Hackers try to poison Florida by changing chemical levels at water treatment plant

Hackers broke into the computer system of a facility that treats water for about 15,000 people near Tampa, Florida and sought to add a dangerous level of additive to the water supply, the Pinellas County Sheriff said on Monday.

The hack was noticed quickly and reversed immediately, so no one in the Tampa suburb of Oldsmar was ever in danger, Pinellas County Sheriff Bob Gualtieri said.

But it underscored the broader threat of cyberattacks to US infrastructure, he added.

A computer operator for the Oldsmar water treatment system noticed Friday afternoon someone remotely accessing the plant's controls, Gualtieri said.

The operator watched the mouse pointer move between various functions for several minutes before opening the controls for adding sodium hydroxide to the water.

The hackers then increased the amount of sodium hydroxide, also known as lye, being distributed into the water supply. The chemical is typically used in small amounts to control the acidity of water, but at higher levels is dangerous to consume.

"This is obviously a significant and potentially dangerous increase," he told a press conference.

"Luckily it was caught right away."

Gualtieri said water users were never threatened because even if the hack had not been spotted immediately, it would have taken at least 24 hours for the water with high sodium hydroxide levels to reach consumers.

In the meantime, he added, safety mechanisms would have alerted officials to the change in water quality.

He said the FBI and US Secret Service were called in to help investigate, but so far there were no suspects.

Investigators did not know if the hack came from within or outside the United States, or why Oldsmar was targeted.

"Water systems, like other public utility systems, are part of the nation's critical infrastructure, and can be vulnerable targets when someone desires to adversely affect public safety," Gualtieri said.

The plant employee alerted his employer, who called the sheriff. The water treatment facility was able to quickly reverse the command, leading to minimal impact.

Oldsmar Mayor Eric Seidel said in a news conference on Monday that the affected water treatment facility also had other controls in place that would have prevented a dangerous amount of lye from entering the water supply unnoticed.

"At no time was there a significant adverse affect on the water being treated. Importantly the public was never in danger," Gualtieri said. The affected water treatment facility is a public utility owned by the town, he explained, which has its own internal IT team. Oldsmar is about 17 miles northwest of Tampa and has about 15,000 residents.

TeamViewer, which says on its website that its software has been installed on 2.5 billion devices worldwide, enables remote technical support among other applications.