Protecting Water and Wastewater Infrastructure: OT and SCADA Threats Explained
by Linda Hart | October, 2025
Automation, Control & Plant Intelligence - Articles, Analysis, Reviews, Interviews & Views
by Linda Hart | October, 2025
Operational Technology (OT) and SCADA environments - the industrial systems that run factories, utilities, pipelines, and municipal infrastructure, including water and wastewater processing as required by regulations - are facing a sharp increase in targeted cyberattacks. Over the last 18 months, the threat landscape has evolved from opportunistic ransomware to sophisticated campaigns combining IT-side compromises, supply-chain exploitation, and persistent actors capable of causing real-world disruption. These attacks now affect both IT assets (mostly ad hoc systems with the option of planned upgrades) and OT/SCADA systems (which must operate 24x7 to control processes and collect data, often with limited downtime and constrained government funding for infrastructure improvements), with OT operations subject to laws and regulations that impose penalties if operators lose data. In water and wastewater treatment plants, pumping stations (PS), and sewage pumping stations (SPS), the convergence of IT and OT systems, aging OT infrastructure, complex system integrations, and limited opportunities for upgrades have amplified vulnerabilities, creating avenues for attackers to compromise automated control systems, disrupt critical operations, and directly threaten public safety, as these facilities provide essential, continuous services that communities rely on around the clock.
Ransomware now targets water and municipal systems: Attackers increasingly focus on operational technology (OT) in water treatment plants, wastewater facilities, and other municipal infrastructure. Disruptions to these critical services can cause significant operational and financial impact, making them high-value targets.
Rising OT exposure on the internet: Industrial control systems (ICS) and OT devices are increasingly accessible online, expanding the attack surface and making municipal networks more vulnerable to cyberattacks.
Municipal infrastructure under attack: Local governments' SCADA-controlled systems-including water distribution, wastewater management, and traffic control - are prime targets for hackers, emphasizing the urgent need for robust cybersecurity in public utilities.
Norwegian Dam Manipulation (April 2025): As publicly reported in multiple media outlets, on April 7, 2025, attackers gained unauthorized remote access to the control system of a dam in the Municipality of Bremanger, Western Norway, and manipulated a water valve-opening it to full capacity and increasing the outflow by roughly 497 litres per second for about four hours before detection and shutdown. The breach was attributed by Norway's domestic security agency, the Police Security Service (PST), to pro-Russian cyber actors as part of a broader "hybrid" campaign intended to sow fear and unrest among Western populations. According to those reports, the root cause was a weak password on a web-accessible human-machine interface (HMI) linked to the dam's industrial control system, underscoring how even modest operational vulnerabilities can translate into real-world physical effects. While no structural damage or injuries were reported, the incident stands as a significant warning about the susceptibility of critical infrastructure to targeted cyber intrusions.
OT/ICS Ransomware Surge (2024/2025): As publicly documented by cybersecurity vendors and trade media, industrial and energy-sector operations have experienced a sharp rise in ransomware campaigns aimed directly at operational-technology (OT) and industrial-control-systems (ICS) environments rather than traditional IT networks. A 2025 Honeywell report found ransomware attacks on industrial operators increased 46 percent from Q4 2024 to Q1 2025, with one trojan family targeting OT systems spiking 3,000 percent in the same period. Similarly, analysis from Dragos indicated ransomware incidents impacting OT/ICS asset owners grew by approximately 87 percent in 2024 over 2023, alongside a 60 percent rise in the number of threat groups targeting such environments. Together these findings reveal a strategic shift by adversaries from opportunistic IT breaches toward deliberate efforts to disrupt industrial processes in manufacturing, energy, and utilities - often by exploiting exposed interfaces, open ports, and insufficient network segmentation.
These incidents highlight ongoing cybersecurity risks to municipal operations, educational institutions, and critical infrastructure, prompting enhanced security measures and monitoring efforts.
The Canadian Centre for Cyber Security has repeatedly warned that municipal water treatment and wastewater facilities face heightened threat levels from ransomware and state-sponsored actors.
In February 2021, an attacker remotely accessed the SCADA system of a water treatment plant in Oldsmar, Florida, attempting to increase sodium hydroxide (lye) levels in the drinking water. The incident was quickly detected and neutralized, preventing any safety impact.
Subsequent reports documented multiple ransomware and unauthorized-access events targeting water and wastewater systems in states including Maine, Nevada, California, and Kansas.
In October 2024, American Water Works experienced unauthorized network activity affecting multiple regions. While operations were maintained, the incident highlighted that attackers are increasingly probing large-scale water utilities.
Federal agencies, including the EPA and CISA, have warned that foreign state actors linked to Iran and China have carried out disruptive attacks on water systems. Utilities were directed to improve cybersecurity immediately to prevent potentially serious consequences.
The Maroochy Shire wastewater breach in Queensland, Australia, remains one of the most notorious cases of cyber sabotage in water utilities. In 2000, a former employee exploited vulnerabilities in the SCADA system to release over 800,000 liters of raw sewage into the local environment. This incident highlighted the critical need for robust cybersecurity measures in operational technology systems.
Poland has been a significant target of cyberattacks, particularly from Russian-aligned groups. In August 2025, a cyberattack aimed at a major city's water supply was thwarted, preventing potential service disruptions. This incident is part of a broader pattern, with numerous cyberattack attempts daily, many targeting critical infrastructure like hospitals and water systems.
In response to these escalating threats, the Polish government significantly increased its cybersecurity budget in 2025, with a dedicated portion allocated specifically to bolster water infrastructure defenses. Additionally, Poland established a joint civilian-military cybersecurity operations center to coordinate defense efforts against persistent cyber threats.
Water utilities across Europe and the Middle East continue to face cyber threats, often due to rapid digitalization without corresponding cybersecurity measures. There has been a sharp rise in cyber incidents targeting drinking water and wastewater sectors, with many utilities lacking the necessary funding, skilled personnel, and technical capabilities to defend against these threats.
In regions such as Africa, South Asia, and the Middle East, vulnerabilities are heightened by the rapid modernization of utilities. Many water and wastewater treatment plants have transitioned from limited manual systems to highly digital ones in a short time span, often overlooking cybersecurity during this modernization, resulting in critical security gaps.
Water utilities worldwide remain frequent targets of cyberattacks due to outdated automation systems, weak remote-access controls, and underfunded cybersecurity programs. These vulnerabilities are exploited by various threat actors, including hacktivists and nation-state actors, to disrupt services and cause widespread concern.
Operational technology and SCADA environments present outsized impact compared with their footprint: a single compromise can interrupt water treatment, power distribution, or traffic management, producing immediate safety hazards and public panic. That immediate consequence makes these systems attractive for financially motivated extortion, nation-state coercion, or politically timed disruption.
Risk is amplified by IT/OT convergence. More organisations now connect business networks, remote access services, and administrative tools to operational equipment for efficiency and visibility - but that also gives attackers a route to pivot from a compromised office workstation or cloud service straight into control networks. Finally, many industrial sites still run legacy controllers and protocols that were never designed with modern security in mind. Unsupported firmware, default credentials, and weak authentication mean that once adversaries get initial access, they can escalate privileges and reach critical assets far faster than in hardened IT environments.
Canadian and U.S. municipalities are learning that cyber resilience is not optional. Recovery costs - covering forensics, remediation, downtime, and insurance - often exceed 10? annual cybersecurity budgets.
However, many companies ? especially in the private sector - for face-saving reasons and due to the high cost of rebuilding, choose to quietly deal with attackers. To avoid losing customer or stakeholder confidence, such incidents often remain undisclosed, handled confidentially, and never reach the public domain.
Beyond financial loss, public safety and trust are at risk when water treatment, wastewater, or emergency services are disrupted.
Cyberattacks are no longer confined to corporate IT. The wave of incidents hitting cities like Hamilton, Durham, Toronto, Halifax, and counterparts across the U.S., Poland, and Australia underscores how exposed water and wastewater systems have become.
Protecting OT and SCADA infrastructure now requires sustained investment, coordination between engineering and IT teams, and board-level prioritization. Waiting for the next major breach could cost far more than prevention.
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