BARRIER AIR SPARGING
Why Air Sparging?
Quick Refresher: air sparging (AS) is a proven groundwater remediation technique that removes volatile organic compounds (VOCs) from groundwater by injecting air into water-saturated formations. There are two common approaches to AS. The first involves injecting air through wells into the impacted area to remediate the plume. The second creates a transport barrier by sparging downstream from the impacted zone, VOCs are removed as the groundwater passes through the sparge barrier and aeration enhances natural attenuation.
How are Barrier Air Sparge Systems Usually Installed?
There are three principal methods: vertical wells, horizontal wells and horizontal trenches.
How Do Vertical Wells and Horizontal Trenches Fall Short? One must ensure there is appropriate overlap to account for radius of influence (ROI) limits with a vertical well network to avoid breakthrough. Vertical well networks require interconnecting piping which can be costly to install and cause expensive business interruptions in commercial areas. There are practical limits to the number of vertical wells that can be networked due to piping friction losses and blower sizing requirements. Horizontal trenches involve depth limitations related to readily available excavation equipment and the potential for expensive business interruptions.
Horizontal AS wells typically have 20-40′ perpendicular ROI on each side of the well screen.
1,000 foot AS Barrier well
installed at a depth of 23′
to protect Lake Michigan.
HRW directionally drilled by
Directional Technologies, Inc.
How Can Horizontal Wells Enhance The Barrier Sparging Process?
Horizontal wells typically have a robust radius of influence if properly designed. Directional Technologies uses a proprietary screen design methodology to ensure uniform air flow across the screen length. Horizontal wells can be designed to effectively protect extensive areas. For example, Directional Technologies recently installed a 1,000-foot long horizontal well to serve as an AS barrier at a site adjacent to Lake Michigan in Waukegan, IL. Horizontal wells do not involve complicated interconnecting piping networks – connect your surface equipment at one location. In addition, horizontal wells can be “stacked”, if required, to provide a deeper barrier. In other words, two horizontal wells could be installed one on top of the other (appropriately spaced to ensure overlapping ROI) from essentially one drilling location. Finally, horizontal wells can be configured to avoid expensive business disruptions in commercial locations typically associated with vertical technologies.
Directional Technologies Installs Horizontal Wells!
Directional Technologies has been successfully installing horizontal wells since 1984! The companies’ experience in the oil field, environmental remediation industry and utility industry allows us to complete projects that were previously considered unfeasible. Give us a call to discuss your next AS system project.
For additional information
contact Kathy Sequino
203-294-9200