Legionnaires’ Disease & Legionella Testing

Authors: Richard DiNitto and Amanda Adams
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Bacterial growth in water-based systems and environments in common commercial and industrial buildings can often lead to an outbreak of Legionnaires' disease, a severe and often lethal form of pneumonia.  The disease is caused by the presence of Legionella pneumophila bacterium. The bacterium in water-based systems results in up to 18,000 people each year becoming infected, with as many as 1,800, or 10%, proving fatal.  Flu-like symptoms such as coughing, fever, headache and shortness of breath are common.
 
While a substantial number of people may die from the disease, it is highly treatable with antibiotics if caught in the early stages.  Facilities with water-based systems or environments should implement a periodic testing program to ensure that the bacterium are either not present, or at levels that are below published guidelines. When detected at elevated levels, prompt action on the part of the property owner or building manager is warranted. Easy and cost-effective solutions are available to eliminate the bacteria.
 
Common locations that Legionella will grow include:

• Shower facilities;
• Decorative fountains;
• Mist machines;
• Water cooling towers;
• Water features, i.e. indoor ponds;
• Humidifiers; and
• Hot tubs/whirlpools.

 
The CDC has published a handy Fact Sheet on the disease, which is available for free at: https://www.cdc.gov/legionella/downloads/fs-legionnaires.pdf.
 
Regular testing of these features can help control and eliminate any bacteria growth. Depending on your operation’s features, recommended testing frequencies may vary. Many facilities will test between one to two times per year, typically in the spring and early fall.
 
When testing for the first time, it is highly recommended that all sources be tested and not just a representative portion. Once the results from the initial testing are obtained, a reduced testing frequency on all sources can be made.
 
Unfortunately, in reviewing water testing results, there are no federal or state-level regulatory standards for comparison, only guidelines for remedial action.
 
A handy guide for comparison by some example water sources is shown below:

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Since growth of Legionella is controlled largely by temperature and water free of compounds not toxic to them, treatment is easy and effective. While the bacterium will die above 122 degrees F, they will become dormant at colder temperatures (< 68 degrees F).
 
Cleaning and disinfecting your water systems, and using a biocide application, is the most effective remedy in controlling and eliminating Legionella.
 
While there are no enforceable regulatory levels, some states and municipalities have established mandatory inspection, testing, cleaning, and disinfection requirements, as well as requirements for registration of possible sources.
 
Our staff can assist you in identifying any local agency registration and inspection requirements, as well as providing further information on a testing regime and disinfecting program.  
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The Isosceles Group is retained to develop, implement and maintain Occupational Health & Safety (OHS) and Environmental Management Systems (EMS) at industrial and commercial facilities. It also manages various EHS issues that affect the operation and expansion of such facilities. 
 
If you would like The Isosceles Group to assist with EHS management at your facility, please contact Richard DiNitto at [email protected] or (617) 330-2800.