FBI Warns of Cyberattacks on U.S. Water Infrastructure

The Federal Bureau of Investigation and the Environmental Protection Agency issued alerts on July 30, 2026, after malicious cyber actors targeted water and wastewater infrastructure in at least seven U.S. states starting July 27. Attackers exploited internet-facing Programmable Logic Controllers, specifically Allen-Bradley MicroLogix 1100 and 1400 series, by altering IP addresses and passwords to disable monitoring and control.

These breaches resulted in pressure loss and localized flooding. Minnesota suffered the most significant impact with over 30 systems targeted, while Michigan identified nine affected systems. Other incidents occurred in South Dakota, California, and Georgia. Local officials stated that drinking water quality remained safe throughout the events.

Federal investigators are currently probing potential links to Iranian hackers. Donald Trump, President of the United States, dismissed claims of Iranian involvement and instead attributed the vulnerabilities to the leadership of Minnesota Governor Tim Walz.