Posted on November 18, 2013 by Mike

DTD recently completed another environmental remediation well at a major Air Force base in central Georgia. This 1200 foot long, 6 inch diameter air sparge well joins previous wells installed by DTD at the base to assist in the cleanup of solvents and fuel that have accumulated in the soil and groundwater as a result of flight operations dating back to the early 1940’s.

For this well, DTD used one of our 100,000 lb. class drill rigs, capable of pulling back well casing with 50 tons of force. The well, like those preceding it, is nearly 60 feet below the ground surface. This particular well was double-ended, with the well extending underneath a taxiway and exiting in the infield before the runway.  The exit side was capped, marked and buried ~3 ft below the surface while the proximal end of the well was set inside of an H-20 rated vault.

DTD has installed a total of nine wells at the site, in four engagements with two separate environmental consulting firms. Among our previous accomplishments at the site has been the installation of single-ended, or “blind”, air sparge wells up to 1450 feet long, in difficult drilling conditions with flowing sand, which can collapse an open borehole within minutes. Several of the wells have extended beneath active taxiways and aircraft runways, with no impact on flights.

To assure well completion in these conditions, DTD developed what we have named the “Knock Off” technology – a drilling method and special tooling designed to enable us to install well casing up to four inches in diameter through the drill rods, “knocking off” the sacrificial drill bit and leaving it in the bore. This method protects the well casing from damage, and prevents the bore from caving in prior to installation. As a result of our successes with this method, DTD has become the “go-to” horizontal drilling contractor for installations at this, and other, Air Force and Air National Guard bases in the region.

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