Almost 50 beaches in Suffolk County were closed for swimming Wednesday due to bacteria concerns.

Suffolk County issued the advisories or closures because of high bacteria levels in the water. Officials say Tanner Park in Copiague has bacteria levels four times the acceptable level, which forced the beach to close.

The Suffolk County Health Department says the high levels are from recent heavy rainfall, runoff and limited tidal flushing.

In a recent national study, Tanner Park topped the list for all beaches in New York that have the most potentially unsafe swimming days last year at 48 days. The majority of beaches in the top 10 were in Suffolk County.

The parks commissioner in the Town of Babylon says it's frustrating because crews are working hard to keep the water clean.

"We are doing our due diligence trying to get an upper hand on it every day by sending out the buildings and grounds crew and using payload to get the seaweed lifted and removed every day," says Celeste Kusmierski, the Babylon parks commissioner. "We have a geese patrol from our environmental group, that is nine people and 13 dogs and they are chasing away the geese at every moment."

Swimming at West Islip Beach was also prohibited by Suffolk health officials because they say bacteria levels in the water were six times the acceptable limit and the highest in the county.

Doctors say swimming or even walking in the water at a closed beach could get you seriously sick. They say to stay out of the water, or if you sit on the sand to wash your hands often.

Suffolk health officials say they hope to lift the swimming ban by Thursday, depending on water tests.