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K12 LibreTexts

8.23: Earth's Fresh Water- Challenge 4

  • Page ID
  • 1. Nutrients, such as ___ in fertilizer, promote algae growth in water.
    2. Radioactive substances, heavy metals, and oils are examples of ___.
    industrial pollution
    3. One indicator of aquatic health is BOD levels, which measure biological oxygen demand. Healthy systems have low BOD levels. A high BOD level indicates ___.
    a highly polluted system due to a scarcity of oxygen and an excess of nutrients (especially nitrates)
    4. While treating drinking water, chemicals are added to make solids in the water clump together in the process of ___.
    5. In water treatment, ___ is the process of removing smaller particles from the remaining liquid.
    6. The first step of wastewater treatment is ___.
    removing the large and small particles
    7. In coastal areas, groundwater mining ___.
    increases groundwater salinity
    8. The ___ region of the U.S. has intense droughts and reduced groundwater levels.
    9. In coastal areas, when aquifers get low, ___ may intrude.
    salt water
    10. Which of the following can pollute groundwater: landfills, hydraulic pumping operations, or mining operations?
    All of these activities can pollute groundwater
    11. While analyzing groundwater contamination, scientists focus on ___.
    the site's geology, the nature of the contaminants, and the soil characteristics
    12. Cleaning an aquifer does no good if you do not also ___.
    eliminate the pollution source
    13. ___ involves injecting microorganisms into contaminant plumes and allowing them to consume pollutants.
    14. Bringing toxic materials to the surface does not solve the problem of ___.
    disposing them cleanly and safely
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