Advancing Measurement Techniques and Methods to Improve Methane Emission Estimates from Urban Natural Gas Infrastructure and Inform Mitigation

Methane (CH4) is a potent short-lived climate forcer (SLCF), and atmospheric concentrations continue to increase despite more attention globally on reducing emissions. This underscores the need to expand mitigations of anthropogenic sources, which empirical measurements can help guide. Urban areas emit large quantities of CH4 in aggregate. In the U.S. and Canada, large proportions of urban CH4 emissions often originate from natural gas infrastructure, presenting a mitigation opportunity. However, the individual drivers of emissions are poorly resolved, with implications for attributing, estimating, and reducing emissions. This dissertation addresses that gap through a review of CH4 emissions studies in U.S. and Canadian cities, development and testing of a new quantification method, and two case studies in Calgary, Alberta. The review synthesizes the current understanding of U.S. and Canadian urban CH4 sources, measurement approaches, and mitigation effectiveness across cities, providing a roadmap of research priorities. In doing so, it confirms that natural gas distribution and end-use are important contributors to U.S. and Canadian urban CH4 emissions profiles, motivating the sources examined in the case studies. The first case study examines CH4 emissions from residential natural gas meter set assemblies. To enable the second case study, a human-portable flux plane method was developed and tested for quantifying emissions from tall sources, addressing the logistical challenges, costs, and limitations with other approaches. This method was then applied in a second case study of CH4 emissions from natural gas distribution stations in Calgary, in collaboration with the gas utility, alongside component-level measurements and modeling to improve characterization, estimation, and mitigation of emissions at the stations. Overall, this dissertation advances understanding of CH4 emissions from urban natural gas sources to improve estimates and inform mitigation by synthesizing the state of knowledge across U.S. and Canadian cities, developing, testing, and applying new measurement methods and techniques, and generating new source-level insights through field measurements and modeling.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Discipline thesis:degree_discipline

Geography

Grantor

Arts

Year dc:date.issued

2026

Author dc:creator

• Vollrath, Coleman Parker

Advisor dc:contributor.advisor

• Hugenholtz, Chris

Committee members dc:contributor.committeemember

• Else, Brent
• Yackel, John
• Du, Ke
• Douglas, Peter

• methane emissions
• cities
• urban
• natural gas
• quantification
• residential
• meter set assemblies
• city gate stations
• flux plane
• mitigation

Statement dc:rights

• Unless otherwise indicated, this material is protected by copyright and has been made available with authorization from the copyright owner. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.

Language dc:language.iso

en

DOI

https://dx.doi.org/10.11575/PRISM/51636

OAI identifier oai:identifier

oai:ucalgary.scholaris.ca:1880/125321