Centers for Disease Control and Prevention:

Building 18, Emerging Infectious Diseases Laboratory

Judges' Award: Best Health Care

Building the Centers for Disease Control and Prevention's Building 18 Emerging Infectious Diseases Laboratory, one of the most sophisticated science facilities in the world, earned McCarthy Building Cos. of Atlanta Southeast Construction's Best of 2006 Judges' Award.

"There is a class system in construction, and McCarthy is one of the few that occupies the top tier," said Matt Stevens, a management consultant and president of Stevens Construction Institute of Winter Park, Fla., and one of this year's Best Of judges. "This project is the kind of monument that not many others can point to."

"From airtight requirements to varying concrete mixes, the design for this facility met each and every challenge while also providing an attractive structure that neighboring areas can enjoy for decades," said another judge, Susan Pendergrass, who is business development/transportation services manager with Ardaman & Associates of Orlando.

The $167.5 million, 12-story, 400,000-sq.-ft. project on the CDC's Edward R. Roybal campus in Atlanta involved construction of one of the few biosafety level 4 labs in North America, as well as multiple biosafety level 2 and 3 labs and office space for 450 researchers. McCarthy started construction in October 2001, and finally completed the project in fall 2005.

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Classified according to safety requirements needed to work within them, laboratories are ranked from one to four, with four being where researchers handle the most lethal pathogens. Level 4 labs must be airtight, leakproof and completely self-contained.

"McCarthy had never completed a BSL-4, and (none of our competitors) had either," said Eddie Harris, project director for McCarthy in Atlanta, adding that there had not been one completed in the United States since the 1980s. "We were able to do everything, and it worked."

Two weeks after McCarthy signed the guaranteed maximum price contract, with 45 percent of the construction documents prepared, the terrorist attacks of Sept. 11, 2001, occurred. The attacks prompted security upgrades and additions to the building, which affected design and schedule. But as McCarthy's drill rig rolled en route, the CDC decided to add two research floors requiring a foundation redesign. Working closely with the CDC and design team of Smith Carter Architects & Engineers, CUH2A and Hemisphere Engineering USA, all of Atlanta, new plans evolved. The CDC also upgraded security to the laboratories. The project's original completion date of spring 2005 was pushed back accordingly.

Construction began in October 2001, with a three-level, 48,000-sq.-ft. central energy plant. Every contractor and craftsman onsite required Federal Bureau of Investigation background checks and security clearances.

"McCarthy built in what some would call a 'fluid moment' - the Sept. 11 attacks, the anthrax threats and don't forget, overall, technology rapidly improves," Stevens said. "McCarthy did not let this wear them down. They worked hard and smart. It is evident in this building."

The 25,000-sq.-ft., high-containment BSL-4 required special techniques and sequences and proved the most challenging aspect of the project. The lab operates at negative air pressure with air-lock buffer zones and decontamination and waste-disposal systems. It is completely self-contained with its own breathing air supplies, HVAC systems, 100 percent HEPA filtering, backup power and security systems.

"There is an elaborate system of electrical conduit and metal embeds for other devices that got welded to the walls," Harris said. "There was a complete coordination of drawings for mechanical, electrical, plumbing and architectural that went beyond what is the normal process."

He added that all conduit and piping required identification and routing from the box in the wall to the destination outside of the lab. The exact route that the conduit and piping took had to be written out before hand, very specifically.

The team spent nine months completing the drawings and then built a mock-up of a portion of the space, with the rough-ins. Once the concrete was poured there would be no changing the locations. Running an extra piece of conduit or moving a drain line could compromise the lab's performance and necessitate tearing down and repouring the wall. Then McCarthy poured the cast-in-place walls, ceilings and floors.

"When you pour the concrete, you don't want cracking immediately or down the road," Harris said. "Concrete does crack, so all you can do from an engineering standpoint is do your best to control the cracking."

McCarthy evaluated aggregate and moisture properties of various concrete mixtures and variables, such as ambient temperatures, formwork materials, finishing methods and curing procedures. It then tested 10 different concrete mixes and monitored shrinkage as the concrete cured during a six-month period.

Narrowing the field to three mixes, McCarthy built mock-up facilities to figure out which mix and formwork material performed best. The team determined the concrete would require a water cure, and it was sprayed 24 hours a day, seven days a week for 28 days.

The floors immediately above and below the lab are dedicated to MEP systems for 100 percent maintenance access, so maintenance crews can at all times access filtration and other MEP running above and below the lab.

The complex filtration system exchanges air at least 15 times per hour, double filtering incoming and existing air through HEPA filters. Fully cured after five months, the walls were sprayed with five layers of a highly chemical-resistant epoxy coating.

Next up, after installing, testing and commissioning architectural and MEP components, McCarthy began pressure decay testing, a six-week process of measuring the negative pressure in each room during a 20-minute period. Any loss of pressure required ultrasound listening devices to pinpoint leaks and to test the bio-seal on the doors and windows.

"The test ensures you have built an airtight room," Harris said. "You put the room to a negative pressure of 2 in., and it has to stay. It cannot go lower than 1 in. within a 20-minute period, or you fail the test. It's difficult to achieve, but we were able to do it without too much of a problem."

More than 450 researchers now work at the facility, which supports the CDC's Bioterrorism Program, the Division of Viral and Rickettsial Disease, the Special Pathogens Branch, the Division of AIDS, STP and TB Laboratory Research, and the Division of Bacterial and Mycotic Diseases.

"It was an interesting job, the most difficult but most rewarding job I have ever worked on," Harris said.

Owner: Centers for Disease Control and Prevention, Atlanta
Construction Manager: McCarthy Building Companies Inc., St. Louis
Architects, Engineers and Consultants: CUH2A Inc., Atlanta; Smith Carter Architects & Engineers Inc., Atlanta; Hemisphere Engineering Inc., Atlanta