Water-quality tests leave scientists perplexed about May River threat

Local officials are losing confidence that some water-quality analyses can identify the cause of pollution in the May River.

High fecal coliform levels raise the risk of shellfish bed closures in the river's headwaters, which the S.C. Department of Health and Environmental Control has deemed a fecal hot spot. The agency has detected rising fecal levels in the headwaters over the past three years and is analyzing the data. A report is expected in June.

To determine what species is causing the contamination, the town of Bluffton and Beaufort County collected water samples and sent them to Source Molecular of Miami for DNA analysis. The tests can check for human, dog, deer, horse,bird and hog waste.

The first analysis pointed only to human sources.

A second study indicated only bird sources.

The sampling is part of Bluffton's May River Headwaters War Plan, a three-year, $3 million project that increases water sampling and analysis to determine the cause of fecal contamination.

Samples collected in late February and early March indicated human waste was the source of the problem, specifically in Rose Dhu Creek. The creek runs beneath a bridge on S.C. 46 and feeds into the river's headwaters.

Those results prompted county officials and the Beaufort-Jasper Water & Sewer Authority to look for failing septic tanks and leaky sewer lines. Both the tanks and the lines are working properly, county stormwater manager Dan Ahern said at a Technical Advisory Committee meeting Friday.

The committee, comprised of local and state officials, scientists and conservationists, studiesMay River water-quality data and efforts to reduce pollution.

"So where is it coming from?" Ahern asked.

The latest analysis indicates birds, not humans, are causing the problem.

This week, the county received an analysis from a sample collected March 19. Officials had asked the lab to expand the DNA analysis to include birds and hogs as possible fecal sources. The results tested positive for birds and negative for all other potential sources, Ahern said.

"We didn't get any smoking guns we were hoping for," Ahern said. "We thought it might be deer, dogs or horses causing the problem."

In a grant proposal to DHEC, Bluffton officials estimate horses in the county produce about 700,000 pounds of waste a year, and that wildlife produces about 200,000 pounds. When Bluffton is at full build-out, town officials also expect about 3,500 dogs will live near theheadwaters, said Jeff McNesby, Bluffton's environmental protection director.

Ahern saidnot much can be done to reduce bird waste.

With two data sets indicating different sources of contamination, officials aren't sure which is correct.

"When they are random, it gives you less confidence," McNesby said.

McNesby said he's waiting for direction from the committee and town officials on what to test for before the town sends another sample to Miami.

Ahern said the county will send more samples this summer to test for seasonal differences.

In the meantime, the committee will study how the volume of runoff flowing into the May affects its health.

Before development in Bluffton, only 10 percent of all runoff flowed into the May River, McNesby said.

As the land was developed, natural areas were replaced with pavement or other impervious surfaces that don't allow runoff to soak into the ground.

Now, about 30 percent of runoff flows into the river, McNesby said.

Committee member Chris Marsh said golf courses also contribute to the volume of water flowing into the May. Many use treated effluent or draw water from the Middle Floridan Aquifer to irrigate the golf greens. Golf courses also use fertilizers. When they irrigate, some of the treated effluent, aquifer water and fertilizer flows into the river.

Freshwater that flows into a salty estuary decreases the salinity levels that help dilute pollution and contaminants.

Marsh said the committee should compare water levels flowing into the river with average rainfall totals to see how it might affect the May.

Jimmy McIntire, a Bluffton resident and committee member, lives on the river. He agrees the committee is asking the right questions, but says it needs to work more quickly in fixing the problems.

"I get frustrated because they continue to talk all this scientific lingo, and I want action," he said. "We are on the right track; it just is getting through the bureaucracy and making sure it gets done is the most important thing."

The committee is scheduled to meet again June 10.