Background Paragraph: Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure below ). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. 
Story: There are two lakes in southern Indiana that are popular places for families of nearby cities to visit for picnics and parties. Lake Mahoe is right next to a large farm that grows all kinds of crops for the town. The owner of the farm also rents out his barn regularly so people can use it for celebrations. Lake Tresco is located near a school and children will often come play at it during recess.
Are dead zones less prevalent in lake Mahoe or lake Tresco? Are dead zones more prevalent in lake Mahoe or lake Tresco? Does lake Mahoe have more or less chemicals in it than lake Tresco? Does lake Tresco have more or less chemicals in it than lake Mahoe? Is the community surrounding lake Tresco or lake Mahoe less likely to have contaminated water wells? Is the community surrounding lake Tresco or lake Mahoe more likely to have contaminated water wells? Which lake will have less algae? Which lake will have more algae? Which lake's water is less safe to drink? Which lake's water is more safe to drink?