One of the incidents described in Verizon's Data Breach Digest involved
a hacktivist group that gained access to an ICS/SCADA system at a water
treatment facility and altered the levels of chemical used to treat
drinking water. The intruders gained access through phishing and SQL
injection attacks. The country in which the incident occurred was not
specified. The attackers were able to gain access to the system through
unpatched flaws in the Internet facing customer payment portal.
http://www.theregister.co.uk/2016/03/24/water_utility_hacked/