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NPL Site Narrative for Vasquez Boulevard and I-70
VASQUEZ BOULEVARD AND I-70
Denver, Colorado
Federal Register Notice: July 22, 1999Conditions at Proposal (January 19, 1999): The Vasquez Boulevard and I-70 site covers an area of approximately 456 acres of contaminated soil in northeast Denver, Colorado. The site encompasses an area situated in the Northern and Central portion of the City and County of Denver, and extends north into Adams County, Colorado.
Historically, this area was a major smelting center for the Rocky Mountain west, receiving ore from as far away as Mexico and British Columbia. Three smelting plants, Omaha-Grant, Argo and Globe all operated in this area from the 1870's through the 1950's, refining gold, silver, copper, lead, and zinc. The Omaha-Grant smelter, located nearest and just west of the area of contaminated soil, is believed to be the primary contributor to the contamination.
On July 16, 1997, the Colorado Department of Public Health and the Environment (CDPHE) collected 25 soil samples from the residential yards in the Elyria and Swansea neighborhoods of Denver, situated to the north of the elevated portion of Interstate 70, to determine if a threat to human health existed in the area due to historical smelting operations. Analysis of the 25 soil samples indicated elevated levels of arsenic, cadmium, and lead. The discovery of these contaminants prompted the need to further investigate the extent of arsenic, cadmium and lead present in soils of North Denver. An extensive soil sampling program was conducted in April, 1998, and included the collection of 3,550 samples from parks, schools, and residences in the area. All samples were screened for contamination in the field and approximately 10 percent were sent for confirmatory laboratory analyses.
An evaluation of residences within the area of contaminated soil indicates that there are an estimated 95 residences subject to arsenic concentrations exceeding health-based benchmarks, 14 additional residences where elevated levels of lead have been detected, and another 750 residences where, though not detected, contamination can be inferred based on the presence of contamination at nearby properties.
Status (July 1999): EPA is considering various alternatives for this site.
For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet at http://www.atsdr.cdc.gov/toxfaq.html or by telephone at 1-888-42-ATSDR or 1-888-422-8737.