Avista’s rates for Washington customers will go up on Dec. 1.
• Electricity hike: Adds about $5.62 per month for a typical residential customer, for a bill of $78.83.
• Natural gas hike: Adds about $2.20 per month, for a bill of $74.28
• Basic monthly service charge: Remains unchanged at $6 per month for residential customers. Avista had asked for an increase to $10 per month.