Summer is here and with it the Natural Resources Defense Council's (NRDC) 23rd annual beach water report on the quality of beach water found throughout the nation's shores.

According to the NRDC, a 2001 Environmental Protection Agency (EPA) statement estimated that 3.5 million people get sick every year from contact with raw sewage from sanitary sewer overflows. The exact number, however, is hard to say because, as the NRDC reports, public health experts believe many are not aware of the cause of their illness and thus fail to report it to doctors or local health officials.

What's more, the Centers for Disease Control and Prevention reported in 2008 that the incidence of infections associated with recreational water use has steadily increased over the past several decades, with fecal contamination in the Los Angeles and Orange County beaches alone causing between 627,000 and 1.5 million cases of gastrointestinal illness each year.

Children are especially vulnerable to illness due to contaminated water, the NRDC report warns, with associated health risks including stomach flu, skin rashes, pinkeye, respiratory infections, meningitis and hepatitis.

For this reason, researchers at the NRDC have compiled a list of the cleanest and dirtiest beaches based on the number of 2012 water samples from each location that contained levels of bacteria exceeding national standards.

Overall, the Great Lakes had the highest rate of exceedance at 10 percent of all regions, followed by the Gulf Coast at 8 percent, western states at 7 percent, the New York-New Jersey area at 6 percent, New England at 5 percent, the Southeast at 4 percent and the Delmarva Peninsula region at 3 percent.

Some beaches, however, stood above their peers, ranking in the NRDC's "5-Star Beaches."

This list included:

Alabama: Gulf Shores Public Beach

Alabama: Gulf State Park Pavilion

California: Bolsa Chica Beach

California: Newport Beach, 38 St., and 52 St.

California: San Clemente State Beach, Avenida Calafia, Las Palmeras

Delaware: Dewey Beach - Dagsworthy

Delaware: Rehoboth Beach - Rehoboth Ave.

Maryland: Ocean City at Beach 6

Michigan: Bay City State Recreation Area

Minnesota: Park Point Franklin Park / 13 St South Beach

Minnesota: Lafayette Community Club Beach

New Hampshire: Hampton Beach State Park

New Hampshire: Wallis Sands Beach at Wallis Rd

The report also listed repeat offenders - beaches where water samples exceeded public health standards more than 25 percent of the time between 2008 and 2012.

This list included:

California: Three separate areas located at Avalon Beach in Los Angeles

California: Six separate areas located at Doheny State Beach

California: Poche County Beach

Indiana: Two separate locations at Jeorse Park Beach

New Jersey: Beachwood Beach

New York: Ontario Beach

Ohio: Lakeshore Park

Ohio: Euclid State Park

Ohio: Villa Angela State Park

Ohio: Edson Creek

Wisconsin: South Shore Beach

In order to improve the quality of beach water nationwide, those at the NRDC argue that policy measures are needed.

For example, because storm water runoff is the source most often identified with beach closings due to contamination, the organization suggests reducing the volume of storm water that flows into storm drains and instead installing porous pavement and rain barrels, among other things, to stop the rain where it falls and either storing it or letting it filter into the ground naturally.

Ultimately, however, the report calls on the EPA to establish a stricter criteria for beach water by revising the level of acceptable risk.

Didn't see your beach on either lists? Click here to learn more about a beach near you.