Cleanup begins today in an effort to prevent gasoline spilled from an overturned fuel tanker on Interstate 84 from reaching the Columbia River. The tanker overturned Sunday, causing 900 gallons of fuel to leak and prompting closure of a stretch of eastbound I-84 for hours. Officials say the gasoline has likely already reached area groundwater. State Department of Environmental Quality personnel are scheduled to begin measuring the reach of the spill today.