The water feature Transylvania won't be bragging about: a steep rise in elevated levels of E. coli
Concentrations of the bacteria in two county rivers frequently exceed the federal safe-swimming standard; heavier rains related to global warming appear to be one cause.
Dan DeWitt
CEDAR MOUNTAIN — The usually clear and presumably clean Little River, flowing silently between grassy banks, completes the idyllic scene in the beer garden of the Cedar Mountain Canteen.
So near its source in this sparsely developed corner of southern Transylvania County, the river should be as clean as any in the region, said Kim Coram, a co-owner of the Canteen.
So when tests supervised by the MoutainTrue environmental organization found the water there contained elevated levels of E. coli bacteria, she said, “it blew my mind.”
The first failing grade for the water that she and her husband, John Wiseman, collect weekly at the Canteen, came in June, Coram said. Then it happened two weeks later, and then again this week, when MountainTrue found levels exceeding the federal safe-swimming standards at all eight of the sites it monitors in the county.
“It’s gut-wrenching,” said Coram, who with Wiseman has a long history of environmental activism.
“We’re three miles from the Continental Divide,” she said of the Canteen. “The water should be pristine.”
Such assumptions about water quality are common in Transylvania, where tourism officials tout the county’s waterfalls, kayaking streams and swimming holes. But also common, at least on the French Broad and Little rivers, are elevated levels of E. coli (Escherichia coli).
All the sites in the county monitored by MountainTrue’s Swim Guide program on these rivers have repeatedly failed weekly tests — indicating at least a slight risk of illness to swimmers — and many are failing with dramatically increasing frequency.
“Unfortunately, across the board it’s getting worse,” said Hartwell Carson, who works with MountainTrue as the French Broad Riverkeeper.
A contributing factor is another of the county’s well-known natural features, heavy rainfall, which in recent years has been unusually heavy “due to climate change,” says MountainTrue’s website.
Surging runoff swamps sources of E. coli such as septic tanks, farms and the city of Brevard’s sewer system, Carson said.
“I do think rain has a lot to do with it,” he said. “Those one- or two- or three-inch rain events are becoming kind of common.”
And partly because of heavy regional rainfall, “the French Broad is the worst river in North Carolina for E. coli pollution,” Carson said.
Testing Sites and Failing Grades
MountainTrue conducts weekly tests at six access points on the French Broad in Transylvania and two sites on the Little — the Canteen and DuPont State Recreational Forest — from May 1 to Sept. 30. The group issues a passing grade if it finds fewer than 235 E. coli “colony forming units” per 100 milliliters of water, the standard for safe swimming set by the federal Environmental Protection Agency.
Findings above that level, result in a red-letter warning on the Swim Guide page: “Failed to meet water quality standards.”
The clearest picture of the increased findings of contamination can be seen at sites that have been monitored since 2015, the first year for which results are available in Transylvania. That year, for example, only 21 percent of the tests of the French Broad at Hap Simpson Park revealed elevated E. coli levels. In 2000, water samples from the site failed every test.
The increasing failure rate has been just as dramatic at the French Broad access point on Wilson Road because the water there was so pure for so long, receiving passing grades on more than 90 percent of tests conducted from 2015 through 2017. By 2020, however, that rate had plummeted to 13 percent.
Falling test results are rarer at the Canteen and DuPont, both of which have come up red in half or less of this year’s tests.
The Forest hasn’t issued warnings of elevated levels — though visitors do swim near its landmark falls — because these features are primarily managed for viewing, said Christie Adams, public information officer for the state Forest Service.
The elevated readings are likely caused by heavy rains, she wrote, and the Little’s basin upstream from the Forest has “no identifiable point sources of E. coli that could contribute to a public health concern.”
The Risks
MountainTrue also says elevated levels of E. coli don’t necessarily mean a high risk of illness for swimmers and tubers.
E. coli is a common intestinal bacteria in humans and other mammals, and most strains are harmless. When other varieties do cause illness, symptoms such as skin rashes and diarrhea are often mild and temporary, according to the federal Center for Disease Control and Prevention (CDC).
Contamination at EPA’s safe-swimming threshold is estimated to cause illness among less than four percent of swimmers who are fully immersed in the water, the agency says. Also, levels elevated enough to prompt a warning are often only slightly elevated, Carson said.
“I usually don’t say, ‘Don’t swim,’ ” Carson said. “We like to use the Swim Guide so folks can make informed choices . . . If (E. coli levels) are elevated, you might want to go canoeing or fishing rather than swimming or tubing.”
But according to a spreadsheet of results provided by MountainTrue, water from the French Broad, especially, is sometimes contaminated at levels far above the EPA standard. That includes readings of more than 1,000 colonies per 100 milliliters recorded at several sites on June 30, including a measurement of 2,815 colonies — about 12 times the EPA’s safe swimming standard — in a sample collected at the river’s access point on Wilson Road.
And the EPA recommends testing of E. coli not just because of its dangers, but because it’s an indicator of the presence of human and animal waste that can contain more harmful microbes such as giardia and cryptosporidium.
Though MountainTrue cannot track the exact threat of illness as contamination climbs above the EPA threshold, according to Anna Alsobrook, the group’s Watershed Outreach Coordinator, she did say “the risk of getting sick gets higher as E. coli levels rise.”
Warmer, Wetter and More Polluted
The highest weekly readings, including those measured on June 30, typically come in the aftermath of heavy rains, and the connection between precipitation and elevated measurements of E. coli is also evident in the annual rates of failed tests.
Generally, the more rain in a given year, the more often MountainTrue issues water-quality warnings. And as years of heavy rainfall have become more common, so have the frequency of elevated E. coli levels.
Annual rainfall totals are hard to come by in small towns, partly because data is often incomplete. Rainfall in Brevard, for example, was measured daily during only 31 of the 70 years between 1950 and 2020, according to statistics provided by the National Oceanic and Atmospheric Administration (NOAA).
But an analysis of rainfall totals during years when complete records are available show a distinct upward trend.
The average annual rainfall over that 70-year span was about 76 inches, while the average during the past five years was nearly 10 inches higher
Before 2013, the city had never received more than 100 inches of rain, according to the NOAA figures, while at least 100 inches has fallen on the city in three separate years since then, including in both 2018 and 2020.
Kenneth E. Kunkel, a research professor at North Carolina State University and the lead scientist for assessments at the North Carolina Institute for Climate Studies, didn’t go quite as far as MountainTrue, which flatly cites climate change as a cause of increased precipitation.
But heavy rains are definitely consistent with warming weather and, particularly, the warming water in the Gulf of Mexico, the ultimate source of much of the county’s rainfall, Kunkel wrote in an email
“The amount of moisture in the air over the Gulf is directly tied to the surface water temperature (the warmer, the more water vapor in the air),” Kunkel wrote. “Gulf surface water temperatures have been gradually rising, unevenly but steadily.”
The Action Plan
But increased contamination isn’t just the result of heavy rains.
Slightly less rain fell in Brevard in 2020 than in 2018, for example, while the rate of failing water-quality grades was significantly higher.
And runoff cannot produce elevated E. coli levels unless it hits significant sources of animal and/or human waste, which, according to the MountainTrue website include “cattle (operations) and faulty and inadequate sewer, septic or water treatment infrastructure.”
Lowering contamination, then, means sealing off these sources.
Brevard is an example of both a cause of the problem and efforts to fix it.
Higher readings are common near the county’s most developed areas, including Brevard, and the city’s sewer system is a likely source, Carson said.
But the city has made significant upgrades to that system in the past decade, and an equalization tank built in 2017 has significantly reduced overflows into the French Broad, according to documents provided at a May 17 City Council meeting. At that same meeting, the city pledged to spend $2.3 million to replace pipes and manholes as part of its Gallimore Road Sewer Rehabilitation Project.
More money should also be spent on state programs that would reduce runoff from livestock and septic tanks, according to an action-plan page on MountainTrue’s website.
The state should provide more help to farmers to create buffers between pastures and riverbanks, says the site. MountainTrue is also pushing for the restoration of the discontinued Waste Detection and Elimination Program, which between 2002 and 2009 helped homeowners detect more than 2,000 sources of water pollution, mostly failing septic tanks.
Finally, the site says, at least $3 million should be devoted to a severely underfunded state program that helps residents fix faulty septic systems once they are discovered.
“I’m rocking the hypothesis that septic is a bigger problem than people previously thought,” Carson said.
“Water Refugees”
Septic runoff is one of the few possible sources of contamination measured in the Little next to the Canteen, Coram said.
Though she has been devastated by these findings, she also said it is “great” to know about them.
She and Wiseman moved to Cedar Mountain to escape fracking-related water pollution in their former home of West Virginia, she said. “We’re water refugees.”
From that experience, they learned that preventing the ill effects of contamination is possible only when it is documented, she said, which is why they volunteered the Canteen as a testing site.
A white board there tells customers the results of the most recent tests, and a gate between the beer garden and the river bank is locked upon the posting of an elevated reading. When a woman recently headed to the river with “her very young grandchild,” Coram was able to warn her away, she said.
“This is all about awareness,” she said. “As people here are learning about (contamination), they are saying, ‘We have to do something.’ Awareness is motivating action.”