Outbreak Pushes Water Treatment Crews Into Overdrive

Where there are water systems, there very often is legionella pneumophila, the bacteria that causes Legionnaires' Disease.

Pete Stempkowski's job is to make sure levels of that and other bacteria — the number of "colony forming units" — in cooling towers remain so low that they don't threaten public health.

"There’s really no way to get rid of all the organisms in a cooling tower," said Stempkowski, a partner at Clarity Water Technologies. "It's all risk minimization."

City health department officials believe the cooling towers that help large heating, ventilation and air-conditioning systems operate more efficiently are the source of the Legionnaires' Disease outbreak in the Bronx. Under an emergency order issued last week, all building owners with cooling towers have two weeks to clean and decontaminate the towers, or furnish proof they were cleaned in the previous month.

That means a lot of work for Stempkowski and his crews. "We're working 14, 15-hour days," he said.

Cooling towers typically contain thousands of gallons of water. Crews begin by blitzing them with an intense dose of bacteria-killing biocide. Then they drain the tanks, don protective gear, climb in and begin power-washing.

"Then you fill it up again, flush it again, fill it back up, and put the normal biocide treatment back online, with the proper dosage for the amount of water that’s being treated," Stempkowski said.

The emergency order has increased business in the short run. Towers that were already have low levels of bacteria and weren't due for cleaning and decontamination for months are all being cleaned. And in the long run, a proposed regulation that would require twice-a-year cleaning and more regular inspections could also be good for business.

Still, Stempkowski said he has mixed feelings.

"I don’t know if it’s necessarily going to be a good thing for the average person," he said. "All of these costs have to come from somewhere. To clean your cooling tower, to clean it twice a year, it’s going to cost building management. Building management has to go back to people and get more money from them."