Established in 1991 as a small environmental drilling contractor with one rig, Connelly and Associates, Inc. now ranks as one of the largest geotechnical, environmental, and well drilling firms in the Washington, D.C. Based out of Frederick, Maryland and Manassas, Virginia, we send experienced drill crews to perform drilling services for water wells, geothermal wells, monitoring wells, soil and ro
ck core borings, geotechnical instrumentation, or supply other services in support of engineering and environmental consultants. We are experienced and certified to install well pumps, pressure systems, and complete geothermal ground loop connection including flushing and filling the system. From track to large truck and ATV-mounted drill rigs, we have the equipment and crews at the ready to complete your drilling project safely and on time. Our drillers are licensed, OSHA trained professionals with experience in all types of borehole advancement, including air and mud rotary, wash borings, hollow stem augering and diamond core drilling.