Prepared by the Water Infrastructure Security Enhancements Standards Committee of the Standards Development Council of the Environmental & Water Resources Institute of ASCE Guidelines for the Physical Security of Water and Wastewater/Stormwater Utilities, ASCE/EWRI 78-24, provides guidelines on the evaluation and enhancement of physical security of facilities used in potable water sources, treatment, and distribution systems, as well as for wastewater and stormwater facilities. It provides a holistic approach to integrate modern security practices into the management, operation, construction, or retrofit of water, wastewater, and stormwater systems. ASCE 78-24 is a revision to and supersedes ANSI/ASCE/EWRI 56-10, 57-10, Guidelines for Physical Security of Water and Wastewater/Stormwater Facilities. Societal changes in the last decade have led to the emergence of new types of foreign and domestic threats such as groundswell attacks on water utilities. Previous water sector security guidelines depended on a methodology that chose only from predefined malevolent actor types, leading to the exclusion of emerging threats. This approach reduced assessing the capability of malevolent actors to guesswork and could result in inaccurate threat assessments and inadequate or superfluous countersecurity measures. ASCE 78-24 provides a cumulative defense strategy that can recommend countermeasures against both known and unknown adversaries. Key concepts and terms covered in the standard will help guide water utilities in creating defense strategies against traditional and new types of attacks.

Reference tables for calculating degrees of difficulty to compromise the physical security countermeasures and an example application on a facility are included in the standard. Protecting critical water assets can ensure continuity of business, protection of water quality, provision of sufficient water quantity, public confidence, and protection of public health and safety. These guidelines will be valuable to water utility operators, as well as anyone involved in monitoring physical security of water, wastewater, or stormwater facilities.