Pinellas County Sheriff Bob Gualtieri said that a hacker gained access into the water system of Oldsmar, Florida, on Friday and tried to increase the levels of sodium hydroxide, commonly referred to as lye, by a factor of more than 100.
The chemical is used in small amounts to control the acidity of water but it’s also a corrosive compound commonly found in household cleaning supplies such as liquid drain cleaners.
The attack in Oldsmar, a city of 15,000 people in the Tampa Bay area, was caught before it could inflict harm.
A supervisor working remotely saw the concentration being changed on his computer screen and immediately reverted it, Gualtieri said.
The plant operator at the water facility noticed access to the control systems about 8 a.m. Friday, he didn’t find this unusual, Gualtieri said. Since the supervisor remotely accessed the system regularly.
Same day at about 1:30 p.m. something strange has happened. He noticed someone accessed the system, took control of the mouse and used the software that controls water treatment for three to five minutes. The intruder increased the amount of sodium hydroxide from 100 parts per million to 11,100 parts per million.
The plant operator noticed the manipulation and reverted it immediately.
City officials on Monday emphasized that several other safeguards are in place to prevent contaminated water from entering the water supply and said they’ve disabled the remote-access system used in the attack.
The Pinellas County Sheriff’s Office is investigating, along with the FBI and the Secret Service, Gualtieri said.
It is not clear why attackers have chosen the City of Oldsmar, but authorities have already alerted other municipalities of the risk of similar attacks on water treatment systems and other critical infrastructure.
“At no time was there a significant adverse effect on the water being treated,” the sheriff said. “Importantly, the public was never in danger.”
Even if the operator hadn’t caught it, he said, it would have taken more than a day for the water to enter the water supply.
“The protocols that we have in place, monitoring protocols, they work, that’s the good news,” said Oldsmar Mayor Eric Seidel. “Even had they not caught them, there are redundancies in the system that would have caught the change in the pH level.
Investigators were unsure whether the attack originated within or outside Pinellas County, Florida or the United States. If the attacker is apprehended, he said, they’ll face state felony charges and possibly federal charges.
According to the National Center for Biotechnology Information, contact with sodium hydroxide can kill skin and cause hair loss. Intake can be fatal. The sheriff’s office, the FBI, and the Secret Service are investigating. No one has been arrested, though investigators have some leads. Other area municipalities have been alerted to the attack.
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