Vineyard Haven beaches from Owen Park to Ralph Packer’s gas station remained closed Monday after electrical storm damage overnight on Friday caused a pump problem that allowed sewage to seep into storm drains which empty into the harbor between the Steamship Authority and the Black Dog Tavern.

Assistant health inspector Maura Valley confirmed that beaches were closed as a precaution on Saturday morning when officials first learned of the storm damage, but remained closed after water samples taken on Saturday showed unsafe levels of fecal coliform bacteria. Samples taken on Sunday were lower but not yet considered safe.

Ms. Valley said samples taken yesterday would come back this morning, and she was hopeful they would show it was safe to return to swimming in the area as early as today but as of last night, the beaches were closed, with signs, guards and town officials warning swimmers off. Tests are being performed on Island at the town of Tisbury’s lab, which Ms. Valley said was not state certified yet but was able to perform the tests quickly.

Though it may have happened before midnight, the problem was not called in overnight, but health inspector Tom Pachico learned of it early on Saturday, Ms. Valley said, adding that it appeared the circuit breakers blew. Mr. Pachico notified the Department of Public Works. Department workers were able to shut the valves that would stop the leakages of sewage and restart the pump, which is located behind the comfort station in the Stop & Shop parking lot.

The Tisbury fire department was called in to hose down the overflow on the streets, which Ms. Valley noted was such that people were walking through the seepage.

She was uncertain how much sewage had leaked out before the pump was fixed. She said it was not necessary to close beaches farther afield.

Swimming in water with fecal coliform bacteria present will not necessarily make anyone ill. However, health symptoms related to swallowing water contaminated with bacteria can range from no ill effects to cramps and diarrhea (gastrointestinal distress) and in rare cases more serious illness.