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Legionella water testing

Each month, we share new results from our ongoing water tests for Legionella. Our goal is simple: to let you know what we're doing—and how we're doing—in controlling Legionella at VA Pittsburgh.

What is Legionella?

Legionella is a bacterium found naturally in the environment. Legionella pneumophila, which causes Legionella pneumonia, is the primary human pathogenic bacterium within the larger group of bacteria.

Almost all natural water sources have Legionella. Medical facilities across the country regularly monitor, find, and treat Legionella in their water systems.

Legionella pneumonia: symptoms, diagnosis, and treatment


Legionella pneumonia is a form of pneumonia. Common symptoms include:

  • Cough
  • Shortness of breath
  • High fever
  • Muscle aches
  • Headaches

Diagnosis and treatment

After we diagnose a patient with pneumonia, we conduct a urinary antigen test to check for Legionella pneumonia. A urinary antigen test is simple and quick, and it detects Legionella pneumonia in most cases. 

Whenever possible, we also collect a sputum sample (a mixture of saliva and mucus) and culture it in on special media in the lab. If a patient has Legionella pneumonia, their culture can grow Legionella bacteria. This test produces results more slowly (as the culture needs time to grow), but it can help us link a patient's infection to an environmental source. Most cases of Legionella pneumonia can be successfully treated with common antibiotics.

At-risk populations

Generally speaking, a person cannot get Legionella pneumonia just by drinking water. To be infected, they must breathe in mist or vapors containing the bacteria. In addition, most healthy people do not become infected after exposure to Legionella, and Legionella pneumonia is not transmitted from person to person.

Some people can fall ill after breathing in the Legionella bacteria. Those at higher risk of getting sick are:

  • People age 50 or older
  • Current or former smokers
  • People with chronic lung diseases (such as COPD or emphysema)
  • People with weakened immune systems
  • People who take drugs that suppress their immune systems 

Up to 18,000 hospitalized cases of Legionella pneumonia occur in the United States each year. Many cases go unreported because this disease is difficult to distinguish from other forms of pneumonia.

How VAPHS is addressing Legionella 

To prevent Legionella growth, we are treating the water systems at both campuses with continuous chlorine drips (chlorine, at certain concentrations, can kill the bacteria). This water is absolutely safe to drink — the chlorine concentrations in our systems are 2ppm (which is well below the Environmental Protection Agency’s  limit of 4ppm). The chlorine does not affect the taste of the water. 

We’ve also installed specialized mixing valves and instantaneous hot water heaters in our plumbing systems at both campuses. These enhancements enable us to safely keep the water in our pipes circulating at a warmer temperature—140 degrees Fahrenheit—to suppress the growth of Legionella.

In addition, we can now superheat this water to quickly kill bacteria as necessary while maintaining cooler, safe temperatures at the tap to prevent people from scalding themselves.

Finally, we have replaced all drinking fountains with bubbler systems, which are easier than the fountains to clean and maintain.

For more information

If you have questions about Legionella pneumonia, please discuss them with your VA provider.

If you have questions about our ongoing water system enhancements, call our water hotline at

The hotline is staffed from 8:00 a.m. to 8:00 p.m. every weekday (except federal holidays), and is open to the public. During off hours and on holidays, you may leave a voicemail — we’ll return your call on the next business day.

Water test results

*All Veterans suspected of pneumonia are tested for Legionella via both a urine antigen test and a sputum culture.

** As of May 21, 2019

Year Veterans Tested for Legionella Pneumonia* Veterans Diagnosed with Legionella Pneumonia Legionella Pneumonia Definitely Acquired at VA Pittsburgh 2013 516 9 None 2014 523 1 None 2015 518 6 None 2016 586 3 None 2017 496 2 None 2018 581 5 None 2019** 207 None None
Year Water Samples Tested Samples Positive for Legionella Positivity Rate 2013 4525 80 1.8% 2014 1636 47 2.9% 2015 2154 20 0.97% 2016 1774 22 1.2% 2017 1689 15 0.9% 2018 1420 14 1% 2019** 1259 2 0.2%