Consider the following scenario:
An elementary school is located near a busy intersection through which hazardous chemicals are routinely shipped by tanker truck. At each corner of the intersection are storm drains that discharge to a small creek that runs along the rear of the school, near the playground. Drinking water for the school is provided from a well that is also located near the edge of the playground, approximately 100 yards from the school building. The depth to groundwater is 220 feet and the aquifer that serves the school is known to be isolated from the surface by a dense clay aquitard of 30’ in thickness at a depth of 120 feet.
Sketch a conceptual model that shows the possible exposure pathways for school children to a volatile, hydrophobic chemical spill (such as gasoline or some other organic solvent) at the nearby intersection. Include all possible routes of entry, and list/describe/include the important physical parameters that should be included in considering the fate of the compounds.
Label all potential sources
Label all potential receptors
Label all possible routes of entry
Write a short discussion of how you should approach the exposure assessment for this site.
Be prepared to share your model and your discussion with the class
If you draw the model by hand, scan it to a file so you can project it to the class
Give an oral overview of your model in 2-3 minutes