I remember when rivers in the U.S. sometimes caught fire.
Public release date: 26-Apr-2012
Contact: Robert Perkins
University of Southern California
First evaluation of the Clean Water Act's effects on coastal waters reveals major successes
Landmark legislation helped clean up LA's coastal waters over the past 40 years, study indicates
Levels of copper, cadmium, lead and other metals in Southern California's coastal waters have plummeted over the past four decades, according to new research from USC.
Samples taken off the coast reveal that the waters have seen a 100-fold decrease in lead and a 400-fold decrease in copper and cadmium. Concentrations of metals in the surface waters off Los Angeles are now comparable to levels found in surface waters along a remote stretch of Mexico's Baja Peninsula.
Sergio Sañudo-Wilhelmy, who led the research team, attributed the cleaner water to sewage treatment regulations that were part of the Clean Water Act of 1972 and to the phase-out of leaded gasoline in the 1970s and 1980s.
"For the first time, we have evaluated the impact of the Clean Water Act in the waters of a coastal environment as extensive as Southern California," said Sañudo-Wilhelmy, professor of Biological and Earth sciences at the USC Dornsife College of Letters, Arts and Sciences.
"We can see that if we remove the contaminants from wastewater, eventually the ocean responds and cleans itself. The system is resilient to some extent," he said.