1. Royer , M.D. 2008 Condition Assessment of Drinking Water Transmission and Distribution Systems Washington, D.C. www.epa.gov/awi/pdf/600f09030.pdf
2. US Census 2011 www.census.gov/
3. USEPA (US Environmental Protection Agency) 2007 Distribution System Inventory, Integrity and Water Quality www.epa.gov/ogwdw/disinfection/tcr/pdfs/issuepaper_tcr_ds-inventory.pdf