OXFORD — Two years after Oxford stopped transporting processed solid waste to Lewiston-Auburn Water Pollution Control Authority to be sold as agricultural fertilizer, the town is set to build an alternative treatment facility. The new system will dry the treated sludge and eliminate PFAS (commonly referred to as “forever chemicals”). The dried by-product will then be taken to landfills.
Late in 2019 Oxford contracted Woodard & Curran to conduct a study on the most effective ways to deal with waste that had to be held in storage at the facility on Mechanic Falls Road.
Woodard & Curran recommended two methods of treating waste after it was processed: one would require expensive de-watering equipment, including a centrifuge for processing. The town would also have to build an additional garage to allow for the extra treatment.
The second option was more of an old-school method using drying beds. It would require a greenhouse to built, measuring about 20-by-60 feet. Sludge would be spread on a concrete pad in the structure and de-water on its own. The sludge would reduce to a dried out “cake” matter that is free of PFAS — short for perfluoroalkyl and polyfluoroalkyl substances — contaminants and safe to landfill with regular waste.
Even with the solution ready to be implemented, Oxford Sewer Department’s Zhenya Schevchenko says that it may be a while before it will happen. He is in the process of collecting bids to build it, but long schedules and supply shortages are affecting the timeline as well as the final expense.
With a significant amount of waste currently in storage Shevchenko says that once the new facility is built on Park Road it will be a priority to transfer sludge there for its final treatment. But he estimates that once the backlog is reduced that the plant will only need to operate about two months to process a year’s worth of waste.
Other towns looking for their own PFAS solutions may look to Oxford to provide de-watering services.
The current wastewater facility, which was built in 2015-16, will continue to operate.
Schevchenko said that PFAS levels in communities still going through the process of testing sludge and water supplies has been decreasing. He expects that over time, as the source is removed from materials that have contained it, sludge will eventually be safe enough to use for agricultural fertilizer again.
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