HAMPDEN – A deadline for the Department of Environmental Protection’s decision to approve or reject an increase in capacity at the Pine Tree Landfill has been extended 10 days, DEP officials said this week.

Casella Waste Systems Inc., which owns Pine Tree, has proposed boosting the landfill’s capacity by nearly 50 percent, or 2.5 million cubic yards. A public benefit application, which is a precursor to the facility’s separate application to increase capacity, has been completed by Casella and is waiting on DEP approval.

Casella has been directed by DEP to prove that the proposed increase would benefit the public before the department will further consider the project.

At a special town meeting in January, several town councilors and residents expressed concerns over groundwater contamination and methane migration related to the landfill. The DEP responded by requesting additional information and was given until Feb. 28 to make a decision on the landfill’s proposal to expand.

DEP representative Cyndi Darling said Wednesday that the decision-makers need more time.

“We have to have the [extra] time; we’re not done yet,” she said. “Basically the upper management [at DEP] has been really busy dealing with other things right now.”

DEP now has until March 10 to make its decision. A draft of that decision will be made public on March 2 to allow five working days for the public to weigh in, Darling said.

Don Meagher, manager of planning and development for Casella, said the company is happy to give the DEP more time.

“We’re certainly OK with the extension,” Meagher said. “We figure that [DEP] is busy right now and have a lot of other things going on.

Many residents and town officials fear that an increase in capacity at Pine Tree would only worsen existing problems.

“When you think about all the problems they have had with methane migration, it seems they are having enough difficulty with the landfill at its current capacity,” Bill Lippincott, chairman of the Hampden Citizens Coalition, which opposes the expansion, said this week.

“I think it’s a positive sign if [the DEP] is taking more time,” he continued. “A fast decision would likely make it easier for DEP to go along with the expansion.”

Hampden Town Manager Susan Lessard agreed that the extension is a good thing.

“I’m pleased that the DEP is giving this matter the time and attention,” she said. “We want this matter to be taken seriously, and if that takes more time, then we welcome that.”

If the DEP decides to deny Casella’s public benefit application, the landfill owner has hinted that it will pursue legal action.

“The application makes it very clear that they reserve the right to be uncooperative,” Lessard said.

“I expect Casella will take some legal action,” Lippincott added. “I think they’re just trying to be nice here.”