Two trucks with Stewart Brothers emblems and a trailer loaded a large earth-moving vehicle were parked Friday in a field off Corrigan Avenue, just outside southeast city limits of Brownwood.

That's the site where the New Mexico-based company will begin drilling a 3,600-foot deep test water well into the Ellenberger and Hickory Sands aquifers. The drilling rig had not yet arrived as of Friday afternoon. Drilling is expected to start next week.

At the Brown County Water Improvement District building about 4 miles away, water board members tended to some late details related to the test well. Board members approved a $37,250 expenditure to Stewart Brothers to increase the length of the main casing that will be cemented in place. The additional casing will be 125 feet long and will be in addition to the 60 feet already planned.

It was decided based on several recommendations that the additional casing was needed so the well can withstand the high pressures potentially up to 500 pounds that could occur when comes to the surface. Without the additional casing, the well could have a "blowout" from the pressure, hydrologist Stefan Schuster of D.B. Stephens and Associates engineers told board members.

A blowout would mean the well would have to be plugged, so the extra casing is good Schuster told board members. The top priority will be keeping people safe, Schuster and board members agreed.

"This is a deep well we're going to encounter this is a very unique situation in terms of going deep," Schuster said. "We're entering a new era in Texas."

Most water wells don't exceed 1,000 feet in depth, Schuster said, although there is a water well near San Saba that is 3,200 feet deep.

Water that is pumped to the surface by the Brownwood test well will be hot 120-130 degrees, Schuster said. Water samples will be analyzed for quality. Water district officials want to know how much it would cost to treat the water and whether it will be economically viable to treat it.

"We don't know what's in the water," Schuster said. "Anything's treatable with technology. It's a matter of cost."

The water potentially contains substances including heavy metals, sulfur and radionuclides, Schuster said. He said concerns will be for dissolved and suspended solids.

Schuster said the $700,000-plus expense of drilling the test well is "absolutely" worth the gamble and is "somewhat visionary and unique."

If the water district decides to pump water out one or both aquifers based on the test well, four to six production wells will be drilled, water district General Manager Dennis Spinks has said. The plan would be to pump 5 million gallons a day, relieving some of the pressure on Lake Brownwood.