Customers throw trash off the back of a pickup truck as heavy equipment operators move the pile at Hatch Hill landfill in Augusta in July 2021. Joe Phelan/Kennebec Journal file

AUGUSTA — With the Hatch Hill landfill expected to be full within four years, the city has submitted an application to build an $18.2 million vertical expansion.

At current usage rates, that would give the city-owned landfill another 14 years of use.

But city officials may seek to extend that lifespan even further to ensure residents have a place to take their trash, on the relative cheap. Doing so could mean the eight surrounding communities that also can send their trash to Hatch Hill would have to find somewhere else to take their trash.

Megan McDevitt, a senior project manager with engineering firm Woodard and Curran, told city councilors Thursday the city’s application to expand the landfill upward to boost its capacity was submitted to the state Department of Environmental Protection. Officials there accepted the application as complete earlier this month, McDevitt said.

She hopes around this time next year the city’s application will be approved and the upward expansion can begin.

McDevitt said the expansion is projected to add about 600,000 tons of capacity to the landfill, where the current remaining capacity is only 165,000 tons and the yearly usage adds up to about 45,000 tons. Currently the landfill is open to residents of eight surrounding communities who contract with Hatch Hill — Chelsea, Farmingdale, Gardiner, Hallowell, Manchester, Pittston, Randolph and Whitefield — as well as private haulers.

She said the city, as owner of the landfill, has other options to lengthen the landfill’s lifespan. The city could restrict use of the landfill only to Augusta residents who have their trash picked up curbside by city workers. That would drop the annual usage to just 6,000 tons a year, which McDevitt said could theoretically extend the life of the landfill for decades — as much as 100 years.

But that would greatly increase the cost to Augusta residents. A previous study, which also considered no outside revenue from private haulers, estimated the restriction to only Augusta residents would add $700,000 a year to the city’s annual costs.

Multiple councilors expressed interest in exploring a middle ground, of allowing trash from only Augusta residents and businesses at the landfill, and perhaps some commercial haulers to help share the cost. Ward 2 Councilor Mike Michaud said accepting the amount of trash that would allow the expansion to operate for 24 years might be a good target.

Ward 4 Councilor Eric Lind urged prioritizing Augusta residents. “Honestly, it’s our landfill; it’s not a regional landfill,” he said. “So I’d kind of like to reserve it for those people in the city.”

Fees to take trash to the facility have increased in recent years, and that is expected to continue while the cost of borrowing the $18.2 million to expand the landfill is paid back.

McDevitt said the current “blended” tipping fee, combining different fees at the gate, is $95 a ton. She said an increased blended tipping rate of $124 a ton would be enough to cover operating costs and pay the debt incurred for the expansion, at current usage rates. The landfill charges the city of Augusta $62 per ton for the trash city crews collect curbside from residents.

The vertical expansion, if approved by the DEP, could begin operations in 2028.

Lesley Jones, public works director, said the city owns about 500 acres at the landfill and could look to expand onto more of that land if needed. She said the upward expansion made the most sense financially because that could be done as an addition to the city’s existing landfill permit. Expanding horizontally would require a new application and be more costly.