Menu
Peer-reviewed studies indicate that drinking water systems are the primary source of legionella bacteria. In addition, The U.S. Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), U.S. Environmental Protection Agency (EPA) and the U.S. Veterans Health Administration (VHA) all list drinking water systems as primary sources of legionella bacteria and Legionnaires’ disease. According to the CDC, more than half of Legionnaires’ disease outbreaks are caused by drinking water. Exposure to legionella bacteria most often occurs when exposed to contaminated water coming out of our faucets, shower heads, and even ice machines. Drinking water systems begin with source water and the public water treatment and distribution system which provides the supply water to our homes, schools, work places, and public buildings.
The World Health Organization says that every year more than 3.4 million people die as a result of water related diseases, making it the leading cause of disease and death around the world. Although the U.S. has one of the safest drinking water systems in the world, there are an estimated 4-32 million cases of acute gastrointestinal illness (AGI) per year from public drinking water systems.
According to the CDC, about 8,000 cases of Legionnaires’ disease are now reported each year solely in the United States. In general, the number of cases reported to the CDC has been on the rise over the past decade. This may reflect a true increase in the frequency of disease due to a number of factors including an older U.S. population, more at-risk individuals and aging plumbing infrastructure. It may also, in part, be a result of increased use of diagnostic testing.
While larger outbreaks get more media attention, the CDC concludes that only 4% of Legionnaires’ disease cases are part of known outbreaks. The remaining 96% of cases are single, sporadic cases.
There are many opportunities for bacteria to get into our water, even after the initial treatment. Since Legionella and other bacteria are naturally occurring in our source water, our public treatment facilities use safe levels of chemicals to eliminate them. Under normal conditions, the bacteria remains in the biofilm. However, our public water systems are disrupted routinely by water main breaks, fire hydrant use, flooding, source water changes, new chemical treatments, and regular maintenance. When this happens, the biofilm where the bacteria lives is often released into the public water system where it can multiply in water storage towers and stagnate in low-flow areas and is then ultimately distributed downstream to our homes and buildings where we live.
It means a more thorough investigation is needed to figure out how the bacteria got there and where else in the building and surrounding area it could still potentially be found. The water used in virtually all building water systems comes from the drinking water supply. In some systems it is refreshed regularly and is sometimes treated by water management professionals on behalf of building owners. If incoming water contains bacteria, it can enter a sub-system and in most cases the water management practices consistent with ASHRAE “Best Practices” will neutralize it. Significant disruptions to the public water system can release large volumes of contaminants into a building and consume the chemical treatments—increasing the risk of bacterial growth.
This is why it is so crucial for state and local health departments to strictly follow the comprehensive testing protocols established by the CDC when investigating the source of any Legionnaires’ disease case.
The risk of exposure to bacteria from our water systems increases significantly during events such as water system maintenance, water main breaks, nearby construction, water pressure changes, changes to water treatment, flooding and source water changes. However, few communities require water users to be notified in those cases. Making matters worse is the significant misinformation provided by authorities leaving residents confused or incorrectly believing there is no risk. Public notification practices need to improve, along with public education on how to best protect ourselves during periods of higher risk.
According to the CDC, more than half of Legionnaires’ disease outbreaks are caused by the drinking water. Exposure to legionella bacteria most often occurs when exposed to contaminated water coming out of our faucets, shower heads, and even ice machines.
There are many opportunities for bacteria to get into our water, even after the initial treatment. Since Legionella and other bacteria are naturally occurring in our source water, our public treatment facilities use safe levels of chemicals to eliminate them. Under normal conditions, the bacteria remains in the biofilm. However, our public water systems are disrupted routinely by water main breaks, fire hydrant use, flooding, source water changes, new chemical treatments, and regular maintenance. When this happens, the biofilm where the bacteria lives is often released into the public water system where it can multiply in water storage towers and stagnate in low-flow areas and is then ultimately distributed downstream to our homes and buildings where we live.
It means a more thorough investigation is needed to figure out how the bacteria got there and where else in the building and surrounding area it could still potentially be found. The water used in virtually all building water systems comes from the drinking water supply. In some systems it is refreshed regularly and is sometimes treated by water management professionals on behalf of building owners. If incoming water contains bacteria, it can enter a sub-system and in most cases the water management practices consistent with ASHRAE “Best Practices” will neutralize it. Significant disruptions to the public water system can release large volumes of contaminants into a building and consume the chemical treatments—increasing the risk of bacterial growth.
This is why it is so crucial for state and local health departments to strictly follow the comprehensive testing protocols established by the CDC when investigating the source of any Legionnaires’ disease case.
The risk of exposure to bacteria from our water systems increases significantly during events such as water system maintenance, water main breaks, nearby construction, water pressure changes, changes to water treatment, flooding and source water changes. However, few communities require water users to be notified in those cases. Making matters worse is the significant misinformation provided by authorities leaving residents confused or incorrectly believing there is no risk. Public notification practices need to improve, along with public education on how to best protect ourselves during periods of higher risk.
According to the CDC, more than half of Legionnaires’ disease outbreaks are caused by the drinking water. Exposure to legionella bacteria most often occurs when exposed to contaminated water coming out of our faucets, shower heads, and even ice machines.
The Incidence of Legionnaires’ disease can be significantly reduced. The best solution for preventing Legionnaires’ disease is reducing, and possibly eliminating, the Legionella bacteria in our public water system to prevent it from entering buildings.
Building owners have many new resources to help them reduce the risks of legionella. Read more at CDC TOOLKIT.
Legionnaires’ disease is preventable. Prevention in the water system & timely diagnosis are keys to saving lives.
Join our newsletter to learn about Legionnaires’ Disease and how it can be prevented!
2023 All Right Reserved. Prevent Legionnaires
