• Arsenic in the Water, Soil Bedrock, and Plants of the Ester Dome Area of Alaska

      Hawkins, Daniel B.; Forbes, Robert B.; Hok, Charlotte I.; Dinkel, Donald (University of Alaska, Institute of Water Resources, 1982-06)
      Concentrations of arsenic as large as 10 ppm (200 times the safe limit for drinking water) occur in the groundwater of a mineralized residential area near Fairbanks. Bedrock of the area contains 750 ppm As, primarily as arsenopyrite and scorodite. The oxygen-poor groundwater is enriched in As(III) and ferrous iron while the surface waters are iron free and contain less than 50 ppb As(V). Arsenic is removed from the water by coprecipitation with ferric hydroxide. Some iron-rich stream sediments contain as much as 1,400 ppm arsenic. The distribution of arsenic in the groundwater is controlled by the distribution of arsenic in the bedrock. The arsenic content of the B soil horizon over mineralized veins is about 150 ppm, while that over barren rock is 30 ppm. The vegetation over the veins is not significantly enriched in arsenic. Lettuce, radishes and tomatoes grown with arsenic-rich water (5 ppm) contain 16, 8 and 1 ppm As, respectively; these amounts are significantly greater than plants not treated with arsenic. Preliminary studies by state and federal health agencies show no detrimental effects on the health of persons drinking these arsenic-rich waters.
    • Investigation of an ozone-filter system for color and iron removal at low temperatures

      Smith, Daniel W.; Hargesheimer, John M. (University of Alaska, Institute of Water Resources, 1975-10)
      The application of ozonation as a disinfectant and as a treatment process for both water and wastewater has been increasing in recent years. The study of ozone application to Arctic and subarctic waters, which are normally at low temperatures, has been limited. Many portions of the Alaskan Arctic and subarctic are plagued with waters which exceed the 1962 Drinking Water Standards for one or more parameters. The iron content and color of the water are among the most common offenders. This project was directed toward the examination of a method for water treatment utilizing ozone to meet the iron and color limits for drinking water. The three principle objectives of the project were: (1) to examine the effect of ozone on several known qualities of water, (2) to examine the effect of ozone on representative samples of surface and ground water, and (3) to develop a laboratory scale system for iron and color removal utilizing ozone followed by sand filtration.