Multnomah County investigates Legionnaires’ Disease outbreak at Rosemont Court – No Threat to Portland Water System   

News Article
shower head with water coming out

The Portland Water Bureau was notified of the outbreak of Legionnaires’ Disease at Rosemont Court on Tuesday morning, Jan. 5.

At this time, there is no threat to our water system. 

“We are saddened by the news of Legionnaires’ Disease at Rosemont Court,” said Water Bureau Director Gabriel Solmer. “We’re assisting Multnomah County by providing expert technical analysis and water sampling.”  

Legionella & Legionnaires’ Disease  

Legionella, a bacteria that causes Legionnaires’ Disease, is the most common cause of waterborne disease outbreaks in the United States. Legionnaires’ Disease is not known to spread from person-to-person or from drinking the water.  

People at increased risk for infection include the elderly, smokers, those with chronic diseases such as COPD or diabetes, and the immunosuppressed. Legionnaires Disease, similar to COVID, has symptoms that are flu-like (fever, tiredness, muscle aches, and headache). Signs of a serious Legionella lung infection (pneumonia) include cough and chest pain. Many people sick with Legionella also have diarrhea.  

Learn more about Legionnaires’ Disease from the Centers for Disease Control and Prevention (CDC)

How does Legionella exposure happen? 

People get sick from Legionella by breathing in small water droplets containing the bacteria, not from drinking the water or contracting it from other people. Legionella can grow in plumbing systems when the water is warm and has low levels of disinfectant. Common ways people breathe in water droplets with Legionella are in a large building that uses a cooling tower, during showering, hot tub use, or exposure to decorative fountains. 

The risk of exposure to Legionella in a single-family home is low. Large buildings that have complex plumbing systems are at a much greater risk to Legionella growth. 

Legionella & drinking water 

Portland’s drinking water is safe to drink, even if you live near this senior living facility. Legionnaires’ Disease is not contracted by drinking or consuming water.

Maintaining water quality and controlling Legionella growth is a shared responsibility. Portland controls microorganisms, including Legionella, with chlorine to deliver safe and reliable drinking water to your property. Once water enters a home or building, the resident or building manager is responsible for maintaining water quality in the home or building plumbing system. 

What can I do? 

If you think you may be sick from Legionella contact your doctor or the Multnomah County Health Department at 503-988-3406.  

If you are an owner or manager of a large building, take steps to manage water quality in building plumbing to control Legionella.  

If you live in a care facility or apartment building and have concerns about Legionella exposure in your building, check with your property manager to see if they have an active water quality management plan to reduce the risk of Legionella growth in your building.

If you live in a single-family home, control Legionella growth by maintaining water heaters at 140 degrees. 140 degrees is very hot and can cause burns. Take steps to prevent scalding risk at that temperature. You or a plumber can install anti-scald valves or faucets to prevent burns. 

The Portland Water Bureau does not have the ability to test water from homes or buildings for Legionella.  

Where can I learn more?  

Centers for Disease Control and Prevention (CDC) Legionella website 

Water Quality in Large Buildings webpage