For homework, the students were asked to investigate water quality in the pipelines using MWRA on-line data. The students remained engaged throughout these lessons and most commented that they enjoyed spending so much time in the lab and the hands-on nature of the instruction. Aside from introducing water quality testing, this lesson served to further engage the students in the unit and help them connect to the issues of water quality through investigating and thinking about their own drinking water and the river in their neighborhood. The Water Quality Parameters Temperature, pH, Turbidity, Fecal Coliform, Total Hardness, and Dissolved Oxygen are the water quality parameters for this unit. These 6 parameters were chosen because they seemed to fit the objectives of this particular unit the best.
Turbidity is basically a measure of how cloudy the water is.
The test used involves looking down at a black dot through a column of water to see how clear the dot appears. The sample is compared to a column of distilled water to which a turbidity solution is added until the two appear to have the same clarity. Fecal Coliform are bacteria that live in the intestines of warm-blooded animals. They are not pathogenic but indicate the possible presence of other pathogenic bacteria. The test involves vacuum filtration of the sample and incubation of the bacteria in a nutrient solution for 24 hours.