The U.S. Environmental Protection Agency (U.S. EPA) is issuing the enclosed Administrative Order (Order) under the authority vested in the Administrator of the U.S. EPA by Section 1414(g) of the Safe Drinking Water Act (SDWA), 42 U.S.C. ? 300g-3(g). The Order finds that you have violated the National Primary Drinking Water Regulations at 40 C.F.R. ? 141.66(b) by failing to comply with the maximum contaminant level (MCL) for combined radium-226 and radium-228 (combined radium).