Water Quality Parameters

Students Testing waterThe pH of the water is measured two different ways: using a LabPro pH probe and a LaMotte pH test kit. The pH is a measure of the concentration of hydrogen ions in the water. The pH of most natural waters ranges from 6.5 to 8.5.

Temperature is measured using a LabPro temperature probe and a standard field thermometer. Temperature is important because it governs the kinds of aquatic organisms that can live in a stream, and because it influences water chemistry, such as the amount of dissolved oxygen in the water.

Dissolved oxygen. Like terrestrial animals, fish and other aquatic organisms need oxygen to live. So, a certain minimum amount of oxygen must be present in water for aquatic life to survive. Dissolved oxygen concentration is measured using a LabPro dissolved oxygen probe and a LaMotte Dissolved Oxygen test kit. Dissolved oxygen levels below 3 ppm are stressful to most aquatic organisms.

Nitrogen and Phosphorous are nutrients essential for growth of plants in aquatic ecosystems. Nitrogen is measured using a LaMotte Nitrate test kit and Phosphorous is measured using a LaMotte Phosphate test kit. Excess nutrients in rivers are usually a result of pollution such as fertilizer run-off or animals wastes. Nutrient loading can result in increased algae growth which can lead to low dissolved oxygen conditions and poor habitat conditions for organisms.

Turbidity is a measure of the suspended solids in the water. Turbidity is measured using a LabPro Turbidity Sensor and a LaMotte Turbidity test kit. Too much turbidity can lead to siltation and sedimentation in streams and inhibit photosynthesis. Many soil particles also “carry” pollutants that may be released into the river.

Alkalinity is a measure of the buffering capacity of the water and is a combination of naturally occurring carbonates and bicarbonates, which help to maintain the pH of the river system. Alkalinity is measured using a LaMotte Alkalinity test kit. Since alkalinity is a buffer, a body of water with a high alkalinity is able to resist rapid changes in pH and therefore helps protect organisms from problems such as acid rain.

Flow rate is a measure of how fast water is moving over a distance. It is typically measured in meters per second. Flow rate is measured using a LabPro Flow probe and with the Orange Flow Method. Flow rate is important because it determines if a stream is eroding or depositing material in its channel.

Last Modified: 3/22/17 4:52 PM