Radium and radon concentrations in tertiary aquifers along the Texas Gulf Coast

High concentrations of radium (Ra)-226 and radon (Rn)-222 were found in ground water which was produced from Tertiary aquifers along the southern gulf coast of Texas. The survey was conducted in a seven county area and included over 100 water samples from public and rural wells. Radium concentrations as high as 19.94 pCi/L and radon concentrations as high as 26,077 pCi/L were present in public drinking water supplies. These high concentrations appear to be the result of the decay of naturally occurring uranium deposits in rocks immediately below the aquifers. The uranium deposits, which are mined when they occur shallow enough to permit economic extraction, are present at depth beneath the Texas Gulf Coast Aquifer. Ra and Rn appear to migrate upward under potentiometric pressure through interconnected leaky aquifers and along faults. A similar juxtaposition of aquifers above uranium-bearing sediments occurs elsewhere along the gulf coast of the United States.