What if the MTA installed wind turbines along its subway and railroad tracks? What if there were recycling bins on subway platforms? What if you could reuse all the water that flows into the system? Those are just some of the recommendations released Thursday in a new report on how to green the MTA.

"We pump between eight and 13 million gallons a day of water out of the subway system, groundwater, and just dump it into the New York City sewer system. So can we can find beneficial reuse for that water?" said Jonathan Rose, Chair of the MTA Sustainability Commission.

The report sets ambitious goals, like drawing 80 percent of the MTA's energy needs from renewable sources by 2050 and extending the system's reach, both through expansion projects and smart land use.

“One of the most effective strategies for reducing our carbon footprint and the other greenhouse gases is really to focus on expanding rapid transit and then clustering commercial development and residential development around it,” said Ernest Tollerson, MTA Director for Policy.

There is also the possibility if the government moves to control pollution through a system of trading credits, also known as cap-and-trade, the MTA could stand to make money.

“If there's going to be a cap-and-trade bill, then putting less carbon in the air becomes a revenue source because you can sell that under a cap-and-trade system,” said Rose.

As for recycling, while subway trash is actually sorted and recycled, the report recommends trying separated bins, as a way of raising awareness.

“If your customer can just throw away garbage in the same old way and then it gets recycled magically in New Jersey or somewhere, we don't feel that that's as good as actually having source separation. We think the building of consumer consciousness about the importance of recycling is an important thing,” said Rose.

The report also recommends what it calls a green MetroCard program, where riders could make voluntary donations by paying a little extra at MetroCard vending machines to help fund green projects at the MTA. Though, with a huge fare hike being planned for June, that could be a tough sell.