Water Quality Testing

Water Quality Tests:


Dissolved Oxygen

This test is the most important of the nine water quality tests to measure water's ability to support plants and animals. There are many different factors that affect the amount of dissolved oxygen in water, the main one being temperature. As temperature rises, less gas will dissolve.


Turbidity measures water clarity, which allows sunlight to penetrate to a greater depth. The main sources of turbidity are erosion, living organisms, and those from human endeavors

Total Solids

Total solids measures both dissolved and suspended solids. There are six major types of total solids; silt, clay, soil runoff, plankton, industrial waste, and sewage.

Ph Level

The PH of water is important to aquatic life. If the PH falls below 4 or above 9 everything is dead.

Temperature and Flow Rate

Temperature is a very important part of a river's ecology. There are many natural and human factors that can affect a river's temperature. Human factors include industry, development, and dams. To measure temperature and flow rate you must find two places along the river that are about 1.6 kilometers apart that have the same conditions, then two people measure the temperature at approximately the same time. If the difference is greater than 2 degrees Celsius, then there is thermal pollution. To find flow rate you use a buoyant object, we used an orange, and float it down the river.


Nitrogen is necessary for plant and animal life. Water is tested for nitrates to monitor and control eutrofication , which causes more plant growth and decay.

Fecal Coliform

This is bacteria that propagate in the digestive tracts of humans and animals. They coexist with other bacteria so they are often used as indicators of possible pathogenic contamination. There are many ways fecal coliform can enter a waterway such as animal waste, untreated sewage, combined sewage overflow, and septic tanks.

Biochemical Oxygen Demand

BOD is a measure of oxygen removed from an aquatic environment by aerobic microorganisms. It measures levels of organic pollution in lakes and streams.


Phosphates is a nutrient needed in growth. The phosphate ion is found in shells, bones, and in animal teeth. By removing phosphorous from sewage the amount of phosphate ions in the water will be lowered.