Swimming because it is healthy may just sink in Tempe, AZ because of water quality issues.
The state agency charged with ensuring that water in Arizona lakes is safe says the time has come to reconsider allowing swimming at Tempe Town Lake, which could jeopardize its status as a prime venue for triathlons and duathlons.
Linda Taunt, deputy director of the Arizona Department of Environmental Quality’s water-quality division, said the state has discussed the issues contributing to the lake’s water quality with Tempe officials for years.
One of the primary problems involves water that has pooled against the eastern dam just upstream from the lake, she said. The water comes from runoff from Valley freeways, the Mesa water-treatment plant and other upstream sources.
“The problem it creates is it’s just sitting there baking in the sun and it’s stagnant,” she said. “If we could avoid that water lapping (into) the lake, it would be in better health year-round.”
Taunt said her agency would like Tempe to use bypass pumps the city installed to send the stagnant water from upstream beyond the western edge of the lake to the dry Salt River bed. The pumps could be used to lower the water level to just below the rubber dam at the east end so that the stagnant water doesn’t spill into the lake, she said.
But Tempe officials say the water is needed to cover the east-end rubber dam and protect it from the type of sun exposure that contributed to the deterioration and eventual collapse of the rubber dam on the west end of the lake last year.
“We understand that they’re trying to protect the dam, but there may be other ways to do that without allowing the (water-quality problems),” Taunt said.
Taunt suggested Tempe could install a sprinkler system over the eastern dam to keep it cool and wet to prevent damage if the water is lowered. Tempe expects to finish installing a sprinkler system over the western dam by August to protect it from the sun.
When Tempe Town Lake opened in 1999, ADEQ allowed swimming. However, it put Tempe on a lake-management plan in 2002 because of sustained water-quality issues in the form of high pH or alkalinity levels. Swimming is still allowed, but only if state-mandated testing shows that pH levels are within state standards.
Each year, the Ironman Arizona triathlon and dozens of other events at the lake draw tourists from across the world. Last month, concerns over water quality after a rainstorm prompted the city to cancel the swim portion of the Marquee Triathlon. On Saturday, however, the water was back within state standards, allowing athletes to compete in the lake for the first-ever Iron Gear Sports Rio Salado Triathlon.
Public documents show Tempe has spent about $3.8 million tackling water quality since July 1999, but the water’s pH level is often not within the range of 6.5 to 9.0, the state standard for swimming.
Jeff Kulaga, Tempe’s assistant city manager, said that the city has to consider a number of options before it would lower the water level east of the dam to the point the state is suggesting.
Kulaga said that he was “surprised” that the state would consider a ban on swimming and other activities involving full-body contact with the water.
“We’ve been working with all parties involved, in particular when it comes to pH levels, we’ve worked collaboratively with ADEQ to ensure that pH levels are at the proper and safe levels to hold swimming events,” he said.
Kulaga said that to “select one solution (lowering the water) at this time without a water-quality analysis, engineering analysis, financial analysis, is premature.”
Taunt said that ADEQ had hoped that refilling the lake after last year’s dam burst would alleviate some of the problems.
“We’re just six months into this water, and we’re looking at the type of problems that we wouldn’t have expected to see until two, three years from now,” she said. “Our job is to protect water resources – be it streams, lakes or rivers. I think considering (Tempe’s) under a (ADEQ) lake-management plan . . . we have to have a serious conversation about the kind of uses in the lake if they can’t maintain (water quality) at the right level.”
Read more: azcentral.com