National Critical Functions - Supply Water and Manage Wastewater

Ensuring the supply of safe drinking water and treatment of wastewater is essential to modern life and the Nation's economy. Every day, more than 150,000 public water systems provide drinking water to millions of Americans and U.S. wastewater treatment facilities process approximately 34 billion gallons of wastewater. Considered National Critical Functions (NCFs), both the ability to "supply water" and "manage wastewater" are functions of government and the private sector so vital to the U.S. that their disruption, corruption, or dysfunction would have a debilitating effect on security, national economic security, national public health or safety, or any combination thereof.

To enhance the security of these functions, CISA's National Risk Management Center is working with the private sector, government agencies, and other key stakeholders to manage the most significant risks to these important functions.


The Water and Wastewater Systems Sector provides essential services that support the operation of all U.S. critical infrastructure. To enhance operations, water and wastewater facilities are increasingly integrating information technology (IT) and operational technology (OT) systems into their operations. At the same time, the integration of IT/OT systems have created new vectors through which adversaries can exploit vulnerabilities in assets, networks, systems, and devices.

Risks vary from cyber adversaries stealing sensitive data, disabling network components, disruption of operations, and more. These risks can also have cascading impacts to other critical services (e.g., hospitals operations, firefighters, and food production) as well as to dependent and interdependent critical infrastructure sectors and NCFs (e.g., energy sector, produce and provide agricultural products, produce chemicals, etc.).


Good cybersecurity posture means taking a comprehensive view of all IT and OT systems and using a layered approach with risk-informed analysis to determine the applicability of a range of mitigations (including policies, security practices, and people) to prevent, detect, and respond to cyber threats and ensure physical and cyber critical infrastructure remain secure and resilient. Some measures include:

  • Implementing cyber hygiene and best practices within IT networks can protect water and wastewater management systems from cyber attacks such as ransomware and data theft, and reduce the risk of lateral movement within systems or networks.
  • Systems owners should ensure that OT systems that help control valves and pumps, and conduct monitoring are properly protected through patching and proper network mapping.
  • Properly segmenting IT/OT systems to ensure that no part of OT systems can directly connect to the internet can greatly reduce the possibility of a successful attack upon industrial control systems (ICS) and Supervisory Control and Data Acquisition (SCADA) systems.


CISA developed two infographics on Cyber Risks and Resources for the Supply Water and Manage Wastewater National Critical Functions to provide water and wastewater systems managers and state, local, tribal, and territorial partners with an overview of the cyber risks they may face and to highlight resources available to help them enhance their cybersecurity.

Each infographic focuses on risks to the Water and Wastewater Systems Sector, and identifies risks under three categories—IT, OT, and IT/OT convergence—to demonstrate the potential risks that can be caused by malicious cyber-attacks.


CISA Resources

Additional Resources

Please note: These resources are provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide warranties of any kind regarding this information, nor does it endorse any commercial product, service, or subjects of analysis. Any references to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by DHS.


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