I know they aren't really that dangerous unless you have a really high worm load, or you're unlucky and one ends up in a part of your body where it doesn't normally live, but their lifecycle is thoroughly disgusting and terrifying. Definitely something I've stayed up at night freaking out about at a few points in my life.
I think its just a couple hookworm species that'll get in through your feet
There are Ascaris-like worms in water that can affect humans, see: Anisakis. But you wouldn't get infected by larvae in the environment, you'd have to eat undercooked fish that ate the zooplankton that ate the L2 worms and get infected through the gut once they are L3 stage.
Ah - Dracunculus aka guinea worm is a another you could get from water, but you'd need to actually drink the copepods.
Who knows where I picked it up. The most likely culprit was the dorm cafeteria I was living in. With the open salad bars and the sharing of serving utensils, it is an ideal location to spread some fecal.
Suffice to say, I now avoid salad bars.