Superfund Information Systems: Site Profile

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What Are the Risks at the Site?

Emissions from smelting operations often contain lead and arsenic, which are hazardous substances. Both lead and arsenic have been detected at elevated levels in residential yards around the Colorado Smelter site. High levels of lead in dust has been identified inside homes within the study area. These hazardous substances may cause a variety of human health problems.

Sources of lead
Individuals may be exposed to site contaminants through inhalation of particles of dust in the air; ingestion (eating or drinking); and dermal contact (direct physical contact). Lead can also come from many sources that are not related to this site, including but not limited to; household paint made before 1978, the glaze on some pottery or dishes, soil, and sometimes drinking water from older plumbing.

Lead contamination and effects
Exposure to lead may cause nervous system damage, anemia, and brain damage. Children are especially susceptible to the toxic effects of lead. The possible effects of higher levels of lead in children are hearing problems, lower IQ scores and delays in development. Children below 7 years of age, unborn children and pregnant women are especially susceptible to the toxic effects of lead; however, long-term exposure in adults may contribute to high blood pressure, kidney problems, and cognitive dysfunction.

Long-lasting (chronic) exposure to lead, even at low levels, may cause subtle but harmful effects to the central nervous system, which can affect learning and behavior. Lead is not considered a carcinogen; however, over time, lead may cause more severe nervous system damage, anemia, kidney damage, brain damage, or at extremely high levels, seizures and even death.

At the site, the levels of lead in the soils and indoor dust may cause levels of lead in the blood that EPA has determined are unacceptable. With the levels of contamination noted as of 2016, children in the Colorado Smelter study area may develop a Blood Lead Level (BLL) above 20 micrograms per deciliter (μg/dL) due to exposure to lead in soils and indoor dust. There is evidence of cognitive function being negatively affected in young children with blood lead levels between 2-8 μg/dL.

Sources of arsenic
Exposure to arsenic may happen through inhalation of particles of dust in the air, and ingestion of, and dermal contact with soils.

Arsenic contamination and effects
Exposure to arsenic may cause a variety of health problems. Health effects linked with being around arsenic for a long time are an increased risk for some types of cancer such as skin, lung, bladder, kidney, and liver cancers.

Reducing your exposure to site contaminants
EPA recommends using best practices to protect against exposure to lead and arsenic for those living within the Superfund study area. We recommend:

  • Removing shoes before going inside the home;
  • Regular washing of hands, toys and pets; especially after being outdoors;
  • Removing, separating and washing clothing that has been worn while gardening or playing in potentially contaminated areas, or from occupational exposures such as landscaping or construction.

By following these practices, a person’s exposure to heavy metal contamination, such as lead and arsenic, can be greatly reduced.

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Contaminant Information

At this time, arsenic and lead appear to be the principal contaminants of concern for the residential properties portion of OU1 at the site. The i-ROD determined that nine contaminants of potential concern apply to OU1 and are as follows:

  • Antimony
  • Cadmium
  • Cobalt
  • Copper
  • Manganese
  • Nickel
  • Thallium
  • Vanadium

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 No 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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