Wild watercress ; is it safe to eat?

[Carey]

Fresh green watercress growing in a flowing stream is safe to eat? There were cattle in the field where the stream is, about two months ago. I'm wary because in U.K. it's a bad idea to eat anything growing where there are livestock (liver fluke), although that may be just for areas where there are sheep.

[Super_BQ]

Watercrest from what i've been told by local harvesters needs very clean water to grow. At least here in Christchurch, the watercrest sold in stores is sourced from local streams and I know for a fact some of the watercrest we ate last month came from water streams where nearby cattle grazed.

When it's cooked in the pot, what harm is left?

[JandM]

But we (UK) don't cook watercress - it's normally eaten raw as salad or garnish.

[Fern49]

Be sure that it hasn't been sprayed by council workers or farmers. they do spray the drains/some waterways, to keep down the weeds that choke up the water flow..