People paddle in Shem Creek and occasionally slip into its water to cool down. But the Mount Pleasant creek is one of at least 20 salt waterways on the coast that the state doesn't require to be as clean as others.
And Shem Creek is simply too dirty to swim most of the time, according to testing by Charleston Waterkeeper, a grassroots organization that patrols rivers for pollution.
That's why the waterkeeper this week petitioned the S.C. Department of Health and Environmental Control to change its rules regarding how it classifies the cleanliness of saltwater.
It's all about fecal bacteria — human and animal waste.
As the rules stand, there are two classifications for how much of this bacteria can be in saltwater and most uses of the water still be allowed. One is five times stricter than the other, but both are designated for the same water activities, including swimming.
As an example, under its current classification, Shem Creek has been considered unsafe 9 percent to 33 percent of the time in six years of testing at various points in the stream.
Under the stricter classification, it would fail from 28 percent to 80 percent of the time, said Andrew Wunderley of Charleston Waterkeeper.
He wants that stricter standard for all the saltwater in the state. If the department's board approves the single standard, people would have a more accurate gauge of which waterways are safe to get wet in day to day, he said.
"The question you want to answer is, 'Should I go in swimming right now?' All these waterways need to have the highest protection for the way the public uses them now," Wunderley said.
The South Carolina Environmental Law Project filed the petition for the waterkeeper.
"You have the exact same uses, except in one you have a lower standard (for cleanliness)," said attorney Amy Armstrong, the project's director and general counsel. "If it's going to be a resource the public uses, we think the state should take protective actions."
There's just one problem: Who pays to keep it clean.
The petition comes as DHEC considers establishing a Total Maximum Daily Load plan for dealing with fecal bacteria in the creek. The maximum daily load plan is just that, a plan or a goal with little enforcement. The reclassification also would set a goal.
Both would make it tougher for property owners to get stormwater discharge permits. But otherwise, local taxpayers largely would pay for more pollution controls.
Public involvement would make the difference, Wunderley said.
"We're going to get people involved in town meetings, city meetings and county meetings, to make sure the elected leaders stay involved getting things cleaned up," he said.
DHEC has 30 days to decide whether to rework to rules. If the petition is denied, Charleston Waterkeeper could take the case to the state's Administrative Law Court, Armstrong said.
Shem Creek is among a growing list of waterways becoming more polluted as population and development expand along the Lowcountry's coast. Shem Creek's problems are thought to be exacerbated by older septic tanks that line its upper banks.
Other waterways with the lower standard classification include Charleston Harbor as a whole, Folly River, and Wappoo Creek, also called Elliott Creek, between West Ashley and James Island.
Water quality in the Charleston Harbor estuaries has been deteriorating for years while the monitoring has fallen off. Efforts to maintain it for fishing or swimming aren’t stopping the degradation.
A lot of it is stormwater runoff: pollution carried by rain from impervious surfaces such as roofs, roads and parking lots. Everything from gasoline to pet waste ends up washing into the stream.