Don’t put the DCS on the internet and you will be fine. If you absolutely must have some capability of remote viewing just point a webcam at the screens. And have that air gapped.
Edit: forgot to mention the article doesn’t say the brand but I am betting since it is Israeli made it is Unitronics. These plants tends towards brand loyalty so if they had one Unitronics chances are all their HMI/PLC combos were that brand. Unitronics dominates pumps and boilers. So might have been a pumping station.