New Jersey Legionella Risk

New Jersey - Legionella Prevention and Costs of Legionnaires Outbreaks

Historical Headlines Related to Legionella in New Jersey

November 29, 2023

New Jersey health officials warned of a Legionnaires' disease outbreak that sickened dozens. The state's Department of Health said 41 people in two counties were sick and tested positive for Legionella. The tests were conducted between August and October when the onset of symptoms occurred. These two counties typically see about six to eight confirmed Legionnaires' cases in that same time frame each year, health officials said. (Source)

November 17, 2023

Trenton Water Works (TWW) will install water-main flushing assemblies in targeted areas of its 683-mile water-distribution system. These flushing assemblies will strengthen its system management and maintain high water quality. “The flushing devices will enable the water utility to flush water mains of aged water and sediment, improving overall water quality,” said Sean Semple, Director of the city’s Department of Water and Sewer, which operates Trenton Water Works. “This $1.7-million capital project is part of TWW’s Legionella mitigation.” (Source)

November 2, 2023

The federal government knows a way to prevent the spread of Legionnaires’ disease, but implementing it could take up to five years. This is an unacceptably long time that will allow more people to needlessly become sick and possibly die, a New Jersey congressman says. Raising the disinfectant levels at water treatment plants is widely regarded as an effective way to stem the spread of Legionnaires, but that would require several years to adopt new rules. In a letter he sent to the U.S. Environmental Protection agency, U.S. Rep. Frank Pallone, D-6th Dist., made the case for quicker action. “The bottom line is that Legionnaires’ disease is really dangerous, and we have to do more to keep people safe,” Pallone said. (Source)

August 24, 2023

The New Jersey Department of Health is investigating a possible cluster of Legionnaires' disease amongst residents of Passaic and Bergen counties. 9 cases have been identified so far in "neighboring Passaic County municipalities, along with one additional case in a neighboring Bergen County municipality." It's the same basic area that experienced an increase in cases last winter. "Early diagnosis is key to effectively treating Legionnaires' disease," said New Jersey Acting Health Commissioner Dr. Kaitlan Baston. "Although the risk of contracting Legionnaires' disease if you live in or have recently visited Passaic or Bergen counties remains low, individuals who develop pneumonia-like/respiratory symptoms should visit their health care provider immediately to be evaluated." (Source)

June 16, 2023

The City of Trenton sent out 63,000 mailers to customers of Trenton Water Works explaining the importance of Legionella and what you can do to prevent its spread. Awareness and prevention are one of the greatest defenses against exposure and disease. Trenton Water Works, alongside the NJ Department of Environmental Protection and the Environmental Protection Agency, are working tirelessly to implement remedial action. (Source)

May 26, 2023

Trenton Water Works has completed three weeks of low-velocity flushing at fire hydrants in targeted areas throughout the Trenton service area. These flushing efforts will continue into the summer months to optimize chlorine residuals which help mitigate pathogens' growth, including Legionella. The process includes opening fire hydrants, sometimes for extended periods, and sampling until the area receives optimal chlorine residuals. By conducting these efforts, Trenton Water Works will be able to identify areas requiring permanent flushing devices. (Source)

May 5, 2023

Trenton Water Works began a low-velocity flushing program throughout its water distribution system in an effort to lessen the growth of pathogens, including Legionella bacteria. Specialized equipment is being used to conduct the flushing of its water mains in the 683-mile water distribution system, according to Trenton Water Works (TWW). “The goal of the low-velocity water main flushing is to mitigate conditions that promote the growth of pathogens, including Legionella, by increasing and sustaining chlorine residuals,” said the acting director of the city’s Department of Water and Sewer, which operates TWW. He added that once they achieve this water-treatment goal, they will execute additional action steps to improve water quality in the TWW system. (Source)

April 19, 2023

Legionnaires’ disease will become a more prominent threat as the weather heats up and Rider University's heating, venting and air conditioning (HVAC) systems are turned back on. Older people and those with compromised respiratory systems being primarily at risk, according to professor James Riggs. According to the University's vice president of facilities and university operations, the facilities department found out about the cases of Legionnaires’ disease in a news article during the summer of 2021. The department then contacted its environmental consultants who recommended that they flush their water systems regularly to ensure constant water circulation. If water is still for too long, bacteria like Legionella can cultivate on its surface. “Every couple of weeks … we flush some of the hydrants around campus, and we’ll tell the custodians to run the showers,” said Reca. “That’s what keeps the water moving so it doesn’t build up.” (Source)

April 14, 2023

In the additional seven cases reported recently, no cases of Legionnaires’ disease were identified for township residents who received water from Trenton Water Works. In response to the additional cases, TWW will perform measures to tackle the Legionella in the water system. They are starting with a low-velocity flushing program throughout its service area. The flushing program will increase the water circulation throughout the distribution system and increase and optimize chlorine levels. “Low-velocity, or conventional flushing, restricts the hydrant flow to such levels that the sediment within the pipes is not disturbed or scoured,” NJDOH added. “The goal is to optimize chlorine disinfection to minimize the conditions that contribute to the growth of pathogens, such as Legionella.” (Source)

April 2, 2023

According to New Jersey Department of Health, seven additional cases of Legionnaires’ disease were reported in Mercer County residents who live in areas served by Trenton Water Works. Officials said that between October of last year and this month, seven people throughout Trenton, Ewing Township, Lawrence Township, and Hamilton Township have contracted the disease. Of the seven people who contracted the disease, officials said, two individuals have died. (Source)

January 13, 2022

A possible cluster of Legionnaires’ disease cases are being investigated by the New Jersey Department of Health (NJDOH). The cluster was discovered among residents of neighboring municipalities across Passaic County and Bergen County. As of December 28, NJDOH is aware of seven confirmed cases of Legionnaires’ disease in the cluster along with a report of an additional suspected case of Legionnaires’ disease. The cases were reported to NJDOH between November 9 and December 21, 2022. (Source)

December 29, 2022

Legislation was passed by the state Senate which is aimed at protecting the public from contaminated water and preventing the transmission of Legionnaires’ disease. According to Senator Linda Greenstein, one of the bill's sponsors, the legislation would require the Department of Environmental Protection (NJDEP), the Department of Health (NJDoH) and owners or operators of public water systems to take certain steps to prevent and control cases of Legionnaires’ disease including setting disinfectant levels and requiring water testing. “This legislation would put in place reasonable measures that protect our children, the elderly, and immunocompromised residents from serious illness,” said Greenstein, “Legionnaires’ disease can be prevented. Through the application of more guidance and oversight, we can better safeguard the health and wellness of all New Jerseyans.” (Source)

December 7, 2022

Hopewell Township officials announced that three homeowner sites tested positive for legionella bacteria. The New Jersey Department of Health (NJDOH) collected water samples in September from homeowners served by Trenton Water Works (TWW). State health officials have informed the volunteer homeowners of the results from the samples taken, according to the NJDOH. (Source)

October 27, 2022

Legionella was found in water supplies from homes throughout Central Jersey, the New Jersey Department of Health announced. The bacteria was found in more than half of the 30 homes sampled in September, including homes in Trenton, Ewing, and parts of Lawrence and Hopewell Township. All the homes were served by Trenton Water Works. This investigation started when Legionnaires’ disease was previously detected in Hamilton Township, with five cases including one death reported since December 2021. The most recent case was reported to health in September 2022. (Source)

October 27, 2022

After an investigation found Legionella bacteria, the New Jersey Department of Health is asking people in certain Mercer County towns to take extra safety precautions when it comes to their household water. In September, samples were collected from 30 homes in Trenton, Ewing, Hopewell and Lawrence -- more than half identified Legionella bacteria in the water samples. It comes after the bacteria was detected in July in several homes in the Hamilton Township area. Officials recommend that if you are at an increased risk for Legionnaires' disease, consider avoiding hot tubs, decorative fountains, power washing or similar activities, which may generate increased amounts of aerosols or mist. Also, keep your water heater set to a minimum of 120 degrees. (Source)

September 9, 2022

In August of this year, two cases of Legionnaires’ disease were reported from the section of Hamilton Township, Mercer County, served by Trenton Water Works (TWW). Two additional cases were reported last year in April and December. One of the four individuals has died. The New Jersey Department of Health (NJDOH) receives approximately 250–350 reports of Legionnaires’ disease each year throughout New Jersey. The Hamilton Township Division of Health continues to work closely with NJDOH to investigate these cases. (Source)

September 9, 2022

Officials in Hamilton Township, New Jersey are concerned about bacteria after a study found 50% of homes tested that are serviced by Trenton Water Works were positive for the legionella bacteria, which can cause legionnaires disease. Trenton Water Works has been aware of the problem since 2020 and has been working on the issue. It is safe to drink, but there are concerns certain residents might be at risk. This is a warning about legionnaires disease, people can get infected when they inhale contaminated water droplets. The legionella bacteria has been found in an abnormally high number of homes in Hamilton Township, Mercer County, which is close to Trent. (Source)

July 21, 2022

A 61-year-old man hospitalized since spring 2022 contracted and has been sickened by Legionnaires disease according to the Department of Health officials in Newark. The resident, who was living at the Seth Boyden Elderly Towers in the city's South Ward, was taken via ambulance to the hospital after experiencing severe pneumonia-like symptoms on April 30th. (Source)

June 10, 2022

The New Jersey Department of Health (NJDOH) announced in May that it was working in with the Parsippany-Troy Hills Health and Human Services Department to investigate three cases of Legionnaires' disease. The outbreak occured last year in guests who had stayed at a hotel in Parsippany. The water testing results revealed the presence of Legionella bacteria in the building's water system that is used for showering, washing hands and brushing teeth.(Source)

June 10, 2022

The New Jersey Department of Health in coordination with the Parsippany-Troy Hills Health and Human Services Department is investigating three cases of Legionnaires’ disease in guests who stayed at the Hilton/Hampton Inn Parsippany Hotel last year. Legionnaires’ disease is a type of pneumonia caused by breathing in Legionella bacteria. The guests visited the hotel, located at 1 Hilton Ct., between July 2021 and October 2021. The individuals range in age from 52 to 77 and have since recovered. (Source)

May 25, 2022

Dr. Hung Cheung, a national expert in environmental health issues, says a bill pending in New Jersey aims to tackle the spread of Legionnaire's Disease by improving water management techniques and public notification. (Source).


Legionnaires’ disease continues to make headlines today. In 2021, the New Jersey Department of Health is investigated a cluster of Legionnaires' disease cases in Union County, with 14 confirmed cases and one death.


In 2020, New Jersey health officials announced that 22 people were infected with Legionnaires' disease and five “older adults,” who had other health problems, had died from the disease.

New Jersey Reported Settlements and Jury Awards

Given the incidence of legionella in New Jersey, and its associated harm, personal injury claims and litigation are also becoming more frequent. Reported settlements and jury awards are unavailable at this time.

State Cap on Jury Awards

New Jersey does not have a cap on the award amounts allowable by law. In addition, public health notices and negative media attention can also lead to business interruption and reputation damage.

Groundwater Temperature Risk Level – Medium

Overall Liability and Risk for New Jersey – High

No, ASHRAE 188 is not part of the state code

Legionella and Water Management Plan Assistance

Need help? For Legionella consulting and services, Water Management Plans, Legionella Control Systems, and Legionella testing please contact us at Legionella Control Systems at 888-416-8626 or

Nancrede Engineering Co., Inc. BBB Business Review