Effects of Hurricanes Katrina and Rita on the chemistry of bottom sediments in Lake Pontchartrain, La.

Concerns about the effect of pumping contaminated flood waters into Lake Pontchartrain following the hurricanes of 2005 prompted the U.S. Geological Survey (USGS) to sample street mud, canal-suspended sediment, and bottom sediment in Lake Pontchartain. The samples were analyzed for a wide variety of potential inorganic and organic contaminants. Results indicate that contamination of lake sediment relative to other urban lakes and to accepted sedimentquality guidelines was limited to a relatively small area offshore from the Metairie Outfall Canal (popularly known as the 17th Street Canal) and that this contamination is probably transient.