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Pre- and Post-Response Mercury Monitoring Results at Abandoned Mercury Mines. Greg Reller gr@burlesonconsulting.com. Acknowledgments. Thank you EPA staff for inviting me. Many co-workers who have taught me. Clients who have provided the opportunity to work on these challenges.
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Pre- and Post-Response Mercury Monitoring Results at Abandoned Mercury Mines Greg Reller gr@burlesonconsulting.com
Acknowledgments • Thank you EPA staff for inviting me. • Many co-workers who have taught me. • Clients who have provided the opportunity to work on these challenges. • Burleson consulting for supporting my efforts to participate.
Introduction Questions Examples Discussion
Focus of this presentation is measurement of CERCLA cleanup effectiveness through monitoring. • Many cleanups are at abandoned mines that affect downstream reservoirs. • Response is intended to reduce mercury entering the system. • Requirements driving many responses are based on mercury in fish tissue
Mercury Mines Primary Sources: Waste Rock, Overburden, Tailings (Calcines), Drainage Mercury Mine Pathways: Vapor, Dust, Surface Water, Groundwater. Mercury Mine Secondary Sources: Sediment, Surface Water. Gold Mines Primary Sources: Soil and Sediment at Stamp Mills, Sluices, Tailings. Gold Mine Pathways: Vapor, Dust, Surface water, Groundwater. Gold Mine Secondary Sources: Debris, Dredge Tailings, Sediment.
Other mercury sources include: Atmospheric Deposition. Ambient Soil: Mean 0.26 mg/kg, max 1.1mg/kg (Kearney Report 1996). Sediment: up to 0.4 mg/kg (various regional monitoring studies, USGS, RWQCB).
What do we measure to evaluate cleanup effectiveness? • Concentration of mercury in sediment/water/biota/air?, • Mass of mercury in sediment/water/air? • Are there pre-response data available for comparison with post-response data? • Are we measuring something related to the mine site?
1979 Earth and Rock Dam 1999 Stormwater controls implemented 1992 Waste Rock Dam graded and covered 0.3 mg/kg OEHHA Screening Value 0.19 mg/kg RWQCB Trophic Level 4 Screening Value 0.09 mg/kg RWQCB Trophic Level 3 Screening Value Sulphur Bank Mercury Mine: Oaks Arm of Clear Lake Total Mercury (mg/kg wet weight) in Large Mouth Bass
Sulphur Bank Mercury Mine: Oaks Arm of Clear Lake Total Mercury (mg/kg wet weight) in Young of Year Juvenile Large Mouth Bass (2005 to 2007)
Coastal California Mercury Mine Mill Site Tailings: Site remediation under order from the California Regional Water Quality Control Board with pre- and post- remediation monitoring. Source Control: Plug adit, remove tailings with high concentrations of total mercury surface water diversion, stabilization, and revegetation.
Coastal California Mercury Mine: Rainfall, Sediment Total Mercury (dry weight), and Total Mercury (mg/kg wet weight) in Large Mouth Bass
Discussion/Questions Greg Reller gr@burlesonconsulting.com (916) 984-4651, extension 11