Delivering high quality environmental, geotechnical and marine drilling & testing solutions for over twenty five years.
Innovative solutions. Sound technical advice.

Our commitment to responsive, reliable and cost effective service means solutions, savings and peace of mind to you and your organization.
Gregg Drilling & Testing, Inc. is directed and staffed by geotechnical and environmental professionals with experience in industry, consulting, and research. All our personnel are highly trained, certified, and experienced in site investigation technologies and applications.
These exceptional qualifications enable Gregg personnel to solve complex problems and create a seamless working relationship between our staff and our clients.

Quality isn't something we test for after the job is done.
It's a way of doing business.
What's new at Gregg
Keep up with the latest news
The services we offer, equipment & technologies we utilize, and project experience.
We want to hear from you
Please use the form below to e-mail us with any questions or project opportunities you may have. We will have the appropriate project manager return your request by the next business day. We hope to work with you soon.
Our offices
We have two convenient locations. Open M-F 7AM to 5PM
Martinez, California 94553Cost Estimates: Chris ChristensenJob Related Questions & Cancellations: Jake WilsonAdmin & Other Questions: Mary Walden
Phone: (925) 313-5800
Fax: (925) 313-0302
Signal Hill, California 90755
Phone: (562) 427-6899
Fax: (562) 427-3314