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WSU/Pend Oreille Extension introduced the Sense of Place series in 1999, with a focus on local landscape and natural history of Pend Oreille County, Washington. A partnership with the Kalispel Tribe of Indians Natural Resources Department has allowed us to expand this program through EPA funding to include more classes, a newsletter and this website.

Beneath the Surface

by Carol Mack

Natural science observations become increasingly difficult as we explore below the ground’s surface. We mine, drill and dig in selected spots, and then try to visualize what exists in between. Both skill and imagination are required to ask the right questions, probe in the right places, and infer the relationships among unseen elements.

Soil scientists use a shovel to expose the soil profile, and then survey terrain and vegetation and apply knowledge of local geology to determine and map soil types. (For a map of local soils, See Soil Survey of Pend Oreille County Area, issued October 1992, by Natural Resources Conservation Service.) Biologists add a layer of fascinating complexity with stories of underground food webs from fungi to pocket gophers.

Well drillers (and miners) ask much deeper questions. Drillers are required to record locations, substrates encountered, depth, and water yield of wells. These well logs cumulatively provide a wealth of information about what exists underground. Well log records are kept by the Washington Department of Ecology and are available to all on the web at http://apps.ecy.wa.gov/welllog.

Technical assessments of groundwater resources in the county were prepared as part of the Pend Oreille Watershed Management Plan (adopted by the Commissioners on May 23, 2005, and available from Pend Oreille Conservation District at 447-5370). These assessments are based partly on a study of well log records, and give a glimpse as to what lies beneath us. For example, Newport sits on a mixture of sands, clays, and gravels deposited during the catastrophic Spokane outburst floods, mostly between 13,000 and 36,000 years ago. These materials form the Newport-West Bonner aquifer. They are up to 200 feet thick and sit on top of bedrock, and cover a 21 square mile region. The productivity of this aquifer is highly variable depending on clay layers, but Newport city wells range from 69 to 180 feet deep, and produce up to 180 gallons per minute.

As the watershed plan points out, there is still much to learn about the hydrogeology of the Pend Oreille basin, especially how groundwater and surface water connect. As often happens, the more we learn, the more we realize how little we understand of the ecosystem interactions beneath our feet.

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