How do you contract Legionnaires’ Disease?

Legionnaires Disease is usually contracted through inhaling water droplets suspended in the air that contain the bacteria Legionella.  In natural settings, Legionella rarely causes concerns, however in man-made settings, Legionella can grow if the water system is not properly maintained. In general, people do not spread Legionnaires’ Disease to other people.

Who is at risk for Legionnaires’ Disease?

Healthy people are at low risk for Legionnaires’ disease. The likelihood of infection increases in the elderly, particularly for men. An infection is also more likely in someone with other risk factors including: people over 50 years of age, smokers and heavy drinkers, people suffering from chronic respiratory or kidney disease, diabetes, lung and heart disease, renal or hepatic failure, systemic malignancy, immune system disorders, and anyone with a weak immune system.

What are common causes and sources of infection?

  • Cooling towers (structures that contain water and a fan as part of centralized air cooling systems for building or industrial processes)
  • Hot tubs that aren’t drained after each use
  • Decorative fountains and water features
  • Showerheads and faucets
  • Hot water tanks and heaters
  • Large plumbing systems

How can you prevent Legionella in your building’s internal plumbing system?

To prevent the growth of bacteria like Legionella in your plumbing, there are actions that you can take that vary in complexity depending on what type of water system you have. Although the risk is low for a healthy person to contract Legionnaires’ Disease (in the home), there are simple precautions you can take to prevent the growth of Legionella. 


Showerheads and Faucets

Clean showerheads and faucet aerators at least four times per year to minimize the growth of the Legionella bacteria.


Are there concerns about PFAS in our drinking water?

Our most recent testing for PFAS in drinking water occurred in June 2019.  Of the 14 compounds tested, only Perfluorooctanoic acid (PFOA) was detected at a level of 2 parts per trillion = 0.002 ug/L.  We are very lucky to have a source as pristine and protected as Sebago Lake.  Over 80% of the Sebago Lake watershed is forested, therefore potential sources of contamination are minimized.  Still, we must continue to be vigilant to ensure water quality.

Here are the complete results of the 2019 testing:


Do you comply with PFAS regulations and testing requirements in drinking water?

There is currently no regulation or standards and monitoring schedule for PFAS chemicals; however,  there is an EPA issued Lifetime Health Advisory level for PFOA and PFOS in drinking water at 70 parts per trillion (ppt) separately or combined. The Portland Water District periodically tests for these substances on a voluntary basis and fall way below suggested levels.

More Information

Are there any concerns about these chemicals in wastewater?

We do share the community’s concern over PFAS chemicals and that is why we are testing for them in the drinking water and our wastewater’s biosolids.  Much of the recent attention has focused on the land application of biosolids. Unlike drinking water, there is no EPA approved method to reliably test biosolids and no federal limits for these compounds have been established.