The North Coast Air Basin
North Coast Air Basin is comprised of three air districts, the North Coast Unified AQMD, the Mendocino
County AQMD, and the Northern Sonoma County APCD. The North Coast AQMD included Del Norte, Humboldt, and
Trinity Counties; the Mendocino County AQMD consists of Mendocino County; and the Northern Sonoma County APCD
comprises the northern portion of Sonoma County.
North Coast Unified AQMD is listed as "attainment" or unclassified" for all the federal and state ambient air
quality standards except for the state 24-hour particulate (PM10) standard in Humboldt County only. Primary sources
of particulate matter in the Eureka area are on-road and off-road vehicles (engine exhaust and dust from
paved and unpaved roads), open burning of vegetation (both residential and commercial), residential wood
stoves, and stationary industrial sources (factories).
view Area Designations for the rest of the North Coast Air Basin, and all other Basins in the state, please click
. You will be redirected to the California
Air Resources Board Area Designation Maps.