The ventilation model predicted the trunk would operate at a slight negative pressure due to the drag forces and closed nature of the sewer (minimal laterals and openings to atmosphere) with in gassing (negative pressures) at each maintenance hole/drop structure, creating a scenario in which the odours would not escape to the ambient environment. However, the region has had issues with corrosion at drop structures and the H2S levels were high enough for the region to request a redesign of the Jane St Trunk to mitigate H2S release and corrosion. The sewer design work is currently underway. Following its completion, the sewer process modelling will be recompleted. Adelaide Trunk System Odour Investigations: 18 of the 21 odour control facilities in the Adelaide Trunk system have been turned off to avoid odour complaints, resulting in a lack of ventilation along the system. The lack of ventilation has been identified as a major risk to a significant asset with severe corrosion consequences. Sampling took place to calibrate sewer process models and an overlaid ventilation model. The calibration of the ventilation model provided numerous challenges due to the large headspace in the main trunks resulting in slight pressures during sampling, uncertainty of the state of repair of large curtains pervious installed in the network to assist with zoned ventilation control and a siphon located close to the edge of the modelled domain. The zone of influence from the current fans was found to be minimal and reinstatement of decommissioned fans was not considered a suitable solution to the systemic odour and corrosion issues in the Adelaide Trunk system. Recommendations from the modelling will be discussed including recommended chemical dosing, lining sections of the trunk sewer and installing a large odour control unit in the vicinity of a new development, see Figure 2. Conclusions The development of a ventilation model which can be overlaid on a sewer process model is a value tool for accessing the generation and release of odours from the collection system and sizing odour control fans.

This paper was presented at the WEF Odors and Air Pollutants Conference, May 16-19, 2023.

SpeakerBerry, Melissa

Presentation time

9:00:00

9:30:00

Session time

8:30:00

10:00:00

SessionDispersion and Ventilation Modeling

Session number6

Session locationCharlotte Convention Center, Charlotte, North Carolina, USA

TopicCollection System Odor Control

Author(s)

M. Ward

Author(s)M. Ward 1; M. Berry 2

Author affiliation(s)The WATS Guys1; Jacobs2

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date May 2023

DOI10.2175/193864718825158761

Volume / Issue

Content sourceOdors and Air Pollutants

Word count11

Base text size -

Berry, Melissa

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