title: Mapping urban pipeline leaks: methane leaks across Boston.
abstract: 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.
authors.affiliation: Boston University, Department of Earth and Environment, 675 Commonwealth Avenue, Boston, MA 02215, USA. nathan@bu.edu
authors.forename: Nathan G
authors.initials: NG
authors.lastname: Phillips
authors.forename: Robert
authors.initials: R
authors.lastname: Ackley
authors.forename: Eric R
authors.initials: ER
authors.lastname: Crosson
authors.forename: Adrian
authors.initials: A
authors.lastname: Down
authors.forename: Lucy R
authors.initials: LR
authors.lastname: Hutyra
authors.forename: Max
authors.initials: M
authors.lastname: Brondfield
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Karr
authors.forename: Kaiguang
authors.initials: K
authors.lastname: Zhao
authors.forename: Robert B
authors.initials: RB
authors.lastname: Jackson
mesh_terms: D000393:Air Pollutants; D000397:Air Pollution / Q000706:statistics & numerical data; D001900:Boston; D004784:Environmental Monitoring / Q000379:methods*; D040362:Geographic Information Systems; D008697:Methane / Q000032:analysis*; D059206:Natural Gas / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D059206:Natural Gas; D008697:Methane