PLEASANTON (CBS 5) — More than 700 women are expected to participate Saturday in the annual See Jane Run triathlon at Shadow Cliffs Regional Recreation Area in Pleasanton. But there are concerns about water quality in the lake where the swimming portion takes place.

Caution signs warning of elevated bacteria levels have been posted. Swimmers are being warned not to swallow any lake water, and once out of the water to shower and towel dry thoroughly.

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In July, water quality tests found coliform bacteria exceeding health standards, but not enough to close the lake. Since then, the levels have dropped. Another round of tests for E. Coli and coliform were taken Thursday as a precaution, with results expected to be released on Friday.

While the lake is still open, athletes have the option to participate in the triathlon or take part in a duathlon without the swim.

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“We have been in contact with the water department and they have reassured us the water safety, the water level is safe,” said triathlon coordinator Melissa Decker. “Every year it’s been fine, the quality has been at the level where they are able to swim safely.”

According to the East Bay Regional Park District, the increased bacteria levels may be attributed to waterfowl or vegetation decay. Similar warnings have been issued in previous years.

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