Hearing set on plan to clean up old Hylebos Waterway chemical plant site

A long-discussed plan to clean up chemical contamination along the Hylebos Waterway from Occidental Chemical’s 76-year manufacturing operation will come up for public comment at a hearing Wednesday (March 8).

The hearing will cover the options for cleaning up the site, which is part of the Superfund-designated pollution of Commencement Bay.

The Occidental Chemical pollution includes chemical waste and heavy metals left behind in the site’s soil and groundwater.

A plume of chlorinated volatile organic compounds left behind by the chemical plant extends 160 feet below sea level. A second plume of high-pH sodium hydroxide has dissolved part of the aquifer, allowing it to move around beneath the surface.

The hearing will help state regulators decide which of the cleanup and containment possibilities identified in a draft feasibility study will be used to address the problems in the soil and groundwater.

The remedies include combinations of containing the pollution where it sits, pumping out and treating tainted groundwater and soils to remove the pollutants and trying to neutralize the most troublesome pollutants without removal.

Occidental will be required to pay for the cleanup plan approved by the state Department of Ecology. Cost estimates listed in the study range from about $50 million to more than $400 million.

The study is open for public comment until March 13, either by attending the hearing or contacting Ecology Department officials by email at at kerry.graber@ecy.wa.gov or by mail at Southwest Regional Office, P.O. Box 47775 Olympia, WA 98504-7600.

This story was originally published March 7, 2017 at 6:09 PM with the headline "Hearing set on plan to clean up old Hylebos Waterway chemical plant site."