Air Sparge and SVE
Air Sparge and Soil Vapor Extraction Wells under Air Force Structures
A 720-acre Air Force manufacturing/maintenance installation with an operational history dating to WWII experienced numerous TCE releases cumulatively exceeding 1,000 gallons from 1974 to 1996. TCE source area concentrations exceeded 250 ppm; the TCE plume extended laterally hundreds of feet beneath multiple buildings. Project goals were to volatilize TCE in groundwater and collect TCE vapors beneath structures via SVE, reduce mass flux in saprolite by 50% and achieve 5 ppb MCL in 30 years. Directional Technologies installed two horizontal air sparge wells and two horizontal SVE wells with a combined length of over 2,500 feet and combined screen length over 2,100 feet at depths ranging from 20 feet to 86 feet. Testing revealed that TCE concentrations in the source area wells were reduced by 40% in approximately 1 year, and an elliptical zone of influence was developed up to 100 feet from the horizontal wells in addition to achieving air distribution along the entire screen length.
For more information on this project, please follow this link to the Power Point Presentation at the Battelle Conference in May of 2010 – Proceedings of the Seventh International Conference on Remediation of Chlorinated and Recalcitrant Compounds: Installation and Operation of An Air Sparge and Soil Vapor Extraction System Using Horizontal Directionally Drilled Wells. R.K. McCord, C.L. Sprinkle, S. Schultz, T.L. Clendenin presented by Kylie McCord (CH2M Hill/USA)
Horizontal Wells under a manufacturing and research facility
The company assembled a design and pilot test team for a horizontal remediation system under an active manufacturing and research facility. The original horizontal well design proposed by the client was amended by the design team and the suggested design changes reduce the installation costs by decreasing the number of horizontal wells. The revised well placement achieved greater remediation efficiency. The design team coordinated and implemented reverse engineering for existing equipment to further enhance maximum well production
Project Results: After the wells were operated successfully for a total of 11 months, the system was turned off. The wells were scheduled to be abandoned when the site experienced another release. The system was then restarted and the additional release was remediated. Engineering Design: Pilot testing and subsurface characterization provided data to design two horizontal air sparge wells and one horizontal vapor extraction well. The system was designed to sparge and extract 250 cubic feet per minute. Sparged air is captured by the extraction well and routed to a catalytic oxidizer for treatment.Remedial Action: The system was installed as designed on time and within budget. The system is removing several hundred pounds of contamination per week.
Blind Horizontal Wells
Directional Technologies, Inc. assisted environmental consultants with developing a remediation plan for the site of a new medical facility. The plan included a remediation system capable of meeting the cleanup objectives. Three air sparge wells and three SVE wells at were installed in a short time frame. The site conditions were challenging, the required steep 45 degree entry angles in order to accommodate site restrictions. The wells had to be placed in such a way as not to interfere with the construction of the building while allowing the hook-up to remediation equipment. New construction activities continued while horizontal wells were being installed and Directional Technologies, Inc. ensured that other subcontractors and the prime contractor on the job site were not affected or delayed by the directional drilling activities.
Project Results: The system ran for one year to non-detectable levels
Blind Air Sparge and SVE Horizontal Wells
Directional Technologies, Inc. assisted environmental consultants with developing a remediation plan for the site of a new medical facility. The plan included a remediation system capable of meeting the cleanup objectives. Three air sparge wells and three SVE wells at were installed in a short time frame. The site conditions were challenging, the required steep 45 degree entry angles in order to accommodate site restrictions. The wells had to be placed in such a way as not to interfere with the construction of the building while allowing the hook-up to remediation equipment. New construction activities continued while horizontal wells were being installed and Directional Technologies, Inc. ensured that other subcontractors and the prime contractor on the job site were not affected or delayed by the directional drilling activities.
Project Results: The system ran for one year to non-detectable levels
Long Air Sparge Horizontal Blind Wells combined with Long Soil Vapor Extraction Horizontal Blind Wells
Security-related restrictions to site access at a Department of Defense site in GA required blind installation of 1,000 foot long air sparge and soil vapor extraction wells. Experience in drilling under a wide range of subsurface conditions was brought to bear as the wells passed through exotic manufacturing and construction debris plus alternating zones of weathered and unweathered bedrock at depths of up to 90 feet. Directional Technologies, Inc. received a Health & Safety award from the client for the safe and efficient execution of the installation under difficult conditions.
A concrete pad was cut and then the drill bit was surface launched to drill to a depth of 30′ under the buildings for a 1,000′ SVE well. The same pit was used also to install a 750′ Air Sparge well at a depth of 70′.
