EPA seeks 1) reimbursement of costs incurred and to be incurred for response actions within certain zones?identified as Zone 1 and Zone 3?of OU 1 of the U.S. Smelter and Lead Refinery, Inc. site and 2) The performance of certain response actions by the Atlantic Richfield Company (ARC) and E. I. du Pont de Nemours and Company within Zone 1 and Zone 3 of OU1