'The Sound of Clean Water'

Our water comes from mountain streams and reservoirs over 100 miles north of New York City. And tumbling down along with the drops of water may be tiny bugs, including Cryptosproidium and Giardia. These are the main parasites the city Department of Environmental Protection is concerned with.

It turns out the best way to manage these tiny threats to our intestine and make sure our water is safe is to expose them to ultraviolet light. In a $1.6 billion facility finished in 2013 water form the Catskill-Delaware watershed cycles through pipes that are criss-crossed with hundreds of ultraviolet light bulbs, creating a unique humming sound that city Department of Environmental Protection officials call "the sound of clean water."

The light doesn't actually kill the parasites, but neuters them, said Jim Hanraty, one of the managers at the UV plant.

"This UV disinfection if you will is really sterilizing the bugs," he explained. "They're breaking the DNA so they can't replicate." 

Think of it as a high tech form of birth control. It takes about 7 seconds for the light to do its job.

The ultraviolet plant was a big reason New York City made it through Sandy without residents having to boil water, according to the DEP. It also means the city does not need to add as much chlorine to the water make sure it is safe to drink.

To hear the "sound of clean water," listen to the story.