- More than half of American beaches have high levels of E. coli bacteria at least one day a year.
- The bacteria, present in animal and human waste, get into water from waste treatment plants or storm water runoff.
- Beaches in the Gulf Coast, West Coast and Great Lakes regions had more than the average number of high-bacteria days.
While Massachusetts beachgoers may be worried about sharks this summer, environmentalists are warning about a much smaller organism. E. coli, a bacteria present in animal and human waste, could hurt many more people—and it shows up on half of America's beaches, according to new research from Environment America and the Frontier Group.
Half the beaches in the U.S. have at least one day per summer season in which it's not safe to swim because of elevated bacteria levels in the water, according to a report the group released recently. Some states had it much worse. In Louisiana, all of the 24 beach sites sampled were potentially unsafe for at least one day last summer. In Mississippi, all 21 of 21 beach sites sampled were.
There are several ways for bacteria to get into water, but two of the most common ones are overflows from sewage treatment plants or runoff during heavy rain.
"Particularly in major urban and suburban areas where we've paved over everything, when there are heavy rains, there's no place to absorb the water anymore," said John Rumpler, senior director of Environment America's Clean Water for America campaign.
"In nature, when it rains, the storm water gets absorbed in the soil, but in a heavily developed world, the rainwater hits the asphalt and picks up bacteria, and gravity brings it to the nearest stream, river or lake."
A third, slightly less common, cause is runoff from industrial livestock operations, Rumpler said. That's why many of the most contaminated beaches in the report sit near the mouths of rivers, where they're more likely to receive runoff.
In New Jersey, Beachwood Beach West, in Ocean County, was the top offender in the state. Nearly two-thirds of the days on which it was sampled showed potentially dangerous bacteria levels. Last summer, there were 20 days during which officials found potentially harmful levels of enterococcus bacteria on Beachwood Beach West, county officials said, although more than half of those tests took place before the beach was open to the public.
"It's part of our tourism, part of our ecology, so we take it very seriously," said Pete Curatolo, the Coastal Cooperative Monitoring Program coordinator.
For a state like New Jersey, where oceanfront counties contribute nearly half of the state's $44 billion in tourist dollars, beach closures can have a significant economic impact. But water recreation is potentially even more crucial in the Great Lakes region, which has seen a spate of water safety closures already this summer.
"Particularly in Erie, Pennsylvania, but I would say across the Great Lakes, the economy in these rural areas is largely focused around tourism and recreation," said Michael Ferguson, an assistant professor of recreation management and policy at the University of New Hampshire. That's especially true since many industrial employers that used to have a presence in the upper Midwest have gone.
"If we're seeing beach closures that are being enforced by the Department of Environmental Protection, they're trying to protect the user, but it's having a big impact on the economy," Ferguson said.
Some two-thirds of Great Lakes beaches that were tested had at least one unsafe day, according to the Environment America report. In Ohio and Pennsylvania, which border Lake Erie, all but three of the tested beaches had at least one unsafe day last year. In Illinois, 19 out of 19 beaches were potentially unsafe for at least one day; in Indiana, it was 22 out of 23. Michigan and Minnesota, with just about half of tested beaches having one potentially unsafe day, fared the best.
Environment America looked at just one metric to determine if a beach was unsafe—the presence of E. coli, which comes from human or animal feces, as tested by the National Water Quality Monitoring Council. (To be deemed "potentially unsafe," a beach needed to have enough a E. coli to sicken 32 per 1,000 swimmers, which is the standard used by the U.S. Environmental Protection Agency.)
Plenty of other issues can make water unsuitable for swimming, including chemical pollution and algal blooms, caused by fertilizer runoff. Toxic algae forced Mississippi to close all the state's beaches earlier this month and caused a state of emergency in Florida last year.
What's more, with greenhouse gas emissions making waters warmer and rainstorms more intense, it's likely that we'll see more instances of both bacteria and algae in swimming areas.
"These are age-old problems, and they're really being exacerbated by climate change," Ferguson said.
But towns aren't helpless when it comes to preventing bacterial overload. Green infrastructure—things like parks, wetlands, gardens and "green" roofs—can help the ground absorb rainwater and reduce storm runoff. Philadelphia is in the middle of a 25-year greening project to reduce its stormwater runoff; Kansas City last year adopted a "green infrastructure" framework aimed at making the city more resilient to floods.
Tighter regulations around industrial animal operations can also help, Environment America suggests.
"One of the top goals of the Clean Water Act was to ensure that all our waterways would be completely safe for swimming by 1983," said Rumpler. "So we're a little late on that."