Waterkeeper volunteers Mike Marcell (left) and Cheryl Carmack taking water samples in North Charleston | Photos by Ruta Smith

Is it safe to swim in the creek?

I f you swim or paddleboard in Filbin Creek in North Charleston, Shem Creek in Mount Pleasant or near some creeks on James Island, basic science suggests you might want to reconsider — or be extra careful.

For years, levels of bacteria that can make you pretty sick have been so high at these three locations that they failed safety tests just about every week from May to October. Four other locations failed tests at least 25% of the time over about 20 weeks this year.

So what’s going on? The storm of increasing development and more paved, impervious surfaces is wreaking havoc on Mother Nature. There is less forested and rural land. And there’s more rain brought on, in part, by climate change. Combined, it’s more difficult for the Lowcountry’s sandy soil to absorb enough water, which causes runoff filled with yard waste, leaking septic tanks, animal waste and road grime to ooze into streams feeding Charleston Harbor.  

“What we see is a constant threat and it feels like we’re just trying to hold the line in terms of water quality,” said Andrew Wunderley, executive director of Charleston Waterkeeper, a nonprofit that monitors water quality and provides its scientific findings to the state. What’s worse, he said, is that South Carolina, which touts its beautiful places, could do so much more: “You see a state that’s only minimally adequate in terms of environmental protection.” 

As water temperatures warm in the spring, Waterkeeper volunteers take samples every Wednesday morning for enterococcus, which is a large biological classification of bacteria that, if ingested, cause all sorts of gastrointestinal problems. Volunteers also check site health by measuring levels of dissolved oxygen, temperature and acidity at each location.

And what keeps scientists like Wunderley awake at night is how we’re not paying attention to what’s happening to the area’s interconnected estuarine system and the bounty that it produces for our tables and the rest of the food chain.

“The pace that this is changing from climate change and growth is beyond the system’s ability to adapt,” Wunderley said.

240 times worse than acceptable at Filbin Creek

Charleston Waterkeeper tracks the enterococcus bacteria weekly to measure someone’s risk of getting sick from being in waters or streams leading to the harbor.  

“It’s the Environmental Protection Agency-preferred indicator of the risk of illness arising with primary contact from recreational activity,” Wunderley said.

The water at Filbin Creek, which is in the shadow of Interstate 526,  and a looming paper mill, is an extreme example. A measurement site for the last two years, it received a passing score only once in 45 weeks for having less than 104 “colony-forming units of bacteria per 100 milliliters of water.” In other words, it failed 96% of the time in 2021 and 100% through September this year, according to Waterkeeper data.

What’s perhaps more alarming is the magnitude of failures. The average reading was 3,297 colony-forming units. But on five different weeks — four in 2021 and once in June 2022, bacterial readings exceeded 10,000 colony-forming units of bacteria. Twice, they were greater than 24,000 units.

While Filbin Creek consistently fails in the bacteria measurement, it and other sites often deteriorate after heavy rainfall, Wunderley said. At those times, there’s just too much water for water treatment centers to handle without harming the infrastructure.  

Cheryl Carmack and Britney Prebis take water samples

“In normal circumstances, most treatment authorities do pretty well at treating and disinfecting sewage,” he said. “It’s when we have heavy rainfall or flash flooding that they struggle to keep up.”

The state Department of Health and Environmental Control (DHEC), which has regulatory authority over water quality, said in a statement attributed to spokesman Ron Aiken that “bacteria concentrations are subject to wide fluctuations over very short periods of time, especially related to rain events, so it’s impossible to say on any given day whether or not bacteria standards in a recreational area will be met or exceeded.

“That is why we focus on broader public education of what to expect when entering a natural waterbody ­— that there is always some level of risk and the most current, real-time data is available through our online resources.

“Frequent installing and removing of stationary signage for temporary exceedances that can often last less than a day isn’t as current a method as our online resources that we work to promote through news releases, social media, water keepers, community groups and other stakeholders.”

The DHEC statement, however, added, “Charleston Harbor is not a designated swimming area. … There is always risk associated with swimming in natural waters.”

What to do about the problem

DHEC didn’t provide an answer about specific pollution and health risks for Filbin Creek, but it hasn’t been measured for too long. But for Shem Creek and James Island creeks leading into the Ashley River, it gave this answer — that each “is a priority area of particular concern in the Charleston Harbor area due to enterococcus bacteria impairment. Total Maximum Daily Loads (TMDLs) identifying necessary reductions to meet WQS (water quality standards) and restore recreation use support have been developed for this waterbody.”

The agency also advised against swimming or rafting during a storm or after it rains. It said to avoid swallowing river, stream or lake water, and to never swim with open cuts or wounds.

Among the ways to lower bacteria levels:

  • Public participation to adopt streams and keep them clean.
  • Detection and elimination of harmful discharges, such as from leaking and inappropriate septic tanks. James Island, for example, is being proactive in connecting more than 200 septic tank locations to a sewer system, which will cut down on leaking human waste, Wunderley said.
  • Building more stormwater control measures.
  • Picking up after pets so their waste doesn’t flow into streams and cause bacterial blooms.
  • Using car washes instead of washing cars in yards.

For fish and shellfish consumption information, DHEC suggested keeping up with its advisories and those of the state Department of Natural Resources. As of last week, Charleston Harbor didn’t have any fish consumption advisories.


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Stay cool. Support City Paper.

City Paper has been bringing the best news, food, arts, music and event coverage to the Holy City since 1997. Support our continued efforts to highlight the best of Charleston with a one-time donation or become a member of the City Paper Club.