We have the experience

Founded in 1985, Gregg Drilling has been providing site investigation services within California and the Western US for over 35-years. In this time Gregg’s clients have grown to include government agencies, industrial owners, engineering consulting firms and construction firms.

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.

Project Summaries

California High Speed Rail

Check out the Winter 2023 article featured in the California High Speed Rail small business newsletter on Gregg’s contribution to this green energy project here in California. Gregg has worked on various sections of the high speed rail project since 2016 and recent work involved our sister company, Pitcher Services. Between Gregg and Pitcher, we […]

Learn More

Big Creek Dam, Newport, Oregon

In December 2022 through January 2023, Gregg Drilling worked with HDR and the City of Newport, Oregon to conduct a site investigation for a new dam to replace the current Big Creek Dam that is currently at risk of failure. The two Big Creek Dams on the Big Creek Reservoir contain the city’s water supply. […]

Learn More

Delta Conveyance

Scope of work: Gregg Drilling worked with AECOM and Kleinfelder on the Delta Conveyance project to modernize the aging infrastructure in the Delta and protect the reliability of water deliveries across California. California’s Department of Water Resources (DWR) was charged with addressing sea level rise and climate change as well as minimizing water supply disruption […]

Learn More

Ocean Wind 1 Project, New Jersey

In the summer of 2002, Sealaska, helped invest in clean energy with their work on the Ocean Wind 1 project in New Jersey. Gregg Drilling, an integral part of Sealaska’s Woocheen hydro sciences group, conducted a successful geotechnical survey to aid in the design and placement of cables to carry power from offshore wind turbines […]

Learn More

Offshore Wind HDD & Cable Route Survey, Delaware

Sealaska Woocheen Marine Services is currently investigating a number of potential cable routes for HDD installation from a planned offshore wind farm to an onshore substation location. The geotechnical design of the cable routes requires 4 deep boreholes and CPTs to 45m depth in two potential locations. In addition, along the cable route, 20 CPTs […]

Learn More

California Aqueduct Investigation with CPT

Gregg Drilling, working under an on-call contract with the Department of Water Resources was called up to provide Cone Penetration Testing (CPT) and Seismic CPT for the California Aqueduct near Los Banos, CA. During 2021, Gregg mobilized two CPT trucks working simultaneously to complete 200 CPTs to 55ft and 8 seismic CPTs to 135ft . […]

Learn More

San Diego Airport Geotechnical Investigation

In 2021, Gregg Drilling was contracted through Kleinfelder to perform a geotechnical site investigation at the San Diego Airport for structural improvements to gates 46 & 47. The work was performed in conjunction with ARRIVE (San Diego Aviation Alliance). Due to the nature of working near and adjacent to the airport runways, all the drilling […]

Learn More

Santa Cruz Island Geotechnical Drilling

Gregg Drilling, working for the National Parks Service and Kleinfelder, was asked to complete a number of geotechnical borings on Santa Cruz Island. The work provided a unique challenge as the island has no dock area to unload equipment. Gregg was able to mobilize a truck mounted rotary drill rig on a National Parks Service […]

Learn More

Remediation Project – Fall 2021

ISCO Injections with Potassium Permaganate Over a 39-day period, Gregg Remediation injected approx. 318,500 total gallons of a 1.5% potassium permaganate solution into 57 direct push locations and 2 horizontal wells. Highlights 25% of injection borings were angle borings. Daily injection average of 8,100 gallons a day. Injected at six (15) simultaneous injection locations. Gregg […]

Learn More

Remediation Project – June 2021

Sodium Permanganate and Activated Persulfate Over a 5-day period, Gregg Remediation injected a mixture of Sodium Permanganate (10 g/l), Sodium Persulfate (20 g/l) and Sodium Hydroxide (20.6 g/l) into two (2) 2‐inch Injection Wells and two (2) Direct Push locations., treating vertical treatment intervals from 13-18ft bgs and 31-33.5ft bgs. Highlights Mixing two ISCO chemicals […]

Learn More

Remediation Project – April 2022

Working with EOS Remediation, Gregg Remediation completed a 5-day project requiring injection of approx. 17,300 total gallons into 18 direct push locations. We targeted 5ft treatment zones from 35-50ft bgs. The injected amendments included: EOS Pro, blackstrap molasses, sodium bicarbonate, sodium ascorbate, and DHC. Highlights EOS Pro is made from enriched EVO used to stimulate […]

Learn More

Multi-level Well Completions

While holding the on-call contract with California’s Department of Water Resources (DWR), Gregg was called-up to drill and install a number of multi-level completion wells near Cuyama, CA over a 3-month period of time in 2021. The initial pilot hole was drilled using an 8- to 10-inch-diameter bit to the depth of bedrock or 1,500 […]

Learn More

Have a question about our capabilities?

If something isn’t listed here, it doesn’t always mean we don’t know how to help you. Visit our Services page to learn more about the services we have to offer. We love to tackle a difficult project or site – just let us know how we can help!