As a result of EPA’s investigation at the W.R. Grace mine in Libby, Montana, the EPA initiated an evaluation of current and former vermiculite facilities in the United States which received ore from the Libby mine. The W.R. Grace/ Zonolite Co. facility (e.g. WRG4 Vermiculite Site or “Site”) in Ellwood City, Pennsylvania was reported by the EPA to have received vermiculite ore from the Libby mine and operated as an exfoliating facility from approximately 1954 to 1969.
An initial assessment was conducted at the WRG4 Vermiculite Site on October 31, 2000, by the EPA Region III START-South Contractor (RAI), who was accompanied by an EPA On-Scene Coordinator. During that site visit, two bulk samples were collected. The results of the October 2000 sampling revealed the presence of tremolite asbestos fibers at concentrations of 2% in one of the bulk samples. The results for the other sample was non-detect. EPA decided to conduct additional sampling based on the presence of tremolite in the sample collected at the facility and the reported volume of vermiculite ore previously processed at the facility.
In May of 2002, EPA conducted additional sampling at the WRG4 Vermiculite Site. Five surface samples and one subsurface sample were collected from the soils surrounding the former vermiculite facility. Samples were initially analyzed using the Transmission Electron Microscopy (TEM) method. The TEM analysis indicated that one sample was identified as containing total asbestos structures, which represents all asbestos structures (fibers, bundles, cluster, and matrix). Five samples were reported as including respirable non-regulated amphibole structures indicative of the Libby ore and referred to as the “Libby Amphiboles”. It was later determined that the TEM analysis may not have assessed larger asbestos bundles due to magnification or weight. Polarized Light Microscopy (PLM) analysis was then performed on the samples using NIOSH method 9002 for asbestos fibers. PLM analysis indicated that three of the six samples were non-detect. However, asbestos fibers (actinolite/tremolite) were reported in the remaining samples at a concentration of less than one percent (<1%).
In September of 2005, ATSDR released a Health Consultation for the Site as part of the National Asbestos Exposure Review (NAER) project. The consultation indicated that not enough information is known about how and how often people came in contact with Libby asbestos from the plant (ATSDR, September 2005). Following the release of this document, ATSDR was contacted by a former resident who described a playground that was located near the plant during its operation. According to the resident, vermiculite waste materials were piled near the playground, and that children may have had contact with them. Since this facility received vermiculite from Libby, Montana, it was likely that some of the waste vermiculite material was contaminated with amphibole asbestos. It was determined that further review of the Site may be necessary.
In August of 2006, START conducted a sampling event at the Site. A direct-push borehole device was used to collect core samples; and where that was not a feasible approach, hand augers were used for sample collection. Samples were analyzed for asbestos fibers via polarized light microscopy (PLM) using NIOSH method 9002. A total of 48 samples were collected from the site. The analytical data reported non-detect for exactly one-half (24) of the 48 samples. The other 24 samples were found to contain between <.25% and 1.75% tremolite. Data from this event was forwarded to ATSDR for review.
The ATSDR’s health consultation concluded that the WRG4 Vermiculite Site could pose a public health hazard if buried/covered asbestos contaminated waste rock were aggressively disturbed and asbestos fiber released to the air and recommended removal and/or containment of asbestos containing materials on-site. (EPA Action Memorandum, 2008)
On April 8, 2008, an Action Memorandum for implementing a removal action at the site was signed and approved by the Director of the Office of Emergency Management for the EPA. The removal site evaluation had identified a threat due to the uncontrolled presence of hazardous substances at the Site. The removal site evaluation had identified that fibrous amphibole asbestos was released into the environment from the processing of vermiculite ore and the disposal of associated waste products at the Site by W.R. Grace/Zonolite Company.
On July 18, 2008, EPA, START, and ERRS arrived on site to begin removal operations.
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