The Old Orchard Beach fire chief charged with arson in connection with a fire that burned 42 acres of marshland has stepped down from the department.

Ricky Plummer submitted a letter announcing he would retire “effective immediately” to the town on Sunday, Town Manager Larry Mead said Wednesday. The Old Orchard Beach Town Council on Tuesday night unanimously appointed William Farley, a lieutenant in the Old Orchard Beach department, to serve as interim fire chief.

Ricky Plummer

READ RICKY PLUMMER'S RETIREMENT LETTER

After his arrest, Plummer was placed on administrative leave. His annual salary was $70,500.

The seven-alarm fire on April 15 burned 42 acres and forced the evacuation of a condominium complex. Flames came within 100 feet of the condo building as more than 100 firefighters tried to contain the wind-whipped flames.

Plummer, 59, was arrested on an arson charge on May 7. Investigators say Plummer, who had been the town’s fire chief since 2014, admitted setting the fire, but said it was an accident.

He told them he had discarded a cigarette butt in dry, chest-high marsh grass, according to court records, but investigators said they found no evidence of a cigarette or smoking material, and no one close to Plummer could confirm ever seeing him smoke.

On the afternoon of the fire, Plummer told dispatch at 2:21 p.m. that he was headed to 221 East Grand Ave. to perform a building inspection, investigators said in a court affidavit. But security footage showed Plummer’s marked fire chief vehicle parked behind a vacant building at 164 East Grand Ave., about a four-minute walk from where the fire began.

In the video footage, which was described in the affidavit, Plummer disappeared from view for roughly 25 minutes, the period when investigators say he set the fire.

During that time, Plummer radioed back to dispatch to say his inspection was complete.

One minute after he returned to his vehicle at 2:53 p.m., someone called 911 to report the fire, according to the affidavit.

In his letter to Mead, Plummer said he has “decided to retire from my position as fire chief for the town of Old Orchard Beach effective immediately.”

He said he had accrued vacation, personal and sick days and requested to know the number of days for which he will be compensated.

Plummer had been a firefighter since 1974. Before becoming fire chief in Old Orchard Beach in 2014, he worked at several departments in Maine, New Hampshire, Massachusetts and Florida.

The state Fire Marshal’s Office is reviewing old cases in the communities where Plummer previously worked to determine whether he may be connected to any of them.

One unsolved fire that has drawn attention is an arson on Jan. 20, 2015, that destroyed the vacant 36-room Americana Motel in Old Orchard Beach, which was scheduled for demolition. No one was injured.

Plummer is next scheduled to appear in court for a conference in the case on Sept. 8.

If he is indicted by a grand jury before then, he could be rescheduled to enter a plea at an arraignment.

If convicted of arson, Plummer faces up to 30 years in prison.

Farley, who lives in Old Orchard Beach, has more than 45 years of fire service experience, Mead said.

Farley served for more than 30 years with the Falmouth Fire Department, including two years as a district chief, two years as a part-time departmental chief and 12 years as deputy chief. He left that department in 1999 when he moved to Old Orchard Beach.

Farley joined the Old Orchard Beach Fire Department call-force in 2000 and has served as a lieutenant for the past five years, Mead said. He owned Radio Communications Management for 18 years until he retired in 2014.

“Chief Farley is well regarded within the Old Orchard Beach Fire Department for his knowledge, experience and dedication,” Mead said in a statement. “He will work closely with the four departmental captains as it relates to department operations and will be responsible for the administrative oversight of the department on a daily basis, including financial and personnel management.”

Mead said the town will immediately begin recruiting candidates for the fire chief’s job.