This is why legionella insurance for water treatment companies is something like $80k p.a heh.
So it's actually quite common for these towers to fail the lab tests and require mandated shock dosing and re-testing. It's also common for the water treatment companies to remove the sodium thiosulphate from the sample bottles and actually dose the sample with chlorine before taking it to the lab. The latter due to the former.
It's a rodeo out there, the equipment on-site is often neglected - leaking chemicals, overdosing/underdosing, infrastructure owners not wanting to pay up to replace broken parts and pumps etc. Broken float valves causing huge amounts of waste water is quite common (this does have the benefit of not growing legionella however!).
The industry will get a shakedown from this, then it will resume like nothing happened.
