Is Hyperchlorination an Effective Legionella Treatment?

Hyperchlorination is a common short-term treatment for Legionella. It is more difficult to implement than the Legionella heat and flush technique but may be more effective. While perhaps more effective than heat and flush, hyperchlorination is often not effective in the long term.

When hyperchlorination is unsuccessful, Legionella growth can rebound resulting in bacterial levels that are higher than originally detected. This is according to the NY State Department of Health in “Environmental Health Information Related to Legionellosis in Healthcare Facilities.”

Therefore, it is important to measure the free chlorine residual during the hyperchlorination as well as conduct Legionella testing for some period of time following the hyperchlorination.

If the initial hyperchlorination treatment does not succeed in mitigating Legionella, the treatment may be repeated and possibly expanded to the hyperchlorination of the entire building.

Given these drawbacks, implementing alternative, continuous Legionella control treatment methods may offer significantly superior long-term cost and health benefits when compared to hyperchlorination. Regardless, the use of hyperchlorination or more effective Legionella control methods should be considered in advance as part of a comprehensive Legionella control water management plan.

If you have attempted hyperchlorination as a Legionella control treatment and found that it was not successful, or even worse, resulted in a Legionella rebound to higher levels, contact our team at Legionella Control Systems right away so we can provide expert advice on a more effective Legionella mitigation approach.