The local and federal authorities are investigating an attempt to poison the water supply of the city of Oldsmar in the US, said the sheriff of Pinellas county, Bob Gualtieri.
Somebody remotely accessed the water treatment system's computer in the city and for a short time increased the amount of sodium hydroxide, also known as lye, by a factor of more than 100, said Gualtieri at a news conference. The chemical is used in small portions in order to control the acidity of the water, but it is also a common ingredient in home cleaning products.
The city's water supply was not affected. A supervisor who was working remotely saw the concentration change on his computer screen and immediately reversed the action. The water supply system was temporarily disabled following the attack.
Other city halls in the area received an alert about the attack and were requested to check the defense measures for their water treatment systems and other infrastructure. Since the computer system at the water treatment facility was set up to enable approved users to access it remotely to trouble-shoot problems, it is possible that the system was the entry vector.
Contact with sodium hydroxide could cause skin problems and hair loss, according to the National Center for Biotechnology Information. Swallowing it could be fatal.