News Release, St. Mary’s County Metropolitan Commission

CALIFORNIA, MD (May 29, 2020) – As businesses begin the re-entry process following extended closures,  the St. Mary’s County Metropolitan Commission (MetCom), is sharing important tips to ensure your internal plumbing system is also ready. If your commercial or retail business has been closed for an extended period of time and is connected to public water supply, we recommend these precautions to ensure your internal plumbing system has clean, freshwater flowing before you open for business.

MetCom’s treated water supply ensures that your water continually meets state and federal safe drinking water guidelines. Unfortunately, disinfectants will dissipate from stagnant water inside of plumbing during long periods of little to no water flow.The stagnant water has the potential to introduce the growth of bacteria and other potential pathogens in your plumbing, including hot water tanks. The good news is that there is an easy and simple way to ensure that your internal plumbing is ready to go for you, your customers and occupants. Please flush your systemusing the following tips:

  • If available in larger buildings, obtain a list or schematic of tagged valve locations and devise
  • Disconnect hoses and close valves to prevent backflow or siphoning of contaminants back into plumbing.
  • Flush hot and cold water through all points of use (e.g., showers, sink faucets)
  • Flushing may need to occur in segments (e.g., floors or individual rooms) due to facility size and water pressure.
  • The purpose of building flushing is to replace ALL water inside building piping with fresh water.
  • Flush the building zone by zone. The first zone to be flushed should be the one nearest the building water supply and then working outward from the supply.
  • Coldwater lines should be flushed before hot water.
  • Remove all aerators from faucets before turning on the water.
  • Run water through all outlets. Most important to be flushed are drinking fountains, ice machines, refrigerators with ice machines and faucets used for drinking water or food preparation, kitchen sink sprayers, and showers.
  • Run water through each line for a minimum of 10 minutes.
  • Repeat the process for your hot water lines.
  • Replace all point-of-use filters, including filters in appliances like a refrigerator.

Follow additional flushing guidance at:

The Metropolitan Commission tests our water supply constantly and is committed to ensuring the water that we provide to our customers is safe to drink.  These simple, easy steps will help ensure the water in your business is fresh.  For additional assistance or questions, please contact the St. Mary’s County Metropolitan Commission at 301.737.7400 or our authorized Cross-Connection Control Program Contractor HydroCorp Toll Free at 844.493.7641.