Region 8
Serving Colorado, Montana, North Dakota, South Dakota, Utah, Wyoming and 27 Tribal Nations
Superfund Program
National Information
Regional Information
Site Information
National Priorities List (NPL) History
Proposed Date
4/9/2009
Flat Creek IMM (Flat Creek Iron Mountain Mine and Mill)
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Site Type: Final NPL City: Superior County: Mineral Street address: Flat Creek Road and Hall Gulch Road Site Alias: Iron Mountain Mine and Mill EPA ID#: MT0012694970 SSID: 08ER MT &Congressional District: state-wide Montana Legislature Senate District 7; Montana House District 14 |
Site Status & Updates
September 23, 2009 - EPA formally adds the Flat Creek/IMM Superfund Site to its National Priorities List (NPL) of Superfund Sites.
EPA proposed the Flat Creek/IMM Site as a Superfund Site on April 9, 2009. There was a 60-day public comment period during which several comments were received. None of the comments opposed the listing. EPA considered the comments and published a notice in the federal register on September 23, 2009 placing this site on the list of final NPL sites. View the Flat Creek/IMM Listing fact sheet (PDF).
Along with Flat Creek, 10 other proposed Superfund Sites became final NPL sites and 10 new sites were proposed for listing.
Documents that EPA used to document the proposed listing of the Flat Creek/IMM Site are available on this web page under Site Documents and at the Information Repositories.
Soil Sampling August 3 – September 25, 2009
EPA’s goal is to sample all local properties that may potentially contain mine waste used as fill material. The more properties that are included in the sampling, the better our assessment of the extent of contamination will be. This helps ensure that potential sources of contamination will not be missed and that any cleanup work will be as thorough as possible. EPA is trying to protect future residents, as well as current residents.
EPA met its target of sampling 300 properties this field season. EPA thanks the community, Town of Superior and Mineral County for their cooperation in helping EPA and the State meet this goal. To date, EPA has received over 350 access agreements, allowing us to sample properties. Access agreements continue to come in. Therefore, for those properties which were not sampled during this field season, EPA intends to sample them during next field season (2010). EPA will now be analyzing the samples and plans to hold a public meeting in early 2010 to discuss the sample results and plans for the 2010 field season.
Your participation in the sampling program is voluntary, and we can’t sample your property without a signed access agreement with you. Sampling takes only about an hour, and you don’t have to be home (although you are welcome to watch). To sample, a small square of sod is cut away from the location, a small hole is dug with a shovel, and about a cup of soil is taken for each sample. After sampling, the hole is refilled and the sod is carefully replaced. Driveways will also be sampled. There is no cost to property owners for the sampling.
If the sample results show cleanup is needed, EPA will perform that cleanup at no cost to the property owner. Property owners who participate in a cleanup will be provided with a letter that explains what was done and why. At other sites, such letters have proven valuable to owners during real estate transactions. Cleanup will generally come after completion of the RI and Record of Decision.
If you would like your property sampled, you need to sign up. Please fill out this Access Form (PDF) and drop it off at the Superior Town Hall. Another option is to mail the signed form to:
Susan Mittelstadt
US EPA Region 8 Montana Office
Federal Building
10 West 15th Street, Suite 3200
Helena, MT 59624
The next round of sampling will be in summer 2010.
Site Description
The area being added to the National Priorities List has contamination from abandoned historic hard rock mining operations at the Iron Mountain Mine and Mill (IMM). The Iron Mountain Mine and Mill operated from 1909-1930 and again from 1947-1953. The mine produced silver, gold, lead, copper, and zinc ores. The Town of Superior is located approximately 3.5 miles downstream of the old Iron Mountain Mine and Mill.
The Site consists of 4 areas potentially needing cleanup:
- Soils in residential areas in and around the Town of Superior
- Former drinking water source
- Abandoned mine and milling properties
- Sediments in and near Flat Creek
The Site contains multiple mine waste tailings piles found to have levels of arsenic, antimony, lead, and manganese that may pose long-term risks to public health and the environment. Superfund Listing would make the Site eligible for funds to cleanup the contamination and would also provide opportunities for technical assistance to local residents, the Town of Superior and Mineral County.
Operable Units (OUs)
Operable Units for this Site have not yet been formally established but EPA intends to divide the Site into two Operable Units:
- Town of Superior (residential soils)
- Flat Creek Watershed (soils, groundwater, surface water)
Site Risk
Tailings piles in the Flat Creek watershed were found to have levels of arsenic, antimony, lead, and manganese that could pose long-term risks to public health and the environment. The full extent of contamination has not been determined, and many of the tailings were directly deposited into and near Flat Creek. Some of the tailings were transported further from flooding after a forest fire in 2000. Water draining from the mine was also found to contain elevated levels of arsenic, lead, and antimony above drinking water standards (Maximum Contaminant Levels or MCLs).
The Town of Superior in the past used a drinking water well (groundwater) two miles downstream from the Iron Mountain Mine and Mill. That well is no longer in use because sampling showed levels of antimony above the drinking water standard (MCL). The municipal water currently provided to residents is safe and is regularly sampled to ensure it is within drinking water standards.
Mine tailings were brought into town and used as fill, road base and driveway material over 40 years ago. In town, contaminants of concern primarily consist of lead and arsenic.
| Media Affected | Contaminants |
| soils, surface water, groundwater | lead, arsenic, antimony from historic mining activities |
Cleanup Progress
In 1993, the Montana Department of Environmental Quality (formerly the Department of State Lands) conducted an abandoned mine investigation of Iron Mountain Mine and Mill area. The investigation found elevated levels of lead, arsenic, copper, mercury, zinc, cadmium, manganese, and antimony. In 2004 DEQ added the Iron Mountain Mill site to its State Superfund List (CECRA). Site boundaries have not yet been determined.
In 1998, the Town of Superior became concerned about the potential public health effects from the Iron Mountain Mine and Mill after a water sample from the Town's well two miles downstream of the Mine tested above the MCL for antimony.
In 2001, because of State and local concerns DEQ asked US EPA to assess the Iron Mountain Mine and Mill, Flat Creek, and Superior areas. EPA conducted some preliminary soil sampling in October 2001 at the Iron Mountain Mine and Mill, along Flat Creek, and at three sites in Superior where tailings from the Mill had been used.
Based on these sampling results, EPA conducted a time-critical removal of mine tailings used as fill in town because of possible short-term health risks from heavy metal contamination of lead and arsenic. The remediated areas included the high school track, portions of the county fairgrounds, and a few private driveways and roads in Superior. In 2003 USFS sampled along Flat Creek and found high levels of metals.
In 2007, US EPA conducted a re-assessment of the Iron Mountain Mine and Mill, Flat Creek, and Superior areas to determine if residual contamination could pose long-term risks to public health and the environment. The results showed that residual contamination exists and needs to be further evaluated to determine what needs to be cleaned up.
From this re-assessment, EPA determined that elevated levels of contaminants exist in the following areas:
- Mine tailings and waste piles at and near the Iron Mountain Mine and Mill
- In and along Flat Creek
- Mine tailings used as fill in several areas in Superior
To do a comprehensive assessment and cleanup, listing the site on the National Priorities list is needed. This will enable the EPA Superfund Program in conjunction with the State and Forest Service to comprehensively address the site and provide funding to conduct the cleanup.
April 9, 2009 EPA proposes Flat Creek/IMM to the National Priorities List (NPL)
April 9-June 9, 2009 Public comment period on proposed listing
September 23, 2009 EPA adds Flat Creek/IMM to its final NPL
Community Involvement
Many opportunities to be involved and stay informed
Over the past several months, EPA and DEQ have meet with local officials and members of the public on a number of occasions: April 21, 2008; June 18, 2008; July 31, 2008; October 13, 2008; October 27, 2008; February 18, 2009; March 10, 2009; and July 8, 2009. During these meetings, EPA provided information and answered questions about the possible listing of the area on the National Priorities List (NPL) and in later meetings, information about the upcoming sampling effort.
For more information about any of the following opportunities, please call or e-mail Diana Hammer, EPA, at 457-5040 or 1-866-457-2690 (toll-free in Montana).
Public Meetings
Public meetings will be held periodically throughout the risk assessment and cleanup. The next public meeting will be held soon after the EPA has the results of the soil sampling effort. That meeting is likely to occur in January 2010.
Community Interviews
In June and July 2009, EPA interviewed over two dozen community members and leaders to learn about residents' concerns, preferred ways for EPA to communicate with the community, and residents' historical knowledge of the area --- information which may be useful in determining areas to be sure and sample for possible contamination. The interviews are confidential. Summarized information from the community interviews will be used to develop a Community Involvement Plan. The CIP should be available this fall.
Community Advisory Groups
During a Superfund cleanup, some communities choose to form and participate on a Community Advisory Group (CAG). A CAG is usually made of about 15-20 residents, representing the diverse interests of the community. A CAG generally meets monthly or quarterly. During its meetings, CAG members receive updates from EPA, review and comment on documents, and discuss any concerns or issues related to the cleanup. CAG members talk with their friends and neighbors, bringing information from this "network" to the CAG. CAG members can help keep the community informed through its community network. If a CAG is formed, EPA would offer to support the CAG with a meeting facilitator and by providing meeting space. Additional support may also be available from EPA. For more information about CAGs, contact EPA or visit EPA's CAG Web site.
Technical Assistance Grants
A Technical Assistance Grant (TAG) is a $50,000 grant from EPA made available to a nonprofit community group for the purpose of hiring an independent Technical Advisor(s). The Technical Advisor(s) reviews and comments on Site documents and shares information with the community. The TAG helps the community better understand, and thus better participate in, Site-related cleanup activities and decisions. By law, only one TAG may be awarded per Superfund Site.
Site Documents
Final NPL Listing Press Release, September 23, 2009
Flat Creek/IMM Listing fact sheet
Property Access Agreement Form (for sampling)
Fact Sheet about Proposed Listing, March 2009
Proposed Listing Public Notice
Proposed Listing Press Release, April 8, 2009
National Priorities List - Hazard Ranking System Package
EPA response to Letter from Montana Governor, January 2009
Letter Supporting Listing from Montana Governor to EPA, January 2009
Letter Supporting Listing from Mineral County to Montana Governor, December 2008
Letter Supporting Listing from Town of Superior to Montana Governor, November 2008
Fact Sheet about Possible Listing, October 2008
Preliminary Assessment, May 2007
Removal Progress Reports:
Information Repositories
Documents are available for review at the following locations:
Mineral County Courthouse
Environmental Health and Planning
300 River Street
Superior, MT 59872
(406) 822-3577
EPA Montana Office
Superfund Records Center
10 West 15th Street, Suite 3200
Helena, MT 59626
(406) 457-5046
Monday-Friday 8:00 am - 4:00 pm
Contacts
Diana Hammer
EPA Region 8
Montana Office
Community Involvement Coordinator
10 West 15th Street, Suite 3200
Helena, MT 59626
(406) 457-5040
Toll-free in MT: 1-866-457-2690
hammer.diana@epa.gov
State Contacts
Daryl Reed
State Project Officer
Department of Environmental Quality
P.O. Box 200901
Helena, MT 59620-0901
(406) 841-5041
dreed@mt.gov