Red Devil Mine Risk Assessment for Mercury Releases to the Kuskokwim - - PowerPoint PPT Presentation

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Red Devil Mine Risk Assessment for Mercury Releases to the Kuskokwim - - PowerPoint PPT Presentation

Mar 02, 2023 308 likes •453 views

U.S. Department of the Interior Bureau of Land Management Red Devil Mine Risk Assessment for Mercury Releases to the Kuskokwim River from the BLM Red Devil Mine Doug Cox, Ph.D., BLM Natl OperaDons Center Red Devil Mine 1 U.S. Department of the

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Red Devil Mine

U.S. Department of the Interior Bureau of Land Management

Risk Assessment for Mercury Releases to the Kuskokwim River from the BLM Red Devil Mine Doug Cox, Ph.D., BLM Nat’l OperaDons Center

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Red Devil Mine

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SLIDE 2

U.S. Department of the Interior Bureau of Land Management

PresentaDon OrganizaDon

  • PART 1: Site seGng and the Kuskokwim River

ØHistory of mercury mining acDviDes

  • Summary of Relevant

Site InvesDgaDons

  • PART 2: Fish telemetry and Dssue study

Ø(Presented by Dr. Angela Matz)

  • PART 3: Human health Risk Assessment

Issues

ØMulDple lines of evidence ØSupplemental RI risk assessment approaches ØOverview of findings

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SLIDE 3

U.S. Department of the Interior Bureau of Land Management

IntroducDon and Project Overview

  • Mercury and other chemicals from Red Devil Mine and

regional mineralized zones are present in Kuskokwim River sediment and biota

  • The methylaDon of mercury and food chain

biomagnificaDon can impact upper food chain organisms, such as pike and burbot

Ø Concerns about human health risk (esp. subsistence) from consumpDon of contaminated fish

  • This presentaDon describes a

“MulDple Lines of Evidence” approach to integrate a number of relevant findings into risk management decision making

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Kuskokwim River

  • Drains much of

southwest AK

  • Ninth largest

river in North America

  • Average

discharge is 67,000 cfs

  • MulDple large

tributaries

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SLIDE 5

U.S. Department of the Interior Bureau of Land Management

Kuskokwim River Adjacent to Red Devil June 2015

Linear shorelines Strong current High Turbidity Few shoreline wetlands

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SLIDE 6

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U.S. Department of the Interior Bureau of Land Management

Important Site Issues Related to RDM and the Kuskokwim River

  • Numerous mercury deposits

and mines across region

  • Elevated background

mercury in mineralized zone

  • Fish are important

local source of protein for subsistence peoples

  • Mercury detected in resident

fish across region and Kusko watershed

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SLIDE 7

U.S. Department of the Interior Bureau of Land Management

Brief OperaDonal History of Red Devil Mine

  • Mercury mine (cinnabar ore) operated intermiFently

from 1933-1971, depending on market price

  • Red Devil Mine produced nearly 87% of all mercury

from Alaska (1,330 Tons)

  • Most
  • f the mining was underground, with later

phases including open pit mining

  • Mining, milling, retorDng, chemical storage, and

waste disposal all done on-site

  • Tailings and retort

waste disposed of on-site, used as fill, and dumped in Red Devil Creek

– Pushed out into the Kuskokwim River

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U.S. Department of the Interior Bureau of Land Management

Historic Ore Processing Area, Red Devil Mine (buildings already removed)

Kuskokwim River

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Kuskokwim River

U.S. Department of the Interior Bureau of Land Management

Red Devil Creek SeFng

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U.S. Department of the Interior Bureau of Land Management

Current Status of Red Devil Mine Site

  • Site is abandoned, leaving BLM

to conduct invesDgaDon and cleanup acDviDes

  • Viable PotenDally Responsible Party (PRP) not

idenDfied

  • BLM

demolished buildings, removed fuel tanks, and buried materials in on-site monofills in early 2000s

  • Red Devil village nearby; no other industrial faciliDes

in the area

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SLIDE 11

U.S. Department of the Interior Bureau of Land Management

Current Status of Red Devil Mine Site

  • BLM

iniDated RI/FS in 2009; RI completed in 2014

ØFocused on groundwater and upland seGng ØDid not fully address Kuskokwim River

  • Supplemental RI

currently underway

ØAddiDonal Kuskokwim River data collected

  • Supplemental Human Health and Ecological Risk

Assessment in development

– Ecological risk not a topic

  • f today’s presenta/on

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SLIDE 12

U.S. Department of the Interior Bureau of Land Management

Early AcDon at Red Devil Mine Monofills, Tailings StabilizaDon

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U.S. Department of the Interior Bureau of Land Management

PresentaDon OrganizaDon

  • PART 1: Site seGng and the Kuskokwim River

ØHistory of mercury mining acDviDes

  • Summary of Relevant

Site InvesDgaDons

  • PART 2: Fish telemetry and Dssue study

Ø(Presented by Dr. Angela Matz)

  • PART 3: Human health Risk Assessment

Issues

ØMulDple lines of evidence ØSupplemental RI risk assessment approaches ØOverview of findings

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