(1) Any funds of the commission may be invested in savings or time deposits in banks, trust companies, and mutual savings banks that are doing business in the United States, up to the amount of insurance afforded those accounts by the federal deposit insurance corporation.

(2) This section applies to all funds which may be lawfully so invested, which in the judgment of the commission are not required for immediate expenditure. The authority granted by this section is not exclusive and is cumulative and in addition to other authority provided by law for the investment of the funds including, but not limited to, authority granted under chapters 39.58, 39.59, and 43.84 RCW.