In recent years, the In Situ Redox Manipulation (ISRM) Barrier, in the 100-D Area at the Department Of Energy’s Hanford Reservation, has been showing signs of losing its reductive capacity -- several of the 66 wells that make up this reactive barrier have lost their ability to chemically reduce chromium and thus remove it as a threat to the Columbia River’s ecosystem.

Needed was the ability to spatially elucidate the distribution of chromium in the aquifer in order to pinpoint the areas of breakdown in the reactive barrier.

ARA took on the major tasks in this project, including:

• gathering of surface self-potential geophysical data

• complex resistivity measurement

• enhance vertical resolution of data