Does human activity make river water dirtier as it flows through a town? You collect five water samples upstream and five downstream from a populated area. Then you test each sample for four things:
- pH (acidity level)
- Turbidity (cloudiness)
- Ammonia content
- Nitrate content
You use pH paper, a turbidity meter, and a freshwater test kit to measure the results. Comparing the upstream and downstream readings shows whether the town's presence changes the water quality.
Hypothesis
The hypothesis is that the water sample taken upstream (where there is less human activity) will contain less pollutants compared to the water sample taken downstream.
As water flows over streets and yards and into a river, it picks up pollutants along the way. This project tests whether that pattern shows up in a real river by collecting five samples upstream and five downstream from a populated area. Each sample is tested for pH, turbidity, ammonia, and nitrate content using pH paper, a turbidity meter, and a freshwater test kit. Higher pollutant readings downstream point to runoff from the town changing the water quality as the river passes through.
Storm drains, construction sites, and eroding banks all add fine particles to flowing water, raising its cloudiness. Collecting five samples upstream and five downstream from a populated area lets you compare turbidity meter readings directly. When human activity is concentrated in the middle, that comparison can flag changes in water quality that are invisible to the naked eye.
Ammonia forms when waste breaks down in water. Human activity near rivers adds waste that raises ammonia levels. Testing ammonia content upstream and downstream of a town shows whether people increase that pollution.
Method & Materials
You will collect 5 samples of the river water upstream and 5 samples of the river water downstream. You will then use a pH paper, a turbidity meter, and a freshwater test kit to measure the acidity, turbidity, ammonia content, and nitrate content of the water samples.
You will need 10 empty resealable bottles, transportation, pH paper, a turbidity meter, a freshwater test kit, and a marker pen.
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The results showed that the acidity of the downstream water samples was higher than that of the upstream water samples. The turbidity, ammonia content, and nitrate content of the downstream water samples was also higher.
Why do this project?
This science project is interesting because it shows how human activity can affect the environment. It also shows how important it is to keep our rivers clean.
Also Consider
Consider testing the quality of the water in lakes and ponds located at different distances from urbanized/densely populated areas. Also consider testing the water samples from different rivers.
Full project details
Additional information and source material for this project are available below.
