The Nassau County Department of Health Wednesday lifted its advisory against swimming at five South Shore beaches.

The agency said all Nassau beaches operating for the summer are open.

That includes beaches closed Tuesday as a precautionary measure because of a risk of elevated bacteria — Biltmore Beach Club, Massapequa; Hewlett Point Beach, East Rockaway; Island Park Beach, Island Park; Merrick Estates Civic Association, Merrick; and Philip B. Healey Beach, Massapequa.

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After heavy rainfall, the agency often issues such advisories for beaches known to have substantial stormwater runoff, which can raise bacteria levels so the waters fail to meet the New York standards for swimming, health officials said.

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.