Disinfectants used to combat Legionella should be effective at re- moving the bacteria while not posing a significant risk to human health. Chlorine and bromine-based solutions (both oxidizing and non-oxidizing types) are a preferred choice for building owners and facility managers. These biocidal chemicals can be used for pre-use/ after-season cleanings and daily, continuous dosing of building water. Dose strength, location and timing will vary from facility to facility and should be evaluated based on sampling results. Does this relate to the current COVID-19 pandemic? Somewhat. Although Legionnaires Disease, the disease caused by Le- gionella, is a bacterial infection rather than viral, it causes essentially the same symptoms as have been reported so far with COVID-19. It also affects immunocompromised and elderly individuals dispropor- tionately. About 10,000 cases of Legionnaires Disease were reported in the United States last year, and this is thought to be an underreported figure. Although Legionnaires Disease is not known to be communi- cable, the CDC reports that approximately 1 in 10 patients diagnosed with the disease will die from complications. What obstacles factor into Legionella compliance and adoption of hygienic practices? Often times, maintenance of cooling tower systems and/or building water resources is handled by an internal, full-time employee. In this specific case of Legionella-prevention where the initial NewYork State regulations were recently passed, there will naturally be pushback from those who are used to operating in a manner now inconsistent with the regulations. Expenses that were previously considered unnecessary such as costs for testing materials, biocides, and hiring of a profes- sional consultant and/or cleaning company now factor into decision- making and compliance. The known potential for Legionella bacteria to spread (up to two miles as mentioned above) and underreporting of infections due to its resemblance to pneumonia are effectively plac- ing an increased responsibility (and liability) on building owners to comply with regulations. Another major obstacle is enforcement of the regulations. There are over 11,000 cooling towers registered in New York State alone, and likely many more than this number have not self-registered. Enforce- ment by the NYSDOH was sparse at the outset of the regulations; but, in the past few years, enforcement responsibilities have been granted to several local health departments throughout the state to promote compliance. It is likely that this pattern will continue and enforcement will eventually become more consistent and routine. A commitment to proper water system maintenance and a regular sam- pling and inspection schedule is the most effective way to ensure that Legionella will not spread. Small changes to existing maintenance and disinfection practices can immediately make a big difference.
Typical cooling tower, located on a building roof.
building water systems as they relate to the wet cooling devices, and how disinfection is being performed. This required Plan is not submitted to the NYSDOH, but must be kept on-site at all times. • Requirement for devices to be cleaned yearly using an approved biocide prior to seasonal operation • Bacterial culture sampling of each device’s water basin for Legionella, paired with an inspection • Notification of the local health department in case of elevated Legionella concentrations - Depending on the severity of the bacteria concentration, an increase in biocide dose and/or an emergency cleaning may be required What evolved from the original New York State Regulations? Five months after the 2016 Protection Against Legionella Regulations came into effect, an updated version was published which made some minor changes (most notably adding monthly bacteriological “dip slide” testing) to the requirements for facilities with cooling towers. The changes were put into effect in Subpart 4-1 – Cooling Towers, which remains current. At the same time, Subpart 4-2 – Health Care Facilities was issued by the NYSDOH (which also remains current). This Subpart mandated the following for all health care facilities, which was to be followed in addition to the existing cooling tower requirements: • Health care facility owners must perform an Environmental Assessment of their facility, which includes information on historical construction details, window configurations, number of beds, etc. • Formulation of a Sampling and Management Plan for the health care facil- ity, where sampling locations are chosen based on the Environmental As- sessment. This is in addition to the required Maintenance Program and Plan. • Sampling is required at intervals not to exceed 90 days for the entire first year after the Plan is adopted, and annually from that point on. There is an exception for water systems which serve solid organ transplant or hemato- poietic stem cell transport patients, which must continue to be sampled at intervals not to exceed 90 days. What type of disinfectants are effective and commonly used to destroy Legionella?
LOU GOLDSTEIN is an Engineer at Walden Environmental Engineering, PLLC in Oyster Bay, NY who helps manage Walden’s Legionella compliance services.
He can be reached at 516-624-7200 or through www.WaldenEnvironmentalEngineering.com.
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july 2020
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