IN 1989, EPA DETERMINED THAT SUFFICIENT DATA WERE AVAILABLE FOR THE SITE TO CONDUCT AN EXPEDITED RESPONSE ACTION, WHICH INCLUDES AN ENGINEERING EVALUATION/COST ANALYSIS STUDY, PUBLIC COMMENT, AND SELECTION AND IMPLEMENTATION OF A NON TIME CRITICAL REMOVAL ACTION. PURSUANT TO ADMINISTRATIVE ORDER ON CONSENT, CERCLA 90-14, ARCO PERFORMED THE EE/CA STUDY, WHICH EXAMINED THE CLEAN UP ALTERNATIVES FOR THE SITE. PURSUANT TO AN AMENDMENT TO THE SAME ORDER, ARCO PREPARED AN ADDENDUM TO THE EE/CA STUDY WHICH EXAMINED POTENTIAL DISPOSAL AREAS, AS WELL AS INITIAL SITE PREPARATION AND SAMPLING ACTIVITIES. ON 12/30/91, EPA SELECTED THE CLEAN UP ALTERNATIVE FOR THE SITE IN AN ACTION MEMORANDUM. THE ACTION MEMORANDUM IS LOCATED IN THE ADMINISTRATIVE RECORD FOR THE LOWER AREA ONE OPERABLE UNIT.