Legionella bacteria has been found in the cooling towers at both Smithtown East and Smithtown West high schools, the district said in a statement posted on its website on Wednesday.
There have been no reports of Legionnaires' disease at any district schools, district Superintendent James Grossane said in the letter.
The testing of the cooling towers was done in response to the recent outbreak of legionellosis in the Bronx, which as of Wednesday had killed 13 people since July and sickened more than 120 others who had been exposed to it. A spokeswoman said the district received the results determining the bacteria's presence in the high schools' cooling towers Wednesday morning.
To prevent the spread of the bacteria, the state Department of Health issued emergency regulations requiring the testing, the district said.
"The results of the culture samples revealed the presence of detectable concentrations of the Legionella bacteria in both of the cooling towers" at Smithtown East and West high schools, the statement said. "Upon notification of the sampling results, the cooling towers were immediately brought offline and, in accordance with emergency regulation protocols, an online disinfection/decontamination of the cooling towers was performed by a professional licensed commercial pesticide applicator. The only area affected were the cooling towers, which are now back up and running safely."
The statement also says the district has opted to voluntarily do a "complete offline system decontamination, which includes an additional chlorine treatment, a system drain and flush, manual surface cleaning, refilling with treated water and re-establishing treatment."