Infrastructures vulnerable to EMP attack:

 Electrical power grid   
 Electronics, computers, internet and computer networks
 Food production and distribution 
 Water treatment and supply, and sewage systems  
 Fuel/energy production and delivery 
 Transportation and air travel
 Telecommunications, communication satellites
 Banking, business and finance   
 Health care, pharmaceuticals and emergency services   
 Environmental protection   
 Government functions, civil security

Infrastructure risk assessment of United States Congressional Commissions:
“EMP is one of a small number of threats that can hold our society at risk of catastrophic consequences. EMP will cover the wide geographic region within line of sight to the nuclear weapon. It has the capability to produce significant damage to critical infrastructures and thus to the very fabric of US society, as well as to the ability of the United States and Western nations to project influence and military power."
" The common element that can produce such an impact from EMP is primarily electronics, so pervasive in all aspects of our society and military, coupled through critical infrastructures. Our vulnerability is increasing daily as our use of and dependence on electronics continues to grow…The current vulnerability of our critical infrastructures can both invite and reward attack if not corrected. Correction is feasible and well within the Nation's means and resources to accomplish.”    
--     From the report of the Commission to Assess the Threat to the United States from EMP Attack, U.S. Congress, 2004.  (Click here to read the full report.)

"The United States should take steps to reduce the vulnerability of the nation and the military to attacks with weapons designed to produce electromagnetic pulse (EMP) effects...From a technical perspective, it is possible that such attacks could have catastrophic consequences. For example, successful attacks could shut down the electrical system, disable the internet and computers and the economic activity on which they depend, incapacitate transportation systems (and thus the delivery of food and other goods), etc."
"Prior commissions have investigated U.S. vulnerabilities and found little activity under way to address them...EMP vulnerabilities have not yet been addressed effectively by the Department of Homeland Security. Doing so could take several years. The EMP commission has recommended numerous measures that would mitigate the damage that might be wrought by an EMP attack. The Stimulus Bill of February 9, 2009, allocates $11 billion to DOE for “for smart grid activities, including to modernize the electric grid.” Unless such improvements in the electric grid are focused in part on reducing EMP vulnerabilities, vulnerability might well increase."   
 --     From the final report of The Congressional Commission on the Strategic Posture of the United States, pp. 90-92; issued May 6, 2009. (Click here to read the full report.)