Site Name: LIBBY GROUND WATER CONTAMINATION
EPA ID: MTD980502736 EPA Region: 08 Metro Statistical Area:
1119 & 1415 DAKOTA, LIBBY, MT 59923
Operable Unit:
ROD ID: EPA/ROD/R08-89/022 ROD Date: 12/30/88
Contaminant: VOCS; ORGANICS; PAHS; OIL
Keys: ARAR WAIVER; BIODEGRADATION/LAND APPLICATION; CAPPING; CARCINOGENIC COMPOUNDS; CLEAN WATER ACT; CLOSURE REQUIREMENTS; DEBRIS; DIOXIN; DIRECT CONTACT; DRINKING WATER SUPPLY; EXCAVATION; GROUND WATER; GROUND WATER MONITORING; GROUND WATER TREATMENT; INORGANICS; INSTITUTIONAL CONTROLS; INTERIM REMEDY; MCLS; O&M; OILS; ONSITE CONTAINMENT; ONSITE DISCHARGE; ONSITE DISPOSAL; ONSITE TREATMENT; ORGANICS; PAHS; PLUME MANAGEMENT; RCRA; SAFE DRINKING WATER ACT; SOIL; STATE STANDARDS/REGULATIONS; TEMPORARY STORAGE; TREATABILITY STUDIES; TREATMENT TECHNOLOGY; VOCS
Abstract:
THE LIBBY GROUND WATER CONTAMINATION SITE (ALSO KNOWN AS THE CHAMPION MILL SITE OR THE LIBBY PESTICIDE SITE) IS LOCATED ON THE CHAMPION INTERNATIONAL CORPORATION LUMBER AND PLYWOOD MILL IN THE CITY OF LIBBY, LINCOLN COUNTY, MONTANA. CHAMPION IS THE THIRD OWNER OF THE FACILITY, WHICH HAS BEEN IN OPERATION SINCE 1946. THE AREA AROUND THE SITE INCLUDES RESIDENTIAL AREAS AND BUSINESSES. THE SITE IS BORDERED ON THE WEST BY FLOWER CREEK, ON THE EAST BY LIBBY CREEK, AND ON THE NORTH BY THE KOOTENAI RIVER. THE CITY AND SURROUNDING AREAS HAVE A POPULATION OF APPROXIMATELY 11,000. THE CONTAMINATED SOIL/SOURCE AREA IS WITHIN THE CONFINES OF THE FACILITY; HOWEVER, GROUND WATER CONTAMINATION EXTENDS WELL INTO THE CITY OF LIBBY. WOOD TREATING FLUIDS AND THEIR CONSTITUENTS, INCLUDING CREOSOTE AND PCP, ARE THE CONTAMINANTS OF CONCERN AT THE SITE. THEY ARE FOUND IN SOIL AND SEDIMENTS AT SEVERAL DIFFERENT LOCATIONS, INCLUDING FORMER WASTE PITS, TANK STORAGE AREAS, AND BUTT DIP AND TREATMENT SITES. THE CONTAMINATION IS THE RESULT OF SPENT FLUIDS, OVERFLOW OF TREATMENT TANKS, AND SPILLS. IN ADDITION TO CREOSOTE AND PCP, CERTAIN CARRIER FUELS OR OILS WERE USED AT THE SITE AND CONTRIBUTED VOC CONTAMINANTS. INVESTIGATIONS AT THE SITE WERE INITIATED BY THE STATE IN 1979 AFTER A RESIDENTIAL WELL WAS FOUND TO SMELL OF CREOSOTE. A ROD SIGNED IN SEPTEMBER 1986 PROVIDED AN ALTERNATE WATER SOURCE TO RESIDENTS WHOSE WELLS WERE CONTAMINATED. THE SITE HAS BEEN DIVIDED INTO THREE OPERABLE UNITS; HOWEVER, THEY REQUIRE CONCURRENT REMEDIATION. THE OPERABLE UNITS ARE THE SOIL/SOURCE AREA WITHIN THE CONFINES OF THE FACILITY; THE UPPER AQUIFER, HISTORICALLY USED FOR DRINKING WATER AND IRRIGATION BUT CURRENTLY SEVERELY CONTAMINATED; AND THE LOWER AQUIFER, HIGHLY CONTAMINATED WITH OIL AND NON-AQUEOUS PHASE LIQUIDS (NAPL). THE PRIMARY CONTAMINANTS OF CONCERN AFFECTING THE SOIL, SEDIMENTS, AND GROUND WATER AT THE SITE ARE VOCS INCLUDING BENZENE; OTHER ORGANICS INCLUDING DIOXIN, PAHS (CREOSOTE CONSTITUENTS), AND PCP; METALS INCLUDING ARSENIC; AND OIL. THE SELECTED REMEDIAL ACTIONS FOR THIS SITE HAVE BEEN DEVELOPED BASED ON OPERABLE UNITS. THE SELECTED REMEDIAL ACTION FOR THE SOIL/SOURCE AREA INCLUDES EXCAVATION AND CONSOLIDATION OF APPROXIMATELY 30,000 YD3 OF UNSATURATED SOIL AND DEBRIS IN THE WASTE PIT AREA, FOLLOWED BY A TWO-STEP ENHANCED BIODEGRADATION PROCESS COMPOSED OF ENHANCED NATURAL BIODEGRADATION AND SUBSEQUENT TRANSFER TO A LAND TREATMENT UNIT CONSISTING OF A 3.5-ACRE LINED TREATMENT CELL FOR LAND FARMING AND FINAL DEPOSITION; IN SITU BIOREMEDIATION TREATMENT OF SATURATED SOIL IN THE WASTE DISPOSAL PIT USING A CLOSED LOOP SYSTEM INVOLVING GROUND WATER PUMPING AND PHYSICAL TREATMENT IN A FIXED BED BIOREACTOR WITH REINJECTION THROUGH A ROCK PERCOLATION BED, AND IN SITU BIODEGRADATION STIMULATION TO PREVENT FURTHER LEACHING OF SOURCE MATERIAL TO GROUND WATER (RECOVERED NAPL WILL BE PROCESSED IN AN OIL/WATER SEPARATION AND STORED ONSITE FOR RECYCLING AND INCINERATION); AND CAPPING OF THE WASTE PIT, BUTT DIP, AND TANK FARM AREAS. THE SELECTED REMEDIAL ACTION FOR THE UPPER AQUIFER INCLUDES IN SITU GROUND WATER BIOREMEDIATION OF THE UPPER AQUIFER THAT IS SEPARATE FROM THE PROCESS USED IN THE SATURATED ZONE OF THE WASTE PIT AREA. THE SELECTED REMEDIAL ACTION FOR THE LOWER AQUIFER INCLUDES IMPLEMENTATION OF A PILOT TEST FOR THE OIL-CONTAMINATED LOWER AQUIFER USING BIORESTORATION IN CONJUNCTION WITH OIL RECOVERY AND OIL DISPERSION TECHNIQUES (THIS IS AN INTERIM REMEDY FOR THE LOWER AQUIFER); IMPLEMENTATION OF INSTITUTIONAL CONTROLS INCLUDING DEED, LAND USE, AND GROUND WATER RESTRICTIONS; AND ONSITE GROUND WATER MONITORING. THE ESTIMATED PRESENT WORTH COST OF THIS REMEDIAL ACTION IS $5,777,000 WITH ANNUAL O&M OF $670,200 FOR YEAR 2, $521,200 FOR YEARS 3-5, $232,200 FOR YEARS 6-8, AND $80,000 FOR 9/30.
Remedy:
THE MAJOR COMPONENTS OF THE SELECTED REMEDY AND THE CONCERNS THAT THEY ADDRESS ARE AS FOLLOWS:
* CONTAMINATED SOILS FROM THE TANK FARM AREA, BUTT DIP TREATMENT AREA AND ANY OTHER SOURCE LOCATIONS AS MAY BE IDENTIFIED WILL BE EXCAVATED AND PLACED IN THE WASTE PIT AREA, WHICH ALSO CONTAINS CONTAMINATED SOILS AND DEBRIS. CONTAMINATED SOILS FROM THE UNSATURATED ZONE WILL UNDERGO A TWO-STEP ENHANCED BIODEGRADATION TREATMENT. AFTER CONTAMINANT CONCENTRATIONS HAVE BEEN REDUCED TO ACCEPTABLE LEVELS, A PROTECTIVE CAP WILL BE INSTALLED OVER THE SECOND-PHASE TREATMENT CELL TO REDUCE SURFACE WATER INFILTRATION AND PRECLUDE DIRECT CONTACT. POST CLOSURE CARE, INCLUDING MONITORING AND INSPECTION, WILL BE CONDUCTED FOR THE TREATMENT CELL AFTER PLACEMENT OF THE CAP.
* THE OIL RECOVERY WELLS WILL ALSO BE USED TO COLLECT HIGHLY CONTAMINATED GROUND WATER, WHICH WILL UNDERGO TREATMENT IN A FIXED BED BIOREACTOR PRIOR TO REINJECTION THROUGH A ROCK PERCOLATION BED. AN IN-SITU, ENHANCED BIORESTORATION PROGRAM, SEPARATE FROM THE PROCESSES EMPLOYED TO DEGRADE CONTAMINATION IN THE SATURATED ZONE OF THE WASTE PIT SOURCE AREA, WILL BE INITIATED IN THE UPPER AQUIFER TO REDUCE CONTAMINANT LEVELS.
* THERE IS CURRENTLY A PROHIBITION ON THE DRILLING OF NEW WATER SUPPLY WELLS IN THE CITY OF LIBBY. THIS SELECTION OF REMEDY PROVIDES FOR CONTINUATION OF THAT ORDINANCE UNTIL GROUND WATER IS CLEANED TO ACCEPTABLE LEVELS.
* THIS SELECTION OF REMEDY REQUIRES ACTIVE MONITORING OF REMEDIATION ACTIONS TO ASSURE TREATMENT EFFECTIVENESS THROUGHOUT THE LIFETIME OF THE ACTIONS.
* SELECTION OF REMEDY CALLS FOR A REVIEW OF THE REMEDIAL ACTIONS CONDUCTED AT THE LIBBY SITE FIVE YEARS FROM IMPLEMENTATION OF REMEDIAL ACTIONS TO ASSURE HUMAN HEALTH AND THE ENVIRONMENT ARE BEING PROTECTED.
* AS PART OF THE REMEDY FOR THE SOILS OPERABLE UNIT, DEED RESTRICTIONS WILL BE REQUIRED OF THE PROPERTY OWNER.