Monitors check river's water quality

Wednesday, March 3, 2010
Gregg Hileman, a hydrologist with the United States Geological Survey, cleans debris from a water quality monitor for calibration.

Have you ever wondered what those big metal boxes are you see next to bridges and dams? The ones with USGS on the side that look like science fiction satellite transmitters?

Well, they aren't science fiction, but they are science and they are, in fact, satellite transmitters. The boxes, such as the one by the dam at Fisherman's Park in Shelbyville and the one by the bridge on Sims Road, are connected to water quality monitors that hang in the Duck River, recording information 24 hours a day, seven days a week.

"The radio system sends information up to the satellite and the satellite beams it back down," said Gregg Hileman, a hydrologist with the United States Geological Survey.

The monitors check the water for turbidity, for toxins -- for anything that might interfere with the health of the river and its environment. Although Hileman and other USGS employees try to visit each station every four to six weeks, they can be called out if something goes wrong or requires additional testing, alerted by the monitor's satellite system.

Sometimes those calls can bring the scientists out in the ice and snow, and even in the bright sunshine of Friday afternoon, the wind chill was enough to keep Hileman's cheeks and nose bright red.

"We try to schedule the visits around bad weather," he said, laughing. "It doesn't always work out that way."

Trained as a geologist, he's enjoying his work.

"The geo chemistry of lava and the geo chemistry of water -- same equations," he said. "I've always liked integrated science, where the chemistry and the critters all come together."

Hileman was checking the monitor on the Sims Road bridge, trying to lasso the monitor with an improvised rope and stick combination.

"This is not standard equipment," he said, laughing.

The probes hang through protective tubes that deter damage -- from accidents, weather or vandals -- but debris had collected at the top of the unit that kept it from being pulled through the cylinder easily. Finally, Hileman worked it out and began doing the real work -- seeing what the monitor had to tell him.

"The idea is," he said, as he separated the parts and stripped away a protective layer, "is to keep the leaves and things away from the monitor."

Hileman would go on to check the monitor's readings and run them against manual, on-site readings, comparing them to make sure the unit was correctly calibrated.

"This site is operated in cooperation with the Duck River Agency and the station in Shelbyville is partially sponsored by the Tennessee Valley Authority," he said. "Typically, the data we collect, we collect with a local agency and often the funding is provided in partnership," said Hileman. Those partnerships make sure that each agency gets the most out of the data, especially as it applies to individual regions.

"It keeps us relevant," he said.