2009-09-25_PERMIT FILE - M2009076 (42)

Home Browse Search

ROCK PILES AND ARE ADDRESSED IN THIS OPERABLE UNIT. THE SELECTED REMEDY FOR THIS OPERABLE UNIT INCLUDES SLOPE STABILIZATION WHICH WILL REDUCE THE POTENTIAL FOR A COLLAPSE OF UNSTABLE TAILINGS AND WASTE ROCK PILES INTO THE CREEKS AND RUNON TROL MEASURES WHICH WILL DIVERT WATER AROUND THE PILES THEREBY ELIMINATING THE IMPACT DUE TO ON. THIS PORTION OF THE SELECTED REMEDY IS THEREFORE PROTECTIVE AND WILL RESULT IN AN IMPROVEMENT OF THE WATER QUALITY IN CLEAR CREEK AND NORTH CLEAR CREEK. THE PUBLIC HEALTH EVALUATION ALSO CONSIDERED IMPACTS TO HUMAN HEALTH RESULTING FROM INHALATION OR INGESTION OF MATERIAL FROM THE TAILINGS AND WASTE ROCK PILES. HOWEVER, AS DISCUSSED EARLIER IN THIS DOCUMENT AND AS SHOWN IN TABLE 1, THERE ARE NO CURRENT IMPACTS TO HUMAN HEALTH FROM THESE EXPOSURE PATHWAYS. FOR THIS REASON, THE SELECTED REMEDY FOR THIS PORTION OF THE OPERABLE UNIT, NO ACTION, IS PROTECTIVE OF HUMAN HEALTH. UNDER THE POTENTIAL FUTURE RESIDENTIAL USE SCENARIO THE RISK FROM INGESTION OF SOIL IS OF SOME CONCERN. FOR THIS REASON, EPA, WHEN SELECTING THE FINAL REMEDY, WILL CONSIDER INSTITUTIONAL MEASURES TO CONTROL FUTURE DEVELOPMENT UPON THE TAILINGS PILES. CONSISTENCY WITH OTHER LAWS: PURSUANT TO SARA SECTION 121(D), REMEDIAL ACTIONS SHALL ATTAIN A DEGREE OF CLEANUP OF HAZARDOUS SUBSTANCES, POLLUTANTS, AND CONTAMINANTS RELEASED INTO THE ENVIRONMENT AND CONTROL OF FURTHER RELEASE WHICH AT A MINIMUM ASSURES PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT. IN ADDITION, REMEDIAL ACTIONS SHALL, UPON THEIR COMPLETION, REACH A LEVEL OR STANDARD OF CONTROL FOR SUCH HAZARDOUS SUBSTANCES, POLLUTANTS, OR CONTAMINANTS WHICH AT LEAST ATTAINS LEGALLY APPLICABLE OR RELEVANT AND APPROPRIATE FEDERAL STANDARDS, REQUIREMENTS, CRITERIA, OR LIMITATIONS, OR ANY PROMULGATED STANDARDS, REQUIREMENTS, CRITERIA, OR LIMITATIONS UNDER A STATE ENVIRONMENTAL OR FACILITY SITING LAW THAT IS MORE STRINGENT THAN ANY FEDERAL STANDARD (ARARS). ON DECEMBER 23, 1986 EPA REQUESTED THAT THE STATE OF COLORADO PROVIDE A LIST OF APPLICABLE OR 0 EVANT STATE REQUIREMENTS, STANDARDS, CRITERIA AND LIMITATIONS FOR THE CLEAR CREEK/CENTRAL Y SITE. THE STATE RESPONDED ON MAY 14, 1987 WITH A LIST OF REQUIREMENTS PERTAINING TO OPERABLE UNIT NO. ONE. THE STATE DID NOT FORMALLY SUBMIT A LIST OF REQUIREMENTS FOR OPERABLE UNIT NO. TWO. SUBSEQUENTLY, HOWEVER, PROBABLE STATE REQUIREMENTS WERE IDENTIFIED BY STATE AND EPA STAFF THROUGH INFORMAL DISCUSSIONS. THESE INFORMALLY IDENTIFIED REQUIREMENTS WERE TAKEN INTO ACCOUNT DURING THE DEVELOPMENT OF ALTERNATIVES FOR TAILINGS AND WASTE ROCK REMEDIATION. EPA CLASSIFIED ALL FEDERAL AND STATE PUBLIC HEALTH AND ENVIRONMENTAL REQUIREMENTS APPLICABLE OR RELEVANT AND APPROPRIATE TO THE TAILINGS AND WASTE ROCK REMEDIATION INTO THREE CATEGORIES: CONTAMINANT-SPECIFIC ARARS, ACTION-SPECIFIC ARARS, AND LOCATION-SPECIFIC ARARS. A DESCRIPTION OF EACH OF THESE CATEGORIES IS PROVIDED IN SECTION 2 OF THE OPERABLE UNIT NO. TWO FS. TABLES 2-1 AND 2-2 IN THE FS CONTAIN A BRIEF DESCRIPTION OF EACH POTENTIAL FEDERAL AND STATE PUBLIC HEALTH AND ENVIRONMENTAL REQUIREMENT IDENTIFIED AND EPA'S ANALYSIS OF EACH REQUIREMENT'S APPLICABILITY OR RELEVANCE AND APPROPRIATENESS TO THE OPERABLE UNIT. EPA HAS DETERMINED THAT THE CONTAMINANT-SPECIFIC ARARS FOR OPERABLE UNIT NO. TWO ARE THE MAXIMUM CONTAMINANT LEVELS (MCLS) ESTABLISHED UNDER THE SAFE DRINKING WATER ACT, AMBIENT WATER QUALITY CRITERIA (AWQCS) ESTABLISHED UNDER THE CLEAN WATER ACT AND STATE WATER QUALITY STANDARDS. THERE ARE CURRENTLY NO IDENTIFIED CONTAMINANT-SPECIFIC ARARS FOR METALS IN SOILS SO EPA RELIED ON ACTION-LEVELS ESTABLISHED THROUGH THE RISK ASSESSMENT. THESE ACTION LEVELS ARE CONTAINED IN TABLE 2-3 OF THE OPERABLE UNIT NO. TWO FS. THE SELECTED REMEDY FOR OPERABLE UNIT NO. TWO IS AN INTERIM REMEDY WHICH IS CONSISTENT WITH THE FINAL REMEDY AND WHICH, PURSUANT TO SARA SECTION 121(D)(4)(A), REQUIRES THE EXERCISE OF THE "INTERIM REMEDY" WAIVER FROM THE CONTAMINANT-SPECIFIC ARARS MENTIONED IN THE PREVIOUS PARAGRAPH, THAT IS, THE SELECTED REMEDY IS ONLY PART OF A TOTAL REMEDIATION THAT WILL ATTAIN SUCH A LEVEL OR STANDARD OF CONTROL WHEN COMPLETED. LOCATION- AND ACTION-SPECIFIC ARARS WILL BE MET. 0 ACCORDANCE WITH SARA SECTION 121 (D)(2)(A)(II), EPA INTENDS THAT THE FINAL REMEDY WILL AT LEAST ATTAIN WATER QUALITY CRITERIA ESTABLISHED UNDER THE ACTS MENTIONED ABOVE. HOWEVER, ADDITIONAL DATA COLLECTION AND USE ATTAINABILITY ANALYSES ARE NECESSARY FOR EPA TO DETERMINE IF SUCH CRITERIA ARE APPROPRIATE UNDER THE CIRCUMSTANCES OF THE RELEASE OR WHETHER SITE-SPECIFIC MODIFICATION TO THE CRITERIA WOULD MORE APPROPRIATELY ESTABLISH CLEAN-UP GOALS FOR THE SITE.