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

• Permit No: M2009076
• IBM Index Class Name: PERMIT FILE
• Doc Date: 9/25/2009
• Doc Name: EPA Superfund Record of Decision
• From: Venture Resources
• To: DRMS
• Media Type: D
• Archive: No

USED TO DETERMINE FINAL DESIGN. FINAL DESIGN MAY INCLUDE ADDITIONAL TREATMENT TO MEET STANDARDS.
CONSIDERATION OF THE NO ACTION ALTERNATIVE IS REQUIRED UNDER SUPERFUND AND OTHER ENVIRONMENTAL
REGULATIONS TO PROVIDE AN ESTIMATE OF THE RISK OR DAMAGE THAT WILL RESULT IF NO REMEDIAL
ACTION IS TAKEN.
1MMENT: ONE RESIDENT ASKED THAT SOURCE CONTROL BE DEFINED.
EPA'S RESPONSE: SOURCE CONTROL IS THE IDENTIFICATION AND ELIMINATION OR BLOCKAGE OF MINE
DRAINAGE AT ITS SOURCE TO PREVENT FURTHER FLOW OF CONTAMINATED WATER THROUGH THE ENVIRONMENT.
IN ORDER TO BE MORE SPECIFIC, EPA HAS CHANGED THE TERM TO DISCHARGE CONTROL. DISCHARGE CONTROL
INCLUDES ANY METHOD TO CONTROL OR ELIMINATE THE DRAINAGE FROM THE TUNNELS.
COMMENT: A COMMENTER ASKED WHY FRESH WATER RUNON HAS TO BE CONTROLLED IF IT DOES NOT CARRY
ACIDS WHEN IT RUNS OVER THE TAILINGS PILES.
EPA'S RESPONSE: AS IT MIXES WITH MINERALS IN THE TAILINGS, FRESH WATER WILL TURN ACIDIC AND
LEACH METALS FROM THE PILES. THE WATER WILL ALSO CARRY SUSPENDED MATERIALS.
COMMENT: A NEWSPAPER REPORTER ASKED WHY REPROCESSING OF TAILINGS WAS NOT THE PREFERRED
ALTERNATIVE, SINCE THE PROPOSED PLAN INDICATES THAT REPROCESSING OF TAILINGS IS THE ONLY WAY TO
REDUCE THE MOBILITY, TOXICITY AND VOLUME OF THE TAILINGS. SEVERAL OTHER COMMENTERS SAID THEY
THOUGHT THE COSTS OF REPROCESSING PRESENTED IN THE STUDY WERE EXTREMELY HIGH, RELATIVE TO THEIR
OWN ESTIMATES. A COMMENTER EMPLOYED BY A COMPANY THAT CONDUCTS FEASIBILITY ANALYSES OF
REPROCESSING MINE DUMP AND MILL TAILINGS MATERIALS IN THE CLEAR CREEK/CENTRAL CITY AREA SAID
THAT EPA'S ESTIMATE OF $27 MILLION FOR REPROCESSING THE TAILINGS AT THE FIVE MINE PROPERTIES IS
OVERESTIMATED BY A FACTOR OF AT LEAST TEN. HE ASKED WHY EPA HAS THE RIGHT TO EVALUATE THE
PROPOSALS AS IF THE AGENCY OWNED THE PROPERTY IN QUESTION. SEVERAL RESIDENTS ASKED WHY THE MINE
PROPERTY OWNERS COULD NOT REPROCESS THE TAILINGS ON THEIR OWN AS THE PRIMARY MEANS OF CLEANING
THEM UP.
ANLA'S RESPONSE: ALTHOUGH REPROCESSING THE TAILINGS IS THE ONLY ALTERNATIVE THAT MEETS THE
ITERION OF REDUCTION OF MOBILITY, TOXICITY AND VOLUME OF THE TAILINGS PILES, THIS CRITERION IS
ONLY ONE OF NINE CRITERIA AGAINST WHICH AN ALTERNATIVE IS EVALUATED. OTHER ALTERNATIVES THAT EPA
CONSIDERED ALSO WERE EXPECTED TO REDUCE MOBILITY AND TOXICITY BUT NOT NECESSARILY VOLUME. COST
ESTIMATES TO REPROCESS THE TAILINGS WERE PREPARED BY METALLURGICAL ENGINEERS CONSIDERED TO BE
EXPERTS IN THE AREA OF REPROCESSING. TO ENSURE THE TAILINGS HAD A REDUCED TOXICITY AFTER
REPROCESSING, METAL CONCENTRATIONS HAD TO BE REDUCED TO LOW LEVELS. THIS REQUIREMENT PRECLUDES
SOME TYPES OF REPROCESSING. EPA HAS AUTHORITY UNDER THE SUPERFUND LAW TO TAKE ACTIONS TO PROTECT
PUBLIC HEALTH AND THE ENVIRONMENT.
COMMENT: CDH EXPRESSED CONCERN ABOUT CONCLUSIONS REGARDING LEACHING PROBLEMS WITH THE WASTE AND
TAILINGS PILES AND SATURATION OF SOME OF THE PILES. CDH SAID THAT SUFFICIENT DATA MAY NOT BE
AVAILABLE TO JUSTIFY THESE CONCLUSIONS. CDH ALSO QUESTIONED WHETHER AIR MONITORING DATA HAVE
BEEN COLLECTED AND HOW SUCH DATA ARE RELATED TO RISK ANALYSES OR ACTION LEVELS. CDH SAID THAT
THE CONCLUSION THAT THE INHALATION PATHWAY DOES NOT PRESENT A SIGNIFICANT HAZARD MAY BE BASED ON
AN UNSUBSTANTIATED RISK ANALYSIS, IF AIR QUALITY MONITORING HAS NOT BEEN CONDUCTED. CDH
RECOMMENDS RECONSIDERING THE AIR QUALITY ACTION LEVELS, AND SUGGESTS SPECIFIC ACTION LEVELS IN
ADDITION TO ESTABLISHING BACKGROUND LEVELS BY AIR QUALITY MONITORING PRIOR TO REMEDIAL ACTION.
LASTLY, THE STATE REQUESTS EPA TO VERIFY THAT SAMPLING OF RUNOFF FROM PILES INCLUDED MAXIMUM
RUNOFF EVENTS.
EPA'S RESPONSE: SITE-SPECIFIC AIR QUALITY SAMPLES WERE NOT COLLECTED. RATHER, SITE-SPECIFIC
DATA FOR SOILS AND REGIONAL/LOCAL AIR DATA WERE'USED TO MODEL WORST-CASE SCENARIOS. GIVEN THAT
WORST-CASE MODELS REVEALED LOW CONCENTRATIONS, NO FURTHER EVALUATIONS HAD BEEN PLANNED.
HOWEVER, THE STATE MAY CONDUCT LIMITED AIR SAMPLING AS PART OF THEIR UPSTREAM SOURCES STUDY.
RUNOFF FROM THE PILES WAS COLLECTED DURING TWO STORM EVENTS THAT OCCURRED DURING THE RI. THESE
?RMS WERE NOT MAXIMUM STORM EVENTS. THE CONCENTRATIONS IN THE RUNOFF WERE EXTREMELY HIGH,
EVER, AND MAY REPRESENT MAXIMUM LEVELS.
COMMENT: CDH COMMENTED THAT THE STATEMENT THAT THE ABUNDANCE AND DIVERSITY OF AQUATIC LIFE IN
CLEAR CREEK HAS BEEN REDUCED DUE TO ACID MINE DRAINAGE (FS REPORT, PAGE 1-32) NEEDS TO BE
VERIFIED BY A COMPARISON OF HISTORIC AND CURRENT POPULATIONS. IF THE STATEMENT CANNOT BE