Water Quality Parameters
The volunteer monitors test surface water samples to obtain quantitative physical and chemical data including: water temperature, turbidity (clarity), pH, dissolved oxygen, water color, conductivity, oxidation-reduction potential (ORP), total dissolved solids (TDS), nutrients (nitrate-nitrogen & ortho-phosphate), and bacteria (E. coli & total coliform).
Water temperature may be one of the easiest measurements to perform, but it is also one of the most important. Water temperature dramatically affects the rates of chemical and biological reactions in the water.
Turbidity (clarity) is a measurement that pulls together many important features of an aquatic system. Turbidity is caused by suspended solid matter that scatters light passing through water.
pH is the measure of how acidic or basic a solution is. Because a variety of chemical and biological processes depend on certain pH values, pH measurements provide information about the state of water quality.
Dissolved Oxygen is a very important indicator of water quality for aquatic life. Available oxygen is essential for the basic metabolic processes of animals and plants inhabiting our coastal waters.
Water color provides general but useful information about the water's source and content.
Conductivity measures the electrical conductance of water and is proportional to the nature and quantity of total dissolved solids.
ORP defines the capability of a substance to either release or gain free electrons. Measurement of redox potential is useful in developing a more complete understanding of water chemistry.
TDS are material left behind after a water sample is filtered and evaporated. The quantity of dissolved matter depends mainly on the solubility of the rocks and soils the water contacts, and each water body contains a unique mixture of dissolved materials.
Nitrogen makes up about 80% of the air we breathe. It is an essential component of proteins and is found in the cells of all living things. Nitrogen is found in several forms in terrestrial and aquatic ecosystems. Nitrates are essential plant nutrients but in excess can cause significant water quality problems.
Phosphorus is an essential nutrient for the plants and animals that make up the aquatic food web. Since phosphorus is a nutrient in short supply, even a modest increase can, under the right conditions, set off a whole chain of undesirable events in a water body.
Coliform Bacteria are generally harmless alone. In fact, water may contain coliforms from a variety of sources besides sewage. However, the presence of high levels of coliform bacteria and, in particular, of fecal coliforms, suggests that sewage is being discarded into the water.
Citizens also record narrative environmental data and weather conditions from their stream reaches, and photograph each site. These observations compliment the quantitative physical and chemical data collected at each established monitoring site.
The objectives of the AWC's Stream Team program are to inventory baseline water quality in the creeks of Anchorage, detect and report significant changes, track water quality trends, and get citizens involved with their creeks.
To promote these objectives the AWC has selected water quality parameters that will enhance the understanding of overall environmental health and testing methods that have proven successful in citizen-based programs throughout the United States.