A delay in completing maintenance at a Biddeford incinerator has sent more truckloads of trash to landfills in Hampden and Old Town, but the operator hopes to have the burn facility back on line by the end of the week.

Twice each year, including once in April or May, Maine Energy Recovery Co. shuts down its Biddeford boilers for scheduled maintenance.

During those shutdowns, the state requires Maine Energy to have a bypass disposal plan or a place to discard trash, said Don Meagher, manager of planning and development for Casella Waste Systems Inc., which owns the incinerator.

Out-of-state waste bypassing Maine Energy has been sent to Casella’s Pine Tree Landfill in Hampden, while trash generated in-state has been diverted to the Juniper Ridge landfill in Old Town, which Casella runs. As a state-owned facility, Juniper Ridge can accept only Maine-generated waste.

As a result, Meagher said, truck traffic to the Hampden and Old Town facilities has been higher than usual during the shutdown.

Meagher said he did not know precisely when the Biddeford maintenance began.

Crews “ran into unanticipated maintenance items they had to work on, [which] kept it going a bit longer,” he said Wednesday.

Using projected fill rates, Casella estimates that Pine Tree will reach its capacity by Labor Day 2007.

The extra waste from Maine Energy this month may contribute to a higher anticipated fill rate in May for which Casella may have to compensate with lower fill rates in the following months to keep the facility open until September 2007.

“We’re probably above budget for this month. We’ll have to adjust [fill rates] later on,” Meagher said.