After being arrested for driving under the influence (DUI) in Washington, the police officer will ask you to submit to a breath test to determine the level of alcohol in your system.
You have two options: submit to a breath test or refuse the test.
If you take the test and blow over 0.08 (the legal limit in Washington), the Department of Licensing (DOL) will suspend your driver's license.
If your refuse the breath test, DOL will also suspend your driver's license (for a longer period of time, actually). And, regardless, the police officer will very likely apply for a search warrant to draw blood, which can also detect alcohol concentration.
You have a right to an hearing before a DOL hearing examiner (who functions like a judge in administrative hearings). But your chances of winning are not good. In most cases, the hearing examiner rules for DOL and upholds your license suspension.
Fortunately, you have the right to appeal your license suspension to the superior court.