The Water Quality Association has developed general guidance and information for water treatment professionals who may be called upon to assist customers with bringing vacant buildings back online, such as when the Shelter-In-Place orders due to COVID-19 are lifted. It addresses the activities necessary to bring the potable water supply treatment systems (treatment systems) in the building back online and suggests appropriate strategies to fit those activities into the overall recommissioning plan.
The document makes the assumption that the building is a commercial or industrial building that has fairly complex premise plumbing, the potential for various treatment systems to be present, and that the building has been completely vacant for an extended period of weeks or months. However, water treatment professionals should take similar precautions when dealing with buildings that were only partially vacant, or residences left vacant for whatever reason.
See the full document here.