How Can Water Utilities Protect Their Control Systems From Cyberattacks?

Water utilities increasingly use connected controllers to watch levels, start pumps and adjust treatment equipment. Remote access can save time and help small teams respond quickly, but it also creates a route from the public internet to machinery. Good security therefore has to protect both computers and the physical process.

What is different about operational technology?

Business information technology handles email, billing and records. Operational technology controls equipment such as pumps, valves, chemical dosing systems and sewer lift stations. A failure in the first environment may expose data; a failure in the second can interrupt a physical service.

Industrial equipment is often expected to run for many years. Some devices were designed before internet connectivity became common, so they may lack modern authentication, secure update systems or detailed logging.

Why are programmable controllers exposed?

A programmable logic controller receives signals from sensors and sends instructions to machines. Utilities may connect it through a cellular modem, vendor portal or remote desktop tool so operators can monitor sites without travelling to each facility.

Exposure becomes risky when a device can be reached directly from the internet, retains a default password or sits on the same network as ordinary office computers. An undocumented vendor connection can also escape routine security scans.

How can a utility reduce the risk?

The first step is knowing every controller, modem and remote connection. Devices that do not need public access should be removed from the internet. Necessary remote access should pass through a protected gateway, use multifactor authentication and be limited to named users and approved times.

Segmentation matters too. Separating office systems from plant controls makes it harder for an attacker who steals an employee password to move into the operating environment. Monitoring should flag unusual logins, configuration changes and commands that occur outside normal operating patterns.

Why does manual operation still matter?

Cybersecurity cannot guarantee that every intrusion will be blocked. Utilities therefore need a safe way to run essential equipment when digital monitoring or remote control is unavailable. Staff should know which functions can be operated locally, how long stored water will last and who has authority to isolate a compromised device.

Backups are useful only if they can be restored, and response plans are useful only if teams have practiced them. Exercises should include communications with public-health agencies and clear rules for telling residents when water quality or pressure may be affected.

What should the public understand?

A confirmed cyber incident does not automatically mean drinking water was contaminated. It may involve loss of remote visibility, a disconnected controller or a brief switch to manual operation. Officials should explain separately whether technology was accessed, service was interrupted and water quality changed.

The best defense combines less internet exposure, strong access controls, network separation, monitoring and rehearsed manual fallback. No single security product can substitute for that layered approach.