Bluffton’s population boom caused rising bacteria levels in May River, study says
Fecal coliform bacteria levels have been rising in the May River for the past two decades and, in some parts, are above what is considered safe for shellfish harvesting, according to a new study at the University of South Carolina-Beaufort.
The bacteria levels near the headwaters of the May River were 15 to 16 times greater in 2017 than in 1999, according to the study.
The study, commissioned by Bluffton and Beaufort County and led by Eric Montie, an associate professor of biology at USCB, and graduate student Jamileh Soueidan, looked at water quality data collected by the S.C. Department of Environment Health and Control from shellfish monitoring stations along the May River. The study found that Bluffton’s building and population boom over the past 20 years has led to increased stormwater runoff, lowering the salinity in the May River and causing fecal coliform to thrive.
Heavy rainfall due to increased El Niño events — complex weather patterns caused by the warming of ocean currents — was also a contributing factor to the rise in bacteria levels in the May River, according to the study. DHEC collected water quality samples at seven monitoring stations in the river from 1999 to 2017 and four additional stations from 2009 to 2017.
Montie said he plans to present his findings to Bluffton Town Council on Dec. 10.
Fecal coliform bacteria — typically originating from the intestines of warm-blooded animals — are analyzed by agencies like DHEC to determine whether disease-causing organisms are present in water bodies. Although not all coliform bacteria may cause illness, their presence indicates that disease-causing organisms could be in water bodies. Bacteria levels directly impact oyster harvesting. If fecal coliform levels exceed a certain number, shellfish harvesting beds are restricted or closed. According to DHEC’s shellfish monitoring map, a large portion of the May River’s headwaters are closed for shellfish harvesting.
“This is what DHEC has to do because, otherwise, people can get really sick or die from oysters contaminated with pathogenic organisms,” Montie said.
The town of Bluffton and Beaufort County each contributed $15,000 last November to pay for the USCB study. Montie presented his team’s findings to Bluffton’s May River Watershed Action Plan advisory committee in late October and said he will continue his research by comparing the data from the May River to other watersheds like the Okatie River if he receives funding. He expects the study to cost $30,000 per year for the next two years.
Montie said there could be several solutions to the high fecal coliform levels. One source of the bacteria could be human waste from septic tanks. In an ideal world, Montie said, all septic systems would be converted to sewer systems.
“We need to come up with ways to limit development and impervious surfaces like paved roads,” he said. “We also need to keep the forested land in our watershed.”
He said charging developers higher impact fees for studies on the May River and creating natural wetlands near developments could help alleviate some of the problems.
If development in the May River watershed isn’t controlled, “you’re going to have deterioration in water quality,” he said. “You’ve got to have some sort of control.”
Alan Warren, Environmental Health Science program director at USCB, said the origins of the problem aren’t in the river, but in the upland areas surrounding the river. He said Bluffton and Beaufort County have been trying to solve the issue of poor water quality in nearby watersheds, but the problem is getting worse.
Kim Jones, watershed management division manager for the town of Bluffton, did not return a call for comment Wednesday.
Bluffton’s population has increased 874% since 2000, according to the U.S. Census, and developers continue to build. The increase in impervious surfaces, such as roads and parking lots, has led to a decrease in water quality of nearby waterways.
The USCB study was released as residents in Bluffton and Beaufort County have complained publicly about rampant development. In recent months, developers have proposed building hundreds more homes.
In many cases, developers whose plans were approved years ago have asked to change their original agreements and increase density. Residents who live along Cherry Point Road, for example, worry about a plan to build more than 600 homes and a mix of commercial developments. They say the plan, called River Oaks, would hurt the water quality of the Okatie River.
This story was originally published November 14, 2019 at 7:30 AM.
