Directional Technologies has completed 100's of horizontal remediation well installations. The following are brief abstracts of representative work performed by DTI. Full project summaries and references are available on request.
Soil Vapor Extractions
Horizontal Remediation Well Pilot Test at JFK Airport, NY
This project was the stepping-stone that literally created the horizontal remediation industry. An environmental consultant needed an experienced directional driller with a creative and educated approach to conduit installation. This pilot test would be the basis to install over 40,000' of horizontal remediation wells. It was crucial that the directional driller chosen be able to contribute his experience and knowledge to the project to insure the pilot test achieved the correct pitch, depth, and radius in challenging site conditions. Directional Technologies, Inc. rose to the challenge and installed three 200 feet horizontal wells at depths of 6, 10, and 14 feet. The wells were installed at a busy airport terminal with major instrumental interference from reinforced concrete and from other equipment in the area. The pilot tests were a success and the full-scale soil vapor extraction and air sparge system is still used today. This project is frequently used as the primary horizontal remediation case study.
Horizontal Liquid Ring Extraction Well under a vehicle maintenance facility
A horizontal liquid ring extraction well was installed under a busy vehicle maintenance facility. The environmental consultant worked closely with Directional Technologies, Inc. to design unique well placement on a property that demanded a discrete remediation approach. DTI also provided the design to reduce the amount of silt that was being pulled into the horizontal well and subsequent procedures to maintain the maximum efficiency of this horizontal well.
Horizontal Wells under an active manufacturing facility
The experienced directional drilling crew drilled and installed 3 SVE wells, two blind wells and one continuous well. During this project, Directional Technologies, Inc. worked with the drilling fluid additives manufacturer to field test prototype directional drilling mud specifically designed for horizontal remediation wells. Blind wells, horizontal wells without an exit point, are typically more difficult to install and these wells proved to be extremely challenging due to the site and soil conditions. The crews were in constant communication with the busy manufacturing facility on site to prevent any disruption to the factory while directional drilling activities proceeded. The crew also overcame challenges presented by manufacturing equipment inside the facility that interfered with the signal needed for the directional tracking instrumentation to function. Despite these challenges, the installation of the horizontal wells was successful.
Horizontal Wells at Aberdeen Proving Grounds
Directional Technologies, Inc. drilled, installed, and developed one air sparge well 15 feet in depth next to a former gas station site. The crew installed the horizontal well in three days despite very limited and confined space at the site. The entire length of the well was swept for unexploded ordinances prior to well installation. Directional Technologies, Inc. conferred with environmental consultants on how to use existing wells to reach a new hot spot.
Project Results: The site achieved closure but was reopened after discovering an unknown "hot spot". The system operated for approximately two years.
Vapor Intrusion – Coming Soon!
Bioamendment Injection with Horizontal Wells
A rail yard with a long history of operation in the metropolitan New York area was ordered by the USEPA to remove petroleum hydrocarbons from soils beneath multiple rail lines. Directional Technologies, Inc. installed 14 wells, crossing as many as 4 railroad tracks while the railroad continued its normal, busy operations. Hundreds of hours of down-time by the railroad and tens of thousands of yards of hazardous waste disposal were avoided by the successful installation of the horizontal well injection system.
Bio-injection via directional drilling
While on site in an upscale neighborhood in Westchester County NY, Directional Technologies, Inc. representatives carefully explained to residents the benefits of horizontal wells and directionally drilled beneath two residential structures for bioremediation. The well bores were drilled to specific target locations and the drill rig was then used as a delivery system for the bioamendment. The residents were extremely pleased with the directional drilling process and lack of disturbance to their well manicured properties.
Project Results: The injections worked as planned and the site was closed.
Horizontal Groundwater Sampling Wells
NJ DEC mandated soil sampling under an existing pharmaceutical company's building. During this high profile project, the company drilled 120 feet under the building through a inch footer into what they thought was going to be fill. After steering through rock to the target point a inch PVC blind monitoring well was installed at a depth of 20 feet under the building. The well is still operating to monitor for contaminants.
Air Sparge and SVE
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, G. Losonsky and T.L. Clendenin presented by Kylie McCord (CH2M Hill/USA)
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.
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 Horizontal Blind Wells
The drill rig was set up outside a parking lot area due to security related site restrictions. The crew successfully installed all wells from a discreet distance.
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.
This could be considered a typical drill rig set up with a mud recycler.
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'.
Dual Phase Extraction
Horizontal Dual Phase Extraction Wells Under A Truck Stop
The owner of a truck stop had zero tolerance for any business interruption. The site required a technology that would allow normal business activities to continue. Directional Technologies' crews coordinated with the on-site manager to install a horizontal well under the entrance to the truck stop that had 20 to 30 trucks an hour passing over the bore path. A walkover locator was used to keep the project cost-efficient without disrupting the business activities. This well had precise entry and exit points, and a 60º turn that was achieved.
Project Results: The system operated for 3 years and the site was closed.
Groundwater or total fluids extraction
Horizontal Wells at a Superfund Site
Directional Technologies, Inc. was contracted because of its reputation for quality work. The experienced crew drill and installed 8 inch HDPE under a building at a percent grade for a total well length of 800 feet. The company worked closely with the environmental consultant during well design to provide his client with the most efficient horizontal system possible for the site. The original well design was amended several times and the final design was implemented. The well currently produces as much as 40 gallons per minute, meeting and exceeding all client expectations. The well is presently used for hydraulic control.
Horizontal Groundwater Extraction Well Project and Prototype Horizontal Tracking Equipment
Directional Technologies, Inc. was involved with an innovative remediation project from design to installation. The in-house environmental engineer used the company's directional drilling experience to select the proper well materials and determine well placement for one of the first horizontal groundwater extraction wells drilled using standard directional drilling equipment. New prototype directional steering tools were field-tested on this project. Also, due to subsurface conditions, this project resulted in pioneering methods to overcome ground interference in the tracking system caused by metallic obstructions.
Chemical Oxidation with Horizontal Wells
A major urban high-rise development project in Annapolis MD required in-situ treatment of dry cleaner solvents. Ten horizontal wells were drilled under an active construction site for potassium permanganate injection. The system was installed in four weeks without disrupting ongoing construction of building and roads. The horizontal well system has successfully injected 1.3 million gallons of oxidant solution. Several injection events occurred while high-rise construction continued at the site.
Air Sparging or Bio Sparging
Horizontal Air Sparge Well at an Air National Guard BaseTwo 180 foot Air Sparge wells were installed a depth of 24 feet. This system was operated for 11 months. Directional Technologies, Inc. was called to abandon the wells but we convinced the consultants to lower the well vaults below the ground surface and leave them in place due to the fact that the site is still an active refueling area.
Horizontal Barrier Wells at a Tank FarmAn EPA mandate required the immediate halt to a migrating plume from a tank farm. The company drilled, installed and developed horizontal air sparge wells in a highly compressed sand and cobble formation. The driller had to overcome formation challenges to maintain elevation and remain on course. The company's experience with cobble and directional drilling fluids provided the client with horizontal air sparge wells that were installed in extremely difficult ground conditions.
Project Results: The wells ran for approximately 5 years in a bio-sparge mode. The system was used for biodegradation of gasoline in and around the tank farm and along the pipeline right of way. As the areas were cleaned the wells in those locations were shut down, with the last of the wells being in and around the tank farm.
Horizontal Barrier Wells beneath a Chemical Plant
The design engineer contacted us to assist in designing horizontal wells that would push directional drilling capabilities to the limit of its capabilities in order to keep the remediation wells within property lines. The design resulted in two horizontal wells with a 70º radius and quick exit. Interference from adjacent buildings during well installation resulted in having to manually calculate depth and direction from pitch readings. These wells were installed with the restrictive specifications between a water line and gas line 8' apart. This project drew on the crew's collective experience in directional drilling, difficult northeastern soil conditions and environmental requirements.
Horizontal Wells beneath a tank farm
A major oil company needed a horizontal well remediation system that would quickly and effectively clean up a property that was about to be sold. The team assembled at the site, designed the wells and immediately installed them. The project goal was to drill, install and develop as many horizontal wells as possible in a short time frame to effectively remediate the site in as little as possible time. The challenge was met. The team became so efficient that a 300' foot well was designed, drilled, installed and developed in a day. The property was sold as planned.
Project Results: Site was cleaned in 2 years and turned into a large retail mall
Horizontal Wells for the United State Postal Services Vehicle Maintenance Facility
Directional Technologies, Inc. drilled, installed and developed 2 air sparge wells at a depth of 22' beneath a vehicle maintenance facility. Regular operations at the facility were not disrupted during the installation. The crews' previous experience in installing horizontal remediation wells made the installation very smooth.
Project Results: This system endured some problems during start-up, due to the change in soil conditions. The system was designed around a homogeneous soil environment, but during the drilling operations large amounts of fill material were drilled through. This caused uneven air distribution along the well screen, so the screen was the redesigned and a new one was installed. The sparge wells were run in conjunction with a vertical SVE system. As the concentrations diminished from the SVE portion of the system it was turned off and the sparge wells were operated as to bio-sparge wells.