An unintended hazard lies in wait for tenants of shuttered buildings poised to reopen in coming weeks: potentially harmful microbes in stagnant water systems.
A unique and unintended health hazard lies in wait for tenants of shuttered commercial buildings poised to reopen in the coming weeks: potentially harmful microbes in stagnant water systems.
Because of stay-at-home orders, building water systems and the municipal supply lines that feed them have experienced dramatically reduced flow, even total stagnation, as the offices, hotels, retail stores and other public spaces they service have been left vacant for months. Public health officials and plumbing experts know this is a recipe for dangerous, perhaps deadly bacterial amplification such as Legionella pneumophila, the microbe that causes Legionnaires’ disease.
An almost annual outbreak already infects pockets of New York city’s cooling towers during summer months. This year, with millions of square feet of normally busy commercial space idle, creating the perfect breeding ground for waterborne microbes, the threat is exponentially worse. Building owners and managers must take the issue seriously.
The science behind the phenomenon is well documented. Water systems in New York and other big cities, including Chicago, were designed for increasing volumes based on projected population growth trends. Drinking water disinfectants, such as chlorine, depend on system-design calculated flows, which include a short time to consumption in order to be effective. A near-overnight shutdown of water flow in large buildings has increased “water age,” allowing chlorine and chloramine disinfectant levels to dissipate, thus causing a systemic failure of a building’s entire water network.
Even if individual owners attempt to do the right thing by flushing systems, there is no guarantee they will return chloramine levels to where they need to be for safe operating. Because chlorine breaks down relatively quickly (think how often pH levels in a swimming pool must be checked), traditional drinking water disinfection methods might contribute to a critical failure under these unique circumstances.
A study by a water systems expert, Dr. Victor Yu of the University of Pittsburgh, finds that L. pneumophila is already prevalent in complex building water systems. Approximately 70% of three-story and taller buildings regularly test positive for the bacteria, for instance. Given the ready-made conditions for microbial infection, obsolete guidance and conventional standard practices simply are not enough to properly ensure tenant and visitor safety.
Water professionals including engineers, licensed master plumbers and contractors have a great opportunity to make a positive difference as New York City reopens by improving the safety of critical water supply systems. Likewise, building owners can seize a rare moment to make important health and wellness updates, many for the first time in decades. The question is will they?
Christoph Lohr is director of education and strategic projects at LiquiTech. Terence O’Brien is an executive vice president at the Association of Contracting Plumbers and senior director of the Plumbing Foundation New York City.
This op-ed originally appeared on the website of Crain’s sister publication Crain’s New York Business.
Read original article here.