completed, the drill string is with-
drawn leaving the washover pipe to provide a conduit to facilitate screen and casing installation. When the well is installed the washover pipe is removed. This technology allows drilling of long holes in a range of geologic con-
ditions. In addition, borehole cave-in is much less of a problem with the use of the washover pipe.

Technology Needs

The major organic contaminant of waste sites at DOE facilities is chlo-
rinated solvents. For instance, at the Savannah River Site, approxi-
mately 70% of the waste units are contaminated by VOCs.

In order to remediate these areas of VOC contamination, new dril-

ling methods need to be develop-
ed that are more efficient, faster, and more cost-effective than exist-
ing technologies.

The use of directional drilling technologies for environmental applications has significant advan-
tages over remediation systems designed with conventional ver-
tical wells. Specifically, the use of directionally drilled wells allows access to contaminated zones that are not otherwise accessible, and the amount of time to remediate sites can be reduced to increase in extraction efficiencies when com-
pared to vertical extraction wells. Additionally, directionally drilled wells can be used for fluid deliv-
ery, thereby expanding treatment options.