One Week Later: Plymouth Looks Back on ‘Unprecedented’ Cyberattack

It was about 12:30 a.m. on Monday, July 27. Fourteen lift stations that control wastewater had just gone offline. Plymouth public works crews quickly realized something was up.

“Then we knew this was a little unprecedented,” said Michael Thompson, Plymouth’s director of public works.

Besides the lift stations, communication systems that monitor water pressure at two towers were no longer sending back readings.

Thompson said it was “all hands on deck” to minimize any issues.

“With critical infrastructure, you always want safeguards, you want to plan for the unexpected,” said Thompson. “So in a case like this, understanding it was a cyberattack, we air-gapped our systems, so basically disconnected everything from the public-facing action, and just went to a full manual operation.” 

The cybersecurity incident affected not just Plymouth, but dozens of other communities across Minnesota.

While the culprit remains under federal investigation, multiple national news outlets citing law enforcement sources reported the incident was likely the result of Iranian hackers.

Michael Thompson, Plymouth’s director of public works, in an interview with CCX News.

‘A Wake-up Call’

Thompson stressed that Plymouth’s water system was always safe.

“It was never compromised. So the water quality, quantity, nothing was affected,” he said.

Still, the city had to resort to manual operations. If the problem wasn’t discovered quickly, there could have been issues.

“If the lift stations weren’t pumping the wastewater, then the pipes get full in the street and once it gets full to a certain level, then yeah, you could have wastewater going into basements,” said Thompson.

While systems are back up and running, the city continues to run manual checks to make sure everything is working properly.

Thompson believes the incident is something everyone can learn from.

“Cybersecurity is a big thing,” he said. “And if people can learn from an incident like that, that’s what you want. So hopefully it’s wake-up call to all operators throughout the country.”

Related: Plymouth, Other Cities Impacted by Cyberattack

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