Legionella Questions – Stump Dr. Legionella

Whether  this is a startup of a system with  “new water” in the system, or a new “approach” to biocide application (e.g. switching from a non-oxidizing biocide) it depends on what you are trying to prove.   If you want to have an “initial” answer you can test as soon as you can be reasonably sure that the water is treated and your oxidant is being fed in to the system water.  Depending on the volume of the water in the system this could be anywhere from several minutes to  an hour or more.  To make sure, check your pump in GPM and the system volume.  E.G. if the system volume is 10,000 gallons and you have a 500 GPM Pump then it would take 20 minutes to “turn the water” over one time.

You must remember however that cooling towers, being that they are constantly (by design) evaporating water and making up water.  So the system is “dynamic.”  As an estimate of the amount of Bromine that it might take to treat the system and maintain a residual you may want to  run some bromine demand testing.  Consult Association of Water Technologies on this procedure. https://www.awt.org.

The same is true of your pH and conductivity testing.  Remember that the system is dynamic and always changing in characteristics and demand.  So if you want “initial results” test after the water has “turned over” a couple of times, but what you should really be focusing on is ongoing  operation.  An ORP driven feeder can help you maintain the level of bromine that you want to keep in the system.

Although Dr. Miler is a Microbiologist and not an Insurance Expert or Attorney we did our homework and asked a well-known insurance company in the business of specializing in providing liability insurance to water treaters to provide out the best answer:

We were informed that although a general liability policy covering General Liability and Omissions and errors (O&E’s) will generally provide adequate coverage to the limit of the policy, the insurance company needs to be notified of any changes in the offerings (products and services) offered and sold by the company proposing to sell the devices. Depending on the coverage of the general liability policy and the company that issues the policy this may be subject to change, and additional insurance premiums may be required.

Where is Legionella Found?

Legionella organisms can be found in many types of water systems. However, the bacteria reproduce to high numbers in warm, stagnant water (90°-105° F), such as that found in certain plumbing systems and hot water tanks, cooling towers and evaporative condensers of large air-conditioning systems, and whirlpool spas. Cases of legionellosis have been identified throughout the United States and in several foreign countries.

Legionella organisms can be found in many types of water systems. However, the bacteria reproduce to high numbers in warm, stagnant water (90°-105° F), such as that found in certain plumbing systems and hot water tanks, cooling towers and evaporative condensers of large air-conditioning systems, and whirlpool spas. Cases of legionellosis have been identified throughout the United States and in several foreign countries.

Outbreaks of legionellosis have occurred after persons have breathed mists that come from a water source (e.g., air conditioning cooling towers, whirlpool spas, showers) contaminated with Legionella bacteria. Persons may be exposed to these mists in homes, workplaces, hospitals, or public places. Legionellosis is not passed from person to person, and there is no evidence of persons becoming infected from auto air conditioners or household window air-conditioning units.

People of any age may get Legionnaires’ disease, but the illness most often affects middle-aged and older persons, particularly those who smoke cigarettes or have chronic lung disease. Also at increased risk are persons whose immune system is suppressed by diseases such as cancer, kidney failure requiring dialysis, diabetes, or AIDS. Those that take drugs that suppress the immune system are also at higher risk.

Pontiac fever most commonly occurs in persons who are otherwise healthy.

Legionellosis is an infection caused by the bacterium Legionella pneumophila. The disease has two distinct forms:

• Legionnaires’ disease, the more severe form of infection which includes pneumonia. Patients with Legionnaires’ disease usually have fever, chills, and a cough, which may be dry or may produce sputum. Some patients also have muscle aches, headache, tiredness, loss of appetite, and, occasionally, diarrhea. Laboratory tests may show that these patients’ kidneys are not functioning properly. Chest X-rays often show pneumonia. It is difficult to distinguish Legionnaires’ disease from other types of pneumonia by symptoms alone; other tests are required for diagnosis. The time between the patient’s exposure to the bacterium and the onset of illness for Legionnaires’ disease is 2 to 10 days.
• Pontiac fever, a milder illness. Persons with Pontiac fever experience fever and muscle aches and do not have pneumonia. They generally recover in 2 to 5 days without treatment. For Pontiac fever, the exposure time is shorter, generally a few hours to 2 days.

Legionella are rod-shaped gram-negative bacteria with over 40 known species. These bacteria survive in free-living protozoa and within biofilms that can develop in water systems.  The first documented outbreak associated with Legionella was at the 1976 Philadelphia convention of the American Legion.  It was here that 221 attendees contracted the disease and 34 died, hints the name “Legionnaires’ disease”.