Records in this collection are classified into one of four categories that best characterizes the data contained within the borehole record. The classifications are:
Geotechnical: Boreholes and pits created with the intent to gain a detailed understanding of the subsurface lithology and soil or rock properties therein. These records have additional data beyond lithologic descriptions including penetrometer resistance, shear and strength tests, density measurements, etc.
Lithologic borings: Boreholes are drill solely for the purpose of identifying subsurface lithology. Material testing techniques were not used (or the results are not provided) to allow for a more detailed understanding of subsurface material properties.
Test pits: Generally shallow excavations with either hand tools or mechanical equipment that are typically less than 20 feet in depth though may expose a greater area or "working face" to observe the subsurface lithology. Material testing techniques were not used on these pits, or the results are not provided, to allow for a more detailed understanding of subsurface material properties.
Water wells: Boreholes drilled with the purpose of extracting or monitoring groundwater. These records often provide detailed hydrologic data including depth to groundwater, flow rates, and draw-down testing that may be used to better understand they hydrogeology of an aquifer system. Chemical testing for potentially hazardous pollutants may also be included for some wells, particularly those focused on monitoring groundwater rather than extraction.
Most if not all records from this collection were originally in paper form now scanned and digitized by the Washington Geological Survey.
