Flushing water lines might not be high on a checklist for a business reopening in a building that has been empty or underused, but it should be. Flushing usually occurs automatically as people run faucets, drink from water fountains, and flush toilets. If this activity hasn’t taken place for several weeks, it’s important to flush the pipes to move out the older water and bring in fresh. The issue is not the quality of water that water utility companies produce.