Malakoff Diggins/Humbug Creek Watershed Assessment

Humbug Creek Watershed Assessment
Pre-Tour Presentation
Reclaiming the Sierra Conference 2012
Malakoff Diggings State Historical Park
• Malakoff Mining Pit and town of North
Bloomfield –intimately connected
• National Register of Historic Places (No. 852)
• Public Resources Code (5019.59) mandates
the DPR to preserve and protect
Overview
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History
Current Conditions
Assessment Goals
Field trip landmarks
North Bloomfield Mining Company
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Formed in 1866
Malakoff Diggings operated from 1866-1900
Largest and best financed mines in the West
Claims covering ~1,600 acres with gravel 250600ft deep
• Estimated capacity of gold in 1870 ~$69 Million
• Sawyer Decision 1884, Caminetti Act 1893
• Debris dams to contain HMD-Englebright
Drain Tunnels
• 1851-Hiller Tunnel 450ft long (over capacity by 1872)
• 1875-North Bloomfield Tunnel 7,874 ft
– Eight shafts ~200ft deep, 4.5 x 9ft wide
– 1,900 ft of sluice
– 6,000ft no sluice use bare rock of tunnel
• 4,000ft of undercurrents to South Yuba
Historic use of Mercury
• Quicksilver was added to the sluices to catch the gold
• 15 flasks, 1,147.5 lbs were added to sluices and
undercurrents each run (Mineralogist Report in 1882)
• Mercury was also scattered over the bank to be
washed and allowed to work down
• 30% of mercury lost, equal to 30lb of mercury per
meter of tunnel lost each year during 1853-1884
(Bowie, 1905)
• 9,778 kilograms of elemental mercury were lost to the
environment at Malakoff Diggins (Moyle, 1993)
• 35-40 Million gallons of water were used each
day-provided by the Yuba Canal Company
• ~40 M yrd3 of rock was mined (Jarman 1927)
• ~29 M yrd3 was discharged as tailings to SYR
Erosive Force of Water
• Pit is 7,000 ft long, 3,000 ft wide and 600 ft deep
Operation Summary
1. Gold bearing gravel was washed from the cliffs
2. Slurry was directed through a series of flumes on the
pit floor
3. Slurry fell 440ft down the pit shaft (Shaft 8)
4. Washed through 7,874 ft tunnel
– 1,900 ft of sluice, where 75lbs flasks of mercury
were added
– 6,000 ft of bare rock
5. Discharged into 4,000 ft of undercurrents
6. Washed into the Humbug Creek and South Yuba
River
Overview
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History
Current Conditions
Assessment Goals
Field trip landmarks
Unstable Landscape
• One mile long pit (7000ft), half mile wide
(3000 ft)
• Surrounded by cliffs 200-750 ft high
• Aqiferous gravels, Quaternary colluvium and
Holocene deposits
• Diggins erosion and deposition processes
– ~50,000 yrd3/yr average erosion
– ~30,000 yrd3/yr deposition of sand and gravel
Air Shafts and Tunnel Openings
Shaft 8 in Pit
Shaft 5 Green
NB Tunnel opening
Shaft 3 Red
Shaft 2 Hole
Shaft 1 Pond
Water Quality
Hiller Tunnel
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10000
Water Quality Measurements
1000
1979 NCRCD and 1986 DWR
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Discharge (cfs)
Suspended Sed. Yield vs Discharge
Turbidity vs Discharge
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10000
1000
Turbidity, NTU
Suspended Sediment Yield (lbs/min)
Suspended Sediment Consentration (mg/L)
Suspended Sediment Consentration vs
Discharge
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1000
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Discharge (cfs)
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Discharge cfs
100
Turbidity
Mercury
Copper
Nickel
Zinc
Potential Sources of Mercury rich
sediments
1) hydraulic pit floor
2) tunnel and associated shafts
3) Humbug and Diggins Creek
channels
4) Gravel and sediment terraces
above waterways
Overview
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History
Current Conditions
Assessment Goals
Field trip landmarks
Watershed Assessment
• A tool to help identify available data or information gaps
 The scientific interpretation of watershed information and
data, leading to conclusions about watershed condition
• An objective problem-solving tool that identifies the
potential causes of problems
• Analysis and findings that can be used to develop
appropriate actions
• A component of a watershed management package that
leads to planning, implementation, evaluation, and
additional monitoring
What will the watershed assessment
be used for?
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Informing a watershed management plan
Regulatory concerns
Restoration or enhancement planning
Monitoring program development
Remediation action development and design
Issue Based Questions
What can be done to improve the water quality of Humbug
Creek Watershed?
Turbidity
Mercury
Other Metals
What is the sediment yield for
Diggins and Humbug Creek?
Where is the mercury coming from?
What restorative actions would improve water quality?
How can the physical hazards be addressed?
Working Hypotheses
• Malakoff Diggins, Hiller, Lake City, and North Bloomfield
Tunnels, and other mines within the Humbug Creek
watershed are releasing sediment and metals in quantities
that are impacting the ecosystem.
• Water quality impaiments could be reduced through
adjustments to physical and chemical conditions at source
areas.
• Alteration or reduction of sediment transport mechanisms
could significantly reduce sediment and mercury
contamination both within mining-related sites and at
downstream locations.
Sampling Plan Components
• Streamage; Hydrology, Turbidity
• Storm event sample collection
– Grab samples for mercury, TSS, other metals
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Air Shaft and Tunnel Water Chemistry
Mercury Source ID-Macroinvertabrates
Pit Erosion and Deposition
Soil Development-quality
Mercury Remediation
Water Quality
Sampling Locations
FTS Sediment Event System
Forest Technologies System web site
Event Driven Sampling Plan for
Mercury and TSS
Brooks Rand Laboratories: EPA Methods 1630
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1-3 grab samples for each storm
3-5 storms
THg (unfiltered and filtered)
TSS
Other metals
TSS, Turbidity and Hg Relationship
Poster by Harihar Napar
Chico State Graduate Student
Stage (ft)
Grab Samples
4/4/2012 23:45
4/2/2012 21:45
3/31/2012 19:45
3/29/2012 17:45
3/27/2012 15:45
3/25/2012 13:45
3/23/2012 11:45
3/21/2012 9:45
3/19/2012 7:45
3/17/2012 5:45
3/15/2012 3:45
3/13/2012 1:45
3/10/2012 23:45
3/8/2012 21:45
3/6/2012 19:45
3/4/2012 17:45
3/2/2012 15:45
2/29/2012 13:45
2/27/2012 11:45
2/25/2012 9:45
2/23/2012 7:45
2/21/2012 5:45
2/19/2012 3:45
2/17/2012 1:15
2/14/2012 23:15
2/12/2012 21:15
2/10/2012 19:15
2/8/2012 17:15
2/6/2012 15:15
2/4/2012 13:15
2/2/2012 11:15
1/31/2012 9:15
1/29/2012 7:15
1/27/2012 5:15
1/25/2012 3:15
1/23/2012 1:15
1/20/2012 23:15
1/18/2012 21:15
11/13/2011 19:15
YYYY/MM/DD HH:MM:SS
Sampling Dates
November 2011-present
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Metal Sampling in Air Shafts and
Tunnels
BSK Laboratories: EPA Methods 200.7 and 200.8
• Water Chemistry of shafts and tunnels
– Sampled with a bailer
• Bacterial processes
• Transport tracing
David DeMaree
Chico State Graduate Student
Mercury Source ID
• Macro-invertabrate sampling
– Summer 2012
Susan Miller
Chico State Graduate Student
Biota
Sampling
Locations
Gage Location
Pit Erosion and Deposition Processes
Keith Landrum
Chico State Graduate Student
Soil Development
Kathy Berry-Garrett
Chico State Graduate
Student
Mercury Remediation
Phyto translocation
Rebecca Bushway
Chico State Graduate Student
Assessment Purpose Statement
To determine the watershed processes that
contribute to the degraded state of the
watershed, specifically with respect to, water
quality.
The primary purpose of determining the processes
contributing to water quality degradation is to
design solutions that mitigate these impacts and
improve ecosystem health.
Overview
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History
Current Conditions
Assessment Goals
Field trip landmarks
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Thank you!
Working Group
Chico State
Graduate Students