While local ponds are helping treat polluted water before it reaches the May River, Bluffton's water quality testing has found that run-off is becoming contaminated as it passes over the wetlands.
Samples taken from local ponds, which catch run-off from development, are relatively clean. But the water tested downstream from the ponds into the river is registering high levels of bacteria, town natural resources manager Kim Jones said.
"The wetlands aren't doing what we all assumed wetlands do, which is treat water," Jones said. "You would think the wetlands would be a sink and not a source."
The town's water quality testing program, ongoing since spring of 2009, has proven the fact over and over again, Jones said. County stormwater manager Dan Ahern said Beaufort County's testing has also found similar findings.
Jones said the high level of contamination could be due to wildlife, or dormant fecal coliform in the wetland bottom reactivated by the pond water moving over it.
Ahern said the real problem is that the ponds -- the preferred method for catching polluted water from development -- must be discharging the water too fast.
Any remedy will have to reduce the volume, Ahern said. Decreasing run-off from a flow to a trickle has been the focus of county efforts to curb pollution in the local waterways.
Encouraging people to retrofit their ponds to use them for irrigation instead of letting them flow onto the river could be one potential solution, Ahern said.
"In retrospect, we should have built retention ponds instead of detention ponds," Ahern said.
The testing has helped the town identify hotspots of fecal coliform which a forthcoming consultant-prepared May River Watershed Action Plan will address, Jones said. The plan is being reviewed by town staff, will be up for public comment over the summer and will be adopted by town council in September.
Jones declined to give details about potential treatment.
The fact that the wetlands are "overwhelmed" with stormwater is obvious, said May River Road resident Brandon Waring, who urged Bluffton Town Council on Tuesday to keep promises to restore shellfishing in the May.
"The science was ignored," Waring said in an interview. "It wasn't unknown."
In Bluffton, the town's water quality testing program is expected to grow. In executive session on Tuesday, town council authorized expanding it from 12 sites to 26 and the number of annual samples collected from 572 to 740.
Also on Tuesday, the town budgeted about $480,000 for May River projects and storm drain improvements in a total Capital Improvement Porgram budget of about $2.5 million.
A new Stormwater Management Department, which town manager Anthony Barrett said will pay "big dividends", will get an annual budget of $649,880. The total general fund is about $10.5 million.