Payne, then on loan to the tribal government, agreed to help a National Park Service ranger work on his water sampling technique. They tested 48 water sources around a national monument near Cameron. What they found appalled them. Uranium levels in the water at Cameron were as high as 139 picocuries per liter in wells and up to 4,024 in abandoned pits like the ones where Lois Neztsosie watered her sheep and filled her drinking bottles.
Source: wiktionary