Uranium in Drinking Water?

A former student asks about water contamination:

My mother went and had
our water tested and discovered that we have high uranium and radon
levels. Radon is not a big deal, its a gas, and as I have read you would
need to take a shower for somewhere around 4 hours to suffer damage from
it. The Uranium is a different story. They are no government set minimums
set for Uranium, what is an appropriate amount of radiation for a year?
Also wouldn’t Uranium pass through our bodies before it decayed? Also how
would I calculate how much Uranium would be dangerous, in a how many parts
per water?

I have no idea, but I bet somebody reading ScienceBlogs knows something about the safe levels of uranium in drinking water. So, well, what would be a reasonable level of uranium in drinking water?