National Geographic News
Wireless sensor in the River Lee
The River Lee is outfitted with five pollution-detecting sensors.

Photograph courtesy Antóin Lawlor, DEPLOY Project

Christine Dell'Amore

National Geographic News

Published December 7, 2009

This story is part of a special series that explores the global water crisis. For more clean water news, photos, and information, visit National Geographic's Freshwater website.

Nature has gone wireless in Ireland, where scientists have outfitted a major river with sensors that detect spikes in pollution in real time.

Sensors recently placed at various points in the River Lee, near the city of Cork, send information on pollution levels back to a data center. Water managers can keep tabs on pollutants entering the river and, if need be, mount an immediate response.

Called the DEPLOY project, the program was developed as a cheaper alternative to sending out scientists to collect water samples several times a day. In addition, the technology can identify a disastrous influx of pollution, such as toxic industrial-chemical spills, before fish go belly up.

(Related: "'Smart Dust' Sensors to Be Used for Eco Detection.")

Citizens can also set up an account to get data reports, so they can receive text messages or emails whenever water quality reaches an unhealthy level at points in the river where people may kayak or swim .

"You can build a story about what is actually happening with the water," added Paul Gaughan, a project coordinator at the Marine Institute in Galway, Ireland, which is co-funding the initiative with the Irish Environmental Protection Agency.

For some, the Irish project is a test case: If successful, DEPLOY and other water-monitoring projects across the globe could help build a case for widespread wireless environmental monitoring.

Testing the Waters

The DEPLOY project launched with five monitoring stations in April 2009 along the River Lee, one of the largest rivers in southwestern Ireland. (See map.)

DEPLOY will last roughly until next April, when scientists will decide if it's both technically and economically feasible to expand the program to other European rivers. (See a map of the world's fresh water.)

The five-sensor system runs for about U.S. $22,619 (15,000 Euros). To outfit the entire Lee River Basin would cost about U.S. $301,592 (200,000 Euros), according to DEPLOY project manager Fiona Regan.

The European Union's Water Framework Directive, which requires countries to thoroughly test freshwater and seas with accurate and reliable technology, spurred the DEPLOY project, organizers say. That's a particularly tall order for Ireland, which has a lot of rivers, lakes, and other water bodies, making a less costly technology like DEPLOY crucial, Gaughan said. (See freshwater pictures.)

Pollution concerns in Ireland include nutrient-rich runoff from farmland and inadequate wastewater treatment—often made worse by Ireland's notoriously heavy rainfall.

The nitrogen and phosphorus in the runoff encourage algal blooms, which flourish in the summer when temperatures rise. The blooms tend to kill off river wildlife by sucking up the water's oxygen. (Test your pollution IQ.)

The sensors not only detect potential pollutants—such as chlorophyll, a warning sign of an algae bloom—the machines also run routine river "check-ups."

For instance, the sensors measure temperature and the amount of dissolved oxygen in the water every 10 to 15 minutes, which tells scientists whether a water body has enough oxygen to support life.

However, the sensors aren't yet advanced enough to catch some harmful substances, the Marine Institute's Gaughan pointed out. For instance, outbreaks of the microscopic parasite Cryptosporidium have occurred in Irish drinking water and would not have been picked up by the sensors.

The existing sensors have not yet detected any dramatic pollution spikes in the River Lee, which is a relatively clean river, DEPLOY's Regan said.

But there "absolutely" is evidence from other projects that real-time water monitoring does improve water quality, she added.

"Why in the World Is This Happening?"

Real-time pollution monitoring has already taken off throughout the United States, where Andy Ziegler and colleagues compile wireless sensor data on the U.S. Geological Survey's (USGS) Waterwatch Web site.

In the past five years, Ziegler, a USGS water-quality specialist in Lawrence, Kansas, has noticed a big upswing in the number of countries using water-specific wireless pollution technology like DEPLOY, he said.

"From our experience, it's definitely increasing awareness of how variable the water quality can be in a very short time period," he said.

"Because you haven't had this kind of information before, you have data sets where you can look and go, Why in the world is that happening?"

But the U.S. needs a "dedicated, nationally consistent monitoring network" of real-time water quality, which would provide data quickly enough for scientists to respond at a national scale, Ziegler said.

Right now the USGS monitors about 7,500 U.S. sites—with or withour wireless technology—for stream flow dynamics, as well as 1,500 sites for temperature and 300 for turbidity, or how clear the water is.

"We're just starting to get on the leading edge of the technology," Ziegler added.




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