The state’s largest landfill in Coventry is set to expand by 52 acres if regulators approve the permit application by Casella Waste Systems submitted this summer.

The landfill currently occupies around 100 acres, with 3 or 4 of those acres in active use at any given time, according to Jeff Bourdeau, a solid waste program staffer with Vermont’s Department of Environmental Conservation. It is the only lined landfill operating in the state since one in Moretown, Vt., shut down several years ago.

The “vast majority” of what goes into the Coventry landfill originates in Vermont, but some amount of waste does come from other states, Casella Vice President Joe Fusco said.