While true it isn't as bad as that sounds. It's low level stuff specifically leached barium sulfate which from what I can find was just used to remove radium from contaminants from the uranium processing. It has fairly poor water solubility which is why it is used for things like medical contrast. Obviously you can't isolate things 100% so there will be some various radionuclides still mixed in but you can get pretty close which is part of why this was overlooked since there was little of value left so ended up getting mixed with some regular soil to cover the landfill. The real bad stuff was moved to other states like Texas
From Churchills link and a more recent one (2012) I found it appears a lot of testing has been done and it's basically been determined that while there are some radionuclides of concern in sometimes slightly higher than drinking water limits in the water on site based on upgradient well levels that it's no greater than the natural occurring in area therefore is probably mostly just natural (which makes sense considering it's not very water soluble) and that it isn't spreading to offsite groundwater. You'll actually have higher levels of those nuclides in basically anywhere with a lot of shale (which from what I'm reading is actually a way they look for shale/oil fields) or granite
Arsenic was actually a higher concern but also doesn't appear to be spreading offsite either
They also did tests before and after various storm condition incase anyone was like but dat rain
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