Article about nasty Tempe Town Lake

Tempe works to clear lake for Ironman

Mesa, Arizona - Holding events like this weekend's Arizona Ironman Triathlon at Tempe Town Lake can be a challenge for more than just the athletes.

Keeping the lake's chemistry in check and the water relatively free of debris has become an event in itself.

This winter's heavy rains had made the lake murky and full of debris for some time, and the pH level had risen to unacceptable levels as recently as a week ago.

But the city hopes Ironman competitors will notice a cleaner lake this year after hiring a new crew to clean the surface. And chemical treatments have brought the lake's pH level into check.

The lake's sometimes dirty water can generate complaints from swimmers, but Rio Salado director Nancy Ryan said the city hired an outside vendor about a month ago to keep the surface cleaner than it's ever been. A city crew used to clean it once a week, but the crew can now focus on the surrounding park while the vendor cleans every Monday and Friday.

"We've increased our tourism numbers and visitor numbers over the last few years," Ryan said. "We wanted to put additional effort into maintaining the lake surface."

The city is spending $85,000 over two years to clean the 220-acre lake and 39 acres of adjacent wetlands.

Tempe had sometimes struggled to keep the pH level low enough to let swimmers in the lake during special events. But it's gotten a better handle on the chemistry since installing a pump last year at the lake's eastern end, where much dirtier river water had trickled into the lake and boosted pH levels.

The city now has that water bypass the lake by pumping it through a pipe and back into the riverbed just west of the lake.

Still, the pH had risen too high last week.

While federal standards only allow swimming in water when pH is below 9.0, the lake had reached 9.1.

Tempe treated the lake with algaecide, which has lowered the level to 8.9. Tempe will continue to treat the water and is confident the pH will be fine for Sunday's event, said Basil Boyd, a city hydrologist.

This weekend's Ironman will draw about 2,200 competitors, most of them from out of state.

Though many might not be used to the silty lake water, race co-director Paul Huddle said he's pleased with the lake's condition.

Events are planned all weekend at Tempe Beach Park, with the race on Sunday. Events begin at 5 a.m. and last until midnight.

For information visitwww.ironmanarizona.com.

http://www.msnbc.msn.com/id/24025064