The New York City Council on Aug. 13 passed legislation aimed at preventing the spread of diseases such as the outbreak of Legionnaire’s disease in the Bronx that has killed at least a dozen people.

The legislation requires cooling towers in the city to be registered with the city’s Dept. of Buildings and inspected on a quarterly basis. If a test comes back positive for microbes, such as the bacteria that cause Legionnaires’ disease, the owner of the tower would have to clean and disinfect the system in accordance with Dept. of Health and Mental Hygiene regulations.

Existing cooling towers must be registered with the city within 30 days of implementation of the law. New cooling towers must be registered before being put into operation. City officials do not know exactly how much cooling towers there are in the city.

New York Gov. Andrew Cuomo intends to use his emergency power to implement the policy statewide.

Legionella bacteria grow in water sources such as lakes, river, hot tubs, and cooling towers. New York City health officials say the city sees 200 to 300 cases a year. It is not yet understood why the current outbreak turned so deadly. Most of the fatalities in the Bronx outbreak, which affected about 135 people, were among people with already compromised immune systems.

Cooling towers can be disinfected by adding chemicals to the water at a cost of a thousand or two dollars or, in more extreme cases, by turning off the system and thoroughly cleaning and scrubbing it at costs that can run into the tens of thousands of dollars.