ON AUGUST 18, 1997, REGION 5 ISSUED A NOV AGAINST IPL FOR VIOLATING THE INDIANA STATE IMPLEMENTATION PLAN. THE REGION ALLEGED THAT IPL EXCEEDED INDIANA'S SIP PARTICULATE MATTER LIMITATIONS ON AT LEAST FIVE OCCASIONS AND SULFUR DIOXIDE LIMITATIONS ON AT LEAST FOUR OCCASIONS. ON SEPTEMBER 24, 1997, IPL REQUESTED A CONFERENCE WITH U.S. EPA TO DISCUSS THE NOV. SUBSEQUENTLY, IPL AGREED TO THE ADMINISTRATIVE ORDER OUTLINED ABOVE. IMPACT: ON JULY 28, 1998, THE ACTING DIRECTOR OF AIR AND RADITION DIVISION, U.S. ENVIRONMENTAL PROTECTION AGENCY (U.S. EPA), REGION 5, SIGNED A SECTION 113(A) ADMINISTRATIVE ORDER ON CONSENT RESOLVING ALLEGATIONS IN A NOTICE OF VIOLA- TION (NOV) ISSUED FOR VIOLATIONS OF THE INDIANA STATE IMPLE- MENTATION PLAN (SIP) LIMITS FOR PARTICULATE AND SULFUR DI- OXIDE, 326 IAC 6-1-12 AND 326 IAC 7-1-9, AGAINST INDIANAPO- LIS POWER AND LIGHT COMPANY (IPL) IN INDIANAPOLIS, INDIANA, IPL HAS AGREED TO OPERATE ONE OF ITS BOILERS AT A DERATED LOAD UNTIL THAT BOILER IS CONVERTED TO COKE OVEN GAS/NATURAL GAS FIRING. ADDITIONALLY, UNDER THE ORDER, IPL WILL CONDUCT STACK TESTS TO ENSURE COMPLIANCE WITH APPLICABLE REQUIREMENT S, AS WELL AS, IMPLEMENT ADDITIONAL REPORTING REQUIREMENTS. BACKGROUND: ON AUGUST 18, 1997, REGION 5 ISSUED A NOV AGAINST IPL FOR VIOLATING THE INDIANA STATE IMPLEMENTATION PLAN. THE REGION ALLEGED THAT IPL EXCEEDED INDIANA'S SIP PARTICULATE MATTER LIMITATIONS ON AT