Well, folks, it looks as if one of you is contaminating the Whetpebble water supply! The EPA has detected unusually high concentrations of oxygen-demanding wastes in the surface and ground water, probably caused by untreated sewage, manure, or industrial waste. The pollution is traveling through the water supply and will eventually be deposited in Lake Hopper, an ecosystem that could be permanently altered by large quantities of this pollution. It is your job to figure out who it is. The EPA has narrowed it down to six possible homeowners. Use the information provided below to identify the culprit. Good luck!

Pay attention to the slope of the land and the direction water flows downhill. How would surface water concentrations be influenced by surface runoff?

Information for the Landfill Lab will be VERY helpful. Look at which rocks are permeable and which ones are not. Note: Streams that run year-round get their water from groundwater sources. Groundwater flows faster through permeable and porous rocks than nonpermeable ones. It also tends to flow identically underground as water on the surface flows.

Biological Oxygen Demand (BOD) is the demand that living organisms and decomposing bacteria place on the water for dissolved oxygen. Oxygen is needed for organic waste to decompose. Therefore, the larger the demand for dissolved oxygen, the larger the quantity of organic waste that needs decomposing.

Typical fresh natural water has a BOD of 2-5 mg/L. Domestic sewage has a BOD in hundreds of mg/L.

The geologic surface bedrock map shows the rock located under the soil, sediment and alluvium in Whetpebble. After water percolates through the soil and sediment, it usually comes in contact with the bedrock underneath it.

Pages 479-481 in the Global Science textbook describe pollution in aquatic ecosystems. Pay attention to how pollution behaves in different bodies of water.

Elevation and the slope of the land are very important because groundwater usually models these same features under the surface.