Vapor Extraction/Air Sparging
Via Horizontal Wells

Task Description

This task involves the injection or air via the deeper of a pair of hori-
zontal wells and the recovery of displaced vapor through the se-
cond, more shallow well (Figure 3.1). Utilizing this technique VOCs such as TCE, PCE, vinyl chloride, and Benzene, Toluene, and Xy-
lene (BTEX) and their daughter products can be removed from the vadose zone. The horizontal wells that form the basis for this techn-
ology provide significant advan-
tages over conventional air sparg-
ing and/or vacuum extraction with vertical wells or infiltration galleries.

The increased surface area treat-
ed by this method will allow more complete and more rapid removal of adsorbed VOCs and better re-
covery of the liberated vapor. Because of the larger surface area being treated the clogging of the formation, at or near the injection and recovery wells is also mini-
mized. The use of horizontal wells also allows remediation of rela-
tively inaccessible areas such as beneath buildings or ponds
(Photo 3.1).

Technology Needs

Air stripping via horizontal wells combines the functions of two baseline technologies: soil vapor extraction (SVE), targeting the va-
dose zone, and pump-and-treat,