All of Lagoon Pond and just outside of the Lagoon Pond Bridge was closed to shellfishing after a sewer pipe broke at Martha’s Vineyard Hospital Tuesday.

The Department of Marine Fisheries issued the closure Tuesday, according to a bulletin on the Tisbury town website. A portion of the pond was reopened by Thursday.

The problem was noticed by hospital staff when water started bubbling through the ground near the hospital helipad at about 4 p.m., said Patrick Hickey, the Oak Bluffs wastewater facilities manager.

Officials turned off the nearby water pumps and found that a there was a small break in a sewer line that runs to the town’s wastewater treatment facility. The hospital used to have wastewater treatment plant on the hospital grounds and an old treatment tank still there was used to take in the overflow of sewer water.

The hospital pavement was treated with chlorine and the nearby grass with lime.

How much sewage escaped isn’t clear, Mr. Hickey said, though he had been told that the state Department of Environmental Protection estimated about 7,000 to 9,000 gallons of effluent went into the ground. Most seems to have spilled over into Brush Pond, potentially limiting any contamination to the rest of the lagoon.

The broken pipe was fixed later by about 8 p.m. Tuesday evening.