HEBRON — Students from Hebron Station School will attend classes in Paris at least through Wednesday, while the state develops a plan to clean up 1,900 gallons of heating oil underneath the school’s basement slab.

School Superintendent Rick Colpitts announced Monday that students would attend Oxford Hills Comprehensive High School in Paris.

Tests showed the air quality at Hebron is safe, but results of water tests aren’t expected until Wednesday, he said.

The oil leak occurred Dec. 24 as the basement tank was being filled. On Friday, the majority of the oil was located under the basement slab where the oil tank sits. A small amount was discovered outside the building and in nearby wetlands.

“Air samples have come back in as safe for the kids to return to school, but there are still some issues in the gymnasium,” Maine Department of Environmental Protection spokeswoman Jessamine Logan said. At this point, “the kids can’t spend much time in there,” she said.

Colpitts said the air will be retested before anyone goes back in the school. The DEP will allow the school to have water brought to the school’s 8,000-gallon holding tank until the well water is declared safe for drinking.

On Tuesday and Wednesday, Hebron elementary students will be bused to the high school where seven classrooms are reserved for them and staff.

On Monday, DEP crews continued their work at the Hebron school, trudging through the nearby wetlands to determine the location of any oil. Colpitts said a trace of oil has been found within 300 feet of the outlet pipe that drains water from the school into the wetland, but the majority was collected through absorbent material placed at the end of the pipe.

The oil spill occurred after maintenance workers at the school asked C.N. Brown of South Paris on Dec. 23 to fill the 2,000-gallon tank because the fuel gauge showed it was running low, Colpitts said last week.

The next day, an oil truck pumped in about 160 gallons before a whistle that indicates available space in the tank stopped blowing. Although the whistle stop usually means the tank is full, the fuel gauge continued to read empty, and the driver decided to continue pumping, Colpitts said.

As a result, oil leaked from an emergency relief valve, which is designed to prevent damage to the tank if it is overfilled. The self-contained concrete bunker under the school filled with about a foot of oil. School employees were told C.N. Brown would be back immediately to pump out the oil, Colpitts said.

But two days later, on Dec. 27, a DEP team was called to the school after school officials found the room empty but suspected the oil had leaked out of the containment room.

Logan said the DEP and a consultant for C.N. Brown are working on a recovery plan for the oil underneath the school.

ldixon@sunjournal.com