Water Quality photo identifier

Water Quality Program

Data Collection

Water quality is important for the health of both our aquatic ecosystems and the people who live and recreate on our rivers, lakes, and coastlines. The most typical problems observed in the state include:

  • Bacteria levels in the waters are too high.
  • Oxygen levels in the waters are too low.
  • Unnaturally high stream temperatures that negatively affect the fish and insects that live in the streams.
  • Stormwater containing toxic and other pollutants.

Monitoring rivers and streams is crucial for understanding where pollution problems exist. Water quality data are collected throughout Washington State by many different organizations. Because many different people and groups collect data, it is important to follow standard operating procedures. This ensures that quality data are collected and follows the state water quality data act to ensure the data’s quality. All of the data that is collected by Ecology (and all other data used in the water quality assessment) is stored in Ecology’s Environmental Information Management database.

Ecology’s Environmental Assessment program conducts water quality studies across the state, including ambient monitoring to detect pollution trends over time and studies focused on TMDL development.













Last updated March 2013