Nassau and Suffolk health officials Wednesday lifted their advisories against swimming at county beaches.

The advisories are a precautionary measure for beaches known to have substantial stormwater runoff caused by heavy rainfall. The runoff can raise bacteria levels, which results in the waters failing to meet New York state standards for swimming, health officials said.

In Nassau, beaches cleared by health officials Wednesday include five on the South Shore and 14 on the North Shore, health officials said. Lifting the advisory means all county beaches operating for the season are open, the health department said.

In Suffolk, 65 beaches were cleared for swimming Wednesday; Lake Ronkonkoma’s beach has been closed since mid-June because of elevated bacteria levels.

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For recorded information on beach closings and openings in Nassau, call 516-227-9700. Health department representatives are available weekdays from 9 a.m. to 4:45 p.m. at 516-227-9717.

For updates in Suffolk, call the bathing beach hotline at 631-852-5822 or check the health department’s beach monitoring web page at http://www.suffolkcountyny.gov/Departments/HealthServices.aspx.