Suffolk's West Islip Beach was closed to swimmers on Wednesday after potentially dangerous levels of bacteria were detected, while Copaigue's Tanner Park Beach remains shut, county health officials said.
Both Suffolk and Nassau routinely bar swimming after heavy rains because they can overwhelm storm or wastewater systems, discharging fecal matter or other contaminants.
Those contaminants can cause gastronintestinal illness, or infect eyes, ears, noses and throats, according to Suffolk County Commissioner of Health Dr. James Tomarken.
The two Suffolk beaches will not reopen until tests show the amount of bacteria has fallen to what the county Department of Health Services in a statement called "acceptable levels."
On Wednesday, Nassau reopened 13 beaches that were shut the day before, according to its help line, though three others remain shut: Biltmore Beach in Massapequa, Hewlett Point Beach in East Rockaway and Piping Rock Beach Club in Locust Valley.
To speak with a Nassau Health Department representative on weekdays, call 516-227-9717. For up-to-date recorded information on Nassau beach openings and closings, call 516-227-9700.
Suffolk's Bathing Beach hotline is 631-852-5822. The public can also call the Health Department's Office of Ecology at 631-852-5760 during business hours.