quality. their report found 7% of beaches violated health standards. noah garrison is defense for national resource defense. good morning. >> good morning. >> we've had 18,000 beaches close and swimming advisories last year on beaches. what is is the major cause of this pollution? >> we found vast majority is due to finding elevated bacteria in the water. bacteria that can make swimmers sick. 75% of closings were due to testing at federal levels that exceeded health standards. >> is it human waste? things being dumped by companies? what is it? >> it's a two-fold problem and depends on sort of a city by city basis. the two largest known sources of contamination in our beaches are either storm water pollution, runoff when it rains and picks up trash and animal waste and