Splish - Splash

The Waterloo community has a natural lake that is used for recreational swimming, fishing, and boating. Surrounding the lake is picturesque farmland that stretches on for miles and miles. In the summer, Waterloo community members gather around the lake with their friends and family for a day of fun and relaxation.

However, recently some parents of young children in the community have grown concerned that the water in Waterloo Lake is not safe for recreational use. After a full day of splishing and splashing at the shoreline, parents have reported that their children have experienced shortness of breath, diarrhea, and spouts of vomiting.

Due to the adverse health effects experienced by the children in the Waterloo community, the local Department of Water Safety suspects that nitrates, specifically potassium nitrate from fertilizer runoff, have contaminated Waterloo Lake.

Your environmental consulting company has been hired to test the water for potassium nitrate contamination. Maximum Contaminant Levels (MCLs) are standards that are set by the United States Environmental Protection Agency (EPA) for drinking water quality. An MCL is the legal threshold limit on the amount of a substance that is allowed in public water systems under the Safe Drinking Water Act.

The MCL for potassium nitrate is 0.1 M.* If the concentration of potassium nitrate is above the MCL, the lake must be closed off for recreational purposes until the issue is resolved.

You have been given a 10 mL sample to test back at your lab. Create a step-by-step procedure to determine the concentration of potassium nitrate in the lake water. Report your findings back to the Waterloo Department of Water Safety.

Things to include in your report (1 paragraph):  The concentration of potassium nitrate in the water sample

 Your recommendation for future recreational use of the lake

 An evaluation of the precision and accuracy of your findings

 Your recommendation for preventing future contamination of Waterloo Lake

Materials available: 10 mL water sample, balance, Bunsen burner, tripod, wire gauze, evaporating dish and lid, tongs

*Modified for the purpose of this experiment. Actual MCL for nitrates is 10 mg/L or 10 ppm.