Western Mineral Products Company/W.R. Grace, 111 S. Navajo Street, Denver, Colorado
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EPA
Region		 Location of facility Type of facility Amount
of ore
received
(in tons)		 Did
EPA
visit
the
site?		 Were
samples
taken?		 Results of
evaluation
8 111 S. Navajo Street, Denver, Colorado Former exfoliation facility 102,980 Yes-February 1, 2000 Yes According to an EPA database compiled from W.R. Grace shipping invoices, 102,980 tons of vermiculite ore from the Libby mine were shipped to this site between January 1967 and November 1988. When EPA visited the facility, it was owned by Minnesota Corn Processors (MCP), which manufactured corn syrup. According to a company representative, the site was purchased from W.R. Grace in 1990 by another corn processing company, which was then purchased by MCP in 1996. At the time of EPA's visit, the buildings on the site were those used by W.R. Grace's vermiculite processing operations--a large processing building and a small office building. The site also had three large silos and a rail line spur, which could have been used to transport the vermiculite, was adjacent to the processing building. The MCP official said the processing building and the silos were clean--without any waste piles or dust--when W.R. Grace vacated them. According to the company representative, before the vermiculite operations, the site had been used by a glass manufacturer. When MCP employees were digging a foundation at the site, they found a lot of glass in the soil but no expanded vermiculite ore. EPA saw evidence that a furnace had likely been in the processing building. EPA observed that most of the land surrounding the structures on the site was paved and appeared cleaned. The immediate area surrounding the site was primarily industrial, although residential homes and commercial buildings were located within a few blocks of the facility. On August 21, 2000, EPA returned to more closely inspect the property and found some vermiculite on an unpaved strip of land along the southern edge of the site. EPA collected three samples from the unpaved area and found they contained 1-, 3-, and 12-percent asbestos, respectively. The samples were analyzed using polarized light microscopy (PLM). After conducting additional sampling, EPA found asbestos at levels of concern along the southern edge of the plant’s parking lot and along the railroad spur. Asbestos was also detected along the main rail line near the site, at a nearby park (Valverde City Park), and at other public access rights-of-way in the surrounding area. On the basis of this information, EPA determined that the site and some of the surrounding area, including a portion of the park, needed to be cleaned up. EPA funded the cleanup, which was completed in 2003. A railroad company was responsible for cleaning up the contaminated areas along the railroad right-of-way areas, and completed this action in October 2005. The Agency for Toxic Substances and Disease Registry’s (ATSDR) health consultation report for this site can be found at ATSDR.

GAO-09-6R