Most people do not think of wastewater systems as significant vulnerabilities or as being prone to malevolent, intentional acts. Most people, except those working at the District of Columbia Water and Sewer Authority (DC WASA) and anyone else concerned with the security of our nation’s capital. In the world of utility security since 9/11, DC WASA, along with the Department of Homeland Security (DHS) and the United States Environmental Protection Agency (US EPA) understood that the threat posed was real and that collections systems, especially the system operated by DC WASA, expose multiple real vulnerabilities with unique, and in some cases, extreme consequences. There are a number of reasons that alone or together make the DC WASA combined collection system unique compared to any other collection system in the nation: • This system is a large combined sewer network. • The system crosses through two states, six counties, numerous cities and the District of Columbia. • The combined collection system empties into the Blue Plains Advanced Wastewater Treatment Plant. This is the largest advanced wastewater treatment facility of its type in the United States with a rated annual average day capacity of 370 million gallons per day and a peak wet weather capacity of 1.076 billion gallons per day. • The combined collection system serves such landmarks as the Capitol, the White House, Supreme Court, Smithsonian Museums, Pentagon, Dulles and Reagan Airports. This paper will focus on the unique issues present in the DC WASA combined collection system, including lessons learned that can be shared with other systems and a discussion of the blend of the RAM-WTM and the VSATTM risk assessment methodologies used in this unique project. In addition, a look at the relationship between asset management and risk management from intentional acts is part of this project.