The presence of legionella, the bacteria that causes Legionnaires' disease, has been detected in more Long Island schools.

Cooling towers at both Smithtown's East and West high schools were found to have the bacteria earlier in the week. Connetquot's administration building was disinfected Friday after the bacteria was discovered there. Now, Hauppauge High School and Centereach High School sent letters to parents today saying water towers tested positive for legionella.

In each district, the towers were taken offline, disinfected and decontaminated.

Brendan Roderick, of Hauppauge environmental testing firm JC Broderick, is not surprised by the findings and expects more positive test results on Long Island.

"We are commonly finding about 50 percent of them are coming up with the presence," says Roderick.