Mapping urban pipeline leaks: methane leaks across Boston.

Natural gas is the largest source of anthropogenic emissions of methane (CH(4)) in the United States. To assess pipeline emissions across a major city, we mapped CH(4) leaks across all 785 road miles in the city of Boston using a cavity-ring-down mobile CH(4) analyzer. We identified 3356 CH(4) leaks with concentrations exceeding up to 15 times the global background level. Separately, we measured δ(13)CH(4) isotopic signatures from a subset of these leaks. The δ(13)CH(4) signatures (mean = -42.8‰ ± 1.3‰ s.e.; n = 32) strongly indicate a fossil fuel source rather than a biogenic source for most of the leaks; natural gas sampled across the city had average δ(13)CH(4) values of -36.8‰ (± 0.7‰ s.e., n = 10), whereas CH(4) collected from landfill sites, wetlands, and sewer systems had δ(13)CH(4) signatures ~20‰ lighter (μ = -57.8‰, ± 1.6‰ s.e., n = 8). Repairing leaky natural gas distribution systems will reduce greenhouse gas emissions, increase consumer health and safety, and save money.

[1]  J. Chanton,et al.  Methane oxidation in two Swedish landfill covers measured with carbon-13 to carbon-12 isotope ratios. , 2001, Journal of environmental quality.

[2]  P. Bergamaschi,et al.  Stable isotopic signatures (δ13C, δD) of methane from European landfill sites , 1998 .

[3]  Daniel C Smith,et al.  Pipeline and Hazardous Materials Safety Administration , 2009 .

[4]  E. Crosson,et al.  A cavity ring-down analyzer for measuring atmospheric levels of methane, carbon dioxide, and water vapor , 2008 .

[5]  Denise L Mauzerall,et al.  Global health benefits of mitigating ozone pollution with methane emission controls. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[6]  Martin Schoell,et al.  The hydrogen and carbon isotopic composition of methane from natural gases of various origins , 1980 .

[7]  E. Hornibrook,et al.  Evolution of stable carbon isotope compositions for methane and carbon dioxide in freshwater wetlands and other anaerobic environments , 2000 .

[8]  Lance E. Christensen,et al.  Isotopic measurements of atmospheric methane in Los Angeles, California, USA: Influence of "fugitive" fossil fuel emissions , 2012 .

[9]  James J Winebrake,et al.  Greater focus needed on methane leakage from natural gas infrastructure , 2012, Proceedings of the National Academy of Sciences.

[10]  Kaarle Kupiainen,et al.  Simultaneously Mitigating Near-Term Climate Change and Improving Human Health and Food Security , 2012, Science.

[11]  E. Dlugokencky,et al.  Global atmospheric methane: budget, changes and dangers , 2011, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[12]  Z Y Han,et al.  Comparison study on qualitative and quantitative risk assessment methods for urban natural gas pipeline network. , 2011, Journal of hazardous materials.