1. Presidential Decision Directive/PDD-63 1998 Critical Infrastructure Protection http://www.fas.org/irp/offdocs/pdd/pdd-63.htm
2. U.S. Environmental Protection Agency 2007 Public Drinking Water Systems Programs. http://www.epa.gov/safewater/pws/index.html
3. National Drinking Water Advisory Council (NDWAC) 2005 Recommendations of the National Drinking Water Advisory Council to the U.S. Environmental Protection Agency on Water Security Practices, Incentives, and Measures http://www.epa.gov/ogwdw/ndwac/pdfs/wswg/wswg_report_final_july2005.pdf
4. Homeland Security Presidential Directive/HSPD-7 2003 Critical Infrastructure Identification, Prioritization, and Protection http://www.fas.org/irp/offdocs/pdd39.htm
5. U.S. Environmental Protection Agency 2007 Water: Critical Infrastructure and Key Resources Sector-Specific Plan as Input to the National Infrastructure Protection Plan http://www.dhs.gov/xlibrary/assets/nipp-ssp-water.pdf