RESPONDENT FAILED TO TIMELY REPORT THE 1990 RELEASE OF HAZARDOUS SUBSTANCES FROM ITS UST SYSTEMS BY TELEPHONE, ELECTRONIC MAIL, OR ANY OTHER METHOD, AS REQUIRED UNDER 40 CFR 280.50. SINCE THE HARM FROM THE RELEASE (SOIL AND GROUNDWATER CONTAMINATION) CONTINUED AFTER THE RELEASE UNABATED, THE ENTIRE PERIOD BETWEEN THE ACTUAL RELEASE AND RESPONDENT'S NOTIFICATION OF THE RELEASE IS CONSIDERED A CONTINUING VIOLATION. RESPONDENT'S ACTS OR OMISSIONS CONSTITUTE A VIOLATION OF SECTION 9003 OF RCRA AND 40 CFR 280.50. RESPONDENT FAILED TO PERFORM THE RELEASE INVESTIGATION AND CONFIRMATION STEPS FOLLOWING THE 1990 RELEASE OF HAZARDOUS SUBSTANCES FROM ITS UST SYSTEMS, AS REQUIRED UNDER 40 CFR 280.52. UNLESS CORRECTIVE ACTION IS INITIATED AFTER A RELEASE OF HAZARDOUS SUBSTANCES IN ACCORDANCE WITH 40 CFR PART 280, SUBPART F, OWNERS AND OPERATORS OF UST SYSTEMS MUST IMMEDIATELY INVESTIGATE AND CONFIRM ALL SUSPECTED RELEASES OF REGULATED SUBSTANCES REQUIRING REPORTING UNDER 40 CFR 280.50 WITHIN 7 DAYS. RESPONDENT DID NOT PERFORM THE INVESTIGATION AND TESTING WITH 7 DAYS OF DISCOVERY OF THE RELEASE AS REQUIRED BY 40 CFR 280.52; IN VIOLATION OF RCRA 9003 AND 40 CFR 280.52. RESPONDENT FAILED TO PERFORM INITIAL RESPONSE AS REQUIRED UNDER 40 CFR 280.61. UPON CONFIRMATION OF A RELEASE IN ACCORDANCE WITH 40 CFR 280.52 OR AFTER A RELEAS