CHICAGO (CBS) — Two beaches in Rogers Park rank as the best in the Chicago area when it comes to water quality, while two beaches in East Chicago, Indiana, were among the worst in the nation, according to a recent study by the National Resources Defense Council.

WBBM Newsradio’s Mike Krauser reports the southern and northern halves of Jeorse Park Beach in East Chicago – just east of the Ameristar Casino – were found to be chronically polluted, with unhealthy levels of bacteria between 40 and 52 percent of the time.

Overall, about 13 percent of water samples taken from Great Lakes beaches failed to meet the U.S. Environmental Protection Agency’s benchmark for swimmer safety.

While no beaches tested in the Chicago area managed in 2013 to rank as what the NRDC called “Superstar Beaches” – meaning they never exceeded the EPA’s water quality threshold – Juneway Terrace Beach and Rogers Beach both exceeded that threshold only 1 percent of the time.

Nearby Howard Beach wasn’t far behind, with only 3 percent of water samples exceeding the EPA’s “Beach Action Value” in 2013.

Chicago’s worst beaches for water quality last year were Montrose Beach and South Shore Beach, with nearly a third of water samples exceeding EPA benchmarks at each spot.

Two of Chicago’s most popular beaches – Oak Street Beach and North Avenue Beach – were among the best, at 3 percent and 7 percent respectively.

The pollution typically is the result of storm runoff and the release of sewage into Lake Michigan after especially heavy storms.

To see the NRDC’s water quality findings for beaches near you, use the following links:

Illinois Summary
Indiana Summary