“…HRW well screens can be hundreds of meters long and multiple VRWs with overlapping zones of influence can be needed to accomplish what a single HRW can obtain with a single zone of influence (EPA, 2017). As an example, in a pilot study of Lundegard et al (2001), was shown that 30 vertical air sparging wells achieved the same results of one horizontal well with 90 m of well screen. Furthermore, analytical studies have estimated that a single horizontal well can achieve remediation targets in one quarter of the time taken by vertical wells (DE, 1998, Sequino, 2014.…”