Covering the ground with a durable plastic or asphalt barrier is one option possible to stop the spread of radioactive waste leaking from Hanford’s underground tanks, said Jane Hedges, manager of the Department of Ecology’s nuclear waste program. She spoke at a work session hearing of the Washington State Senate Energy, Environment and Telecommunications Committee this morning. Two of the barriers were built earlier at Hanford to prevent rain and snowmelt from driving contamination deeper into the soil. That contamination was left from earlier tanks spills or leaks. The barriers have markedly decreased the amount of water infiltrating the ground...