Page 52 - EATS Case ( B)

While legislation allows for either chlorine or UV to be used

on wastewater, the installed base is still overwhelmingly
chlorine-based. That is changing, however. “We are seeing

50% of new plants (in the US) going with UV. Older plants

undergoing retrofits are going 25% with UV.”

Thanks to the pioneering efforts of such companies as

Philips, Europe has been using UV to sterilise drinking water

for several decades, but it was relatively rare in North
America until a cryptosporidium outbreak in the city of

Milwaukee in 1993 killed more than 100 people.

“That outbreak led to big interest in developing treatment
technologies for cryptosporidium removal,” says Dussert.

“Research showed that three things can eliminate it: UV,

ozone and membranes. Ozone is five to 10 times more

expensive than UV, and membranes are 20 times more
expensive for capital and operational costs. UV is by far the

best available technology.

Before Milwaukee, drinking water in the US was a niche

market for UV. Now New York City will install UV to treat 2.4

billion gpd, Seattle and Cincinnati are going UV, and

Vancouver has already installed a 600 million gpd [system].”

UV is also making great strides with industrial users. “You

have food and beverages, pharmaceuticals, high technology

semi-conductors,” says Adam Donnellan, director of sales for
UV products at Siemens.

Aquaculture also has great potential, says Donnellan. “People

are farming shellfish and fish, which are susceptible to
different diseases, like whirling disease. Most fish hatcheries