Voters could get primary ballots as soon as Wednesday after Benton and Franklin counties mailed them Tuesday.
They will have until Aug. 4 to mail or bring the ballots to a drop box.
In Benton County, the Kennewick, West Richland and Benton City city councils have primary races on the ballot, as well as the Richland school board and the Kennewick Public Hospital District.
Voters in parts of west Pasco and rural Franklin County get to vote in a special election to fill the unexpired seat of former state Rep. Susan Fagan, who resigned amid an ethics scandal.
Rep. Mary Dye, R-Pomeroy, who was appointed to fill the seat by area county commissioners, will take on former Franklin County Sheriff Richard Lathim, also a Republican, and Democrat Kenneth E. Caylor, a former Othello city councilman.
Three Pasco city council races also are on the primary ballot.
The top two finishers in each of the primaries will move on to the November general election.