Drilling Deeper on Geotechnical Investigations

Michigan-based Rosendall Well Drilling LLC began in 1985 focused solely on water well drilling. Now four decades later, it's serving geotechnical, environmental, and water well clients across the region.

"Dad started the business in 1985 drilling water wells," Jeff Rosendall, owner, said. "Demand has increased as new construction has taken off in the area, so we've diversified during the past 10 years."

Those changes started with a calculated risk: a used 7822DT purchased to break into environmental drilling. Three years later, demand had grown enough to justify a new 7822DT. Today, their fleet includes a Geoprobe^® DM250, the 7822DT, and the company's newest addition: a 3126GT.

Hitting a Wall at 30 Feet

The decision to add the 3126GT came down to geology.

"As requests from clients for geotechnical drilling increased, we wanted more power to be able to drill deeper," Rosendall said. "We have a lot of clay in our region, and the 7822DT struggled to drill below 30 feet."

When they reviewed the specifications on the 3126GT, the choice became clear. The rig now handles the majority of the company's geotechnical investigation work, along with a fair amount of environmental drilling for 2-inch monitoring well installations.

More Power Than Expected

Even understanding the rig specifications on paper, the performance of the 3126GT delivered surprises.

"We knew it would be stronger, but the torque is impressive," Rosendall said. "The winches are more powerful. Everything is just bigger and more powerful than our 7822DT."

Top feature: the centerline head side shift.

"The way the head slides over the hole makes operations efficient," he said.

The rig's weight has proven to be an asset, helping the team drill deeper and faster without the machine lifting off the ground. That translates directly to productivity gains on every job.

Geotechnical Investigation to 120 Feet

The 3126GT has opened doors. On a recent geotechnical project for a water tower, the crew reached 120 feet while collecting split spoon samples.

"We're also able to switch to mud rotary partway through when encountering heaving," Rosendall said. "All made doable thanks to Geoprobe^®."

Today, geotechnical investigation work accounts for roughly 80 percent of the company's projects unrelated to water well drilling or service. The team typically uses the drop hammer for split spoon samples on commercial developments and residential real estate evaluations. The consistent theme across these jobs: better overall performance.

The Business Case

Adding the 3126GT hasn't just improved field operations — it's driven business growth. When you can say "yes" to deeper holes, tighter timelines, and more challenging soil conditions, clients take notice.

"It's produced more work, generally by being able to better serve existing customers," Rosendall said.

Why Geoprobe^®?

For Rosendall, the equipment is only part of the equation. What keeps him coming back to Geoprobe^® is the support behind it.

"No matter whether it's a water well, environmental, or geotechnical rig, the technical help is second to none," he said. "Even when we had a used rig not directly purchased through Geoprobe^®, they stand behind all their products."

That support extends across the entire organization.

"From sales to technical support for tooling and parts, everyone is very knowledgeable," Rosendall said. "The quality of Geoprobe^® representatives is head and shoulders above others I've dealt with — that's what keeps me coming back."