Water distribution systems and cooling towers of large buildings, including hospitals and hotels, are major sources of Legionella contamination. Legionella outbreaks can lead to Legionnaires’ disease, which is a form of bacterial pneumonia contracted from breathing in mist from water contaminated with Legionella. The mist can come from showers, sinks, hot tubs or air-conditioning units. According to the Center of Disease Control and Prevention Legionnaires’ disease hospitalizes between 8,000 and 18,000 people annually and can cause death in up to 30% of cases. Adequate water treatment is necessary to prevent Legionella outbreaks and to ensure the safety of delivered water.

How Does A Water System Become Contaminated With Legionella Bacteria?

Legionella bacteria are inherently found in natural aquatic bodies and can survive under a wide range of conditions. Organic sediments, scale and inorganic precipitates provide Legionella with an ideal surface for biofilm formation. Biofilm matrices provide shelter for the bacteria and prevent primary disinfectants like chlorine from eradicating them.

Why Is Legionella Prevention Important?

The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) is proposing new standards regarding the control and prevention of waterborne bacterial outbreaks in building water systems. These new standards will be applied to human occupied buildings, excluding single family residential buildings and is intended for use by the owners/managers of most commercial, industrial and institutional buildings in the United States.

ASHRAE advises buildings to have up-to-date Hazard Analysis and Critical Control Points (HACCP) documents. HACCP is the most widely used risk management process for preventing environmental-source diseases, such as Legionella, from harming people. These HACCP documents will expect building management to identify the uses of potable and utility water, create diagrams of their water systems, identify control points and critical control points and establish monitoring procedures and corrective actions if an outbreak occurs.

Legionella Prevention With Clearitas

Clearitas 401 from Blue Earth Products is a proprietary form of oxidized chlorine that attacks and eliminates the organic and inorganic precipitates that provide Legionella with a surface for attachment and growth. Used in conjunction with a primary disinfectant, Clearitas effectively removes and prevents the medium in which Legionella thrives.

Clearitas is a safer and more cost-effective alternative to other methods of Legionella water treatment. This nonhazardous chemical is NSF 60 certified and safe for use in all water systems, including drinking water. Injected directly into the water line, Clearitas is applied online with low up-front capital costs and minimal maintenance.


  • Lower total bacterial counts
  • Improved disinfectant effectiveness
  • Low capital cost solution to bacterial remediation
  • Organic and inorganic deposit removal
  • Quick results