About Gregg Drilling

Widely recognized as a leader and innovator, we are fueled by our passion to provide quality service.

Gregg Drilling, LLC. (Gregg) offers a wide range of services for environmental, geotechnical and marine site investigation and remediation. Since our inception, Gregg has been widely recognized as a leader and innovator in drilling, sampling, and subsurface investigation, providing clients in industry and government with the highest quality services.

Over the past 37 years, Gregg Drilling (Gregg) has earned the position of a leader within our industry by building a team of highly experienced personnel and management who reflect our mission and embody our commitment to providing the highest quality services.

Gregg Drilling is proud to be 100% Native American-owned as part of Sealaska. We are working with others within Sealaska’s Woocheen business arm to bring exceptional people together to heal and protect our environment. Together with Pitcher Services, CS Marine and Sealaska Marine Services, Gregg is supporting the development of Offshore Wind and other green economy initiatives with a focus on ocean health.

Gregg is a Federally recognized 8a disadvantaged business enterprise (DBE) and is a registered DBE through the California Unified Certification Program (CUCP) which includes Caltrans, Metro, BART and other transportation agencies in the Golden state. In addition, Gregg is a Minority Business Enterprise (MBE) through California Public Utilities Commission (CPUC).


To provide our clients with high-quality, innovative services performed in a timely and cost effective manner.


We have collaborative, long-term partnerships with our clients

Many of our client relationships date back to the founding of our company. We’re proud of this fact. These long-term partnerships have been a collaborative effort built on trust and are a result of the high rate of client satisfaction with our overall performance. We work to earn our clients’ trust and satisfaction by consistently responding to their needs with sound technical advice and innovative solutions.

and more!


Delivering excellence through client-focused solutions


Delivering high quality services is a key focus of our business

Quality isn’t something we test for after the job is done. It’s a way of doing business, an integral part of our daily activities, something we instill in our personnel and something we build into our equipment and technologies.


Protecting our workforce, our clients and the general public from injuries and hazardous incidents

Because of this a “safety first” policy has been integrated into all areas of our operation and is put into practice by all Gregg Drilling personnel on a daily basis. The emphasis we place on safety has enabled us to successfully manage the risks inherent in our industry, control costs and provide a secure, sensible, and productive work environment for our employees and our clients.


Add significant value to the professional services we offer

We are committed to providing cost effective solutions that consistently meet or exceed project requirements. This commitment blended with the innovative thinking of our personnel and research backed equipment and technologies add significant value to the professional services we offer our clients.

Say Hello to the
Gregg Drilling Team



Mr. Boyd is the President for Gregg Drilling, LLC. He oversees day to day management of Gregg’s drilling and testing services.  Mr. Boyd also serves as the Division Manager for Gregg’s Northern California operations.

Mr. Boyd has broad experience related to the management of geotechnical and environmental site investigations. He has extensive experience related to cone penetration testing (CPT) methods, both through his academic work at the University of British Columbia and during his work at Gregg. Mr. Boyd has managed numerous nearshore marine and in-land marine projects during his career. He has also managed large offshore deepwater geotechnical site investigation projects for global oil and gas related projects (predominately involving the use of seabed-based drilling equipment).

Email Tim: tboyd@greggdrilling.com


Health and Safety Manager

Mike is the company wide HSE Manager. He has extensive experience in Health & Safety management and project coordination with Gregg Drilling for both on-land and over-water operations. He is also experienced in environmental site investigation techniques and remediation.

Email Mike: mhaske@greggdrilling.com


Southern California Operations Manager

Mr. Velazquez has been employed with Gregg Drilling for 13 years. He is currently serving as the Operations Manager for Gregg Drilling’s Southern California headquarters.  Mr. Velazquez is responsible for the supervision of drill crews and yard personnel.  Mr. Velazquez has in-depth knowledge of drilling equipment and project requisites to ensure project completion. He collaborates with Project Managers, Safety Compliance Managers and Drillers to coordinate personnel and project needs.

Email Frank: fvelazquez@greggdrilling.com



Southern California Project Manager - Hollow-Stem Auger & Direct-Push

Mr. Contreras serves as Project Manager for Gregg Drilling’s Southern California hollow stem auger and direct push drilling projects.  Mr. Contreras’s duties include project bidding, procurement, supervision of drill crews and support personnel, and project scheduling.  Working with Gregg Drilling for 32 years, Mr. Contreras has in-depth knowledge of Gregg’s equipment and the requirements for a successful project. His experience of working in the field as a crew member and as a driller provides valuable perspective. In addition, he has 23 years of experience as a project manager and has managed a large variety of environmental and geotechnical drilling projects. 

Email Joe: jcontreras@greggdrilling.com

Sam Corsaro

Special Projects Manager

Sam Corsaro joined Gregg Drilling as our Special Projects Manager heading up our more challenging projects in the mining, offshore wind and other emerging markets. Sam holds a civil engineering degree and brings a wealth of experience as a project manager in the construction industry to this role.

Email Sam: scorsaro@greggdrilling.com


Northern California Operations Manager

Mr. Moses has been employed with Gregg Drilling for 13 years. He is currently serving as the Operations Manager for Gregg Drilling’s Northern California headquarters.  Mr. Moses is responsible for the supervision of drill crews and yard personnel as well as a Project Manager for Gregg’s direct-push and well installation department.

Email David: dmoses@greggdrilling.com



Northern California Project Manager - Sonic & Hollow-Stem Auger

Ryan Lea’s responsibilities include creating quotes and management for Gregg Drilling NorCal’s hollow stem auger, sonic, development and air-vac truck services. Ryan has over a decades experience in hollow stem auger drilling and management. He also has experience in environmental drilling as well as geotechnical projects.

Email Ryan: rlea@greggdrilling.com


Diamond Coring Project Manager

Mr. Murphy has a wealth of experience with difficult access and diamond coring and we are excited to have his as part of the Gregg team! Lyle is based in Washington and assists with projects across the US.

Email Lyle: lmurphy@greggdrilling.com


Northern California Project Coordinator

Mr. Wood has a background in geography and leads our specialized geotechnical testing program including SPT energy calibration, vane shear testing and pressuremeter testing. He assists with project management and coordination for Gregg’s Northern California operations.

Email Ian: iwood@greggdrilling.com


Northern California Project Manager - Rotary Drilling

Mr. Chaves has over 30-years experience in the drilling arena as a project manager and lead driller working on geotechnical and construction projects. He brings a wealth of knowledge to Gregg Drilling as our Northern California rotary project manager and supports projects for geotechnical drilling and instrumentation, water resources, environmental drilling/sampling/monitoring wells and deeper rotary projects.

Email John: jchaves@greggdrilling.com



CPT Data QAQC & NorCal CPT Project Coordinator

Eleni currently compiles Gregg’s CPT data and other specialized testing data into final reports for clients, responding to questions and requests on a day to day basis. In addition, she creates proposals for CPT services in Northern California. Her excellent skills with data management, Microsoft excel and mathematics has enabled her to efficiently work across various software packages with ease while creating visually inspiring presentations.

Email Eleni: epateras@greggdrilling.com



Gregg Drilling maintains a valid C57 license as a contractor in the state of California.


Gregg Drilling’s C57 license number

We are licensed contractors in the following states

  • Arizona
  • California
  • Nevada
  • New Mexico
  • Oregon

We also carry extensive insurance coverage, which includes general liability, automobile, workers compensation, and contractor’s pollution insurance. Copies of our licenses and certificates of insurance are available upon request.

We’re ready for you

With over 30 years experience drilling in California and surrounding states, Gregg Drilling can handle any size project from land based geotechnical and environmental investigations to near-shore marine projects and complicated mobilizations.