Last month while in New York, I spent some time walking around Gowanus Canal because I’m an environmental engineer, and I couldn’t resist an opportunity to visit a body of water, infamous for being incredibly polluted. The Gowanus Canal is a Superfund site due to contamination with polycyclic aromatic hydrocarbons (PAHs), volatile organic contaminants (VOCs), polychlorinated biphenyls (PCBs), pesticides, and metals. However, the Gowanus Canal is also polluted with more ordinary pollutants such as bacteria from untreated wastewater from combined sewer overflow outfalls and other urban pollutants from surface runoff (and possibly illegal outfalls). The area residents are understandably pushing to get the canal cleaned up quickly, and the cleanup is a joint effort between the city, state, and federal government. The area around the canal is an interesting mixture of industrial, art galleries, and up and coming residential. It is actually a nice area. There is a Whole Foods Market next to the canal that has a nice little canal walk on the property, which features signs that say “This is the greenest supermarket in New York State. No smoking, please.” I will take them at their word about being the greenest supermarket, as I did notice solar panels and wind turbines in the parking lot. However I still had to laugh at the irony of the sign. On the bright side, the Gowanus Canal is not so polluted that should someone smoke near it, it is not in danger of catching on fire, like the Cuyahoga River did in 1969. While I was walking along the canal, I spotted a small boat with two people who seemed to be monitoring the water and also two people in a canoe. I guess the canal is safe to canoe on, if you just make sure you don’t touch the water to your skin and most definitely don’t let any get into your mouth, nose, eyes, or any other orifices. The canal does not look that polluted. There are areas with floating trash, but there are very few places where I saw a sheen. When I was there it did not smell either, but evidently especially in summer, it can smell. However, it is a good example of how appearance is not a good way to tell if something is polluted. If you want to read more about the Gowanus Canal, this article in Popular Science is pretty interesting.