ARD treatment of Swift Gulch Drainage in the Little Rocky

1
ARD treatment of Swift Gulch Drainage in the
Little Rocky Mountains of North Central
MontanaBy John L. Kill EagleHydrogeological
EngineeringB.S. Environmental Engineering
2
Approximate Project Location
3
Topics Summery

• Background History
• Field Trip
• Ongoing Work
• Results
• Prospective Work
• Questions, Comments, or Suggestions

4
Background History

• Mining History
• Gold first mined in 1884
• Placer mining in Swift Gulch
• Underground Hard rock mining in Swift Gulch
• Pegasus Gold Mining Corporation
• 1979 Open-pit in Zortman and Landusky mines
• 1997 Filed for Bankruptcy Protection

5
Mining Closure and Reclamation History

• 1998 Mining Company Declares Bankruptcy
• DEQ now operates water treatment plants
• 1999 Significant deterioration of Water Quality
  First Noticed in Swift Gulch
• June 2004, BLM placed the mine sites under its
  Comprehensive Environmental Response,
  Compensation, and Liability Act (CERCLA)

6

• Project History
• November 2005, decided on Swift Gulch
• Immediately began Literary Search
• June 2006, Toured Zortman Landusky mines and
  Swift Gulch. Met with DEQ
• Field Trip in July 2006

7
Landusky Mine Pit
8
Host Rock

• Acid Generating potential Paste pH
• Unoxidized Porphyries (grey) lt 3
• Partially oxidized Porphyries (olive green to
  yellow) lt4
• Oxidized Porphry materials (orange red)
  4.5 to 6
• Neutralization Potential
• Mines Humidity cell tests indicates little or no
  neutralizing potential

9
Field Trip Heading Down Swift Gulch
10

• Visited Swift Gulch July 18 19, 2006
• Montana Tech
• Willis Weight, Professor
• John Kill Eagle, Student
• Fort Belknap Environmental Protection Office
• Dean Stiffarm, Environmental Liaison
• Morris Davy Belgard, Water Quality Specialist
• Fort Belknap College
• Dan Kinsey, Insructor

11
Water Quality Parameters

• pH
• Alkalinity
• Specific Conductance
• Temperature
• Stream Flow

12
Dean Davy

• Alkalinity Field Titration

13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
Summery of Results

• Very First Sample (Sample 12) Elevated Al
• Water goes acidic at Fe seeps near shear zone
• Water gets better after Impoundment
• Water improves from there

22
Preliminary Contaminates of Concern
23
(No Transcript)
24
Field Experiments

• Tested for Cu, Fe, Ni, Zn
• Field Treatments
• Lime to a pH of 6 7
• Peroxide
• Aeration
• NaOH pH 10
• NaOH pH 5 6

25
Ongoing Work

• 30 gallons of Swift Gulch water
• Stepwise pH adjustments
• Analytical Testing
• Bench Scale Experiments
• Computer modeling

26
Zinc Results
27
Models

• Forward modeling using PHREEQC
• Mixing demonstration
• Water shed modeling using HEC-HMS
• 100-year rainfall event

28
Acknowledgments

• Montana Tech
• Willis Weight
• Chris Gammons
• Steve Parker
• Mark Peterson
• Kevin Mellot
• Montana DEQ
• Wayne Jepson
• George Furniss

• Fort Belknap Environmental Protection Office
• Dean Stiffarm
• Morris Davy Belgard
• Fort Belknap College
• Dan Kinsey

29

• Questions?
• Comments?
• Suggestions?