Protect your home's water

These simple steps help keep the water in your home safe. If you rent or live in shared housing, your property manager usually maintains the building's water system.

Run the water

If the water has not been used for a while, such as after a week away, run it for several minutes.

Maintain your water heater

Follow the manufacturer's instructions to flush and clean it. How to drain and flush a water heater (PDF)

Clean your shower and faucets

Scrub shower heads and faucet tips to remove slime and dirt. How to clean a shower head (PDF) and a faucet aerator (PDF)

Use safe water in devices

Use distilled or sterile water in CPAP machines and humidifiers, and clean them as the manufacturer directs.

Maintain your hot tub

Keep the chemicals at the right levels. At a vacation rental, ask when the tub was last cleaned.

Signs and symptoms

Legionella can cause two illnesses. Legionnaires' disease is a serious lung infection. Pontiac fever is milder and feels like the flu.

See a healthcare provider right away if you have a high fever, a bad cough, or trouble breathing. Legionnaires' disease is easier to treat when it is caught early.

Who is at risk

Most healthy people exposed to Legionella do not get sick. You are more likely to get Legionnaires' disease if you are:

• 50 years or older
• A current or former smoker
• Living with a chronic lung disease, such as COPD or emphysema
• Living with a weakened immune system, or taking medicines that weaken it, such as after a transplant or chemotherapy
• Living with cancer
• Living with another serious illness, such as diabetes, kidney failure, or liver failure

How it spreads

1. Starts in nature

   Legionella lives naturally in water and soil, usually in amounts too small to make people sick.

2. Grows in water systems

   In plumbing, hot tubs, and other water systems, warm, still water lets the bacteria multiply to riskier levels.

3. Spreads through mist

   When that water is sprayed or misted by a shower, hot tub, fountain, or cooling tower, people can breathe in tiny droplets that carry the bacteria.

Less often, people get sick when water with the bacteria goes down the wrong way while drinking. This is more likely for people who have trouble swallowing. Legionnaires' disease does not spread from person to person.

How common it is

Legionnaires' disease can happen any time of year, but more cases are reported in summer and early fall. In New Jersey, 309 cases were reported in 2025, about 3.3 per 100,000 residents (NJSHAD). The true number is likely higher because the illness is often not diagnosed.

Diagnosis and treatment

A healthcare provider checks for pneumonia with a chest x-ray or physical exam. A urine or phlegm (sputum) test can confirm whether Legionella is the cause.

Legionnaires' disease is treated with antibiotics, and most people recover fully. Finish all of your antibiotics, even if you start to feel better, unless your provider tells you otherwise. Pontiac fever usually clears up on its own.