Challenges & solutions for controlling Legionella in commercial buildings
Over the last few years, the U.S. has seen an influx of Legionella in the water supply across the country. According to the Centers for Disease Control and Prevention (CDC), drinking water outbreaks have been on the rise, particularly those caused by bacterial microorganisms. In fact, between 2013 and 2014, a total of 42 outbreaks associated with drinking water were reported across 19 states, the majority of which (57%) were due to Legionella. In the last year alone, a steady cadence of Legionella outbreaks have been observed. Last summer, 10 people in New York City were hospitalized with Legionnaires’ disease. A few months later, two people contracted the disease at an Embassy Suites in Chicago, followed by outbreaks reported in Boston, New Hampshire and other locations.
Municipal infrastructure supplying water to buildings has aged significantly, in some cases almost 100 years, and in reality, was never designed to last indefinitely. The good news is that progress is being made. In October, the government passed America’s Water Infrastructure Act of 2018, a bipartisan law that authorizes funding for water infrastructure projects and seeks upgrades to wastewater, drinking and irrigation systems. While this is a good first step, realistically it could be years before actual improvements are made to pipelines and water treatment facilities.
At the Source
In many systems, water lines tend to run straight from a tank to the tap, and when not running the water sits static and can warm to the ambient temperature, allowing biofilm to form and harbor the growth of Legionella. Biofilm, which feels like a slime, can host a range of bacteria, algae and other microorganisms. These conditions are ideal breeding grounds for bacteria such as Legionella to grow and spread, putting the water that subsequently is released from a faucet or showerhead at risk. As taps are opened, the water flowing out can shear the biofilm, releasing pathogens into the water stream. Legionella also can enter the air through steam and then infect those who breathe it in. When Legionella becomes airborne, it quickly spreads to the air throughout the entire
building, and once it is present in the water system, containing and eliminating the bacteria is time consuming and expensive.
However, pipes and water infrastructure are not the only culprits of bacteria growth. Many
building owners who find themselves dealing with a Legionella problem do not realize that water equipment, such as water heaters and coolers, hot water tanks, beverage equipment, washing machines, and even central heating and air conditioning systems are all susceptible to bacteria growth.
Most water utilities add chlorine to water to control and mitigate bacteria growth within distribution infrastructure. Once water reaches an appliance, such as a water cooler or beverage machine, it often passes through a carbon filtration device that has been installed in the appliance to remove the chlorine from the water. It is at this point where the equipment becomes unsafe, as the dechlorinated water passing through or being stored in the equipment now is susceptible to bacteria growth.
Legionella is difficult to detect, and quickly reacting to address it is nearly impossible, so in almost all cases an outbreak cannot be stopped before it happens. Legionella commonly is detected when someone is diagnosed with Legionnaires’ disease. The contamination then can be traced back to the possible source. From there, it can take several days to measure and test for the bacteria, and if confirmed, the remediation process is both time consuming and expensive, particularly in terms of lost revenue and productivity.
Equipment can be treated with chemical or hot water flushes, which require intense, high concentrations of chlorine or hot water to flow through the system for several hours. The entire process can take days, as there often are multiple rounds of flushing required. Therefore, from initial testing through the treatment process, water systems can be out of commission for up to two weeks before being safe for use.
The reality is that bacteria growth is inevitable. Resolving issues in municipal water delivery systems is a resource-intensive issue that faces increasingly complex challenges. Practically, municipalities are not able to address infrastructure issues quickly enough. While municipalities, government and environmental agencies are working hard to update policies and fix underlying water infrastructure, they are up against major roadblocks like limited budgets, competing priorities and even natural disasters. For instance, residents in Austin, Texas, last October were forced to boil their tap water or purchase bottled water when unexpected severe flooding overwhelmed the city’s water treatment facilities.
Regardless of upgrades to infrastructure, our pipes always will have Legionella, and the water systems fed by those pipes always will be at risk for harboring the bacteria. Legionnaires’ disease is therefore an institutional problem. Building owners, property managers and maintenance workers are the ones who must address the issue and be responsible for preventing it. With this in mind, it is critical for water equipment to have a mechanism for disinfecting water as close to the point of use (POU) as possible to mitigate the risk of exposure to consumers.
Pros of POU
Water appliances can become vulnerable to bacteria growth, which can be difficult to eliminate entirely once detected. Water safety is becoming increasingly dependent on POU treatment, as it offers a fool-proof approach to water purification.
By selecting and installing equipment that is outfitted with POU purification at every exit point, building owners can help prevent serious health and financial implications in the future. For instance, by installing ultraviolet disinfection technology or appropriately certified nanofiltration for Legionella before the tap of a faucet or a water cooler, the water is disinfected in seconds as it passes through, mitigating health risks to the consumer while simultaneously protecting the building owner from the chance of an infection leading to required remediation efforts.
Reducing the risk of Legionella becoming a widespread issue within a building requires a proactive approach to disinfection. By installing POU disinfection technology, building owners are taking the extra step to future-proof their building infrastructure and assure consumer safety from dangerous waterborne bacteria—a problem that is quickly becoming the norm.