Manhattan’s underground pipelines leak three to five times more than cities with newer infrastructure, according to the Environmental Protection Agency.
In a recent survey, the EPA found that Manhattan suffers 90% more methane leaks per mile than Cincinnati, Ohio and Durham, North Carolina. The study highlights problems facing New York’s aging infrastructure, at a time when most of the city’s energy suppliers have switched from less efficient sources to natural gas.
Though natural gas produces only half as much carbon dioxide as coal, studies have shown that frequent methane leaks could offset the benefits. And while some cities have updated their facilities to adapt to this trend, New York lags behind, facing nearly 10,000 leaks in 2012 alone.
Methane leaks can cause immediate problems as well. In 2014, a methane leak in East Harlem triggered an explosion, killing eight people. The leak was blamed on a 127 year old iron gas main. According to a report by the Center for an Urban Future, the average iron pipe main in New York City is 56 years old.
Many utilities believe that replacing the iron pipes with plastic will make for safer transportation of gas. According to the U.S. Department of Transportation, New York City has one of the highest percentages of cast-iron mains in the country.
The good news is New York is working on it. As part of a $6.5 billion, 20-year plan unveiled in 2010, Con Edison is in the process of replacing the 60% of natural gas pipes made of cast iron or bare steel underneath New York. The effort now replaces 65 miles of those pipes every year.
The utility has also increased its gas leak patrols of New York to 13 times a year, up from once a year previously. Con Edison is also conducting research to help determine the rate of methane emitting from non-hazardous gas leaks. This information will help it prioritize repairs and in turn protect the environment.