(Portland, OR)  --  Voters in Multnomah County may be asked this fall to decide on whether to add a tax to the purchase of sodas and other sugary drinks.  The tax would amount to one-and-a-half-cents per ounce on sugary drinks like soda, sweetened teas and energy drinks.  Seattle Mayor Ed Murray is proposing a two-cents-per-ounce tax on sodas and other sugar-sweetened drinks, a plan that would need approval by the Seattle City Council.  Both Murray and Multnomah County officials say a soda tax would reduce sugar consumption.