We have a plumbed-in water filter at work, but the person responsible
for changing the cartridge says he's stopped bothering because the
water continues to flow.

The woman who was supposed to get air conditioning maintained but
didn't bother because it still worked got prosecuted for causing
seven deaths by legionaires disease a while ago...

http://news.bbc.co.uk/1/hi/england/cumbria/5061752.stm