"RICHLAND, Wash.- Fluor Hanford is just finishing a second round of chemical injections to prevent contamination of the Columbia River. It is called a chemical barrier. They're injecting the apetite in an aquifer along 300 feet of Columbia River shoreline in hopes that it will stop radioactive strontium from seeping into the river. Over the past two days, about 80 gallons a minute of Calcium-Phosphate has been injected into the shoreline aquifer where contaminated water from the N-Reactor used to be dumped up until 1992."
KNDO/KNDU has interesting video at the link given above. This station has been doing a commendable job on covering this important story.