HEBRON — Efforts by the Maine Department of Environmental Protection continued this week to recover about 1,500 gallons of heating oil believed to have seeped into wetlands surrounding the Hebron Station School when a basement oil tank was accidentally overfilled in December.

DEP spokeswoman Jessamine Logan said about a gallon of oil was pumped out of the recovery well in the oil tank room of the school on Friday. The basement floor has been sealed and caulked with a permanent lid placed on the recovery well, she said.

“We are getting negligible amounts of oil out of the recovery well,” she said.

Logan said it is probable that Friday would be the last time the DEP attempts to pump oil from the recovery well unless they see more oil there.

“Oil floats so we can open it up and see if there is any oil in the recovery well,” she said Tuesday.

The major cleanup of the oil, which is trapped in the snow and ice in the wooded wetland, is expected to begin in the spring. Absorbent pads were placed in the area early on to absorb as much oil as possible.

About 192 gallons have been recovered from the wetlands by absorbent pads and most of the rest has been captured in ice and snow, according to DEP officials.

“Sorbent pad change-outs continue to happen regularly in the wetland area and will be the main focus as we move into spring,” Logan said.

Sheryl Bernard, head of the Department of Environmental Protection response team sent to the school Dec. 27 to assess the spill in the oil-tank room, told the 60 or so people at a public meeting last month that she will be ready to collect the inaccessible oil once the weather warms up and the water begins to move. She said the team knows where the oil is and knows what to do to make sure it doesn’t move farther into the wetlands until that time.

Meanwhile, air quality readings were taken Monday at the Hebron Station School. The results are expected to be back from the lab as early as Friday, Logan said.

The air quality readings taken Monday from a hand-held monitor were described as “very low,” she said.

Readings were also taken Monday from a Summa canister, a stainless steel electropolished container. The valve on it is opened and the canister is left in a designated area for a period of time to allow air to fill the canister to get a representative sample. The valve is closed before it is sent to a laboratory for analysis.

About 1,500 gallons of oil leaked out of the school basement tank shortly after midnight Dec. 25 as it was being filled by a driver from the C.N. Brown Co. in South Paris. The accident forced about 135 elementary school students to be relocated to Oxford Hills Comprehensive High School in Paris for more than a week.

ldixon@sunjournal.com