A top official at the Environmental Protection Agency is warning that toxic chemicals in the New Orleans flood waters will make the city unsafe for full human habitation for a decade. EPA veteran Hugh Kaufman told the Independent of London that the clean-up needed will be 'the most massive public works exercise ever done in this country.” Kaufman is the former chief investigator to the EPA's ombudsman. He is now a senior policy analyst in the EPA’s Office of Solid Wastes and Emergency Response. He said “It will take 10 years just to get everything up and running and safe.” Kauffman criticized the decision to pump the contaminated flood water back into Lake Pontchartrain and the Mississippi River. He said this could endanger people using the water downstream.