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Legionella Oubreak Places Emphasis on Outdoor Air Quality
September 1, 2016 - HVAC
By Ray Field
Indoor air quality is a term we hear frequently. But last year’s Legionella outbreaks in New York City and other major metro areas highlight the need for maintenance and engineering managers in institutional and commercial facilities to discuss and evaluate corporate responsibility for maintaining outdoor air quality (OAQ).
Why should you care about OAQ?
It’s time for businesses and facility management to take a new and hard look at how current maintenance practices for their cooling systems have an impact on OAQ, especially if cooling towers are a part of the HVAC system. The air quality created by the mist and vapor released from these systems can have a significant effect on the health of visitors, pedestrian traffic and employees to facilities.
Citizens too are bringing greater awareness to the need for better air quality, especially as their risk increases in major cities with heavy concentrations of cooling towers. And while litigation and legislation is ongoing from these recent breakouts, it’s a simple matter of risk assessment to understand that individuals may be able to sue facility management and owners if they contract Legionnaires Disease or other illnesses from contaminated air linked to dirty cooling towers. As we’ve recently seen with legislation in New York City, mandated cooling tower management programs now include stricter sanctions, increased oversight and ultimately more responsibility placed on private companies.
For more on the Legionnaires outbreaks in 2015, click here for a podcast from Goodway.
Cooling tower maintenance can often be overlooked, but systems that are dirty are more likely to harbor deadly bacteria such as Legionella. While cooling towers are not the only culprit when it comes to Legionella, it is one of the most common and studies have shown that between 40 and 60 percent of cooling towers tested positive for Legionella.
What can you do about it?
Before you panic, you can be proactive to ensure your cooling systems are properly maintained to reduce negative impact on both indoor and outdoor air quality, and taking precautionary action to prevent Legionella. The ANSI/ASHRAE Standard 188-2015, released last summer, is prepared for building owners and management to effectively implement a management and cleaning program to lower the risk of Legionellosis and establish minimum requirements for building water systems and HVAC systems.
For starters, consult with your building management and HVAC professionals to put together a maintenance plan that includes the following steps:
Inspect Towers Monthly. Sediment, scale and slime can lead to buildup and help legionella grow and thrive. Regular inspections will help determine when to schedule cleaning.
Clean Tower Basin Surfaces. If sediment is visible, the basin needs to be cleaned, and cooling tower vacuums make it easier to remove contaminants without shutting down or draining your system.
Treat Circulating Water. Use biodegradable descalers and antiscalant technology as well as appropriate corrosion inhibitors and dose biocides at recommended levels. Using a biofilm dispersant in conjunction with biocides enhances biological control. A descaler will help remove tough scale on tower fill, allowing biocides to tackle legionella in the fill sections more effectively.
Drain and Clean. Set aside time annually to drain your system and perform a thorough cleaning before turning it back on. If your system has been offline for any length of time, be sure to disinfect.
Clean the Fill. The tower fill provides the perfect environment for bacterial growth, especially legionella. A cooling tower fill cleaner will clean lime scale and debris, and inhibit growth of other bacteria when utilized in conjunction with appropriate biocides. Protocols for disinfection of Legionella are well defined by the Occupational Safety and Health Administration, the Centers for Disease Control and Prevention and the U.S. Environmental Protection Agency.
Arm Yourself with Proper Equipment. Make sure you have the right products for each maintenance need. There is equipment available that makes it even more convenient, such as clean-in-place solutions that reduce downtime. Invest in products that not only save time and money, but also performs effective cleaning.
Maintaining your cooling tower system is one component of reducing the risk of Legionella and the potential implications for OAQ surrounding your business. The Centers for Disease Control and Prevention also cites hot water tanks and heaters, large plumbing systems, hot tubs and decorative foundations as examples of water systems.
In addition to regular maintenance, it’s important to evaluate your water treatment program, or create one if it doesn’t exist, to identify potential risks and determine both mechanical and chemical solutions.
Get ahead of the game and take the time now to proactively help tackle air-influenced diseases and review your environmental impact.
Ray Field is the Director of Liquid Solutions at Goodway Technologies.