Dewatered sludge from screw presses falls from a conveyor belt into a trailer at the Greater Augusta Utilities District’s wastewater treatment plant in Augusta in April. A compromise reached by lawmakers means that sludge will not have to be trucked to Canada for at least the next two years. Joe Phelan/Kennebec Journal
Maine’s sludge disposal crisis is over for now, but the search continues for a permanent solution.
Maine communities are once again burying sewage sludge in the state-owned landfill at Juniper Ridge near Old Town and no longer have to pay extra to haul the waste to New Brunswick, Canada. The last truckload of Maine sludge headed to Canada on July 7.
“Our last bill was down, but we should see the full effect in our next bill,” said Dave Hughes, superintendent of the Scarborough Sanitary District. “We’re better off than most. The district has reserves, so we didn’t have to raise rates right away, but it was hugely expensive, and reserves don’t last forever.”
Before the sludge crisis, Scarborough was paying Casella Waste Systems, the contractor that operates Juniper Ridge for Maine, about $400,000 a year to dispose of its sludge at the state landfill. After Casella started trucking sludge to Canada, Hughes put Scarborough’s annual disposal rate at $600,000.
Casella started hauling sludge to Canada in February after it concluded that the landfill could no longer safely accept sludge from its three dozen municipal customers. That much wet material posed a threat to the landfill’s structural integrity, putting the pit itself in danger of collapse, Cassella said.
Casella blamed the sludge crisis on two new laws intended to protect Maine’s environment: one prohibited the use of sludge as an agricultural fertilizer due to elevated levels of potentially dangerous forever chemicals and the other banned out-of-state waste from Maine landfills.
The sludge fertilizer ban went into effect in February and resulted in an increase in sludge shipments to the landfill, Casella said. At the same time what had to be landfilled was getting wetter, Casella found itself cut off from the out-of-state construction debris it used to “bulk up” the sludge for safe disposal.
Environmentalists and some lawmakers questioned Casella’s landfill safety assessment, wondering why the company didn’t bring in a structural engineer to assess or remedy the potential dangers, and what it had done to prepare for legislation that it knew was coming but simply didn’t like.
COMPROMISED REACHED
In June, lawmakers reluctantly reached a compromise. They didn’t agree to the outright repeal of the out-of-state ban that Casella had wanted, but the Legislature passed a bill allowing Casella to accept up to 25,000 tons of out-of-state waste a year for the next two years so it can bulk up sludge so it can be safely landfilled at Juniper Ridge.
“One of the requirements of (the bill), which was signed into law on June 23 with an emergency provision, was that we would be able to manage the disposal of existing Maine customer sludge at the state-owned Juniper Ridge Landfill within 15 days,” said Jeff Weld, Casella’s director of communications.
The law was intended to buy Maine time to look for long-term solutions to its sludge disposal problem.
At the height of the crisis, the Maine Department of Environmental Protection seemed ready to explore a wide range of solutions, from hauling sludge by train car to deep-injection wells in the South to building a regional sludge treatment facility.
With the crisis averted, at least for now, the DEP appears more interested in finding ways to reduce the volume of sludge that requires disposal so Casella will not need nearly as much demolition debris in the future to landfill it.
Commissioner Melanie Loyzim said the DEP has joined with the Maine Water Environment Association to hire a contractor to evaluate infrastructure investments needed at the state’s wastewater treatment plants to reduce the amount of sludge produced.
Casella is joining in management discussions over the next two years that will include sourcing more in-state bulking material, evaluating methods to further dry sludge before landfilling, and developing new end markets and processors within the state, Weld said.
The Portland Water District hasn’t wasted any time taking steps to tackle Maine’s sludge problem, both how and where to dispose of it and how to handle PFAS, the potentially harmful chemicals that compelled state lawmakers to ban sludge as a fertilizer and make its disposal so tricky.
Maine’s largest water district is taking the lead in exploring the construction of a regional sludge treatment facility that could use advanced thermal destruction technologies, such as pyrolysis and gasification, to safely and economically reduce or eliminate PFAS from biosolids.
Portland held a two-day summit last week to talk with potential developers about such a facility, which would be one of the largest of its kind to go beyond sludge volume reduction and actually tackle the issue of PFAS reduction or elimination. If possible, a fertilizer ban might no longer be needed.
Perfluoroalkyl and polyfluoroalkyl substances were developed as coatings to protect consumer goods like nonstick cookware, food packaging and outdoor gear from stains, water, heat and corrosion. PFAS are often called forever chemicals because they can linger indefinitely in the environment.
Studies of lab animals given large amounts of PFAS have found they may affect growth and development, reproduction, thyroid function, the immune system and the liver. PFAS have been found at high levels in the soil and water of about 50 Maine farms that once fertilized with sludge.
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