right to speedy trial under WA state criminal procedure

Criminal defendant's right to a speedy trial is guaranteed by both our federal and state constitutions. The right to a speedy trial begins on the commencement date of the action. The commencement date occurs at arraignment. From your question, you have not been arraigned. Thus "speedy trial" is not applicable.
There is a question of whether the "statute of limitations" has run. Presuming you have been charged with a gross misdemeanor (for the paraphernalia charge), the prosecutor can charge you within 2 years. In your case, it has been a year. Thus the statute of limitations have not run.

I agree the correct question here is not speedy trial, but instead the statute of limitations. I read this is likely being a one year statute of limitations, however. RCW 9A.04.080 limits simple misdemeanor actions to one year after the offense date. Possession of Drug Paraphernalia is a simple misdemeanor under RCW 69.50.412 - so you may have a statute of limitations issue. As an ex-prosecutor, however, I find it unlikely that they have blown the statute of limitations. You can ask your attorney if there was any justification for their delay in filing though. There is a line of cases where you can argue for a dismissal if an unjustified delay in filing caused you to lose evidence or witnesses. As a juvenile, you can also inquire about diversion.