Lab: Groundwater Well Contamination | Ms. Laura Branch

Arsenic Poisoning Problem:

You are a physician in a small community (~1,000 residents).  Yours is an old family in this area; your great-great-grandfather settled here in the 1800s and was a famous officer in the Civil War.  Several members of your family are buried in the local cemetery.

Over the past couple of years, a few members of the community have described to you their puzzling physical symptoms.  Recently, a patient presented you with similar but more serious complaints:  weakness, tingling and numbness in his hands and feet, and dark warts on the palms of his hands and the soles of his feet.

You listen carefully as your patient responds to questions related to his medical history.  He works in the small, local factor (Private Well #6, on the Community Map) that produces wood preservatives.  He has lived in the area for about 10 years.  He and his wife of 10 months have a private well at their home.  His wife has not exhibited similar symptoms.  He quit smoking three years ago and does not drink alcoholic beverages.  He takes no medications, only vitamins.

You meet with members of the town council and express your suspicions—that the symptoms you have documented over the last few years are related to chronic arsenic poisoning from contaminated drinking water.  You advise them the arsenic standard for drinking water set by the EPA (Environmental Protection Agency) is 10 parts per billion (ppb).  The town council votes to budget money for ground water testing that will initially be limited to wells already in existence.

Finding the Culprit:

In order to figure out where the arsenic poisoning came from you need to do the following:

1)   If family members living in this house find nitrates in their drinking water (which comes from a well), where should they look for the source of the contaminant?

2)   On your Community Map with the community level data (Data Set 1).  Identify the top right-hand corner of the map as the point of highest elevation and the low spot as the bottom left-hand corner.

3)   On the Community Map, draw arrows to show the direction groundwater will move. 

4)   Look at Data Set 1.  Noticed which wells are abandoned, private or city wells.  Plot contamination levels from the bottom of the map to the top.   To solve the problem of arsenic poisoning, this is a race against time!  You are to plot contamination levels from the bottom of the map to the top!  As soon as you know the source of the arsenic, quit plotting and write it on the board!

5)   Get into 4 teams TOTAL.  Discuss and write a summary to the following questions:

a.     What should the town do with this information?

b.     What options should the factory be given?

c.      The factory is a major employer of people in the community.  Will this situation affect your discussions with factory owners?

6)   Wrap up:  In your group, decide which coordinates on the map you want to research more in-depth.  Choose 1-3 coordinates!  Once given the data for the coordinates, decide if you need more readings for more wells. 

7)   Decide where the arsenic problem lies, where it came from and how your group believes the arsenic moved through the ground water system.

8)   Read article, “A Grave Mistake…Groundwater Contamination”, from Project WET.

9)   In your team (you can choose to get into smaller groups if you wish)—create a PowerPoint or Prezi presentation that will include:

a.     The background for The Battle of Gettysburg, including why the battle occurred, what type of casualties resulted and what the outcome was.

b.     Explain how they embalmed the bodies of the casualties in the 1880 to 1900s and how this could tie into our arsenic poisoning problem in this lab.

c.      Explain the causes of arsenic in ground water resources of the United States and give 2 locations where contamination has occurred and what types of problems have ensued.

d.     Give 2 processes of how arsenic can be cleaned up in the ground water system.

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© Laura Branch 2017