A to Z
Data &
Forms &
News &
Licensing &
Rules &
Public Health
Print this Article   Bookmark and Share
Lower Bridge Mine
Lower Bridge Mine

The Lower Bridge Mine site is located 5.5 miles west of Terrebonne, Oregon near Redmond. It is a former diatomaceous earth mine, encompassing 570+ acres.

Starting in the early 1900's the site was strip mined for diatomaceous earth (DE). For 30 years, DE was processed into a form of crystalline silica known as cristobalite. Hazardous and radiological waste was stored on the site for approximately 8 years, before being cleaned up in the mid-1980s by the Department of Environmental Quality (DEQ).


In December 2008, the Deschutes County Planning Commission granted a re-zoning of the mine site property to residential use. This re-zone was conditional upon the developers receiving a certification of "no apparent public health hazard" from Oregon DHS' Environmental Health Assessment Program (EHAP).

EHAP developed and sent a Scope of Work document (SOW) to the developers on July 13, 2009, which describes the information EHAP needs in order to determine if there are or would be risks for future residents of the proposed residential development. The development is currently only proposed for the eastern portion of the property, but EHAP will need to confirm that potential hazards from the western portion would not migrate onto the eastern portion, where people would be living.

Based upon the SOW, the developers will submit a comprehensive Plan of Work (POW) that will include a site-wide sampling plan. The Scope of Work document provides the developers with a framework within which they can develop their POW for the proposed residential site, which requires approval by EHAP prior to implementation. View the cover letter EHAP sent to the developers (pdf). Once the POW is developed and approved, it will be posted here.

Educational Materials

Public Participation

  • A public availability session was held in May, 2009 to answer questions about the final health consultation. This was an informal open house held at the Redmond Senior Center.
  • EHAP accepted comments from the public on the draft health consultation report until December 8, 2008.
  • EHAP held a public meeting at the Redmond Senior Center in November, 2008. EHAP staff talked about the health consultation findings and answered questions from the public.
  • EHAP held an initial public meeting at the Redmond Senior Center in August, 2008. Staff from the Oregon Public Health Division, Department of Environmental Quality, and the Department of Geology and Mineral Industries were available to talk to citizens who had individual questions. Formal presentations began at 6:30pm.


Related Websites

In the News