Nuclear plant construction: firm offers unique excavation technique.

Homeowners planning projects in their yards see them all the time--the warning signs reminding them and their contractors to call a utility before digging in certain spots. The reasons are obvious: No one wants to rupture a water or gas line or, even worse, dig into electric wiring.

But what about when a utility needs to dig, even on its own property, especially when that property is the site of a nuclear plant? The stakes are even higher then, and, in many cases, traditional excavation can't be done without substantial risk.

That's where Sumter, S.C.-based Thompson Industrial Services comes in.The company has been in business since 1986, performing water-blasting, vacuuming, chemical cleaning and general industrial cleaning, with about 600 employees staffing 13 offices in nine states in the Southeast. In 2004, it added excavation services.

But these aren't the traditional digs using backhoes and other heavy equipment to rip blindly into the ground. Using a technique developed in Canada, Thompson conducts hydro and pneumatic excavation. meaning that it uses air and water to break up and siphon dirt from sites. It started using the process in 2004. when Charlotte-based Duke Energy Corp. asked if there was a way the company could dig on its property without disturbing anything.

Currently, it's performing that job at the V.C. Summer Nuclear Generating Station in Jenkinsville. S.C., where South Carolina Electric & Gas--a subsidiary of Cayce, S.C.-based SCANA Corp. - and its partners are building two additional nuclear reactors. Christopher Niebuhr, Thompson's president and chief operating officer, says Utilities have embraced the new excavation technology. "Historically, digging at any plant site was primarily done with a backhoe. The plant sites have drawings of what's underground, but they're not always exact. They don't want to take the risk of hitting something."

[ILLUSTRATION OMITTED]

That risk is eliminated because of Thompson's process. "We're using either water or air pressure in a vacuum to loosen the soil, then...