Monte Cristo Mining Area CERCLA Removal Action Update

Transcription

1 Monte Cristo Mining Area CERCLA Removal Action Update Bernard Kronschnabel Cascade Earth Sciences October 28, 2014 Background Abandoned gold mine district/ghost town Mining activity 1890s 1900s 1

2 Project Location Snohomish County Mt. Baker Snoqualmie National Forest Henry M Jackson Wilderness Legacy Scattered mines which fed ore to centralized location (Townsite) Townsite Features Tram terminal and haulage routes Ore Collector Concentrator Assay Shack Rainy Mine 2

3 Legacy continued Remote Mines along Glacier Creek and Seventysix Creek Glacier Creek Mines Justice Golden Cord Mystery Comet Pride of the Woods Pride of the Mountains New Discovery Seventysix Creek Mines Sidney Mine 76 Sheridan Boston American Removal Action Hurdles Access Old county road washed out in mile hike from Mountain Loop Hwy to Townsite Helicopter required for data gap monitoring Power Off grid no electricity or reliable communication Weather Short season: late June mid September Wilderness Some sites located in HMJ wilderness equipment restrictions 3

4 Removal Action Components Access Route Tailings/waste rock repository Temporary Glacier Creek crossing Removal activities Townsite and Rainy Mine cleanup Remote mine cleanup Adit discharges (Mystery, Justice, and Pride of the Woods) Button up Access Route Repair County Road or alternate route? If the road washed out before, it will wash out again Must permit access for O&M Follow general path of Sauk River Wagon Road Saving most intact portions of the road/bridges Tie into Python logging road (1980s?) Ultimately tie into County Road ~2 miles in Extend to Rainy Mine Temporary GC crossing to Townsite 4

5 Access Route Access route crosses three drainages Log stringer bridges Alaska yellow cedar Permanent leave behind for O&M access Improved public access Additional parking Safe crossing for pedestrians (no more fording of GC on wet log) Car and ATV access for USFS and local property owners Repository Located north of County Road ~1.5 miles from Townsite Inputs Rainy Mine 3,100 bcy Concentrator 8,100 bcy Ore Collector (tram terminal, haulageways, Assay Shack) 3,900 bcy Pride of the Woods 2,000 bcy 5

6 Repository Design Native fill/vegetative cover Gravel drainage 60 mil HDPE Tailings/waste rock Compacted native fill Repository continued Installed 3 monitoring wells this summer Monitor groundwater elevation during high flow Allows collection of background water quality before RA 6

7 Justice Mine Mean flow rate = 120 gpm 279 g/l As Near neutral ph Adit seep at trail and impacts GC Mystery Mine ph = g/l As Mean flow = 115 gpm Ferrous hydroxide Fe(OH) 3 precipitates classic yellow boy 7

8 Pride of the Woods Mine ph = 4.4 1,000 g/l As Mean flow = 0.5 gpm Adit seep at trail and into GC Challenges Wilderness/Remote Areas Must invoke CERCLA to operate machinery in HMJ Wilderness Roadless need to helicopter equipment in Limits O&M activity Endangered and threatened species Spotted owl Access Route Marbled murrelet Access Route Bull trout Glacier Creek Cultural/Archaeological Concerns Railway alignment Artifacts 8

9 Challenges continued Concerns of local property owners Private and Federal property Property/claim owners Local concerns Disturbance/impact to access Community involvement Monte Cristo Preservation Association Weather Short working season High rainfall (rainforest) Response to Challenges Detailed survey of Townsite Delineate Federal and private land Determine where we can work and where we can t Incorporate public in early stages of process Public review Response to concerns and questions Cultural Survey Archaeologist present at all excavations Document findings/clear work ahead of time 9

10 Response to Challenges continued Access Route Restrictions on size of trees that can be felled Restrictions on number of 30 trees that can be felled Restrictions on working hours and decibel levels Erosion control measures and turbidity monitoring Public input has led to more robust controls and awareness of potential impact Repository Engineering controls Stop work during precipitation Cover repository Looking Ahead 2015 Removal Action Complete Access Route to Rainy Mine Temporary GC crossing Townsite removal action Pride of the Woods removal action and diversion of adit discharge Mystery and Justice adit diversions Close the repository and demob 10

11 Acknowledgments Joe Gibbens USFS Ryan Tobias, Tim Otis, Jay Williams, Kyle Billings, Sara Rodriguez Cascade Earth Sciences Dustin Wasley TriHydro Rod Lentz USFS (retired) Phil Moyle (retired) and Bob Lambeth (CDM) Mining engineers/geologists Geezers GeoEngineers geotech ASM cultural Questions?? 11