Superfund Information Systems: Site Profile

Superfund Site:

CHEVRON QUESTA MINE
QUESTA, NM

Health & Environment

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What Are the Risks at the Site?

Site Risks

The Human Health Risk Assessment (HHRA) and Baseline Ecological Risk Assessment (BERA) evaluated potential human health and ecological risks that may result from current and future exposure to mining-related contamination present at the Site if no remediation is performed. 

Mill Area: The HHRA found a potential risk to future workers exposed to polychlorinated biphenyl (PCB)-contaminated soil in the Mill Area. This potential risk has been alleviated by the excavation of PCB-contaminated soil at the Mill Area.

Mine Site Area: The HHRA found a potential risk to future recreational visitors exposed to seepage in mine site catchment basins and to drainage (i.e., seeps/seepage) from the waste rock piles. This potential risk will be addressed by the remediation of the Mine Site Area waste rock piles and through groundwater protection.

The HHRA found a potential risk to future residents exposed to groundwater as a drinking water source. This potential risk will be addressed by the remediation of the waste rock piles.

Tailing Facility: The HHRA found a potential risk to future residents exposed to groundwater as a drinking water source and to future recreational visitors exposed to sediment at the Tailing Facility. These potential risks will be addressed during the remediation of the Tailing Facility.

The BERA found a potential risk to grazers (i.e., elk and deer) at the Tailing Facility from consumption of terrestrial plants (e.g., grasses) that have accumulated molybdenum from the tailings. These potential risks will be addressed during the remediation of the Tailing Facility.

Red River, Riparian and South of Tailing Facility Area: The BERA identified an unacceptable risk to aquatic life (e.g., fish) in the Red River from groundwater discharge into the river. This risk will be addressed by the additions to extraction systems to capture groundwater before it reaches the Red River at Springs 13 and 39.

The BERA found a potential risk to soil dwelling organisms and terrestrial birds (e.g., birds that eat insects) from tailing spills. This potential risk has been alleviated by the excavation of tailing spills.

The BERA found a potential risk to wildlife (e.g., deer and elk) and livestock in the South of Tailing Facility Area from terrestrial plants (e.g., grasses) that have accumulated molybdenum from the soil.

Eagle Rock Lake: The BERA found a potential risk to aquatic life (e.g., aquatic insects) from sediments in Eagle Rock Lake. This potential risk has been eliminated by the removal of sediment in Eagle Rock Lake and the installation of inlet stormwater controls.

 

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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.

Performance
Measure
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 No

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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