FAILURE TO PERFORM THE REQUIRED MONITORING FROM THE EFFECTIVE DATE OF THEIR MODIFIED PERMIT, FEBRUARY 14, 1987 THROUGH OCTOBER 31, 1988, EXCEPT MONITORING PERFORMED ON APRIL 1988, JULY 1988, SEPTEMBER 1988, AND OCTOBER 1988, IS IN VIOLATION OF PART I.C.4.A. OF THE PERMIT. FAILURE TO TAKE SAMPLES AS REQUIRED FROM THE EFFECTIVE DATE OF THEIR MODIFIED PERMIT, FEBRUARY 14, 1987 THROUGH OCTOBER 31, 1988, RELATING TO SEMI-ANNUAL MONITORING, IS IN VIOLATION OF PART I.C.4.B. OF THE PERMIT. FAILURE TO FILE THE REQUIRED REPORTS WITHIN THE TIME PROVIDED, RELATING TO THE REPORTING OF MONITORING RESULTS, IS IN VIOLATION OF PART I.C.6.B. OF THE PERMIT.