Three hypothermia victims were released from Mount Desert Island Hospital on Thursday after their snowmobile plunged into Long Pond, which is Southwest Harbor’s drinking water supply.

[Man, girls rescued after snowmobile plunges into icy Maine pond]

Steve Kenney, manager of the Southwest Harbor Water and Sewer District, closed the town’s water treatment plant on Wednesday night, shortly after Eli Strauss, his 12-year-old daughter and her 13-year-old friend went into the southeast end of Long Pond.

The plant supplies about 600 Southwest Harbor winter customers, but the incident poses “no immediate threat” to the town’s water supply or an inconvenience to its customers, Kenney said.

“The water flows away from our water plant, so anything that was in the water from the accident — fuel, oil or grease — would flow away from us,” Kenney said Thursday.

Strauss, his daughter and her friend went into the water after he veered slightly from a local snowmobile trail onto the lake sometime after dark on Wednesday. With the 43-year-old Strauss clearing the way, the three swam to shore and rescuers alerted by Strauss’ wife found them within a few hours, Maine Warden Service Cpl. John MacDonald said.

Warden Service aircraft flew over the site on Thursday to determine the snowmobile’s location and alert Strauss and the water district. If the accident had been just a bit more toward the center of the pond, the three victims might very well have died, MacDonald said.

Strauss told authorities that a contractor would remove the snowmobile from the pond on Friday. Under state law, Strauss is responsible for getting the snowmobile out of the pond, MacDonald said.

Estimates vary, but a gallon of gasoline can pollute hundreds of thousands of gallons of drinking water. Nevertheless, if undamaged, snowmobiles typically seep pollutants gradually, if at all, Kenney said.

The treatment plant will resume operations on Friday. The water district typically has two days of water supply available, and draws about 240 million gallons a year, a small fraction of what the pond could supply, Kenney said.

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