Bacteria levels in Waccamaw River not high after flooding

Test results show bacteria levels in the Waccamaw River haven’t increased to dangerous amounts in the aftermath of the recent historic flooding.

Horry County officials were concerned about bacteria levels in the river after runoff, some of which contained human and animal waste, caused the river to swell, along with record rainfall.

Samples of the river were collected and tested for the bacteria e.coli, which is found in waste, and Horry County officials said results revealed harmful quantities were not present.

“All the numbers are below water quality criteria set by DHEC [Department of Health and Environmental Control], and that’s a good thing,” said Tom Garigen, of the Horry County Stormwater Department.

Last week while awaiting results, scientists said two possibilities existed for the river in terms of its bacteria levels after flooding: one scenario was bacteria levels could have soared to dangerous amounts. Another likelihood was a dilution effect could have watered down all the bacteria, keeping it at safe levels.

The recent testing revealed the latter happened, which has officials breathing easier.

“We believe that’s the cause because there was such a tremendous volume of water,” Garigen said of the dilution effect the test results showed.

Garigen said this result is typical of the Waccamaw and was also the case after minor flooding during the summer 2013.

Dr. Susan Libes -- environmental quality lab program director at Coastal Carolina University, whose staff took and processed the recent samples after receiving Horry County funding -- said dilution also watered down bacteria levels in the river after Hurricane Floyd sent the river to its record crest of 17.8 feet in 1999.

Samples of river water were gathered by scientists last week from various points including Buck Creek, Highway 9, Reaves Ferry, Crabtree, Conway, Bucksport, Hagley, Galivants Ferry, Savannah Bluff, and Cox Ferry Wildlife Refuge, according to lab reports.

“…E.coli levels measured yesterday were well below water quality criteria at all sites,” Libes said in a report.

Samples did show different amounts of bacteria in the water at various locations tested as Waccamaw Riverkeeper Emma Boyer predicted they would while awaiting results last week, but none of those tests showed any hazardous levels.

Boyer said the river always has higher levels of bacteria present in certain locations after flooding, especially around urban areas where trash, animal waste, and septic tanks are kept.

Samples were also collected by volunteers with Coastal Carolina University's Waccamaw Watershed Academy and Waccamaw Riverkeeper’s program and their official read on bacteria levels is not available yet.

While the river’s bacteria levels look healthy, preliminary testing completed by volunteers determined that the river’s oxygen levels are seriously low for river wildlife and that the acidity levels are hazardously high for them.

Test samples gathered by Libes’ team also reflected low oxygen at various spots along the river including water quality criteria at Crabtree, Conway, Bucksport and Hagley.

“As is typical with flood events, dissolved oxygen levels have declined to very low levels that are well below the water quality criteria. This is due to the flushing of colored dissolved organic matter from the flooded swamps as evidenced by the elevated true color observed at most sites,” Libes said in a lab report.

Libes said oxygen and acidity levels are routinely measured, along with various other river elements.

Organic matter from nearby swamps regularly flows into the river, and when it decomposes it lowers oxygen levels and gives the water its murky color.

However, flooding pushed a greater amount of swamp matter into the river, causing the oxygen levels to plummet and sending acidity levels soaring.

Libes said as a result of the lower oxygen fish will swim to places in the river with higher levels and may also visit the surface. She said there is a species of fresh water mussels found only in the Waccamaw, and their shells are at risk for dissolving from the high acid levels.

While this acidity level is dangerous to them, it wouldn’t affect humans, river experts said.

Although the Waccamaw habitat is strained by flooding, Libes said the ecosystem is used to experiencing environmental stress and should naturally sustain and correct itself over time.

Experts said it will simply take time for the river to shift back to its normal balance.

Garigen said bacteria present in the river now will be flushed out into the ocean. He also said he didn’t anticipate any spikes in bacteria levels as the river recedes.

While the Waccamaw River is showing signs of good health in terms of bacteria levels, officials have continuously warned about the possible contamination in floodwaters in community areas outside the river area.

These waters are often filled with bacteria because this water flows by more septic tanks, trash cans, and animal waste in yards, swallowing up pieces of it all, along with chemicals, officials said.

As cleanup continues, DHEC officials have warned residents about the dangers of tetanus and have offered free shots to flood victims by appointment at state health department locations in Florence, Georgetown, Lexington, Richland and Williamsburg counties.

“The vaccine is recommended if it's been 10 years or more since your last tetanus vaccination or you have experienced an injury and your shot is more than five years old,” DHEC spokesman Derrec Becker said in a press release.

Garigen said that while the Waccamaw River isn’t showing signs of dangerous bacteria levels, he recommended that riverbank community residents also get a tetanus shot if needed.

The river could still have branches and things in it from flooding and a cut from such debris could lead to tetanus.

“Anyone doing home repairs and cleanup should get a tetanus shot,” Garigen said.

This story was originally published October 20, 2015 at 3:06 PM with the headline "Bacteria levels in Waccamaw River not high after flooding."