Closed again. That was the word on Seth’s Pond from the West Tisbury health agent Wednesday morning, one day after the freshwater pond had been reopened for swimming.

Town health agent John Powers said in an e-mail Wednesday that the pond was closed again due to water test results from Monday.

The popular swimming pond off Lambert’s Cove Road has been closed for most of the summer due to high levels of enterococcus bacteria.

On August 9 Mr. Powers said he had five clean water samples that met the state criteria for a geometric mean of levels at or below 33 colony forming units (CFU) per 100 milliliters of water.

He said the shallow depth of the pond during the dry summer could be affecting bacteria levels.

The pond also closed three times in June.

According to the state Department of Public Health, swimming in water with high levels of enterococci can be dangerous for young children, the elderly, and people with compromised immune systems.