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HAS BEEN ONE RI CONDUCTED AT THE SITE; THE FS HAS BEEN DIVIDED INTO THE FOLLOWING OPERABLE <br />UNITS: <br />- OPERABLE UNIT NO. ONE, ACID MINE DISCHARGE; <br />- OPERABLE UNIT NO. TWO, TAILINGS AND WASTE ROCK REMEDIATION; AND <br />OPERABLE UNIT NO. THREE, DISCHARGE AND BLOWOUT CONTROL. <br />IN ADDITION TO THE ABOVE OPERABLE UNITS, THE STATE OF COLORADO WILL INVESTIGATE 1) CONTAMINATION <br />UPSTREAM OF THE SITES AND 2) REGIONAL GROUND WATER CONTAMINATION. BASED ON THESE <br />INVESTIGATIONS, REMEDIAL ACTIONS MAY BE RECOMMENDED. <br />THE RI REPORT AND THE DRAFT FS REPORT ON OPERABLE UNIT NO. ONE, WHICH CONSIDERED MINE DRAINAGE <br />ISSUES, WERE COMPLETED AND RELEASED TO THE PUBLIC IN JUNE 1987. THE RI REPORT DESCRIBES THE <br />RESULTS OF EPA'S INVESTIGATION OF THE ENTIRE SITE TO DATE. THE DRAFT FS REPORT ON OPERABLE UNIT <br />NO. ONE DISCUSSES AND EVALUATES METHODS FOR CLEANING UP CONTAMINATED MINE DRAINAGE. THE RECORD <br />OF DECISION (ROD) FOR OPERABLE UNIT NO. ONE WAS SIGNED SEPTEMBER 30, 1987. <br />THE SELECTED REMEDY FOR OPERABLE UNIT NO. ONE, MINE DRAINAGE DISCHARGES, INCLUDED BOTH PASSIVE <br />AND ACTIVE TREATMENT OF MINE DRAINAGE. COMMUNITY RESPONSE TO THE PROPOSED PLAN FOR OPERABLE UNIT <br />NO. ONE WAS GUARDED -- THAT IS, RESIDENTS EXPRESSED CONCERNS ABOUT EPA'S PLANS AND ACTIONS TO <br />SOLVE AT GREAT EXPENSE PROBLEMS THAT RESIDENTS BELIEVE TO BE MINOR. <br />THE DRAFT FS REPORT ON OPERABLE UNIT NO. TWO DISCUSSES AND EVALUATES METHODS OF REMEDIATING <br />CONTAMINATION RESULTING FROM WASTE ROCK AND TAILINGS PILES. ALTERNATIVES FOR REMEDIATION OF <br />TAILINGS AND WASTE ROCK CONTAMINATION WERE PRESENTED TO RESIDENTS IN EPA'S PROPOSED PLAN, DATED <br />NOVEMBER 9, 1987, WHICH WAS MAILED TO THE APPROXIMATELY 100 INDIVIDUALS ON THE CLEAR <br />CREEK/CENTRAL CITY MAILING LIST. EPA'S MAJOR CONCERNS ASSOCIATED WITH OPERABLE UNIT NO. TWO ARE <br />POTENTIAL HUMAN AND ENVIRONMENTAL EFFECTS RESULTING FROM CONTAMINANT AND SEDIMENT LOADING CAUSED <br />BY WATER RUNNING OVER THE TAILINGS AND WASTE ROCK PILES AND INTO SURFACE WATER BODIES; POTENTIAL <br />COLLAPSE OF THE PILES, WHICH COULD RESULT IN CONTAMINATION OF THE STREAM; AND DIRECT CONTACT <br />ROUGH INHALATION OR INGESTION OF MATERIAL FROM THE PILES. <br />SIX REMEDIAL ALTERNATIVES WERE CONSIDERED FOR REMEDIATION OF THE TAILINGS AND WASTE ROCK <br />CONTAMINATION AT THE FIVE MINING TUNNELS: <br />- NO ACTION; <br />- SLOPE STABILIZATION AND RUNON CONTROL; <br />- CAPPING; <br />- OFF-SITE DISPOSAL; <br />- CHEMICAL FIXATION; AND <br />- REPROCESSING. <br />EPA's SELECTED ALTERNATIVES VARY FOR EACH OF THE MINE TUNNEL LOCATIONS BECAUSE OF THE DIFFERENT <br />CONDITIONS AT EACH PROPERTY. IN GENERAL, ALTERNATIVES WERE SELECTED THAT WOULD MINIMIZE COSTS <br />AND REMEDIATE THE MOST CRITICAL RISKS PRESENT AT THE PROPERTIES. <br />EPA'S SELECTED ALTERNATIVE FOR DEALING WITH POTENTIAL TAILINGS COLLAPSE AT THE GREGORY INCLINE <br />AND AT THE BIG FIVE TUNNEL IS SLOPE STABILIZATION. THE GABION WALL AT THE GREGORY INCLINE WILL <br />BE CAREFULLY MONITORED AND REPLACED ONLY IF NECESSARY. THE SELECTED ALTERNATIVE FOR DEALING <br />WITH WATER RUNNING OVER THE TAILINGS AND WASTE ROCK PILES AND ENTERING THE CREEKS AT THE FIVE <br />MINE PORTALS IS TO REDUCE "RUNON" (WATER RUNNING ON TO THE PILES FROM ABOVE) BY BUILDING <br />DIVERSION DITCHES ABOVE THE PILES. THE SELECTED ALTERNATIVE FOR INHALATION OR INGESTION OF <br />TERIAL FROM TAILINGS AND WASTE ROCK PILES IS NO ACTION. THIS IS AN INTERIM REMEDY, BECAUSE <br />ME RISK EXISTS FOR POSSIBLE FUTURE RESIDENTIAL EXPOSURE. EPA WILL WORK WITH STATE AND LOCAL <br />OFFICIALS TO EVALUATE LAND USE CONTROLS THAT WILL MITIGATE RISKS ASSOCIATED WITH FUTURE <br />DEVELOPMENT.