Part 4: Hanford Groundwater Contamination

Note: You will need internet access for this assignment

Procedure: Students will first want to access the following two sites:

(The above is sourced from a report entitled “Vadose Zone Hydrogeology Data Package for Hanford Assessments” prepared for the U.S. DOE in June 2006)

A file containing this image is also available on the SERC page.

  1. Begin by surveying the first map. Locate the Hanford boundary.
  2. Identify the formations present within the Hanford reservation and list them along with their approximate location on the site.
  3. If you completed Activity 2, review where the bulk of the reactor and waste storage acitivy took place, and then identify what formations are likely to have been impacted by radioactive contamination.
  4. Go to the second website, which is an index of all Washington State geological maps. You’ll notice the Hanford is shown on two quadrangles, the Priest Rapids and the Hanford quads. You’ll need to use both of these.
  5. Compare the geologic maps from the two sources. You’ll notice that in some cases, different information is offered that describe a particular formation. For instance, the first map identifies orange areas as the Hanford formation, while the second two maps refer to the same areas as outburst flood deposits, gravel and that it’s from the Lake Missoula floods. They also indicate the age of the deposits. Both maps provide important information. Make a table that lists all the formations within Hanford, their ages, lithologies, and other information. If possible, print out a color copy of the first map, number the different formations, and then key the numbers to your table.
  6. Liquids such as water that contain contamination can move the contamination further and faster in permeable materials. Permeable materials include well sorted sediments. Non-permeable material includes non-porous, unfractured rock material. Knowing this, what formations at Hanford would best allow for contamination to enter through the surface move in the subsurface?
  7. The above cross-section is a generalized example from a location on the Hanford site where the Hanford formation is the top unit. Examine the formations from the surface downward. What formations would most easily allow liquid contamination to enter from the surface and migrate downward? Which would contaminated groundwater to migrate beneath the surface? Which would likely hinder or prevent groundwater from passing?
  8. Summary and conclusion. In a paragraph, summarize the geology at the Hanford site. Indicate what formations would likely transmit contamination and which would likely not. With this information, make an argument as to whether contamination from point source inside the site is prone to migration.