National Lab Software Helps Safeguard Public Water Supplies

Software developed at Sandia National Lab in Albuquerque, New Mexico gives public water utilities early warnings of water quality threats from terrorists or natural contaminants. The open-source code, written in partnership with the U.S. Environmental Protection Agency, is available as a free download.

The software, known as CANARY, can tells utility operators in minutes of water quality problems, giving them time to warn and protect the public. Utility operators can also use the software to provide comprehensive real-time data about changes in water quality for day-to-day management.

Any system for detecting contamination has to distinguish reports of real contamination from background noise caused by the environment and the utility infrastructure itself. The researchers developing CANARY devised numerical algorithms to analyze data coming from multiple sensors and differentiate between natural variability and unusual patterns that indicate a problem.

The program uses a technique known as a Multivariate-Nearest Neighbor algorithm that groups data into clusters based on time and distance. As CANARY receives new data, the software decides whether a potential contaminant reported in the data is close enough to a known cluster to be considered normal or whether it’s far enough away to be deemed anomalous. If the report falls outside the normal range, CANARY alerts the utility operator

The computer program also uses a moving 1.5- to 2-day window of past data to detect abnormal events by comparing predicted water characteristics with current observations. To avoid costly false alarms, a single outlier will not trigger an alert. Instead, CANARY aggregates information over multiple 2- to 5-minute time steps to build evidence that water quality has undergone a significant change.

Sean McKenna, the Sandia researcher who led the team that developed CANARY, notes that the software as well provides utility managers with a tool to improve the day-to-day quality of their water supplies. “What we found from utilities we work with is that a better managed system is more secure, and a more secure system is better managed,” says McKenna.

Sandia says CANARY is being used in Cincinnati and Singapore, and Philadelphia is testing the software system. A number of other U.S. utilities also are evaluating CANARY.

Read more: New Material Filters Radioactive Drinking Water Contaminates

Photo: Greg Riegler/Flickr

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