Considerations for large building water quality after extended stagnation

Abstract

The unprecedented number of building closures related to the coronavirus disease (COVID‐19) pandemic is concerning because water stagnation will occur in many buildings that do not have water management plans in place. Stagnant water can have chemical and microbiological contaminants that pose potential health risks to occupants. Health officials, building owners, utilities, and other entities are rapidly developing guidance to address this issue, but the scope, applicability, and details included in the guidance vary widely. To provide a primer of large building water system preventative and remedial strategies, peer‐reviewed, government, industry, and nonprofit literature relevant to water stagnation and decontamination practices for plumbing was synthesized. Preventative practices to help avoid the need for recommissioning (e.g., routine flushing) and specific actions, challenges, and limitations associated with recommissioning were identified and characterized. Considerations for worker and occupant safety were also indicated. The intended audience of this work includes organizations developing guidance.

Critical Review: Propensity of Premise Plumbing Pipe Materials to Enhance or Diminish Growth of Legionella and Other Opportunistic Pathogens

“…Another field study identified their most frequently Legionella positive sites as being located at the end of the distribution system and having the highest turbidity, iron, TOC, and water age, as well as the lowest flow [ 247 ]. The association between OPs and stagnation has created interest in strategies to reduce building water stagnation effects such as removing dead-legs, flushing, maintaining the hot water system, and shock disinfection [ 248 , 249 , 250 , 251 ]. The effectiveness of these strategies should be evaluated within the context of the specific pipe materials that are present.…”

Flushing of stagnant premise water systems after the COVID-19 shutdown can reduce infection risk by Legionella and Mycobacterium spp

“…Building inactivity results in stagnant water in the premise plumbing that can adversely affect water quality, including the loss of residual chlorine, growth of bacteria, and release of harmful metals like lead. 1-4 Temporarily idle buildings is not a new issue (e.g., during the annual summer recess of schools). Yet, there are gaps in the peer-reviewed literature regarding microbiological water quality changes during such closures and the corresponding risks.…”

Water science under the global epidemic of COVID-19: Bibliometric tracking on COVID-19 publication and further research needs

“…Another potential secondary risk comes from the stagnant water in reopening buildings after extended stagnation during the pandemic. Stagnant water can have chemical and microbiological contaminants that pose potential health risks to occupants [80] . In particular, water stagnation in buildings may lead to Legionella growth, but study on the relationship between Legionnaires' disease cases and COVID-19 lockdowns is still limited [81] .…”