Experience That Runs Deep
Serving the Mid-Atlantic since 1991 with integrity, innovation, and care.
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Why Choose Us
30 Years of Experience
Proven experience with a nationwide reach.
Proven experience with a nationwide reach.
Licensed & Trusted
We follow strict compliance standards
from OSHA, EPA, and state authorities
in all operations.
We follow strict compliance standards
from OSHA, EPA, and state authorities
in all operations.
Modern Fleet
With one of the most advanced
and responsive drilling fleets,
we handle jobs of any size and terrain.
With one of the most advanced
and responsive drilling fleets,
we handle jobs of any size and terrain.
Our Core Services
Rapid, clean, and efficient drilling in
unconsolidated formations using
vibration energy for accurate sampling.
unconsolidated formations using
vibration energy for accurate sampling.
Subsurface soil testing,
standard penetration testing (SPT),
and borehole sampling for foundation planning.
standard penetration testing (SPT),
and borehole sampling for foundation planning.
Installation of monitoring wells,
vapor intrusion systems, and safe
boreholes for contamination checks.
vapor intrusion systems, and safe
boreholes for contamination checks.
We provide specialized drilling
solutions for tight, restricted,
or hard-to-reach areas.
solutions for tight, restricted,
or hard-to-reach areas.
We provide drilling
for residential wells and
geothermal loop systems.
for residential wells and
geothermal loop systems.
Our Equipment
We operate one of the most diverse and advanced drilling fleets in the Mid-Atlantic, suitable for both remote and urban drilling environments.
Sonic Drilling Rigs
Mud Rotary and
Air Rotary
Air Rotary
Direct Push Units
(Geoprobe)
(Geoprobe)
Auger Rigs – Standard Sampling & Low Clearance
Support trucks
and service trailers
and service trailers
Support Services MOT and Air Knife/Soft Dig
Featured Projects
As part of the preliminary geotechnical investigations for the replacement of the Francis Scott Key Bridge, our team successfully completed a critical subsurface exploration program along the Patapsco River in Baltimore, Maryland.
As part of an environmental remedial investigation for the Florida Department of Environmental Protection (FDEP), our firm successfully executed its first Direct Push Technology (DPT) drilling project in Florida. This milestone effort was conducted at the Co-Ops Fuels & Lubricants site in Gulfport, utilizing our newly acquired Geoprobe® 3216GT.
Our team was engaged to support an emergency geo-stabilization effort on the Chesapeake Bay Bridge-Tunnel (CBBT), a 13-mile transportation corridor composed of a series of bridges and tunnels connecting Virginia Beach to the Eastern Shore. The project, which expands the capacity of U.S. Route 13, was nearing completion when a tunnel boring machine (TBM) encountered unstable ground conditions, halting progress on a critical segment of the tunnel.
This was a large-scale geotechnical drilling project in support of a proposed wind farm development along an eastern ridge of the Allegheny Mountains near Mount Storm, West Virginia. The project involved the replacement and installation of wind turbines as part of a renewable energy infrastructure initiative led by Barr Engineering.
Selected by HDR Engineering, we provided geotechnical drilling services for the Virginia Department of Transportation’s (VDOT) I-95 Bidirectional Lanes project. This major infrastructure initiative addresses congestion on one of the busiest sections of Interstate 95 between Springfield and Dumfries, Virginia.
Let's Drill Into Success
Partner with Connelly & Associates for reliable, efficient, and certified drilling services tailored to your unique project needs.
Testimonials & Reviews
What Our Clients are Saying
"ECS Mid-Atlantic has used Connelly for our geotechnical and environmental needs in the Mid-Atlantic for over 25 years. They have consistently provided quality service using the best equipment and personnel in the industry. Their knowledge on geotechnical drilling, rock coring, specialty testing, and environmental sampling is unparalleled. I have always valued my relationship with the Connelly family, the way they listen to our needs, and their coordination to efficiently complete the work on time and within budget!"
— Jeff McGregor, P.E. | Vice President ECS Mid-Atlantic, LLC
"We continue to use Connelly because of their reliability and quality. They have the fleet and staff to be able to cover our wide range of projects. When we work with Connelly, we know we are getting quality drilling with data we can rely on."
— Stephen J. Gyurisin, P.E. | Geotechnical Services Manager, Triad Engineering, Inc.
"Specialized Engineering has partnered with Connelly & Associates for over 30 years, and they remain a trusted drilling subcontractor and invaluable part of our team. Their crews are always dependable in the field, delivering excellent results on our geotechnical and environmental drilling projects. We value their professionalism, responsiveness, and commitment to safety."
— Jeremiah Cook, P.E. | Geotechnical Engineer, Specialized Engineering
Have a question or need a quote?
Use the form below to reach out and our team will respond promptly.
About Connelly & Associates, Inc.
Connelly & Associates, Inc. is a leading drilling contractor serving
Frederick, MD and the Mid-Atlantic region. We specialize in geotechnical and environmental drilling, sonic drilling, limited access projects, and water well and geothermal drilling.
Frederick, MD and the Mid-Atlantic region. We specialize in geotechnical and environmental drilling, sonic drilling, limited access projects, and water well and geothermal drilling.