World's Biggest Ultraviolet Water-Cleaning Plant to Open
One of the UV lamps that will disinfect water for New York City.
The world's largest ultraviolet light-disinfected drinking water system will start serving New York City in two months. As Scientific American explained, "When the lights go on, the facility's 56 massive UV units will neutralize waterborne pathogens in all the drinking water coming from the city's major sources — the Delaware County and Catskill watersheds."
The UV light will act as a second cleaning step, after a chlorine step that New York water already undergoes. The UV rays will damage the DNA of cryptosporidium, giardia and other organisms that cause nausea, cramps and diarrhea, Scientific American reported.
The $1.6 billion plant is New York City's response to new requirements from the U.S. Environmental Protection Agency, which call for a second water cleaner besides chlorine. Of the city's two options for this second cleaning step, UV light is cheaper and less environmentally damaging, according to Hazen and Sawyer, the engineering company the city government hired to plan and construct the facility. Otherwise, the city would have to set up a filtration facility with layers of sand, gravel and charcoal, Scientific American explained.