PLUMBING SYSTEM SAFETY AND RE-OPENING FACILITIES AFTER SHUT-DOWN
The domestic plumbing systems in any building or part of a building that has been shut down or has experienced reduced use due to COVID-19 policies are at risk for causing disease and death due to the effects of increased water age, including corrosion and growth of bacteria. Before re-opening any such building, steps need to be taken to minimize these risks, and a licensed plumber should be consulted.
The Illinois Department of Public Health (IDPH) has written a general guidance document for returning these systems to regular use, available at https://www.dph.illinois.gov/covid19/community-guidance/plumbing-systems-water-quality-guidance. In Attachment B of this document, Section II, Step 2. b., IDPH recommends setting the water heater to at least 120 degrees F prior to flushing the domestic hot water plumbing. We recommend a higher temperature of at least 142 degrees F as this will kill Legionella bacteria in the heater within 30 minutes. However, do not use water at this temperature for flushing if the building’s Drain Waste Vent (DWV) materials and/or plumbing system components cannot handle this higher temperature. WARNING: 142 degree F water can cause third degree burns in seconds. Note that Legionella bacteria can continue to grow at temperatures up to 122 degrees F.
The Environmental Science Policy and Research Institute has written a useful guidance document, “Reducing Risk to Staff Flushing Buildings”, available at https://esprinstitute.org/wp-content/uploads/2020/05/FINAL_Reducing-Risk-to-Staff-Flushing-Buildings-20200501.pdf.
Use the IDPH guidance in conjunction with your facility’s Legionella Water Management Program (WMP). If none exists, we recommend writing a remediation and/or recommissioning plan. Then later, a full WMP can be written. The Centers for Disease Control (CDC) offers a free training program on how to write a WMP, available at this web link:
CDC has also created a toolkit to assist in developing a WMP, available at this link: