Pipeline replacement programs in cities can cut natural gas leaks by 90 percent, curbing the release of the powerful greenhouse gas Detecting natural gas leaks in Times Square, NYC. methane and boosting public safety, according to a study published in Environmental Science & Technology Letters. Researchers drove cars equipped with sensitive methane-mapping instruments through thousands of miles of city streets in Manhattan, Boston, Cincinnati, Durham, and Washington, D.C. They discovered that Durham and Cincinnati, where public-private partnerships have replaced outdated pipelines, have 90 percent fewer gas leaks per mile than Manhattan, Boston, and Washington, D.C., where hundreds of miles of corroded natural gas pipes date back to the 1800s. Researchers estimate that, in the U.S. alone, $2 billion worth of natural gas was lost to leaks last year.