COLUMBIA, SC Riverbanks Zoo has shut down a popular children’s wading pond after learning that youngsters were using it as a kiddie pool, which the zoo wasn’t prepared to operate.
The man-made wetland, commonly called the "tadpole pond,'' opened April 7 as part of a new children's section at the zoo's botanical gardens. It featured boulders and a collection of frogs and tadpoles that swam in the shallow water. Children could hop from rock to rock, or step into the water and scoop up tiny amphibians.
But as temperatures rose in May, children began sitting, splashing and swimming in the water, which raised concerns since the pond was not designed for that purpose, Riverbanks officials said this week.
Bacteria levels in the water soared on five occasions from May 10 to June 1, according to test results from the zoo and the state health department. In one case in mid-May, E-coli bacteria were seven times higher than the standard for safe swimming, records show.
The pond closed in early June and has been permanently drained. It will be replaced by a splash pad, like one that has already been established in the children’s area of the zoo’s botanical gardens.
“We never intended for children to swim in that,’’ said Satch Krantz, the zoo’s chief executive officer. “Clearly those children and their parents had a very different concept of how they wanted to use it than’’ the zoo.
No one at Riverbanks knew last week what caused the bacteria problems, but Krantz speculated that they resulted from heavy use of the tadpole pond. Some children may have relieved themselves in the water, he said.
Each time bacteria levels went up, zoo officials said they drained the tadpole pond, scrubbed it and brought in fresh water. The bacteria levels would then go down for several days, before rising again, according to the results of zoo water tests.
Krantz said the zoo had decided to shut down the pond before bacteria levels went up, but the water quality problems hastened the tadpole pond’s demise.
Exposure to high levels of E-coli and other types of bacteria can give people upset stomachs or cause open cuts to become infected. Riverbanks officials said children’s health was not threatened because the zoo acted quickly to clean the pond when bacteria levels went up.
In an email to The State newspaper, state health department spokeswoman Jennifer Read said her agency is satisfied that Riverbanks Zoo acted properly in monitoring, overseeing and eventually closing the tadpole pond.
“It sounds like they saw a problem, stepped up and did something about it,’’ said Congaree Riverkeeper Bill Stangler, who monitors water quality issues along the Saluda River.
Even so, closing the tadpole pond is a blow to the zoo’s original idea of providing a wetland specifically designed for children to interact with nature. Other botanical gardens are starting to add those features to teach children about nature, Krantz said.
“What has happened in the last 15 years is all or most every major botanical garden has built a children’s area,’’ Krantz said.
As first-designed, the zoo planned to pump water into the pond from the nearby Saluda River to save money and to provide a more natural water source. But Riverbanks had problems with a pump and chose instead to use water from the city of West Columbia, Krantz said.
Because of the way it was originally proposed, the Riverbanks tadpole pond was not regulated as a swimming pool, but as a natural swimming area. That meant the zoo wasn’t required to disinfect or recirculate the water as is required to keep swimming pools clean.
Natural swimming areas typically are places where a property owner or manager charges a fee so people can swim in a river, lake or pond. DHEC has certified four man-made water bodies, including the tadpole pond, under the natural swimming program, agency spokeswoman Read said in an email Friday. DHEC required the zoo to check water quality every 14 days for the presence of bacteria. The information had to be reported to DHEC, she said.
Krantz said the new splash pad will be regulated by DHEC as a swimming pool. He said the tadpole pond was a good concept that didn’t work as anticipated.
“The concept as we designed it was that the children would stay on the rocks — and maybe occasionally one would step off the rock and look at a fish or a tadpole,’’ he said, noting “that never happened.”
“We reached a point where we said ‘Are we going to continue to push that rope up the hill? Or are we going to back up and redesign it?’ ‘’