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Monthly Water Quality Sites and Data
At these sites, volunteers measure temperature, dissolved oxygen, conductivity, pH, and turbidity:
Temperature
High water temperatures present one of the biggest challenges to healthy aquatic ecosystems in the Willamette Basin. The entire mainstem Willamette and many tributaries suffer from impaired water quality due to high temperatures. Many of the aquatic organisms important to us are dependent on cold water – particularly salmon, trout, and many types of aquatic insects. Human disturbance has a great impact on temperature through direct thermal pollution and loss of streamside vegetation. A temperature shift of more then 1-2 degrees C can cause thermal stress and shock in native species, and can make an ecosystem more susceptible to disease and invasive species.
Dissolved Oxygen
Dissolved oxygen (abbreviated DO) is simply the amount of oxygen gas that is present in the river, and it’s one of the most valuable parameters to measure when it comes to overall water quality. Fish and aquatic insects need water to breathe – and some require more than others. For example, our native cold-water salmon species need more DO than non-native bass and carp, pollution-sensitive stoneflies need more than mosquito larvae, and incubating salmon eggs need more than adult salmon.
Conductivity
Conductivity measures how well water conducts an electric current – and more importantly, it indicates the strength of dissolved ions (particles with a positive or negative charge) in the sample. The “typical” amount of dissolved ions at each site varies according to natural conditions (such as surrounding geology and precipitation), but unusually high conductivity results may indicate inputs of fertilizer, pesticides, sewage, or other pollutants that contain charged particles.
pH
pH is a measure of the hydrogen ion concentration, or the acidity, of water. pH is measured on a scale of 0-14, with 7 being the pH of "pure" (neither acidic nor basic) water. Natural variations in pH are caused primarily by plant photosynthesis and respiration, while pollution can affect pH both directly and indirectly. pH is important to aquatic ecosystems because it determines the solubility of nutrients and chemicals in the water. Solubility affects how easily organisms can take up needed nutrients and absorb harmful chemicals. As with any water quality parameter, there is a happy medium for pH. The state DEQ (Department of Environmental Quality) standard values for pH in the Willamette River are between 6.5 and 8.5. Our data very rarely shows values outside this standard.
Turbidity
We use turbidity to estimate the amount of sediment, or Total Suspended Solids (TSS) being transported in the water column. The higher the TSS in a sample, the murkier it will appear, and the greater the turbidity. TSS can be clay, silt, sand, and small organic material. Movement of sediment downstream is an important beneficial processes in the life of a river. It occurs naturally, particularly during flood events, and helps create habitat and distribute nutrients. Unnatural sediment movement, including an excess of fine sediment inputs, can be detrimental to fish eggs, macroinvertebrate habitat, and visibility for resident and migrating fish. TSS naturally increase after heavy rainfall and during high flow. Unnatural TSS increases can be a result of construction and agricultural activity, municipal and industrial wastewater discharge, runoff from roads and other impervious surfaces, vegetation removal, dredging, channelization, and recreation. To some degree all of the above TSS sources are present on the Willamette River.
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