A leach field replacement and up to two-years of increased water testing are planned for Medomak Middle School after 2087 gallons of No. 2 heating oil were accidentally pumped into part of its septic system Feb 4.
The school district has provided drinking water for the students since the accident, and Interstate Septic has been pumping out the school’s septic tank several times a day to prevent any more oil being introduced to the leach field.
State and school officials and representatives from Rockland-based Maritime Energy, the company that delivered the oil, spoke about remediation plans at the school Feb. 12.
George Bridges, the facilities and transportation director for Regional School Unit 40, explained how the issue was discovered.
The school’s oil tank had an issue with its instrumentation and so a smaller amount of fuel than normal was ordered from Maritime, Bridges said.
A vendor repaired the instrumentation after the fuel was supposed to be delivered, but following the repair the instrument immediately went into a low-level alarm, Bridges said. A check of the tank found it contained only about 500 gallons, he said.
Maritime confirmed it had made its delivery and, after speaking with the delivery driver, district staff had a pretty good idea where the fuel had gone – into the access to the septic system’s lift tank, Bridges said.
Both the lift tank access, which is above ground, and the oil fill, which is located just below grade, are four-inch pipes with similar quick-connect fittings.
The lift tank stores liquid from the septic system, and pumps transfer the liquid from there out to the system’s leach field, MMS Principal Kate Race said previously.
Charlie Page, an assistant vice president of Maritime Energy, said the school’s oil deliveries are normally made by the company’s transport division. This particular delivery was instead made by a home delivery truck because of snow and weather concerns, Page said.
The fittings on the lift tank access and the actual oil fill are almost identical, Page said,
Maritime does have other customers who have an above-ground fill pipe similar to the lift tank access, and the school’s oil fill does not have a whistle like home oil fills do, Page said. “It was an honest mistake.”
The driver who made the delivery has worked in the industry for 30 years, according to Page.
“He feels tremendously terrible [for] what happened,” Page said.
Jeff Marcotte, Maritime’s safety and training coordinator, said the lift tank access at the school is going to be locked, both that access and the oil fill are going to be colored coded, and a sign has been put up indicating the location of the oil fill.
“Not only will this never happen again, it is not going to happen again,” Marcotte said, obviously stressing the later half of his comment.
An estimated 780 gallons of oil were pumped out of the system on Feb. 5; the balance of the oil had likely already been pumped by the septic system into the leach field, Bridges said.
Testing found there was no backflow into the septic tank itself or the grease trap, Bridges said previously.
The plan moving forward is for the school’s two sections of leach field to be dug up and removed from the site along with any contaminated soil, before eventual replacement.
According to Marcotte, excavation is anticipated to start on Monday, Feb. 16, following a safety meeting and the installation of proper erosion controls.
“We’re getting rid of anything that could possibly be contaminated,” Marcotte said.
Marcotte estimated the project will take around 45 to 55 days, but said the timeframe would become more clear after the first section of leach field is excavated.
The plastic from the system will be put into lined, covered containers, and taken by environmental services company ENPRO to be processed in Rhode Island, Marcotte said.
George C. Hall & Sons, the Rockland-based general contractor for the project, will store the contaminated soil – covered and on top of plastic – at their property on Buttermilk Lane in Thomaston before the soil is incinerated at the Dragon Products cement facility nearby, Marcotte said.
No waste will be stored overnight at the school, Marcotte said.
There will be continuous air quality monitoring outside during the excavation work, and periodic air testing in the school, according to Jon Woodard, an oil and hazardous materials responder for the DEP.
The oil already recovered from the septic system will be “fuel blended” and burned at sites such as paper mills, he said.
Both company and government officials believe the oil is contained to the school’s leach field, and Mike Abbott, a hydrogeologist for the Department of Health & Human Services’ Drinking Water Program, believes the school’s well is the only well even potentially at risk of contamination.
Water samples taken at the school the week of the accident came back negative after testing for contamination, according to Principal Kate Race.
“They came back yesterday [Feb. 11] and our water is absolutely fine,” Race said.
The DEP will be monitoring the clean-up, Abbott said, which is planned to include removal of material to the point where the fuel oil is no longer detectable in the soil.
“We’re very optimistic when this clean-up is done, there’s not going to be anything in the ground to worry about,” Abbott said.
“We truly believe … the product is not going to be anywhere else. That’s the scenario we’re looking at,” Marcotte said. “This is quite captive.”
Even if some oil were to be missed, Abbott said it would take months or years for any oil to reach the school’s well.
The well is 300 feet away from the leach field, not directly downhill from the field, and shielded from shallow groundwater and is instead bedrock-fed, Abbott said.
Medomak Middle School’s water may be tested monthly, or if all the oil is believed to have been recovered and did not enter the groundwater, it may be tested quarterly, Abbott said. Two years of testing would be standard, he said.
As far as Medomak Valley High School’s well or any private wells, “most of the others just aren’t very close,” Abbott said.
The high school’s well, about 1000 feet away and uphill from the leach field, will likely still be tested quarterly, Abbott said.
The Drinking Water Program does not have jurisdiction to test private wells, according to Abbott, but Jon Woodard said a DEP staff hydrogeologist will evaluating whether any private wells are at risk.
If there are, those private wells would also be tested, Woodard said.
Should any private well owners have major concerns about their water, Maritime is willing to have their water tested, Marcotte said. The testing likely wouldn’t start for another 90 to 180 days, however.
“The oil can’t physically get from here to there that quick,” Marcotte said.
Regarding financial implications from the clean-up and testing, Marcotte said, “There will be no impact, from our belief, on the school at all.”
Maritime plans to make future information about the clean-up project available through the school, but other avenues for interested parties are also available.
Brian Bachmann, who works for St. Germain Collins, an environmental consulting firm Maritime hired to assist with the cleanup, said real-time testing data will be available on-site at the school.
The Drinking Water Program’s testing data is public record and will also be available, according to Abbott.
