PRN SENT TO DOJ IN 1994 (SEE MATTER NUMBER 04-94-0481). PRN WITHDRAWN AND AO ISSUED. SYSTEM HAS VIOLATED THE NATIONAL PRIMARY DRINKING WATER REGULATINS BY CONDUCTING ONLY ONE 6-MONTH FOLLOW-UP MONITORING FOLLOWING THE INSTALLATION OF OPTIMAL CORROSION CONTROL TREATMENT, INSTEAD OF CONDUCTING THE REQUIRED MONITORING DURING TWO CONSECUTIVE 6-MONTH PERIODS AT 40 SAMPLE SITES DURING EACH MONITORING PERIOD.