Wash. Rev. Code § 70.44.054
If the voters of the district approve the ballot proposition authorizing the increase in the number of commissioners to either five or seven members, the additional commissioners shall be elected at large from the entire district; provided that, the board of commissioners of the district may by resolution redistrict the public hospital district into five commissioner districts if the district has five commissioners or seven commissioner districts if the district has seven commissioners. The board of commissioners shall draw the boundaries of each commissioner district to include as nearly as possible equal portions of the total population of the public hospital district.
If the board of commissioners increases the number of commissioner districts as provided in this section, one commissioner shall be elected from each commissioner district, and no commissioner may be elected from a commissioner district in which another commissioner resides.
RCW 70.44.054
Effective date-1997 c 99: See note following RCW 70.44.040.