MOUNT PLEASANT — As public awareness grows about pollution in Charleston-area waterways, town officials are wondering if a warning system is needed to tell people when bacteria levels are high in Shem Creek, which is popular with kayakers, paddle-boarders and boaters.
Meanwhile, Mount Pleasant Waterworks is asking the town for funding to help connect homes with septic systems to public sewer system, and the town is awaiting the results of a study of the Shem Creek watershed.
"Obviously, Shem Creek is something that's near and dear to all of Mount Pleasant," Waterworks General Manager Clay Duffie said during a Town Council committee meeting Thursday.
Citing a recent Post and Courier report, Duffie said: "It's obvious that rainfall does spike bacteria levels in Shem Creek."
Weekly testing conducted by Charleston Waterkeeper has shown that levels of bacteria associated with animal and human waste soar in Shem Creek and other waterways when there's rain. Stormwater carries the waste into creeks and rivers.
It's not uncommon to see bacteria levels that are several times, or even hundreds of times, the level considered acceptable for swimming after a rain storm.
One thing the town's study hopes to determine is, how much of the bacteria washing into Shem Creek is from animal waste, and how much is human.
Councilman Gary Santos is skeptical that septic systems play a large role. He noted that when Isle of Palms studied a similar issue about 15 years ago, it was determined that waste from pets and wild animals caused most of the problems.
"It seems to me that runoff is causing most of the problems, not septic tanks," Santos said.
Duffie said Friday that septic tanks — there are nearly 1,100 in the Mount Pleasant area — are a part of the problem, and not just for Shem Creek. Most of the septic systems are outside town limits, in parts of unincorporated Charleston County surrounded by the town, he said.
"A septic system might be sitting there failing, every day, but during dry weather that (waste) may not be leaving the property," he said. "Then, here comes the rain, and it’s not just dog poop that gets washed into the creeks, it’s septic tank poop."
Santos and Councilman Elton Carrier raised questions about developing a warning system to alert people using Shem Creek for recreation when bacteria levels are high. Santos said it could be something simple, such as flags at the landings.
A challenge would be that water testing takes place weekly, on Wednesdays. The test results are posted on Charleston Waterkeeper's website on Fridays. But rain can dramatically change the bacteria levels.
The results of the town's Shem Creek watershed study are expected in August. At that point the town hopes to meet with Waterworks and S.C. Department of Health and Environmental Control officials, and other interested parties, to create a plan. That would come in addition to about $7 million of stormwater improvements under way as part of road improvements on Coleman Boulevard.
When the study is finished, that's when Duffie's request for funding from the town to reduce the number of homes using septic systems would be considered.
In the spring of 2016, Charleston Waterkeeper urged DHEC to reclassify Shem Creek as one used for recreation, which could lead to more stringent rules and faster state action to develop a plan to keep the creek clean. On Friday Jeff Taillon, DHEC spokesman, said that request is still being evaluated.
"While reclassifying waterbodies is an option, it is a lengthy process that requires approval from both the legislature and the EPA," he said.