Contra Costa County, CA isn't checked yet
We haven't checked police, fire and EMS here yet, so we can't tell you which scanner works.
Cities in this county
Concord · Pittsburg · Antioch · San Ramon · Walnut Creek · Brentwood · Danville · Pleasant Hill · Martinez · Moraga · Rodeo
Until then, four questions will help you choose:
Don't buy the wrong scanner