As the shutdown of the L train between Brooklyn and Manhattan moves closer, some environmentalists are asking why the MTA's solution involves adding more polluting diesel buses to city streets. The subway tunnel will be temporarily shutdown for repairs in 2019, which is when the buses will be added. NY1 Political Reporter Zack Fink has the story.

Parts of Williamsburg, Brooklyn, sit in the shadow of the elevated Brooklyn-Queens Expressway, one of the most trafficked motorways in the city.

Residents in the area have long complained about pollution — even before the MTA announced plans to add diesel-burning public buses to the streets.

"This is going to have a very negative impact on the air quality of North Brooklyn, which is already notorious for having bad air quality," Brooklyn City Councilman Rafael Espinal said. "This is an environmental justice issue, this is a social justice issue."

The L train subway tunnel between Brooklyn and Manhattan was damaged during Hurricane Sandy more than five years ago. The MTA is planning on shutting it down for repairs, adding 180 new diesel-burning buses to shuttle affected straphangers.

"It was pretty surprising, especially to go with diesel when there are some other options, especially with electric being on the cutting edge," said Kat Fisher of environmental group Sierra Club. "We see not only other U.S. cities making this change; we see commitments coming out of cities in Europe."

According to the MTA, the agency is launching a pilot program next year to introduce zero-emissions electric buses, but it will take some time to get them out on the streets.

If all goes well, there will be 70 electric buses by 2020. One-third of the city's fleet currently run on alternative fuels like natural gas.

In a statement, MTA Communications Director Jon Weinstein said, "New York City Transit has been a leader in implementing environmentally-friendly bus technology and as we evaluate the results of our all-electric bus pilot, we will look to expand it."

Critics say diesel was the worst option. "There is an irony there. How are we going to buy diesel-powered buses to further have a negative impact on the environment, to mediate a problem that was caused by climate change?" Espinal said. "So, let's get serious."

The L train shutdown is scheduled to begin in April 2019 and last 15 months. It's expected to affect about 225,000 daily commuters between Brooklyn and Manhattan.