EPA Designates Troutdale Aquifer "Sole Source"
In August 2006, EPA designated an aquifer system in Clark County, Washington a “sole source aquifer.” A sole source aquifer is an underground water supply designated by EPA as the sole or principal source of drinking water for an area. The system EPA designated is commonly known as the Troutdale Aquifer System and is 2,000 feet thick in some areas. It lies underneath about one half of Clark County.
This aquifer system provides approximately 99% of the available drinking water to people living over the aquifer area. There are no other sources of drinking water nearby that would be economically feasible to supply all residents in the area.
Troutdale Final Support Document - August 2006 (PDF, 31pp. 947KB)
Comment Period Open Until May 1, 2006
Support Document (840kb, 27pp, pdf document)
About the Request to Designate the Troutdale Aquifer System as a Sole Source for Drinking Water
Aquifer Receives Special EPA Label (PDF, 2pp. 16KB)
Petition to Designate Troutdale and Unconsolidated Alluvium Aquifer System (in Clark County, Washington) as a Sole Source Aquifer (pdf file, 2514 Kb, 51 pgs)
Fact Sheet (pdf file, 117Kb 2 pgs)
Information on Submitting Comments (pdf file, 57Kb, 1 pg)
Troutsdale Sole Source Aquifer Slide Show (pdf file, 589Kb, 14 pgs)
General Information About Sole Source Aquifers
Steps to Designate a Sole Source Aquifer
Questions and Answers about the Sole Source Aquifer Program
Overview of EPA Region 10's (Pacific Northwest and Alaska) Sole Source Aquifer Program
General Information about the Sole Source Aquifer Program