PSAPCA's ambient air monitoring network is a composite of meteorological and pollutant-specific monitoring equipment. This equipment is both manual and automated, meaning that data measurements are collected by our field staff or sent directly via a telemetry network. Sites are operated by both PSAPCA and the Washington State Department of Ecology. Air quality monitoring is conducted for PM10, PM2.5 , lead, carbon monoxide, ozone, sulfur dioxide, oxides of nitrogen and visibility. Weather conditions are monitored for temperature, wind speed and wind direction.

Monitoring equipment is sited on the basis of numerous parameters. EPA siting criteria are followed in order to obtain a consistent and representative picture of air quality. Some sites are selected to focus on the emissions of a single air pollution source or group of sources. Some sites are intended to be representative of an industrial area while others may be oriented toward residential air pollution.
    All 34 monitoring sites in our four-county area, their locations, and type of monitoring conducted at each site are shown here. The map also shows how these monitoring stations are spread geographically throughout our area.