UC Davis

Residential natural gas is estimated as responsible for almost 15% of California’s total methane (CH4) emissions from natural gas. It is not known what fraction of these emissions is due to fugitive leaks in the low-pressure portions of the natural gas distribution network. This research aimed to diagnose and potentially seal leakage in the low-pressure portions of natural gas distribution networks by using aerosols. This included developing and testing protocols for measuring leakage downstream of the meter in houses and commercial buildings, applying those protocols in 10 different locations, designing a system to seal leaks in those systems remotely, and applying the sealing process in a make-shift pipe network. Only 2 out of the 10 locations tested were above the leakage detection limit in unsealed networks; the variation in gas temperature posed a challenge to diagnosing the leakage rates. The aerosol process employed for remote sealing appeared to be capable of sealing leaks in natural gas distribution pipes but will require more refinement to address the extremely low leakage levels observed in this study.