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Uma, Tumbo, and a clean river

Uma and Tumbo spend much of their day submerged up to their eyeballs in the same aquifer water that supplies the San Antonio River. They don’t seem to mind at all, even with all the spectators gawking at them. It’s the price they pay for being the resident Nile hippopotami in the San Antonio Zoo.

But their idyllic lifestyle has come under the scrutiny of the San Antonio River Authority, which is working at an aggressive pace to lower fecal coliform bacteria levels in the river to meet Environmental Protection Agency and state clean-water requirements. SARA must meet an August deadline to reduce the river’s bacterial level to under 200 bacterial organisms per 100 milliliters.

That means Uma and Tumbo will have to stop doing their business — namely No. 2 — in their little cove by the riverside, because it’s contributing to the 19 percent of fecal coliform in the river that is attributed to the zoo.

The San Antonio Zoo is about to break ground on a $12 million Africa Live project, to be located in a two-acre area formerly known as Monkey Island. Uma and Tumbo will someday live in a self-contained, larger aquarium, among other animals that hail from Africa. “We need to complete the Africa Live exhibit and get the hippos out of there,” says Zoo Director Steve McCusker. SARA, which has designed a watershed-protection plan, commissioned a series of water tests along the San Antonio River from its source at the University of the Incarnate Word to its exit from the City to the south, and found that of 700 samples of feces taken from the river, wildlife contribute 32 percent of the bacteria; the zoo contributes the aforementioned 19 percent; domestic pets dump 10 percent; livestock drop about 4 percent; and 23 percent comes from unidentifiable sewer leaks in the City.

McCusker says the majority of zoo animals are not contributing feces to the coliform counts in the river, as most of their habitations are cleaned and flushed to the sewer, and any water used in the zoo is filtered, treated, and recycled after it is pumped from a single aquifer well on zoo property.

The problem, McCusker says, is a host of opossums, skunks, raccoons, rats, rabbits, egrets, ducks, and other wild birds who think the zoo is a great place to roost, and little can be done to prevent their contributions to the bacteria in the water.

“The coliform count is seasonal, and water sampling `techniques` are not perfect,” says McCusker. “A lot of birds nest here, and temperature also affects water quality.”

Michael Gonzales, manager of the environmental-sciences department at SARA, says a single entity such as the zoo is not the sole culprit in the river’s pollution. “Twenty years ago, the river had serious water-pollution problems. We’ve made significant progress, but it is not up to contact standards.

“The study says the river has a problem,” Gonzales says. “But Woodlawn and Elmendorf lakes with their tributaries also contributed to the problem. It’s our river, our back yard. If we don’t tell the state how we’re going to fix it, the state will come and take over.”

Gonzales acknowledges that much of the fecal coliform in the river comes from wild cormorants, egrets, and other water birds, and that SARA hasn’t figured out how to remedy that.

The San Antonio Water System for the past 20 years fixed sewer leaks downtown, where the river used to have from 20,000 to 40,000 coliform organisms per 100 milliters because of leaks, and these days the river is flushed with recycled water at three different locations.

McCusker says construction on the Africa Live habitat will take approximately 16 months, but once it is finished, Uma and Tumbo will be doing their part to clean up the river.

By Michael Cary

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