RICHLAND - A groundwater sample shows the presence of tritium at 400 times the federal drinking-water standard in a monitoring well 3.6 miles from the Columbia River at the Hanford nuclear reservation.
An internal Hanford memo, obtained by the Tri-City Herald, says it could take the underground plume from three to 30 years to reach the river. Monday, the U.S. Department of Energy's Pacific Northwest National Laboratory and the state departments of Ecology and Health will begin additional tests.
"We're hopping on this," said Mike Thompson, the Department of Ecology's official in charge of groundwater monitoring.
He hopes to know better in a couple of weeks the concentration of the tritium and how serious a threat it poses to the river.
A tritium concentration of 20,000 picocuries of radiation in one liter of water is the federal drinking-water limit. The reading at the monitoring well was 8 million picocuries.
The well monitors Hanford's 8.6-acre "618-11" burial site, which is adjacent to the northwest corner of the Energy Northwest complex. Radioactive wastes from nuclear fuel tests and other experiments were buried at the 618-11 site from 1962 to 1967.
Although Hanford did not produce tritium for defense purposes, it did research on tritium production. Some tritium-producing targets that were bombarded with radiation in Hanford reactors are buried at the site and could be leaching out, Thompson said.