The purpose of this health consultation is to determine whether contaminants in groundwater from the Motorola 56th Street facility represent a threat to public health. The facility was first occupied in the spring of 1950 as the Western Military Electronics Center. From 1950 to 1958, it was primarily used for bench type electronics, electronic assembly, and semiconductor production. The chemicals used in these processes included solvent degreasers such as trichloroethylene, acetone, and freon, and metals such as cadmium, chromium, and arsenic. From 1959 through 1961, the facility was used primarily for document storage. Beginning in 1962, manufacturing of electronics resumed to include assembly of circuit boards, plating, and degreasing. Chemicals used between 1962 and 1974 included trichloroethylene, tetrachloroethylene, and a number of acids and metals including arsenic. In 1975, the facility began manufacturing liquid crystal products. These activities continued until 1982, when it was converted to office use. The investigations that have been conducted to date have shown that there are residual levels of arsenic and fluoride in down-gradient private wells west of the facility. Solvent contaminants that were found in the 1980s are no longer present at detectable levels in down-gradient private wells.

The W.R. Grace facility in Phoenix, Arizona, received vermiculite concentrate from the Libby, Montana, vermiculite mine. W.R. Grace Company has owned and operated the Arizona site since 1964. In 1964 W.R. Grace purchased the company that had previously occupied the site and, following the relocation of its vermiculite exfoliation furnace from Glendale, Arizona, began processing vermiculite concentrate and marketing it under the Zonolite® brand. The objective of this health consultation is to evaluate exposure pathways and potential health effects in those persons who, between 1964 and 2002, may have been exposed to Libby asbestos as a result of vermiculite concentrate processing activities and waste materials from the W.R. Grace exfoliation facility in Phoenix.