While news readers steadily lose access to investigative journalism (writers with resources, time and money for quality reporting), The New York Times' "Toxic Waters" series offers just that. The ongoing series exposes the dangerous shortcomings of the Safe Drinking Water Act a dinosaur of a health provision that overlooks thousands of contaminants in municipal water supplies.
The online version includes a resource pool (with help from the Environmental Working Group) for readers to see what conditions are like where they live. Of course, Louisiana's information isn't present "Louisiana did not provide recent data to The Environmental Working Group," the site says. Neither did Colorado, Georgia, Kansas or Mississippi. Another search on the EWG site by entering a New Orleans ZIP code produces this result, showing the Louisiana Department of Health and Hospitals' failure to report its 2006-2007 information. Going through the department's Web site, you'll find that, hey, they've scheduled to do a water quality test after all: Tests at the Carrollton Waterworks plant begin... February 2010.
A quick check on the Environmental Protection Agency's link to Louisiana water boards provides a dead link to New Orleans' recent water quality reports, while those of Jefferson Parish are readily available. Backtrack to the Sewerage & Water Board's main page, and there you'll find the 2008 water quality report released in June.
The report found relatively safe levels of contaminants, but found that "some homes in New Orleans have elevated levels of lead in their tap water." The number is fairly insignificant, though the Times as well as the feds recommend a good filter.