Superfund Information Systems: Site Profile

Superfund Site:


Health & Environment

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What Are the Risks at the Site?

Risks and pathways addressed by the cleanup include health risks from people ingesting or touching contaminants in soil, wastes and ground water.

Historic mining operations at Ely Mine have left behind sulfide-containing waste rock, tailings and roast ore that are responsible for the contamination of the Site’s soil, sediment, groundwater and surface water.  The major issue at the Site is acid mine drainage.  Acid mine drainage occurs when sulfide-containing mine waste is exposed to water and oxygen, producing sulfuric acid, which leaches metals from waste (including aluminum, cadmium, cobalt, copper, iron, manganese, and zinc) and releases them into groundwater and surface water.  This low-pH water with elevated levels of metals is highly toxic to many aquatic organisms.   As a result, severe ecological impacts have been documented in  Schoolhouse Brook, Ely Brook, several small tributaries to Ely Brook, and two on-site ponds.   The sediments of these surface water bodies was also found to be toxic to aquatic organisms.  The metals leaching from the waste piles and mine tunnels also make groundwater beneath and adjacent to the waste areas and in the underground mine tunnels unsuitable for human consumption.  Elevated levels of several metals also my pose a risk to children exposed to waste and soils at the Site under residential use scenarios.

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Contaminant Information

View a full list of contaminants of concern for this site.

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Performance Measures

EPA uses performance measures to track environmental results at Superfund sites. If you have any questions or concerns about the measures at this site, please contact the site team members listed under Site Contacts.

Read more about Superfund Remedial Performance Measures.

Status at this
Superfund Site
What does this mean?
Human Exposure Under Control Yes Yes means assessments indicate that across the entire site:
  1. There are currently no unacceptable human exposure pathways; and
  2. EPA has determined the site is under control for human exposure.

No means an unsafe level of contamination has been detected at the site and a reasonable expectation exists that people could be exposed.

Insufficient data means that, due to uncertainty regarding exposures, one cannot draw conclusions as to whether human exposures are controlled, typically because:
  1. Response to the contamination has not begun; or
  2. The response has begun, but it has not yet generated information sufficiently reliable to evaluate whether there are currently any unacceptable human exposure pathways at the site.
Groundwater Migration Under Control Insufficient Data

Yes means EPA reviewed all information on known and reasonably expected groundwater contamination. EPA concluded the migration of contaminated groundwater is stabilized and there is no unacceptable discharge to surface water. EPA will conduct monitoring to confirm that affected groundwater remains in the original area of contamination.

No means EPA has reviewed all information on known and reasonably expected groundwater contamination, and the migration of contaminated groundwater is not stabilized.

Insufficient data means that due to uncertainty regarding contaminated groundwater migration, EPA cannot draw conclusions as to whether the migration of contaminated groundwater is stabilized.

Construction Complete No

Yes means the physical construction of the cleanup is complete for the entire site.

No means either physical construction is not complete or actions are still needed to address contamination.

Sitewide Ready for Anticipated Use No Yes means:
  1. All cleanup goals affecting current and reasonably anticipated future land uses of the entire site have been achieved, so there are no unacceptable risks;
  2. All required land-use restrictions or other controls have been put in place; and
  3. The site has achieved Construction Complete status.

No means that one or more of these three criteria have not been met. However, a site listed as no may still have redevelopment occurring on portions of the site and may be eligible for additional redevelopment.

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