When the Emerging Infectious Diseases Laboratory at the Centers for Disease Control and Prevention (CDC) opens this fall in Atlanta it will house some of the deadliest viruses in the world. Hazmat-suited medical investigators will examine deadly pathogens sent from public health labs across the country to figure out what makes them so lethal and how to stop them. And they'll do most of their work hunched over high-powered electron microscopes.

That kind of research equipment requires an extra level of protection from power surges and transients, so when Steve Milby, facility program manager for the National Center for Infectious Diseases, made a list of what he wanted for the building's electrical system, he put shielded circuits toward the top.

And right after that came flexibility. Viruses are always evolving, so a laboratory entrusted with preventing nationwide outbreaks has to be able to add the latest and greatest in research equipment, and Milby wanted to be able to easily reconfigure circuits whenever the need arose.

For Inglett & Stubbs, the Atlanta-based electrical contractor that won the $17 million project three and a half years ago, surge protection and flexible configurations were the easy parts. The challenge came in helping the CDC contain its lethal samples.

With previous experience wiring medical laboratories in the Southeast — including another building in the CDC campus — Inglett & Stubbs had the history to complete the job, but they were still only partially prepared for making sure those microscopic murderers stayed put. “It took us nearly six months to figure out how we were going to tackle [the labs with the highest safety requirements],” says Stan Manous, one of the contractor's general foremen assigned to the project.

Four of the nine labs in Building 18 (as the CDC refers to it) have a biosafety level (BSL) 4 classification because they'll be used for studying level 4 pathogens — the deadliest and most easily transmitted diseases known to science. Even the slightest leak can put the lab's employees at risk of infection, or worse, lead to an outbreak.

That meant Inglett & Stubbs had to pay extra attention to one of the most basic parts of any electrical installation: the wireways. In any other building, conduit and junction boxes are pathways for cable. In Building 18, they're potential escape paths for airborne diseases. To prevent tainted air from passing into common areas, the team of electricians tested every junction box and piece of conduit for leaks with a technique they devised especially for the project (Sidebar below). Then the conduit was buried under several inches of concrete.

Keeping the viruses where they belonged went beyond sealing up the cracks, though. Each lab is protected by environmental controls that maintain positive air flow and negative pressure, and samples and reference agents are stored in freezers. Both systems require continuous power, regardless of the situation. “Those samples have to be contained and protected,” Milby says. “Power reliability is critical.”

Although Inglett & Stubbs wasn't responsible for hooking up the standby generators that will kick on in the event of power loss, they did install dedicated UPS systems for the circuits that feed the four BSL 4 labs. Should the facility lose power, those units will keep the containment operational until the generators fire up.

Backup power is crucial to keeping the samples from escaping, but Milby says it's also there for continuity of operations. The CDC is where the rest of the country turns for help in times of a health crisis, so downtime isn't an option. “Our operations are critical,” he says. “If there were an outbreak, we can't tell the world that we can't work on it because a truck ran into a pole down the street.”

Sidebar: Stopping Leaks Before They Start

The CDC can't afford an airborne viral jailbreak in the BSL 4 labs, so Inglett & Stubbs whipped up a homemade pressure test to gauge the integrity of the welds in their custom-manufactured ¼-inch steel junction boxes before installing them. Inglett & Stubbs' electricians started by sealing the points-of-entry with rubber stoppers and closed the front of each box with a ¼-inch steel plate equipped with a bicycle pump plug and a pressure gauge. With that done, the only thing left to do was pump them up.

The crew filled each box to 8 psi, dunked it in a pool of water, and prayed for no bubbles. As it turns out, it's a good thing they went to the trouble. Manous says the test helped them find leaks in several of the boxes that they then re-epoxyed before installing in the floors.