USGS: Science 
for a Changing World

Arsenic in Ground Water of the Willamette Basin, Oregon

By Stephen R. Hinkle and Danial J. Polette



Water-Resources Investigations Report 98-4205

Prepared in cooperation with the
Oregon Water Resources Department

Portland, Oregon

PDF icon PDF version (1.2 MB)



Summary and Conclusions


Study Design and Methods

Data Quality: Sampling and Analytical Variability versus Environmental Variability

Distribution of Arsenic

Geochemistry of Arsenic

References Cited




       Plate 1 (222 KB map) Arsenic concentrations in ground water, and selected geologic units

  1. Map showing location and features of the Willamette Basin, Oregon
  2. Well-location system
  3. Comparison of arsenic concentrations determined by various processing and analytical methods
  4. Temporal variation in arsenic concentrations
  5. Arsenic concentrations for sites sampled in the Willamette Basin, Oregon
  6. Relation of arsenic concentration to well depth



  1. Comparison of historical arsenic concentrations with arsenic concentrations measured during this project
  2. Comparision of arsenic concentrations for various processing and analytical methods
  3. Temporal variation in arsenic concentrations and specific conductance
  4. Speciation of arsenic
     A1. Wells discussed in report text, tables, and figures

The use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.

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Last modified 9/22/99