One of Baltimore’s most well-known figures isn’t on a sports field or in a city hall office. Instead, he’s doing the mundane job of cleaning the city’s waterways. But that is precisely what has made him famous. Perhaps you’re one of his millions of Twitter followers, or you’ve eagerly posed for a selfie next to him.

Mr. Trash Wheel is a large garbage interceptor who works nonstop to clean trash in Baltimore’s Inner Harbor’s Jones Falls stream. With a gaping maw of a mouth, he’s winning hearts and minds by improving Maryland’s prized waterfront. And by preventing trash from entering the Chesapeake Bay and the Atlantic Ocean, he is making a difference far beyond the city limits.

The original Mr. Trash Wheel’s creator, John Kellet, is the founder of Clearwater Mills, a locally owned and operated logistics company based in Baltimore. He said he was inspired to create the wheel after seeing the amount of trash that washed into the harbor after it rained.

Kellet’s observation is not unique to Baltimore. Our planet is in the grip of a plastic-pollution crisis. Kellet drew his idea on a napkin and built a small working prototype after realizing that the mouth of the main river feeding the harbor was the most logical place to capture trash. The wheel was then set in motion. Mr. Trash Wheel has intercepted over 3 million pounds of trash since its installation, making the harbor not only cleaner and more beautiful, but also a better home for local wildlife and waterfront businesses. Four different wheels are now in Baltimore’s rivers, and more will be added soon to help clean other cities around the world.

The Trash Wheels use simple technology: the flowing river turns a large water mill, which powers a system of pulleys that turn a large conveyor belt and an array of rakes that help scoop floating debris onto the conveyor belt as trash floats down stream. The trash wheel has two long floating buoys that catch garbage floating on the surface and funnel it into Mr. Trash Wheel’s mouth. It is then transported up the conveyor belt and emptied into a large dumpster. As the floating dumpsters fill up, a small crew easily removes and empties them.

The belt is powered by river currents that turn the water mill, but the Trash Wheels also have solar panels and batteries for when the river isn’t flowing fast enough to turn the wheel.

Kellet can remotely activate pumps from his smartphone, which then pump water onto the wheel, ensuring that it never stops turning and gobbling garbage. Mr. Trash Wheel also has an internet connection, allowing Kellet to monitor what’s going on on the ship via webcam and intervene if necessary.

Kellet contacted the city after designing his concept, which was open to new ideas for combating the trash flowing into the harbor. He eventually teamed up with the Abell Foundation, a non-profit organization that provided funding to develop and refine the Trash Wheel concept. Mr. Trash Wheel was installed in Baltimore’s Harbor after much trial and error and months of testing and building.

When Mr. Trash Wheel became operational, business and community leaders noticed an immediate improvement in the harbor’s pollution levels and lobbied to have the wheel installed permanently. The Waterfront Partnership of Baltimore, a nonprofit supported by a coalition of local businesses, then got involved and launched a campaign to produce more Trash Wheels and install them in other parts of Baltimore.

Mr. Trash Wheel and his cousin Trash Wheels resemble large steamboats, with their large water wheels turning constantly and directing trash onto the conveyor belt. But that’s not all they have in common. Mr. Trash Wheel was given a persona by the Waterfront Partnership of Baltimore, who gave him a name and a cute face with large googly eyes. It also provided Mr. Trash Wheel with an online media presence, allowing him to raise his profile and become a city attraction. People come to see Mr. Trash Wheel, take selfies, and help spread the word about keeping the environment clean and sustainable.