Western Washington 425-869-2372
Eastern Washington 509-735-9283
Drilling Professionals You Can Count On

Geotechnical Drilling Services

Ensure Your Drilling Jobs Run Smoothly

When you are managing a large construction project it is important that your geotechnical drilling team gets the job done on schedule. Breakdowns, the wrong equipment, or inexperienced drillers can delay your project and lead to unnecessary expenses. The Gregory Drilling team has a reputation for delivering as promised, even in challenging circumstances. Based on our competitive bidding and reputation for excellent performance we were selected for the geotechnical drilling, soil investigating, and installation of monitoring wells for numerous high profile projects.

When it comes to your geotechnical drilling jobs select a team that will help your project run smoothly. Contact the Gregory Drilling team today and put your project in capable hands.

"We depend on accurate, timely information in order to negotiate what are often complex environmental issues. Gregory Drilling enables us to collect the data we need in a timely manner. Their drilling teams are professional, adhere to each job’s unique site requirements, and get the job done right regardless of the challenges. We are consistently pleased with their results and how easy they are to work with. I highly recommend Gregory Drilling."

Sean W. Donnan, P.G., Principal
Environmental Service Line Director, Western Operating Group
Mountlake Terrace, Washington

Put Reliable Equipment and Experience to Work On Your Jobs

Your geotechnical drilling needs demand the best equipment and team. With Gregory Drilling, you have reliable equipment, capabilities, and experienced drillers working for you.

Experience Your Geotechnical Drilling Projects Will Benefit From

  Central Link Sound Transit: drilled and installed over 100 multi-point extensometers and inclinometers over 300’ deep. Work included truck-based drilling, track-based drilling, night drilling, and weekend drilling.
  Alaskan Way Viaduct SR 99: drilled and installed over 180 multi-point extensometers and inclinometers over 300’ deep. Work included truck-based drilling, track-based drilling, night drilling, and weekend drilling.
  I-405 Lane Additions: drilled over 70 borings for sub-surface investigations. Work included truck-based drilling, track-based drilling, night drilling, and weekend drilling.
  Bellingham Port Investigation: work included over 30 borings on land, and over water drilling in the port and settlement lagoons. Required the onsite construction of barges and cranes to place equipment in lagoons. Work included fully trained HAZMAT crews, decon of equipment, and full containment of IDW.
  Everett I-5 HOV Expansion: eight-month job included drilling and installing monitoring wells; soil investigating; and night, road, truck and track work.
  Transalta Coal Mine: used Foremost DR-12 dual rotary rig to drill 12 monitoring wells/sites 600 - 700 feet deep.
  Brightwater Wastewater Treatment Facility: during this seven-month job completed 500+ cores, including coring overburden and PQ coring using several rigs according to the depth of location.
  Bremerton Naval Base: new pier at the naval base involved over-the-water drilling of 15 holes of 175 feet each using casing advancer drilling. Crews worked 24 hours a day and finished two weeks ahead of schedule!

Equipment and Capabilities Your Drilling Job Will Benefit From


  Limited access hollow stem auger rig: rubber track-mounted, can fit through a 38” wide doorway, has a working height of 12' 9"
  CME 85, truck mounted drilling rig
  CME 75, truck mounted drilling rig
  CME 55 LCX low clearance, rubber track-mounted hollow stem auger rig
  Foremost DR-12 truck mounted dual rotary drilling rig
  Geo-Loop grouter (2)
  Portadrill 524
  Several support vehicles for removing cuttings, hauling water, and hauling supplies to and from drill sites


  Installation of a wide variety of geotechnical instrumentation including piezometers, inclinometers, multi-point array extensometers, vibrating wire piezometers, strain meters, and more
  Sampling with SPT, Shelby tube, or Dames and Moore
  Array of mud shakers and systems from small to large for all project sites
  Mud rotary, air rotary, casing advancer (HQ and HWT)
  Core drilling with HQ and PQ
  Hollow stem auger from 3 ¼” to 12 ¼” ID
  Grout mixing plants
  Construction site dewatering, including installation of vacuum wellpoint dewatering systems
  Cathodic protection installations

Contact us today to discuss your geotechnical project with an experienced drilling professional.

  • New, limited access rubber track drilling rig conducting soil sampling in tight quarters in dense brush.
  • Drilling beneath high rises on a busy city street.
  • Drilling to take soil samples for testing.
  • Loading a drill rig onto a barge for over-the-water drilling.
  • Drilling at a high-security facility.
  • Tight quarters? No worries, no mess, it's done.