Directional Technologis, Inc. installed a Horizontal AS/SVE Well System at a site originally planned to have a 36-vertical well system installed.  

The original remedial design consisted of 36 vertical wells: 18 Air Sparge (AS) with 5 feet of screen per well for a total of 90 feet of screen and 18 Soil Vapor Extraction (SVE) with 10 feet of screen per well for a total of 180 feet of screen covering an impacted area roughly the size of a football field. The 36 vertical wells were to be connected to the surface treatment system via an extensive subsurface piping system. The piping system installation would require the excavation of hundreds of feet of trenching through the new parking lot and then repaving the entire parking lot. The parking lot would be unavailable for at least six weeks during remedial construction of the vertical system, greatly disrupting college operations at an institution catering to commuting students.

DTI engineered and implemented an alternative Horizontal AS/SVE Well System design consisting of just three horizontal remediation wells (HRWs): two air sparge wells each 450 feet long with 250 feet of screen for a total of 500 feet of well screen and one SVE 450 feet long with 250 feet of well screen. DTI installed the HRWs in two-weeks in December 2013. The parking lot remained operational during HRW installation and there was minimal impact from drilling operations-just asphalt patching of three small horizontal well entry points.

DTI expects the Horizontal AS/SVE Well system to provide outstanding results: think about it: 3 horizontal remediation wells with 750 feet of continuous well screen vs. the vertical well system of 270 feet of interrupted well screen. You would need 75 vertical wells each with 10 feet of screen to match the three HRWs, relying on overlapping radius-of-influence, hoping there are no dead spots. Remember: it’s all about the screen contact with impacted media and the physics of delivery.