Duck manure tea?

There's a small agricultural area in the northeast corner of California called Tule Lake. It used to be home to over 6 million waterfowl (ducks & geese) until they drained most of it to create farmland back in the early twentieth century. A million or so waterfowl still call it home and excrete in the fields and water on a regular basis. That water is what the farmers irrigate with. I'd say you're probably safe using yours, but I'd thoroughly wash the harvest to be sure you're not picking up any unwanted bacterial terrors.