Asbestos emissions data tracked movement of vermiculite fibers

Records from the Oregon DEQ indicate that W.R. Grace was granted an expansion of the plant’s emissions limitations in 1982 when a second furnace was installed, which increased the plant’s production capacity from 6,000 to 12,000 tons of vermiculite annually, likely boosting asbestos emissions.

In 1983 similar review documentation of the plant indicates that the air particulate emissions were 2.51 tons/year and were in compliance with DEQ’s emissions limitations. Compliance was similarly noted in a 1990 review report.

A preliminary analysis of emissions for the time the facility was in operation indicate that several factors contributed to the unlikelihood that fibers would move toward residences.

The wind direction, a significant change in elevation and the nature of fugitive emissions acted together to concentrate emissions closer to the source along the general pathway of the river, and generally in the industrial area bordering the plant.

Emissions sources identified

The Oregon DEQ records indicate three emissions contaminant sources at the Harding Street plant, including two vermiculite exfoliation furnaces, each with baghouses installed after 1975. The third source was the Monokote mixer, with a baghouse installed in 1978.

Permits

Records obtained from the Oregon DEQ document permits recorded for the years 1975, 1978, 1982, 1983 and 1993. These records indicate that DEQ was monitoring the production capacity of the plant as well as emissions.

There is no indication that the plant exceeded emission limitations. However, emission limitations at the time focused on visible particles of dust and particulates rather than microscopic fibers, and these same emissions today may not be considered safe.