NJ Department of Health, Hamilton Twp. Officials say Water is Safe to Drink, But Urge Precautions During Ongoing Legionnaires’ Disease Investigation

HAMILTON, NJ – Four cases of Legionnaires’ disease were reported in Hamilton Township, Mercer County between May-August 2021, along with an additional reported case from November 2020. The Hamilton Township Division of Health continues to work closely with the New Jersey Department of Health (NJDOH) to investigate these cases as part of a larger investigation, which was initiated in August 2020 following a reported cluster of four cases. Hamilton Township reported two deaths in August 2020 and an additional death was reported late last month in an elderly township resident among the nine reported cases.

Legionnaires’ disease is a type of pneumonia that people can get after breathing in aerosolized water (small droplets of water in the air) containing Legionella bacteria. Symptoms of Legionnaires’ disease include cough, shortness of breath, fever, muscle aches, and headaches which are similar to symptoms caused by other respiratory infections, including COVID-19. Most healthy people exposed to Legionella do not become ill. However, people who are 50 years or older, especially those who smoke cigarettes, or those with certain medical conditions, including weakened immune systems, chronic lung disease or other chronic health conditions, are at increased risk for Legionnaires’ disease.

Legionnaires’ disease is treatable with antibiotics so it is important that anyone who thinks they have symptoms of Legionnaires’ disease contact their health care provider and seek medical evaluation. Healthcare providers use chest x-rays or physical exams to check for pneumonia. Your provider may also order tests on a sample of urine and sputum (phlegm) to see if your lung infection is caused by Legionella bacteria.

Health officials are urging residents and business owners in Hamilton Township to take actions to reduce the risk of Legionella growth in their household and building plumbing. Recommendations for homeowners and building owners are available below. It can be possible for Legionella to enter buildings (including homes) when receiving treated drinking water. Health officials are partnering with NJ Department of Environmental Protection (NJDEP) and Trenton Water Works (TWW) to monitor for Legionella in the Hamilton Township water distribution system owned and operated by TWW. While water samples collected at TWW treatment plant and central pumping station have consistently shown no presence of Legionella, water samples collected from homes and businesses in Hamilton Township served by TWW, have identified the presence of Legionella. There is concern that Legionella may be present in other buildings and homes in the area.

“The water is safe to drink, but there are basic precautions that residents can take to help protect themselves – such as regularly flushing water at their taps and maintaining their hot water tank,” said State Epidemiologist Dr. Tina Tan. “Additionally, home A/C units do not use water to cool, so these home units do not aerosolize water and are not a risk for Legionella growth.”

“We continue to work with our partners at the New Jersey Department of Health and Hamilton Township to empower residents in Hamilton and in our service area on how to protect themselves and their families from Legionnaires’ disease,” said Mark A. Lavenberg, Director of the City of Trenton’s Department of Water and Sewer, which operates Trenton Water Works. “To that end, starting on October 1, Trenton Water Works is launching a public awareness campaign to educate our service-area consumers on this critical public health issue.”

NJ Department of Health, Hamilton Twp. Officials say Water is Safe to Drink, But Urge Precautions During Ongoing Legionnaires’ Disease Investigation

Hamilton Township Division of Health and NJDOH want to remind healthcare providers to maintain a high index of suspicion for Legionnaires’ disease when evaluating patients for community-acquired and healthcare-associated pneumonia, especially among residents of Hamilton Township. This is important to ensure patients receive appropriate and timely treatment.

“I want to thank NJDEP and NJDOH for their involvement in studying the frustrating frequency of Legionnaires’ disease cases in Hamilton over the past decade and working with TWW and our Division of Health to keep the residents of Hamilton safe,” said Mayor Jeff Martin. “Clean and safe drinking water is a human right – one that we will continue to fight to make sure all residents can comfortably know they have access to.”


According to NJDOH, residents can follow recommended best practices to reduce Legionella growth in their household water. For more information on best practices, please visit NJDOH’s Legionella webpage at: https://www.nj.gov/health/cd/topics/legion.shtml


Follow recommendations from the NJ Department of Health when reopening your facility following a prolonged shutdown or reduced operation due to the COVID-19 Pandemic. Recommendations are available at: bit.ly/2XxlBaw


NJDOH receives approximately 250–350 reports of Legionnaires’ disease each year reported throughout New Jersey. Legionnaires’ disease is a type of pneumonia (lung infection) caused by the bacteria Legionella. Legionella is a type of bacteria found naturally in freshwater environments such as lakes and streams and becomes a health concern when it enters and grows inside human-made water systems. People can get Legionnaires’ disease by breathing in aerosolized (small droplets) water containing Legionella. Aerosolized water can come from plumbing systems and devices such as cooling towers (air-conditioning units for large buildings), hot tubs, cooling misters, and decorative fountains. Less commonly, people can get sick by aspiration of tap water containing Legionella. This happens when water accidently goes into the lungs while drinking (“goes down the wrong pipe”). People at increased risk of aspiration include those with swallowing difficulties. Home A/C units do not use water to cool, so these home units do not aerosolize water and are not a risk for Legionella growth. Legionnaires’ disease is generally not spread person to person.