(CBS4) – Earlier this month the swim beaches at both Cherry Creek and Chatfield State Parks were closed to due concerns about high levels of E. coli. Now, CBS4 has learned either the test results or readings were likely errant.

Colorado Parks and Wildlife tests water samples from the swim beaches once a month. The July 6 test at Chatfield State Park and the July 7 test at Cherry Creek State Park found higher than allowable E. coli bacteria levels.

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(credit: CBS)

Both swim areas immediately closed.

Tests conducted 24 hours later at both beaches found safe levels of E. coli and the swim areas were reopened.

Jason Clay, a spokesman at the Colorado Parks and Wildlife, says all along they suspected the test or reading was wrong because all summer their levels were well below the limit which the Colorado Department of Public Health and Environment requires for a closure.

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Then retesting the following day found levels were back well below the acceptable level.

(credit: CBS)

He says there are a number of factors that can contributed to errant testing, including a crowded beach where swimmers stir up the bottom of the reservoir or a possible error in the lab.

Last week’s episode of “Colorado Outdoors – the Podcast for Colorado Parks and Wildlife” explains how CPW tests for and responds to algae blooms and the presence of E. coli. CPW’s Water Quality Coordinator, Mindi May, says high E. coli levels and toxic algae blooms appear to be more common in the past few years, but, generally our water is safe.

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“People shouldn’t be afraid to recreate,” May said on the podcast. “Most of our waters are safe. Most of our algae is safe. Just keep an eye out for signs. When Parks and Wildlife posts signs that warn of a closure be sure to respect that.”

Laura Phillips