Methane well heads may also be a source of leaks (Image: Environmental Images/Universal Images Group/Rex)

Now Google Street View cars can do more than let you explore places you have never visited. Sensors strapped to the top of the cars have mapped hundreds of methane leaks around Boston, New York’s Staten Island and Indianapolis.

The cars found about one leak per 1.5 kilometres in both Boston and Staten Island. Leaks were slightly less common in Indianapolis, occurring about once for every 320 kilometres driven.

Methane leaks are a triple threat: they can cause explosions, accelerate the growth of global warming and waste money. A study last year found that US methane emissions are 1.5 to 1.7 times higher than current estimates, a discrepancy that has been attributed to hard-to-detect leaks.


The mapping project – developed with the Environmental Defense Fund, an advocacy group based in New York City – aims to pinpoint these problematic spots and encourage gas companies to fix them.

Methane maps

Three Street View cars were fitted with sensors, developed at Colorado State University, that could identify where the leaks were coming from and estimate the amount of gas escaping. Since March last year, the cars have travelled over thousands of kilometres of road in each of the cities. Leak sites were revisited at least once by the cars to verify that a problem was there.

The three cities were chosen as each exhibit characteristics that make them susceptible to methane leaks. Many of the pipes in Boston and Staten Island are more than 50 years old and made of materials that are prone to corrosion, for example. Staten Island is also home to a massive landfill site – a likely source for undetected methane.

Methane leaks in Staten Island (Image: Google, 2014)

Starting today, maps of the methane leaks will be available to the public online. The Environmental Defense Fund says it plans to look at more cities in the future, and to expand the project to include other types of pollutants besides methane.

Maps like these are an important first step to understanding how pervasive this problem can be, says Nathan Phillips of Boston University. Phillips has previously discovered thousands of gas leaks in Boston and San Francisco. He added that he would be curious to see the group create maps near spots with ageing gas infrastructure.