Every Wednesday from May through October, Andrew Wunderley and a rotating crew of volunteers pilot a boat out into the Charleston Harbor basin, stop at 20 sites, and dip in a sample tube.
They've done this since 2013.
The result is the longest-running citizen water quality dataset in the region. The Post & Courier's Jonah Chester reported this week on what that dataset says — and what it says about Filbin Creek is hard to look away from.
The numbers
South Carolina's "safe to swim in" threshold is 104 colony-forming units of enterococci bacteria per 100 milliliters of water. Past that, you start running real risk of diarrhea, vomiting, or just plain skin trouble.
Filbin Creek in North Charleston routinely tests at 24,196 cfu/100mL. That's not the actual peak — that's the number where Charleston Waterkeeper's instruments cap out. The real figure is higher. The state classifies Filbin among South Carolina's "impaired" waterways.
For perspective: in five years of testing, Filbin has come in under the safe standard exactly once — June 9, 2021. One week later, it had spiked to 12,000 cfu/100mL. A 12,371 percent jump.
What's killing it
Filbin used to be a tidal creek. Now its upper reaches past Spruill Avenue are basically a drainage canal cutting through hard, impervious, runoff-heavy development. A tide gate keeps the water from flushing properly. Septic tanks leak. Sewer systems overflow during storms.
The result, Wunderley said in the Post & Courier: a low-salinity stew of bacteria that "thrives" in exactly the conditions humans built for it.
"Filbin Creek is pretty emblematic of really the development of Charleston and the greater Charleston area," he said.
The other usual suspects
Shem Creek — where Waterkeeper itself is headquartered — regularly clears the safety standard the wrong way. James Island Creek, long plagued by leaking septic tanks, also routinely spikes.
Even on a relatively cool spring sampling day this month, three of the 20 sites came in unsafe. Filbin clocked 473 cfu/100mL — more than four times the limit — before climate change runs its summer warm-up routine.
Why this matters
Sea level rise is pushing groundwater up. Heavier storms are washing more contaminated runoff into the system. Septic tanks fail silently. And the Department of Environmental Services — which treats Waterkeeper's data as a reliable input — is "hopefully" close to publishing reduced-pollutant standards.
"Hopefully" isn't a particularly reassuring word when paired with public health.
The takeaway
If you're planning to paddle, swim, oyster, or just dunk a child in any of these waters this summer — Filbin, upper Shem, James Island Creek — check Waterkeeper's weekly Swim Alert results first. They're free. They're posted online. And they're the most actionable Charleston-development-meets-climate story you'll see this week.
This is a summary of an article published in the Post & Courier. Click here if you'd like to read that article.
