WATER SYSTEM EXCEEDED THE MCL FOR BARIUM AND COMBINED RADIUM -226 AND RADIUM-228. THE AO SUPERCEDES AN AO ISSUED 7/25/97. IT REVISES THE COMPLIANCE SCHEDULE FOR COMPLIANCE WITH THE MCL FOR BARIUM AND DROPS THE REQUIREMENT TO REMEDY THE COM- BINED RADIUM-226 AND RADIUM-228 MCL VIOLATION BECAUSE THE U.S. EPA IS REVIEWING THE RADIONUCLIDE REGULATION (A NOTICE OF DATA AVAILABILITY IS EXPECTED TO BE PUBLISHED IN AUTUMN OF 1999). A SEPARATE AO WILL BE ISSUED FOR REDIUM ONCE U.S. EPA HAS ISSUED FINAL REVISIONS TO THE REDIONUCLIDE REGULATIONS. THE AO REQUIRES THE SYSTEM TO CONTINUE TO MONITOR QUARTERLY FOR BARIUM, AND RADIUM-226 AND RADIUM-228, AND TO CONTINUE TO NOTIFY ITS CUSTOMERS OF ITS FAILURE TO COMPLY WITH THE MCLS FOR BARIUM AND COMBINED RADIUM-226 AND RADIUM-228.