East Hampton’s Georgica Pond, arguably one of the classiest addresses in all of the Hamptons, may have famous residents — it was Bill Clinton’s Summer White House for two years — but a new study has shown there is one thing Georgica Pond clearly does not have.

That’s blue-green algae, which Lake Ronkonkoma and Agawam Lake in Southampton both experienced this year.

The study came about because last year the State Health Department ended up with a report from a local vet that a small dog that died in the area may have ingested toxic blue-green algae, possibly by drinking water from Georgica Pond.

The trustees turned to the Stony Brook’s Marine Sciences Center in Southampton to test the water in all of the town’s ponds and streams this year. It turned out that Georgica Pond had never been tested for algae before.

The testing was expanded to lakes in other towns as well, and showed there was virtually no blue-green algae in Georgica Pond, or in several other small ponds on the East End, including Big Fresh Pond, Wildwood Lake and Camp Baiting Hollow.

East Hampton Trustee Diane McNally said Monday she was not surprised that Georgica got a clean bill of health, because there are few homes near the water and it has a large wetlands buffer to soak up pollution. But, she added, road runoff is always a concern, and that the pond would likely be tested again in the future.

A program on understanding Alzheimer’s disease will be held at Bethpage Public Library.

The Nov. 7 seminar, sponsored by state Sen. Kemp Hannon (R-Garden City), will be from 7 to 9 p.m. at the library, 47 Powell Ave.

Scheduled speakers are Dr. Alan Mazurek, a neurologist, and Tracey Kuczinski, who has worked in the field of geriatrics more than 15 years.

Their topics will include the signs and symptoms of Alzheimer’s, what part of memory loss is age-related and what loss you should worry about, who to consult if you suspect someone is suffering from the illness, medications that can help, what can be done to lower the risk of the disease, what kind of quality of life sufferers can expect, and types of living accommodations available to them.

Reservations are required; call 516-739-1700 or look under events at www.kemphannon.com. — BILL BLEYER

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