Daily summary of air quality at specified locations in King County (Particulate Matter - PM2.5 LC). Using a nationwide network of monitoring sites, EPA has developed ambient air quality trends for particle pollution, also called Particulate Matter (PM). PM2.5 describes fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller. Under the Clean Air Act, EPA sets and reviews national air quality standards for PM. Air quality monitors measure concentrations of PM throughout the country. EPA, state, tribal and local agencies use that data to ensure that PM in the air is at levels that protect public health and the environment. Nationally, average PM2.5 concentrations have decreased over the years.

Daily summary of air quality at specified locations in King County (Ozone). Air quality monitors measure concentrations of ozone throughout the country. EPA, state, tribal and local agencies use that data to ensure that ozone is at levels that protect public health and the environment. Nationally, average ozone levels declined in the 1980's, leveled off in the 1990's, and showed a notable decline after 2002. The charts below show national and regional trends in ozone concentrations.

Daily summary of air quality at specified locations in King County (Particulate Matter - PM10). PM10 describes inhalable particles, with diameters that are generally 10 micrometers and smaller. Under the Clean Air Act, EPA sets and reviews national air quality standards for PM. Air quality monitors measure concentrations of PM throughout the country. EPA, state, tribal and local agencies use that data to ensure that PM in the air is at levels that protect public health and the environment. Nationally, average PM10 concentrations have decreased over the years.

Daily summary of air quality at specified locations in King County (Carbon Monoxide). Air quality monitors measure concentrations of CO throughout the country. EPA, state, tribal and local agencies use that data to ensure that CO remains at levels that protect public health and the environment. Nationally, average CO concentrations have decreased substantially over the years. The charts below show national and regional trends in CO concentrations.

We are committed to monitoring the water quality of the County's lakes to ensure their continued health, as well as the health of the public who utilize the lake's many resources. We invite you to learn more about our program by looking through the pages listed on the left. This site contains detailed graphs of water quality data, photographs of water sampling, and general information about the water quality of King County's lakes.

Welcome to the Lakes Data and Descriptions application! Use this application to search, view, and download water quality data resulting from volunteer monitoring efforts at more than 50 lakes in western King County. Choose a lake by location on the map below or by name on the list next to the map. For a synopsis of data and a discussion of long term trends among all small lakes of western King County, view the current regional assessment on the reports page.

Interactive map of current freshwater swimming beach sampling stations in King County, and downloadable data.