December 2008, Carpenter-Snow Creek Mining District NPL Site, Cascade County, MT
 EPA Issues A Revised
 Proposed Plan  for Clean
 Up  of Soils in  Neihart,  MT
Site Timeline
• 2001. The Carpenter-Snow Creek
  Superfund site (includes the
  Neihart OU) was added to EPA's
  National Priorities List of
  Superfund sites.

• 2002 and 2003. EPA sampled
  soils, surface water, sediments,
  and tailings in Neihart.

• 2004. Soil removals in residential
  areas conducted to eliminate very
  high lead levels.

• 2005. Remedial Investigation
  completed.

• 2006. Human Health Risk
  Assessment completed.

• 2006. Cleanup Feasibility Study
  completed.

• October 2006. Original Proposed
  Plan describes EPA's Preferred
  Alternative for cleanup.

• 2007/08. EPA reassesses
  proposed lead cleanup action
  level.
• October 2008. EPA conducts
  additional yard soil sampling.

• December 2008. Revised
  Proposed Plan issued.

• Winter 2009. Record of Decision
  issued that documents cleanup
  details.

• Spring 2009. Yard cleanup
  designs prepared with property
  owner involvement.

• Summer/Fall 2009.  Yard
  cleanups initiated.
     On December 22, 2008, the U.S. Environmental Protection
    Agency (EPA) issued the Revised Proposed Plan for Neihart
    Operable Unit (OU) 1. This fact sheet summarizes that plan
       and the opportunities for public review and comment.
           Why A Revised Proposed Plan Is Needed

In October 2006, EPA issued the original Proposed Plan for the Neihart
community soils area. Two public hearings were sponsored by EPA and
Montana Department of Environmental Quality (MDEQ). At that time,
EPA's Preferred Cleanup Alternative was Alternative 2B with a soil
cleanup action level for lead of 1,200 parts per million (ppm). EPA is
retaining Alternative 2B but has lowered the soil lead cleanup action
level to 400 ppm. This change has increased the number of residential
properties to be cleaned up and the  associated cost. Since the cost
increase is greater than 50 percent of the original cost and could not
have been reasonably anticipated by Neihart property owners, town
officials, Cascade County, or any other stakeholder, EPA is required to
issue a revised Proposed Plan.

EPA is seeking additional public comment on the revised Proposed
Plan, which was released December 22, 2008, before a final decision
will be made and before the Record  of Decision is issued.

As described in more detail in the Proposed Plan and the Feasibility
Study (available at the document repositories—see box on page 3),
Alternative 2B involves the excavation of contaminated residential soil
and non-paved road base material from the town of Neihart and the
disposal of that material in an engineered, safe repository outside of any
flood plain. Alternative 2B includes the excavation and disposal of the
Belt Creek Tailings pile, located north of Neihart,  and reclamation of the
stream channel at that location. Institutional controls are also a key
component of this alternative and are summarized on page 3.

The original Proposed Plan estimated that 14 properties (includes
residential, commercial, and vacant  lots) and 10 sections of earthen
roadway in Neihart would require cleanup at an estimated cost of $3.8
million. Based on the revised soil lead cleanup action  level, 66 properties
and 24 earthen roadway sections would be addressed at an estimated
present value cost of $11.8 million. This change does not affect the Belt
Creek Tailings pile, which will be removed regardless of the final
selected cleanup strategy for Neihart.

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        Questions  and Answers  About EPA's  Revised
 What Type of Sampling was  Done?
 Samples have been collected from mine waste, surface
 water, sediment, groundwater, and soils to characterize the
 nature and extent of mining contamination in and near
 Neihart. Soil at 153 properties (residential, commercial,
 public-owned, and vacant lots) have been sampled in
 Neihart since work was initiated in 2002. This represents
 85% of the properties in the Neihart community soils area
 (original townsite) and 95% of properties north of the
 Community Center.

 Any property owner desiring information or sampling
 should contact Scott Brown at 406-457-5035.

 Soil lead levels are generally higher north of the community
 center compared to the residential area south of the center.
 This observation is consistent with the town's former mills
 and the main ore transportation corridor previously located
 north of the Community Center. Soil lead concentrations
 range from about 22 to 2,700 ppm, with an average of
 approximately 447 ppm. Elevated lead levels have also
 been found in unpaved roadway material.

 Surface water is contaminated in Broadwater, Compromise,
 and Rock Creeks,  but water quality in Belt Creek and
 O'Brien Creek (the local drinking supply) meets water quality
 standards. Four residential groundwater wells and three
 springs were also sampled. One well had a slightly elevated
 concentration of mercury, and two springs had elevated lead
 concentrations. None of these levels are of concern as long
 as these water sources are not used for drinking.
                                              What Health Risks Were Identified?
                                              EPA's human health risk assessment showed that lead and
                                              arsenic are the mining-related contaminants of concern.
                                              The primary concern driving the cleanup is children's
                                              exposure to elevated concentrations of lead.

                                              In Neihart, residential soils are the primary pathway by
                                              which people may be exposed to mining-related
                                              contaminants. Exposure occurs when soil is inhaled (dust)
                                              or ingested (on unwashed vegetables, hands, toys, etc.).
                                              Other pathways (surface water, groundwater, or stream
                                              sediment) were shown to not be a health concern.

                                              Based on EPA's lead exposure model, exposure is a
                                              concern mainly for full-time resident children at
                                              properties having lead concentrations greater than 400
                                              ppm.  In addition, EPA has set a cleanup action level for
                                              arsenic of 100 ppm. Visitors or recreationists do not contact
                                              soils frequently enough to have elevated exposures.
                                              Approximately 66 properties are either known or expected
                                              to exceed the 400 ppm lead
                                              concentration. By removing the elevated
                                              concentrations of lead and arsenic in
                                              residential soils in Neihart, human
                                              health risks associated with mining-
                                              related contamination will be reduced to
                                              acceptable levels.
                                                                                Lead and Arsenic
                              EPA's Cleanup Objectives in Neihart
               •  Prevent resident exposure to elevated lead levels in residential soil, dust, and road base.
                      • Control the spread of contaminated material by wind and water erosion.
           • Prevent contamination of cleaned areas by preventing the use of mine wastes as construction fill.
                           •  Remove the Neihart Tailings from the Belt Creek flood plain.

What Cleanup Alternatives Were Evaluated in the  Feasibility Study?
   1
No Action. Superfund requires this alternative to be considered. Cost estimated at $240,000.
  2a
Removal/Replacement/Disposal of all Contaminated Soil, Plus Institutional Controls (ICs). Excavation of contaminated
residential soil and non-paved road base material from Neihart and disposal of the excavated material in an engineered
repository. ICs will protect the remedy. Original cost estimated was $1.8 million. Using the new 400 ppm lead level this cost is
now~$9.1 million.
  2b
Removal/Replacement/Disposal of all Contaminated Soil and Removal of Neihart Tailings, plus ICs . Same as
Alternative 2a, but includes excavation and removal of the Neihart Tailings. Original cost estimated was $3.8 million. Using the
new 400 ppm lead level this cost is now ~ $11.8 million.
         Selective Removal/Replacement/Disposal of Contaminated Based on Home Occupancy, plus ICs. Same as Alternative
         2a, but only at properties that are occupied by children under seven years of age. Requires annual consultation with Cascade
         County and town of Neihart to determine changes in demographics and to collect soil samples. Original cost was estimated at
         $0.7 million. Using the new 400 ppm lead level this cost is now ~$1.1 million.
   The primary difference between the alternatives is the amount of contaminated soil removed
                          and whether the Belt Creek Tailings are removed.

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        Proposed  Plan  for Cleanup  in Neihart,  Montana
How Would A Cleanup Be Done Under
Preferred Alternative 2B?
EPA will prepare a detailed cleanup plan for yards having
greater than 400 ppm lead or 100 ppm arsenic in soil.
Homeowners will be consulted in advance to discuss details
of the  cleanup, schedule, and any specific homeowner
needs. All details will be agreed upon in writing prior to the
start of construction.

EPA will use proven yard cleanup protocols in Neihart. Soil
will be removed with conventional equipment, supplemented
by hand shovels close to buildings, septic systems, trees,
etc. Excavated areas will be backfilled with clean soil and
graded. Vegetation that is removed will be replaced, along
with any structures, such as fences. EPA's on-site
representative will be happy to assist property owners with
any questions or concerns during the construction.
What Are Institutional Controls?
Institutional controls (ICs) are non-engineering actions,
such as legal controls, that help minimize the potential for
exposure to residual contamination once the construction
has been completed. ICs are meant to supplement the
engineering (construction) controls.

Before the soil cleanups are completed, the Cascade
County Health Department, county commissioners, and
Neihart town council will help determine what ICs are
needed. An especially important 1C will be to prevent
the importation of contaminated material  into or out of
Neihart.  Much of the contamination being cleaned up in
Neihart resulted from the practice of using mine waste from
the dozens of nearby active and inactive mines (see Figure
1)  as fill material.

Other important ICs will help prevent residents from being
exposed to residual contaminated material during home
construction  and other projects, medical monitoring of
children's blood lead, and developing educational
programs.


Site Contacts: For answers on questions about the
cleanup, please call or write either of the following:

• Scott Brown
 US EPA,10 W. 15th St, Suite 3200 Helena, MT 59626
 406-457-5035/brown.scott@epa.gov

• Catherine LeCours
 MDEQ,1100 N. Last Chance Gulch, Helena,  MT 59620
 406-841-5040/clecours@mt.gov

• Sandy Johnson
 Cascade City County Health Department
  115 4th Street South, Great Falls, MT 59401
   405-454-6950
  How Many Yards Will be Cleaned Up?
  Based on the sampling conducted to date, it is estimated
  that 66 residential type properties and 24 earthen
  roadway sections will have lead or arsenic concentrations
  exceeding the cleanup level and will therefore require soil
  replacement.

  In addition to yards, Alternative 2B includes the removal
  of the Belt Creek Tailing pile and the reclamation of the
  stream channel in that location.

  The preferred alternative will excavate approximately
  61,679 cubic yards of material. This includes 29,742
  cubic yards of residential soil, 4,087 cubic yards of
  roadway material, and 27,850 cubic yards of Belt
  Creek Tailings.
     J Major Mine Si!

       Other Mine Sites
 Figure 1: Historic Mine and Mill Sites

Document Repositories

Documents such as the Remedial Investigation, Risk
Assessment, and Feasibility Study can be viewed at any
of the locations listed below:
• EPA, 10 W. 15th St, Suite 3200 Helena, MT
• Cascade County Health Department, 115 4th Street
 South, Great Falls, MT
• Belt Creek Ranger Station, (north of Neihart)

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US Environmental Protection Agency
10 West 15th Street, Suite 3200
Helena, Montana 59626
      Do You Want to Learn More or Provide Comments on the

      Proposed Plan? A comment period for the revised Proposed Plan will run from December 22 to
      January 30, 2009.  Interested individuals are encouraged to provide their thoughts, ideas, or comments to EPA
      during that time period. EPA will review and consider all comments before making its final cleanup decision in the
      Record of Decision. There are several ways to learn more about the Proposed Plan and to provide comments:
      • Read more about it. This fact sheet summarizes the Proposed Plan. Copies of the plan are available for
       viewing at the Belt Creek Ranger station and the Cascade County Health Department.
      • Attend the public meeting. EPA will hold a public meeting to discuss the plan (see below). Everyone is
       welcome!
      • Provide oral comments. If you attend the public meeting, you can provide comments verbally. A stenographer
       will be present to record oral comments for the public record.
      • Provide written comment. You may provide comments to EPA Project Manager Scott Brown in writing by
       letter or email (see page three).

                                                   Public Meetings
                                                 Neihart Community Center
                                                     (on US Hwy 89 in Neihart)
                                                  January 6, 2009 at 7:00 pm
                                          (in conjunction with the Neihart town council meeting)

                                         Cascade County Commissioner's Chambers
                                            325 2nd Avenue North, Great Falls, MT
                                                 January 13,  2009 at 9:30 am
                                             (in conjunction with the Commission's meeting)

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