Town officials ask UNCW to study problem at Banks Channel

As part of the YMCA-hosted event, participants complete a 1,500-meter swim.

But how safe are the waters they're entering?

Over the past several years, a number of swim advisories have been issued for the channel, said Steve Dellies, stormwater manager for Wrightsville Beach.

High levels of enterococcus, a fecal form of bacteria that's an indicator for organisms that can cause gastrointestinal and skin problems in swimmers, is the cause for concern from recreational water quality and town officials.

Those advisories prompted town officials to allocate $25,000 for a study that's just begun by the University of North Carolina Wilmington Center for Marine Science to discover the source of the bacteria, specifically to determine if it's human, animal or fowl waste. The study will run through mid-summer 2008, Dellies said.

The N.C. Department of Environment and Natural Resources, or DENR, tests the water in Banks Channel about once a week during the spring and summer months.

Stan Sherman, an environmental technician for DENR, said he issued three swim advisories for Banks Channel over the summer: July 11 following a sewer spill, and Aug. 1 and Aug. 30 after heavy rainfall. Sherman said the enterococcus bacteria levels were higher after the August storms than after the sewer spill.

After rainstorms are typically the worst times for elevated bacteria levels because of the stormwater runoff, said J.D. Potts, with DENR's recreational water quality department.

"Stormwater runoff is really magnified by the more impervious surface that you have," said Mike Mallin, a UNCW research professor and water quality specialist who is heading the Banks Channel study.

Impervious surfaces are roofs, sidewalks, roadways - basically any surface covered by an impenetrable material like concrete. Mallin said he conducted a study published in 2000 that found the more impervious the surfaces, the higher the bacteria count in six New Hanover County tidal creeks.

"It's a huge problem," Mallin said.

There are numerous storm drains from Waynick Boulevard that spill into Banks Channel, sending untreated runoff directly into the channel.

Adding to the problem is bird and pet waste being washed from yards and roadways into the water, Potts said. Also, a large number of pigeons and ducks spend time in the wet sand on the banks of the channel, with high tide picking up their waste from the shores, he said.

Wrightsville Beach officials have been addressed about the stormwater runoff problem, Potts said, but to treat stormwater there has to be room.

"These are very difficult issues to address," Potts said. "You have pavement all the way down to the beach. It's no easy thing to try to fix."

The Environmental Protection Agency requires that municipalities apply for permits for stormwater runoff and place restrictions for new construction sites and residing homeowners, such as not rinsing driveways or emptying pools into storm drains, Dellies said.

UNCW graduate student researchers will be testing the water after periods of heavy rain and heavy boat traffic, he said.

Some studies have shown that boaters dumping their fecal waste into waterways can lead to problems with high concentration of bacteria in the water, Mallin said.

Testing for possible sewer leaks will round out the team's research, Mallin said.

The town does periodic sewer pipe inspections, Dellies said, and no leaks have been found.

Despite the research taking place, Dellies and DENR's Sherman agreed that any significant amount of rainfall just before the upcoming triathlon could mean health hazards for the swimmers.

YMCA officials wouldn't comment on what they would do in the event of heavy rain just prior to the race or whether there is an alternate swim location.

If a swim advisory is issued by DENR, the New Hanover County Health Department would stand behind it, said Dianne Harvell, the environmental health services manager.

The health department wouldn't close the channel to swimmers unless there were an imminent health threat, she said.

Brittany Butcher: 343-2075

britt.butcher@starnewsonline.com