Lake Water Quality
Sample Results by Year
General Reports
Third Party Reports
Lake Washington Improvement Association previously used PLM, a third party agency, to conduct water sampling tests. Listed below are the results. You can also access previous newsletters to specific to each year to view additional information.
Definitions
PHOSPHORUS
Total phosphorus (micrograms/liter): A measure of nutrients in the water, lower is less nutrients for aquatic vegetation.
CHLORPHYLL
Chlorophyll-a (micrograms/liter): A measure of the amount of Algae in the water, lower is less algae.
TSI
TSI characterizes water’s ability to produce vegetation – higher means more vegetation.
- TSI of 0-30 is oligotrophic, where water is clear, phosphorus is low, and algae is limited.
- TSI of 40-50 is mesotropic where there is an increase in aquatic vegetation due to more phosphorus in the water.
- TSI of greater than 50 is eutrophic with high levels of aquatic vegetation and high levels of phosphorus to support the vegetation.
SEECHI