Now, Swim Guide app finds clean beaches in New York

A smartphone app that pinpoints the closest, cleanest beach has expanded to include the New York area and had gained 10,000 new users as of yesterday, accounting for a nearly 20 percent spike across North America.

"The Swim Guide started with me trying to track water quality -- I was thinking, where can I swim in Lake Toronto?" said Krystyn Tully, vice president of Lake Ontario Waterkeeper and writer of the app. "My boyfriend, who's a computer programmer, was watching me and said, 'You know, I think there's an easier way to do this.' "

Tully started drafting spreadsheets for the Swim Guide app in 2007, she said, and it was launched in June 2011, growing to include 2,500 U.S. beaches from California to Florida -- and 70,000 customers in North America. Last week, the app expanded to New York City, Connecticut, Massachusetts, the Carolinas and the Chesapeake Bay region.

That means 253 Long Island shores are covered by the app, which finds close-by beaches and determines the safety of the water in real time, Tully said.

"Every year, millions of people get sick from coming into contact with polluted water at local beaches," said Pete Nichols, national director for the Waterkeeper Alliance.

One pollutant beachgoers often forget, Tully said, is fresh rain. "You get a mix of oil, animal droppings -- anything that's on the pavement and gets washed with the rain to the ocean. Stay away from swimming for 24 hours."

The app is mostly full of data collected by county and state waterkeepers, Tully said. "It's exciting to see a local project blowing up all over North America," she said.