2. Upper Blackfoot Mining Complex
4 May 2006
David Bowers

3. Upper Blackfoot Mining Complex (UBMC)
Historical Overview
Agency Involvement
Current Activities
Areas of Concern
Questions

4. Heddleston Mining District includes the Anaconda, Carbonate, Mike Horse, and Paymaster mines.
Mines were mostly silver and lead operations that had only sporadic activity from 1890s to 1960s.

5. Mike Horse Mine was the “flagship” of the mines in the area
Height of operations occurred during the 1940s as a war effort mine – lead and zinc
Includes a tailings impoundment known as the Mike Horse dam
A 1975 breach of the impoundment dam released approximately 200,000 cubic yards of metal-bearing tailings downstream

6. Historical Overview Early Regulatory History
1991 – Under legislative action, the regulatory authority for the UBMC was transferred from the Department of State Lands to the Montana Department of Health and Environmental Sciences (MDHES)
1992 – MDHES noticed Asarco and Arco as potentially liable persons
1993 – With agreement from the Director of MDHES, Asarco and Arco began a five-year voluntary interim remedial action program at the UBMC
2000 – After a petition by Asarco, temporary water quality standards for the UBMC were implemented
1991 – Comprehensive Environmental Cleanup and Responsibility Act (CECRA) Program

7. Historical Overview 1993-1998 – Voluntary Interim Remedial Actions
Attempted to address critical sources of contamination related to the various mines in the UBMC
Conducted without DEQ approval
All work plans, design documents, etc. were submitted to DEQ for review and comments.
However, based on the 1993 agreement between DEQ and Asarco/Arco, these Interim remedial action work plans, design documents, etc. did not require DEQ approval.
Therefore, Asarco/Arco proceeded at its own risk.

8. Mine waste removal to three constructed repositories

9. Construction of Mike Horse Repository

10. Adit-discharge flow control

11. Plugging Mike Horse Adit

12. Adit-discharge treatment system

13. Current Agency Involvement - State
DEQ
Comprehensive Environmental Cleanup and Responsibility Act (CECRA) Program
Water Quality Protection – Temporary Water Quality Standards
Permitting and Compliance – Montana Pollution Discharge Elimination System (MPDES) permits
Planning and Prevention – Total Maximum Daily Loads (TMDL)
Legal Unit
Comprehensive Environmental Cleanup and Responsibility Act (CECRA)
UBMC is a State Superfund Site
Water Quality Protection – Temporary Standards
Temp Standards includes an Implementation Plan to cleanup areas of the UBMC that are impacting State waters
Permitting and Compliance – Montana Pollution Discharge Elimination System (MPDES) permits
Permits for adit discharge treatment systems
Planning and Prevention – Total Maximum Daily Loads (TMDL)
TMDL performed for the Blackfoot River Headwaters
Identified the Temp Standards IP as a major component to meet TMDL objectives for the area
Legal Unit
Asarco Chapter 11 Bankruptcy
Litigation against Asarco and Arco
Asarco Trust Fund Coordination

14. Current Agency Involvement - Federal
United States Forest Service (USFS)
Administrative Order on Consent (AOC) with Asarco to develop an Engineering Evaluation/Cost Analysis (EE/CA) for the Mike Horse dam and USFS land containing mine waste at the UBMC
Department of Justice (DOJ)/Environmental Protection Agency (EPA)
Asarco Trust Fund – determine annual funding allocations for various sites across the US
EE/CA: non-time critical removal under CERCLA, the Federal Superfund program administered by the EPA
USFS – Important to stress that AOC for remedial actions has not been negotiated. The USFS and Asarco have signed an Administrative Order on Consent (AOC) but the AOC only covers the development of an EE/CA. Another AOC or modification of the one in place will be required to actually implement the removal actions on federal lands.

15. Current Activities Temporary Water Quality Standards
Asarco petitioned the Board of Environmental Review (Board) in 1999 to adopt temporary standards for:
A portion of Mike Horse Creek
A portion of Beartrap Creek
A portion of the Blackfoot River
The Board adopted the temporary standards for the UBMC in 2000 the implementation plan,
UBMC Temporary Standards currently run through 2008
IP details:
A progressive series of site delineation/condition assessments and remedial actions to remove mine wastes from the floodplain.
Surface and ground water chemical monitoring of the petitioned streams and biological monitoring at a site near the downstream extent of the temporary standards.
Although the temporary standards do not apply to the tailings impoundment, several impoundment studies were identified to be conducted including:
Geotechnical stability evaluation of the dam
Design and construction of an emergency spillway
Dam seepage studies
Impoundment sediment sampling

16. Current Activities
Temporary Water Quality Standards Implementation Plan (IP)
Actions Initiated or Completed
Initial delineation and mapping of floodplain mine waste
Removal of mine waste piles at the upper Mike Horse
Annual water treatment system operation, maintenance, and enhancement
Annual work plans and monitoring reports
Work performed under the IP is currently funded by the Asarco Trust and Asarco corporate funds
Submittals were not always timely

17. Areas of Concern Temporary Standards Implementation Plan
No one event is the cause for the slow progress and schedule deficiencies
Concurrent actions have complicated the execution of the Implementation Plan (IP)
Asarco’s recent corporate history has impacted the IP
Limited funding (Trust Fund) has impacted the IP
Concurrent Actions – Actions by DEQ and the USFS that are not directly part of the Temp Standards have complicated the planning and execution of the IP
Asarco’s Recent Corporate History – The purchase of Asarco by Grupo Mexico in 2003 and Asarco’s bankruptcy in 2005 added additional constraints and uncertainty to the IP
Limited Funding – The Trust Fund (a result of the Grupo Mexico purchase) administered by the US DOJ has limited the annual funding for work proposed in the IP

18. Areas of Concern Specific Issues regarding the IP Schedule
Inability to meet required deadlines for annual data summary reports and annual work plans
Numerous removal and reclamation activities have not been completed according to the IP schedule
Lower Mike Horse Creek (2003), Beartrap Creek (2004), Flosse and Louise (2004), Upper Blackfoot River drainage (2005), Stevens Gulch (2006)
Unlikely that cleanups targeted for USFS land can be completed under the Temporary Standards framework
Lower Mike Horse Creek

19. Areas of Concern Mike Horse Dam Stability
USFS Dam Stability Report recommends removing the dam from operation
Emergency Action Plan has been developed for the interim
EE/CA for the dam and tailings impoundment is scheduled for completion in August 2006

20. Board of Environmental Review Options
Option 1: No Action – Keep Present Plan and Schedule
Possible outcomes include:
Temporary standards will expire 31 May 2008
Unknown amount of work will be completed
Treatment system discharge permit must be revised to meet DEQ-7 standards after 2008
Federal and State Super Fund activities continue at own pace, including Mike Horse Dam removal/reclamation

21. Board of Environmental Review Options
Option 2: Modify the Plan and Schedule
Possible outcomes include:
Revision of implementation plan and schedule would likely only include Asarco owned lands
Renewal of the treatment system discharge permit will require minimal modification
Federal and State Super Fund activities continue at own pace, including Mike Horse Dam removal/reclamation
Revision challenges:
Much of the mine waste removal and stream stabilization is located on USFS land and is tied to the Mike Horse Dam removal/reclamation. It will proceed at own pace regardless of IP schedule. Again, it is unlikely that cleanups targeted for USFS land can be completed under the Temporary Standards framework.

22. Board of Environmental Review Proposal
Option 3: Initiate Rulemaking to Rescind ARM § (2)
Possible outcomes include:
Reissue treatment system discharge permit to meet DEQ-7 standards (B-1 Classification)
Federal and State Super Fund activities continue at own pace, including Mike Horse Dam removal/reclamation
Treatment system discharge permit would include a compliance schedule
Two compelling facts
Most of the remaining work found in the current IP is located on USFS land. As previously stated, it is highly unlikely that cleanups targeted for USFS land can be completed under the Temporary Standards framework.
Both State and Federal Agencies will proceed with the cleanup at the UBMC regardless of the Temporary Standards status.

23. Montana Department of Environmental Quality
Questions?
David Bowers
Site Response Section
Montana Department of Environmental Quality
Phone: