The New York state Department of Health says there are now three confirmed cases of Legionnaires' disease in Rockland County.

The department says one of the cases involves a Rockland resident who worked in the South Bronx, which is the source of an outbreak that has killed 12 people and sickened more than 100 others in New York City. A county spokesperson tells News 12 that the two most recent cases are "sporadic." 

Meanwhile, the Orangeburg facility where a worker was diagnosed with Legionnaires' disease reopened Monday morning after a major cleanup over the weekend.

The Chromalloy Gas Turbine Corporation plant in Orangeburg resumed operations three days after officials closed the facility because an employee had contracted the disease.

Officials say that the worker lives in Rockland County and has been treated and released from the hospital. They have not yet determined how he became infected with the disease.

Legionnella bacteria is known to breed in the water of cooling systems. Biocide was injected into the building's cooling towers to kill any possible bacteria. The work area was also quarantined.

The Rockland County Health Department is sending letters to area doctors reminding them of the symptoms of Legionnaires', which include cough, shortness of breath, fever, muscle aches and headaches. The department is also asking businesses with cooling towers to make sure they are properly cleaned and maintained.