Stagnant water and Legionella

[Sam Leon]

For those who buys foreclosure properties to flip or hold, many times the property has been vacant for a long time, and may even have the water shutoff due to non-payment.  We could be talking about months or years.  This mean you have stagnant water in the supply system with the Legionella bacteria.

Legionella, Causes, How it Spreads, and People at Increased Risk

Just curious once you have the water turned back on, what are your steps to flush the system out if you know it hasn't been used for a long time?

My understanding is if you just say turn a hose bib on outside the water would jet out with the bacteria into the air and into your lungs.  Same if you say have a broken stop valve inside and you have to cut the pipe to replace the valve or run the water through the tub/shower valve to the shower head.

Do you take any extra precautions when flushing the system out initially, if so care to share what you do?