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GSI Mid-Atlantic


Tagged: Direct Push

GSI is looking for the right person

Environmental Field Technician, Driller Helper, Driller

GSI Mid-Atlantic, Inc. provides specialized environmental drilling and direct-push sampling services to environmental consultants and engineers.

Looking for entry to mid-level person to assist with operation of direct push drilling equipment on environmental investigation and remediation sites.  Position will work out of our Glen Burnie and White Marsh yards.  Must be reliable, have good work ethic and be customer service oriented.

Job Descriptions

  • Assist with operation of direct push drilling equipment
  • Operate and assist with grouting equipment
  • Drive company vehicles including pickups and trailers
  • Assist with maintenance on drilling and other equipment


  • Highs school diploma or equivalent
  • Ability to perform physical labor and lift heavy objects
  • Work outdoors on regular basis
  • Drive company vehicles
  • Good Driving record
  • Pass DOT physical and drug test
  • 40 hr OSHA training a plus (but not required)

Some experience in the environmental industry a plus, but if you are a willing to work and mechanically inclined, we will train the right person. Pay dependent on experience.

Send Resume or job history to

GSI Adds Low Clearance Limited Access Capabilities

light track 1 light track 2

GSI Mid-Atlantic, Inc. has added a Geoprobe 54lt to it’s fleet. The 54lt is a capable limited access and low clearance machine. The machine will fit through a standard 36″ doorway allowing access to inside most buildings, as well as through small fence openings and other narrow previously inaccessible areas.  Our 54lt is equipped with a low clearance probe cylinder that allows the machine to operate with under 8′ of overhead clearance, perfect for low parking garages and inside of buildings.

Ali Berenbrok-Niblett passes Maryland Well Drillers Exam

Congratulations to Alexander “Ali” Berenbrok-Niblett for passing the Maryland Well Drillers Exam.

GSI Mid-Atlantic, Inc. collects sediment samples from the bottom of Baltimore’s Inner Harbor

GSI utilizes Geoprobe equipment to collect sediment samples from the bottom of Baltimore’s Inner Harbor. The Geoprobe tooling was lowered through holes cored in a concrete industrial pier that extended out into Baltimore’s Inner Harbor. Once the bottom was encountered the tooling was advanced into the bottom sediments. A modified core catcher was utilized in the sample liners to allow the soft sediments to enter the sample barrel, but still prevent sample loss upon retrieval.


sampling on pier 2 Sampling on pier

GSI Takes Delivery of Geoprobe 6620DT

GSI continues to keep it’s Geoprobe fleet up to date. Taking delivery of Geoprobe 6620DT. After a complete refurbish, the Geoprobe 6620 returns to GSI better than new. Complete restoration with the addition of all the modern upgrades makes this workhorse better than when it was brand new. The 6620dt will compliment our fleet of Geoprobe 7822 machines, as well as our truck mounted machines.

IMG geoprobe 6620 delivery 050615

Don Marchese adds Delaware License to his Resume

Congratulation to Don Marchese, GSI, for obtaining his Delaware well driller license. The addition will provide essential support for GSI’s increasing workload in Delaware.

Drilling Deep In Delaware (Deep water sampling and prepack well installation)

GSI recently completed a scope of work in Delaware that included water sampling to 100′ below ground surface (BGS) and installation of prepack monitoring wells to 75′ BGS. The scope was follow-up sampling to fill data gaps from previous investigations GSI has assisted with at the same site.

The initial task consisted of vertical profiling at three locations by collecting a grab water sample from every 10′ to a depth of 100 feet. Static water level was between 6 and 8 feet. GSI utilized the Geoprobe Screen Point sampler(SP16). GSI used one of their Geoprobe 7822 machines to drive the closed SP16 sampler to the 100′ depth and then exposed the stainless sample screen. A peristaltic pump was used to purge the interval until the groundwater ran clear. Once the sample was collected the SP16 was pulled up 10′ to the next interval and again purged to remove water from the previous interval and produce clear formation water for a sample. This process was repeated until a sample from the shallow 6 to 10′ interval was collected. The three 100′ borings were completed on schedule in 1 1/2 days.

The next task consisted of installing nine (9) 1 1/2-inch prepack wells ranging from 45′ to 75′, with five of the nine specified for the 70 to 75′ range. Continuous soil cores were collected from each of the five deep well locations for logging the lithology. The more shallow wells were nested with a deep well and installed by driving closed casing to the target depth (45′-55′). Each well was completed with 10-foot prepack well screen and a 2-foot bentonite sleeve. Wells were then sealed with cement-bentonite grout placed through the drill casing . By grouting through the casing, GSI could be sure the wells were continuously sealed throughout the entire borehole. Wells were finished with flush mount covers and pumped for development. All wells were completed on schedule in about 5 days.

The photo below shows grouting the prepack wells through the casing and collection of the displaced water.


GSI Uses Geoprobe DT45 for Monitoring Well Installation on DNREC Sites

GSI Mid-Atlantic, Inc. recently completed monitoring well installation on two DNREC sites using the Geoprobe 4.5″ dual tube system (DT45).

The first site was a former waste site along the Delaware Bay. The scope of work consisted of installing 6 shallow piezometers, 3 along each side of a remediation trench, and 2 deeper (20′) monitoring wells. All wells were specified to be 1.5″ diameter conventional PVC monitoring wells. The challenges of the site included extremely shallow water table (2 to 3′ BGS) and several feet of large gravel in some areas. GSI determined that the DT45 system would provide enough annular space with the 1.5″ casing to install the sand pack and bentonite seal through the annular space inside the DT45 casing. This would ensure a good sand pack and well seal despite the challenges of the shallow water and collapsing gravel. All 6 piezometers and the 2 monitoring wells were installed in 2 days.

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The second site, also a former waste site, was follow-up to a previous Geoprobe investigation. The scope of work called for installation of five 2-inch diameter standard monitoring wells. GSI again utilized the Geoprobe DT45 system. Use of an oversize cutting shoe created a nominal 6″ diameter bore-hole, which provides the 2″ annular space required for a standard built 2″ diameter monitoring well. Using the DT45 system allowed the wells to be installed using direct-push, rather than conventional hollow-stem auger. This created a significant savings on time and generation of investigation derived waste. All five wells were installed and developed in 2 days.

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GSI Mid-Atlantic, Inc. injects RegenOx PetroCleanze in Northern Virginia.

GSI Mid-Atlantic, Inc. was contracted to mix and inject Regenesis’s RegenOx PetroCleanze at a commercial warehouse LUST site in Northern Virginia.  Regenesis describes RegenOx PetroCleanze as, “a customized formulation of the widely used RegenOx in situ chemical oxidation technology whose primary function is to increase the desorption rates of hydrocarbons bound in saturated soil and make them available for more efficient and rapid treatment.”

Injections were performed in a series of three one day events spread approximately a month apart.  During each injection event approximately 100 gallons of chemical was mixed and injected through each of four Geoprobe borings, spaced around a central monitoring well.  The consultant followed each event with a vacuum fluid recovery event from the monitoring well to recover any product mobilized from the soil as a result of the PetroCleanze injections.

If deemed successful to remove contaminant mass, additional events or a larger scale chemox injection may follow.


GSI Mid-Atlantic, Inc. works on Landfill Sites in September

September found GSI Mid-Atlantic, Inc. completing work on two different landfill sites in Maryland.

On the first site, GSI was contracted to complete continuous soil borings at an inactive landfill site in Anne Arundel County.  Using the Geoprobe dual tube 22 system and one of our Geoprobe 7822 machines, GSI successfully completed 13 soil borings ranging in depths from 55’ below ground surface to 75’ below ground surface.  The purpose of the borings were for logging and identifying specific zones and geologic layers in the subsurface.  During boring advancement, GSI successfully collected groundwater samples from multiple water bearing zones as identified by the on-site geologist.  Below is a photo of soil cores from a 75’ boring.  All borings were pressure grouted upon completion.

landfill soil cores 2

GSI was also contracted to install landfill gas monitoring wells along the perimeter of 2 landfills in Howard County.  In a single day, GSI installed 3 landfill gas monitoring wells ranging from 20 to 35 feet below ground surface.  Wells were installed using the Geoprobe dual-tube 32 system.  This system creates a 3.5” borehole while continuously sampling the soil.  Half-inch PVC well-screen and riser were installed though the casing.  As seen below, the gravel pack was placed through the casing as the casing was removed.  Each landfill gas monitoring well was completed with steel stick-up protection.

landfill tremmie gravellandfill gas monitoring well


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