IE 11 is not supported. For an optimal experience visit our site on another browser.

Rio's not alone. How clean are America's beaches?

Americans are feeling smug about Rio's sewage-strewn waters. But our own waterways are rife with much the same foul blend of feces and urban slobber.

After a report revealed torrents of raw sewage in the waters where Olympians will compete next summer in Brazil’s first games, you could almost feel the air of smug disapproval emanating from America. But was it justified? Hardly.

Our own waterways are rife with much the same foul blend of feces and urban slobber, the result of sewers overwhelmed by ever more toilets and ever stronger storms. It’s not as bad as Rio, where human waste runs through open-air ditches that feed the Olympic water sites, but it’s bad: 850 billion gallons of untreated sewage mixed with rainwater belch into city waters each year, according to the most recent federal estimates.

RELATED: Rio’s tainted waterways signal larger ills threatening the Olympics

“It’s beaches, rivers, streams, the Great Lakes, it’s everywhere,” said Larry Levine, an attorney who tracks national water issues for the Natural Resources Defense Council. “There’s a crisis in urban water infrastructure.”

And it’s making people sick. Sewage teems with viruses, bacteria and pathogens that can make people ill. That's why an estimated 3.5 million swimmers a year end up with eye, ear, and stomach ailments, among other health problems, after a dip in contaminated U.S. waters, according to the Environmental Protection Agency.

The real number may be much higher, however, because most people don’t connect their day at the beach with their day at the doctor. New York is believed to lead the nation is sewage runoff, with 27 billion gallons a year pouring into the harbor alone, according to the city’s own figures.

Dan Shapley has been monitoring New York City’s water as the manager of Hudson Riverkeepers. On a dry-weather day, he told msnbc, the water is safe for swimming. But wet-weather discharges can start after as little as a tenth of an inch of rain, turning everyday recreation into a roll of the dice. It’s not just sewage, but all the trash and toxins on city streets.

Almost half of the water samples that Riverkeepers recently took around the city failed federal standards for safe swimming, according to a report released last month. People still jump in, of course, thousands of them, including kayakers and triathlon participants. Most don’t get ill, but many get a “Hudson Mustache,” a nickname for the finger of silt that curls over the lip of swimmers.   

Washington, D.C., Detroit, Kansas City, Cleveland, and Cincinnati are also among the worst offenders, according to research by the Natural Resources Defense Council. The culprit is combined sewer and storm water systems, which are found in more than 700 cities nationwide. They are designed to occasionally discharge overflow, but as the population grew and we paved more of the land, these systems started discharge huge amount of sewage — blighting harbors and beaches in the process.

RELATED: The next California water war

Other problems include the more intense rain associated with climate change, and a backlog of pipes in disrepair. On the national level, we need $298 billion in capital investments to modernize our wastewater and stormwater systems over the next 20 years, according to a 2013 report by the American Society of Civil Engineers. They give our wastewater systems a “D” grade.

Miami’s problem is more about an old system, which openly dumps offshore. Dade County and its neighbors have six pipes that no one sees but every day pump million gallons of partially treated sewage into the ocean.

That doesn’t include malfunctions, like the one that happened earlier this year. More than a million gallons of raw sewage spilled from Miami-Dade County’s aging sewer system over a six month period, according to a recent report by The Miami Herald. It’s supposed to take more than 10 years and cost more than $10 billion to fix everything in Miami alone.

But maybe there’s a shorter term solution: a filter. A company called +Pool has designed a large plus-shaped pool that – when dropped directly into a body of water – filters it for recreation. The short-term goal is to allow New Yorkers to swim like the last 400 years of development didn’t happen. And after years of testing, the founders say their technology can zero-out fecal matter.   

“We’re dealing with a big problem in New York,” said Archie Lee Coates, the executive director of +Pool, “but our research shows that 90% of major metropolitan areas have waterfronts that are too full of well, shit, essentially, for people to swim in.”   

The Brazilian government, meanwhile, has recommitted to cleaning up the polluted water that laps its shore. Before Americans get too self-satisfied with their own beaches and bays, they might consider asking their own government to do the same.