from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Of, relating to, or being water that is located in the zone of aeration in the earth's crust above the ground water level.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of or pertaining to water beneath the surface of the earth which is located above the level of the permanent groundwater.
from The Century Dictionary and Cyclopedia
- Shallow: specifically applied to those ground waters which seep into rocks and soil from the surface, as opposed to the construction waters which were built into the rocks at the time of their formation.
Such transition zones are areas of high microbial activity and diversity and occur between saturated and vadose parts in soils, at the boundary of aquatic sediments and the water column, or in tidal regions.
Planning work for the deep vadose zone has been given another four or five years to allow DOE to develop new technologies for cleaning up the soil and preventing the contamination from moving into the ground water.
The vadose zone includes contamination that can be too deep to just dig up at 250 or 300 feet below the surface of the ground.
Those include the huge processing canyons for removing plutonium from irradiated fuel, waste burial grounds, liquid waste disposal areas and the deep vadose zone.
"It became apparent to us we needed more time for the deep vadose zone," said Dennis Faulk,
In addition, DOE officials in Washington, D.C., are considering ways to find solutions, including establishing a research center at Hanford for deep vadose zone contamination.
The researchers studied how contaminants move through the vadose zone, which is the area between the soil surface and the groundwater zone.
Among other findings, the team concluded that tracer transport in soils and shallow groundwater could be strongly affected by gaps in the vadose zone's restrictive fine-material layers.
Radioactive water is draining out of this single-hulled container and a broken subsurface pipe into what geologists call the "vadose zone," the stratum of subsurface soil just above the water table.