1. Hospital districts are authorized by the Washington Constitution, Art. VII §2(a) and RCW 84.52.052 to have a one year special levy in excess of the regular levy. It can be used for any purpose and can be in any amount. The hospital district can take the issue to the voters at a general or special election. The ballot proposition must state the amount the hospital district proposes to collect and it must also estimate the levy rate required to achieve the proposed amount.

2. The voters must approve a special levy. In order for the levy to pass supermajority and validation requirements must be met. For special levies, supermajority and validation requirements can be met in two ways.
a. When the number of voters voting does not exceed forty percent of the number of voters voting in the last preceding general election... THEN the number of “YES” votes must constitute 60% of a number equal to 40% of the number of voters voting at the last preceding general election.
b. When the number of voters voting exceeds forty percent of the number of voters voting in the last preceding general election… THEN the number of YES votes must be a majority of at least 60% of the voters voting on the proposition.

So, notice that 40% is the threshold that determines which method to use.