This is Side Door, a podcast from a Smithsonian with support from PRX.

I'm Tony Cohen.

Back in May I visited the Port of Baltimore.

It's this high traffic port that's one of the largest in the country for cars, farm equipment, and that kind of thing.

The port takes up 45 miles of shoreline along the Batapsko River.

Here you see the sea of cars behind us.

I'm here with Peter May.

I'm Dr. Peter May.

I'm a senior environmental scientist

with the Baltimore-based ecological engineering

from biohabitets, and I'm also a lecturer at the

University of Maryland College Park in the Environmental Science and Technology

program. And I want you to really imagine an ocean of cars. Parking lots filled with cars that stretch for miles.

Okay, or maybe more like a mile, but still it's a lot of cars.

And when we imagine pollution created by cars, we usually think about the air, carbon dioxide, that

kind of a thing. But cars also cause problems for oceans, lakes, and rivers.

Cars drop little bits of metal and those kinds of things and oil and grease and

and those things are part of that whole pollutant load that goes on to a parking lot

that when it rains it gets swept off into the harbor and really really the water quality in the harbor is,

is, it depends on which, you know,

what day of the week did it most recently rain?

Baltimore is a city surrounded by a lot of water, the Patapsco River, the Chesapeake Bay, and a lot of smaller lakes, reservoirs and streams.

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