http://www.nytimes.com/2009/11/23/us/23sewer.html?_r=1&hp
...In the last three years alone, more than 9,400 of the nation’s 25,000 sewage systems — including those in major cities — have reported violating the law by dumping untreated or partly treated human waste, chemicals and other hazardous materials into rivers and lakes and elsewhere, according to data from state environmental agencies and the Environmental Protection Agency.  But fewer than one in five sewage systems that broke the law were ever fined or otherwise sanctioned by state or federal regulators, the Times analysis shows.