The last thing you want to consider on a relaxing day at the beach is whether or not the water is contaminated with fecal matter, but one recent study indicates that Americans across the country could have cause for concern. 

No swimming sign with flag at beach
The research team sampled 218 beaches in Hawaii, and 90 of them proved potentially unsafe for at least one day in 2018.

According to the report, published in July, samples collected last year revealed that more than 4500 beaches in 29 coastal and Great Lakes states and Puerto Rico harbored potentially unsafe levels of contamination. More than half the sites tested were deemed potentially unsafe for swimming at least one day that year, and 518 were found to be potentially unsafe at least 25% of the time. (In this case, “potentially unsafe” is measured against the U.S. Environmental Protection Agency’s Beach Action Value threshold, a conservative metric that’s still associated with an estimated illness rate of 32 per 1000 swimmers.)

Breaking it down by region, the Gulf Coast was the worst offender, with 85% of samples revealing potentially unsafe waters for at least one day in 2018—and 100% of the sites tested in Mississippi and Louisiana showing the same. Great Lakes beaches were next with 68%, followed by West Coast (67%) and East Coast (48%). California, Hawaii, and other states known for their oceanfront properties didn’t escape untarnished, but lesser-expected summertime destinations like Pennsylvania, Illinois, and Ohio also showed surprising rates of contamination. 

unsafe beaches infographic
In 2018, the research team tested for bacteria in every region of the country with ocean and Great Lakes beaches, including Puerto Rico, and found days of potentially unsafe fecal contamination in all of them. Image courtesy Frontier Group and Environment America Research & Policy Center

That polluted water can really put a damper on an otherwise peaceful vacation, causing gastrointestinal distress, respiratory disease, ear and eye infections, and skin rash. “Each year in the U.S., swimmers suffer from an estimated 57 million cases of recreational waterborne illness,” write Gideon Weissman and John Rumpler, the study’s authors. “In 2018, there were 871 beach closings resulting from elevated bacteria or sewage in the US, and 4824 beach contamination advisories warning people not to go in the water. [But] while beach advisories are a critical tool to protect swimmers, many testing programs rely on a testing process that requires nearly 24 hours to show results, meaning that swimmers have already been exposed to unsafe water by the time advisories are posted.”

A boy swimming in clear waters.
Those waters might look inviting, but they may not be safe for swimming.

The study, which comes courtesy of two environmentally-minded organizations – Frontier Group, a non-profit think tank, and Environment America Research and Policy Center, a 501(c)(3) dedicated to protecting air, water, and open spaces – calls for preventative measures as well as same-day bacteria testing and warning systems. 

“To keep our beaches safe for swimming and protect Americans’ health, policymakers should work to protect beaches from runoff and sewage pollution,” the authors write. “Solutions include dramatically increasing funding to fix sewage systems and prevent runoff pollution through natural and green infrastructure, including rain barrels, permeable pavement and green roofs; protecting and restoring natural infrastructure, including riparian areas and wetlands that can filter bacteria, sediment and nutrients; strengthening enforcement of standards for municipal wastewater treatment, [and] enacting moratoria on new or expanded industrial-scale livestock operations, particularly in areas that threaten our beaches and other waterways.”

To see how your favorite beach measures up, check out the full report at

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