After a heavy storm the waste water holding tanks at a waste

After a heavy storm, the waste water holding tanks at a waste water treatment plant on the New River overflowed dumping 1,000,000 gallons of sewage into the New River. You are part ofthe New River Citizen Watch Group, which monitors the health of portions of the New River for government agencies like the EPA and USDA. This sewage discharge event causes your group to wonder if the event has had a negative impact on the quality of the water downstream of the waste water treatment plant. To test your group\'s idea that the sewage has negatively impacted water quality, you measure in triplicate the EPT of a site upstream of the waste water treatment plant and a site downstream of the waste water treatment plant. You calculate the mean 9% EPT of both sites and the 95% confidence intervals of both samples. Your results are shown below. Use this scenario and data to answer the following questions. 120 1000 60 Upstream site Downstream site

Solution

Here you want to check the negative impact on water quality at upstream of the tank. So the upstream water will be your experimental site. And you are comparing upstream water quality to the downstream water quality. Therefore downstream water will act as a control.

Answers:

Control: (f) The collection site downstream of the waste water treatment plant.

Experimental: (e) The collection site upstream of the waste water treatment plant.

[What is control and experimental during an experiment: The experimental group is one which is exposed to the experimental conditions or where the experiment is performed (As we have upstream water) and control is which is at original/ normal condition (as we have downstream water in tank).]