Dependable and safe water infrastructure is essential to human health and the nation’s economy. Water systems, like other utilities, can face an array of threats from both natural hazards (e.g., floods, hurricanes) and malevolent acts (e.g., cyber-attacks, contamination). By using this document, systems can identify and take steps to reduce the risk that a specific system will experience if one of these threats occurs or deter a threat from occuring. By assessing threats, systems across the country can identify, prepare for and manage any risks they may have by adopting an “all-hazards” approach that:

• Identifies, deters, detects, and prepares for these threats.
• Reduces vulnerabilities of critical assets.
• Mitigates the potential consequences of incidents that do occur.

The information included in this document is not a threat analysis for a specific system and it should not be used as such. The values are intended to serve as a starting point for systems to consider when they are estimating the threat likelihood of malevolent acts as part of a risk and resilience assessment. When conducting site-specific assessments, systems may determine that lower or higher threat likelihood values are appropriate. The process systems will go through to identify their specific threats will take into account their unique situations, which cannot be reflected in the baseline numbers. It is also important to note that threat likelihood is not an assessment of the risk that malevolent acts may have on public health.  While the resources provided in this document are already publicly available, this is the first time EPA, or any other federal agency, has compiled this important information for systems across the country.  

Why is EPA providing this document?

Pursuant to the requirements of America’s Water Infrastructure Act (AWIA) Section 2013(a), the U.S. Environmental Protection Agency (EPA), in consultation with federal, state, and local government partners, has developed this guidance document to provide baseline information regarding malevolent acts of relevance to Community Water Systems (CWSs).

Does this mean that my drinking water is at risk from these threats?

No, the information included in this document is not a threat analysis for a specific system and it should not be used as such. It is also important to note that threat likelihood is not an assessment of the risk that malevolent acts may have on public health.

What is a threat likelihood?

Threat likelihood in this document does not refer to public health impacts, but rather the likelihood of a threat happening to a CWS.

What do the default likelihood values mean?

The values are intended to serve as a starting point for systems to consider when they are estimating the threat likelihood of malevolent acts as part of a risk and resilience assessment. When conducting site-specific assessments, systems may determine that lower or higher threat likelihood values are appropriate. The process systems will go through to identify their specific threats will take into account their unique situations, which cannot be reflected in the baseline numbers.

How can I learn if my drinking water is safe?

This document does not provide information on the safety of your drinking water. The likelihood of a threat does not mean that the potential threat will impact the safety of the drinking water itself.  To learn more about your drinking water, contact your water utility or download a copy of your Consumer Confidence Report at: www.epa.gov/ccr

• Baseline Information on Malevolent Acts for Community Water Systems (PDF)(51 pp, 1 MB, November 2019)