San Jose Water Encourages Businesses, Schools and Operators of Vacant Properties to Flush Pipes to Maintain Water Quality

Quality can deteriorate when water is left sitting in pipes. Building owners should proactively flush water pipes before reoccupying.
Photo Credit: SJ Water


San Jose, CA — June 08, 2020 — As Gov. Newsom announced a staged plan for re-opening many businesses, San Jose Water recommends that building owners and property managers flush the water pipes upon returning to any building that may have been vacant or infrequently occupied over the last several weeks.

Water delivered by San Jose Water into a building through the water main will be safe to drink and continues to meet all state and federal drinking water requirements, according to Francois Rodigari, Director of Water Quality at San Jose Water. He added, “Water that sits inside a building’s pipes for long periods of time can become stagnant and may become discolored or cause unwanted contaminants to leach from a building’s pipe materials. Bacteria may also grow in the stagnant water. This is why flushing the water within the pipes is highly recommended before resuming use.”

Most property owners can flush their buildings by running the taps from all points of use for roughly 10 minutes. (For example: showers, all sink faucets, ice machines, drinking water fountains and coolers.) Flushing may need to occur in segments depending on facility size and water pressure.

The purpose of the flushing is to replace all water inside the building’s piping with fresh water from the water main. Flush until the hot water reaches its maximum temperature and flush the cold water until it reaches a steady cool temperature. It is also a good idea to replace any filters if water filtration systems are used in the building. Discard all ice from the building appliances. Larger facilities may need to take additional measures.

Owners of residential properties that have been vacant should also flush their cold water lines before using or consuming the tap water. 

For additional information, head to our website.

Also, you can read the U.S. Environmental Protection Agency’s Flushing Best Practices; the Centers for Disease Control and Prevention’s Guidance on Building Water Systems, or the American Water Works Association’s Return to Service Guidance.

About San Jose Water

Founded in 1866, San Jose Water is an investor owned public utility, and is one of the largest and most technically sophisticated urban water systems in the United States. Serving over one million people in the greater San Jose metropolitan area, San Jose Water also provides services to other utilities including operations and maintenance, billing, and backflow testing. San Jose Water is owned by SJW Group, a publicly traded company listed on the New York Stock Exchange under the symbol SJW. SJW Group also owns: Connecticut Water Company, Avon Water Company and Heritage Village Company in Connecticut; Maine Water Company in Maine; and SJWTX, Inc. (dba Canyon Lake Water Service Company) in Texas. To learn more about San Jose Water, visit:

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