Stream Health Blog Post

Several tests are performed on water in streams to determine how healthy these environments are.

Nitrates

The levels of nitrates, a nutrient needed for plant growth, are measured in streams. High levels of nitrates can cause algal blooms and lessen the quality of the water. Contamination by fertilizers can cause excess levels of nitrates. As algae dies in the process of eutrophication, the level of DOC goes down.

pH

pH is the measure of the concentration of hydrogen ions. Most aquatic organisms live within a range from 5.5 to 9.5 on the pH scale. Carbon dioxide levels in water can create an acid called carbonic acid. It is important to measure the pH of a body of water to determine if it is too acidic.

Conductivity

Conductivity is the water's ability to conduct electrical current. Conductivity reveals if the water is pure, because pure water is a poor conductor of electricity. It also reveals high or low levels of dissolved solids.

Turbidity

Turbidity is the measure of total suspended solids in the water of a stream. Waters with high turbidity are murky and are contaminated with high levels of dissolved solids. These waters are also impure and generally unhealthy for most living organisms.

Dissolved Oxygen

Dissolved oxygen is measured to determine how many ppm are available for aquatic organisms to survive. The higher the temperature of a body of water, the less dissolved oxygen it can hold. Healthy measures of DO are from 6 ppm up to 9 ppm.

Temperature

Temperature is important in the measurement of stream health because of how it affects aquatic life. Most organisms live in the range of 0 to 32 degrees Celsius. Rapid changes in temperature are not healthy for aquatic life forms. Lower temperatures also allow for higher levels of dissolved oxygen, and healthier streams. Warm water may be stressful to aquatic organisms.

Alkalinity

Alkalinity measures the ability a body of water has to neutralize acids. The presence of limestone indicates a higher level of alkalinity. Areas of limestone bedrock such as caves and sinkholes are called karst. Acidic water and low alkalinity levels are dangerous to the health of aquatic ecosystems.  Alkalinity is important to keep pH levels in a healthy range for life.

E. coli

Escherichia coli are bacteria found in the intestines of warm blooded animals. Though the E. coli bacterium is generally harmless, it often indicates the presence of bacteria that are harmful to living organisms. Levels of E. coli bacteria are measured in order to discover other harmful strands of pathogens often present along with E. coli.