THE ST. REGIS PAPER COMPANY SUPERFUND SITE IS A NATIONAL PRIORITIES LIST SITE LOCATED IN CASS LAKE, MINNESOTA IN CASS COUNTY. THE SITE INCLUDES A WOOD PRESERVING OPERATION THAT BEGAN TREATING WOOD WITH CREOSOTE, PENTACHLOROPHENOL AND WATER SOLUBLE METAL SALT PRESERVATIVES, IN THE LATE 1950'S. SLUDGES AND WASTEWATER GENERATED BY THIS OPERATION WERE DISPOSED OF AT A LANDFILL AREA ON THE SITE AND IN WASTEWATER DISPOSAL PONDS. GROUNDWATER MONITORING BY THE MINNESOTA POLLUTION CONTROL AGENCY (MPCA) DETECTED THE RELEASE OF HAZARDOUS SUBSTANCES FROM THE (PCP); POLYNUCLEAR AROMATIC HYDROCARBONS (PAH); PHENOLS; HEXA, HEPTA, AND OCTOCHOLORODIBENXO-P-DIOXIN (PCDD); POLYCHLORINATED DIBENZO-P-FURANS (PCDF), AND METALS. IN 1985, MPCA AND RESPONDENT SIGNED TWO RESPONSE ORDERS BY CONSENT UNDER MERLA AND IN 1986 MPCA ISSUED TWO MINNESOTA ENFORCEMENT DECISION DOCUMENTS (MEDD) FOR THE SITE. THE MEDD CALLED FOR AN AGGRESSIVE PUMP AND TREAT SYSTEM, THE CONSTRUCTION OF A ON SITE CONTAINMENT VAULT FOR THE DEPOSITION OF THE SLUDGES AND CONTAMINATED SOIL TO BE EXCAVATED, LONG TERM GROUNDWATER AND VAULT MONITORING, EXTENSION OF THE COMMUNITY WATER SYSTEM, AND LONG TERM OPERATION AND MAINTENANCE OF THE PUMP AND TREAT SYSTEM AND THE VAULT. DUE TO THE FACT THAT THE SITE IS SITUATED ON NATIVE AMERICAN LANDS, THE U.S. EPA DECIDED TO BECOME THE LEAD AGENCY IN THE HANDLING OF THE SITE AND ISSUED THIS ORDER.