Under Clean Sweep, SWW has removed more than 200 crude outfalls which used to discharge around the coast and there are now 40 state-of-the-art treatment facilities.

BBC: NEWS | UK | England | Devon | Concern over who pays for beaches

It says the scientists found no signs of the carp in Chicago locations where they should have been abundant, such as sewer outfalls, if the alternative explanations were accurate.

WSJ: Report: Asian carp may have reached Great Lakes

"A study was released about three years ago that showed swimmers are 50 percent more likely to become ill if they swim within 50 yards of storm drain outfalls or river mouths -- and that's where the surf is best, " says Michelle Kremer, interim executive director of Surfrider Foundation.

CNN: Surf's up for beach water quality