See below for examples of different ways utilities are elevating the need to freshen building water systems before reopening.
AWWA recommends postponing water shutoffs
Given the importance of hygiene and sanitation in mitigating the spread of COVID-19, AWWA recommends utilities postpone water shutoffs during the COVID-19 pandemic.
Note: AWWA’s Statement of Public Policy on the Discontinuance of Water Service for Nonpayment states that “certain circumstances may require some flexibility because water service is a necessity in maintaining sanitary conditions in the home, and may be required for life‐sustaining equipment, or for other critical purposes.” The current pandemic is such a time.
Notice on returning homes to service
When homes are returned to service after an extended period of discontinued service (e.g., weeks or months), an adult should be present in the home to ensure that the meter works, leaks are minimized, wastewater piping is intact, and the building’s plumbing is flushed. A thorough flushing process is appropriate in such situations.
Note: Social distancing protocols will need to be considered when engaging residents about customer assistance programs, managing lead, and other steps in returning service to the home.
Flushing instructions provided to occupants will vary depending on the structure. This is an area of active research. However, key elements of existing protocols include:
- Remove or bypass devices like point-of-entry treatment units prior to flushing.
- Take steps to prevent backflow or the siphoning of contaminants into plumbing (e.g., close valves separating irrigation systems from home plumbing, disconnect hoses attached to faucets, etc.)
- Organize flushing to maximize the flow of water (e.g. opening all outlets simultaneously to flush the service line and then flushing outlets individually starting near where the water enters the structure).
- Run enough water through all outlets (e.g., hose bibs, faucets, showerheads, toilets, etc.), removing aerators when possible. Typical durations in existing protocols range from 10 to 30 minutes for each outlet (duration varies based on outlet velocity).
- Flush the cold water lines first, and then the hot water lines. Note: the hot water tank can be drained directly; it can require roughly 45 minutes to fully flush a typical 40-gallon hot water tank.
- Replace all point-of-use filters, including those in refrigerators.
- Additional precautions may be warranted if there is excessive disruption of pipe scale or if there are concerns about biofilm development. Actions that might be warranted include continued use of bottled water, installation of a point-of-use device, or engaging a contractor to thoroughly clean the plumbing system.
Residents should be reminded that if point-of-use devices are installed, POU devices should be properly installed and adequately maintained.
CDC guidance
U.S. Centers for Disease Control and Prevention (CDC) issued guidance to ensure the safety of building water systems and end-use devices after a prolonged shutdown. Additional information for building owner/operators is in existing CDC resources, such as the Toolkit: Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings.
Water systems should be prepared for questions from building owners/operators managing hotels, schools, childcare facilities, office buildings and public buildings. Properties that are managed as large campuses (e.g., business parks, colleges, etc.) should also be considering this CDC guidance.
Some state agencies are prompting building owners/operators to take appropriate steps to prevent water quality problems prior to re-entry into buildings after the COVID-19 crisis including reminding businesses and schools about existing guidelines for seasonal systems.
Building owners/operators will need information regarding:
- Whether a water system maintains a free chlorine or chloramine residual disinfectant;
- Current residual disinfectant levels;
- Updates on any scheduled free chlorine periods in systems employing chloramines; and
- Any measures the water system is taking to maintain disinfectant residual levels in portions of the distribution systems with reduced utilization due to COVID-19 stay-at-home order.
Because prolonged building water stagnation can lead to elevated lead, copper, and Legionella levels at the tap, there may be a need to raise awareness about lead and copper or other local water quality considerations.
EPA Guidance
The U.S. Environmental Protection Agency (EPA) distributed “Information on Maintaining or Restoring Water Quality in Buildings with Low or No Use” to assist building owners and managers in addressing water stagnation following extended closures due to the COVID-19 response. The guidance says stagnant water presents optimal conditions for the growth of pathogens like Legionella. Stagnant water also changes water chemistry, which may increase corrosion and leaching of metals, including lead. “Turning on the water for immediate use after it has been stagnant can pose a risk to public health if not properly managed,” the guidance notes. “Additionally, turning on water after a prolonged period of non-use could disrupt pipe and plumbing scales to such an extent that microbial and chemical contaminants could be released into the water.”
Communicating to commercial customers
Fresh water should be drawn into building water systems and stagnant water flushed out before they are reopened. It's important to note, however, that each building's water system is unique. Building owners and operators should be aware of information provided by their state or local water system. Examples of different ways utilities are elevating this issue to their commercial customers are below:
Louisville Water Company, Kentucky
Madison Water Utility, Wisconsin
Miami-Dade Water and Sewer Department, Florida
Pittsburgh Water & Sewer Authority, Pennsylvania
WaterOne, Johnson County, Kansas
Reference List
Flushing Guidance for Premise Plumbing and Service Lines to Avoid or Address a Drinking Water Advisory
https://www.waterrf.org/research/projects/flushing-guidance-premise-plumbing-and-service-lines-avoid-or-address-drinking
AWWA C810-17 Replacement and Flushing of Lead Service Lines
ISBN: 9781625762696
AWWA catalog no: 43810-2017
High‐Velocity Household and Service Line Flushing Following LSL Replacement
Richard A. Brown and David A. Cornwell
First published:01 March 2015
https://doi.org/10.5942/jawwa.2015.107.0012; Journal AWWA 107 (3) E140-E151
Analysis of building plumbing system flushing practices and communications
Lisa Ragain, Sheldon Masters, Timothy A. Bartrand, Jennifer L. Clancy, Andrew J. Whelton
https://doi.org/10.2166/wh.2019.024; J Water Health (2019) 17 (2): 196–203
Effectiveness of Prevailing Flush Guidelines to Prevent Exposure to Lead in Tap Water
Adrienne Katner, Kelsey Pieper, Komal Brown, Hui-Yi Lin, Jeffrey Parks, Xinnan Wang, Chih-Yang Hu, Sheldon Masters, Howard Mielke, and Marc Edwards
Published: 20 July 2018
https://doi.org/10.3390/ijerph15071537; Int. J. Environ. Res. Public Health (2018) 15(7): 1537