Human palate best for identifying water impurities

The Southern Nevada Water Authority already has one team of water tasters, whose palates were trained to recognise and describe dozens of water tastes and odours three years ago, reports the Las Vegas Review Journal. The scheme has proved to be so successful, that the water authority is contracting consultancy firm Arthur D Little to train up a second set of tasters.

“The use of trained human beings is more sensitive than any of the instruments that we have available,” said Roy Desrochers, Senior Manager of AD Little’s sensory technology group. The tasters assemble three times a week to evaluate the taste and mouth feel of Las Vegas’ tap water, gauging flavours such as chlorine, pungency and mustiness on a scale of one to three. Plant administrators are notified if any taste receives two or higher from the entire group, and unknown or highly unusual tastes or odours also result in alerts, prompting closer examination of water quality.

Around 12 new workers from the water authority will be selected for the training scheme on their ability to recognise and describe tastes and odours. They will be taught to distinguish grassy characteristics from woody ones and recognise smells from turbine oil to sewage. Once trained, the new tasters will test the effectiveness of $80 million worth of new equipment to treat water from Lake mead with ozone gas.

In the past, the tasting panel has discovered sewage and machine oil in customers’ private well water, and has alerted administrators to algal tastes from a large spring bloom in nearby Lake Mead.