Reoccupying a Building After an Extended Closure

Guidelines for safe drinking water

1. If you have a building engineer or facility manager be sure to consult with them to assist in flushing the internal plumbing.
2. Turn on the cold water inside the building (break room sinks, drinking fountains, utility closets, restrooms, etc.) on each floor.
• Start from the furthest point away from where water enters the building (e.g., for a building with five floors, start on the fifth floor and work your way to the first floor.) Remember to run only cold water.
• The cold water has been successfully flushed when you feel the water temperature go from slightly warm to cold.
3. Flush hot water storage tanks (boiler and/or hot water tanks per manufacturer’s flushing instructions) to displace stagnant/discolored water with fresh water.
4. Repeat step 1 using hot water.
• The hot water has been successfully flushed when you feel the water temperature turn from warm to hot.
5. Flush and perform preventative maintenance on point-of-use devices or systems, such as cooling towers, systems providing additional water treatment, etc., per the manufacturer’s recommendations as applicable.

Once all domestic water service lines, internal plumbing, and point-of-use devices/systems are flushed/properly maintained, it will be safe to drink the water.

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