MONMOUTH – Two Maine Drug Enforcement Agency investigators and a Monmouth firefighter were overcome by heat Thursday while they were collecting and processing evidence at the scene of a methamphetamine lab.

The three were treated at the scene, a mobile home at 307 Cressey Road, officials said.

The search of the meth lab followed the arrest of three men Wednesday afternoon, all on charges of trafficking in methamphetamine: Robert R. Dumont Jr., 27, and James W. Renaud, 33, both of Monmouth, and Brandon A. Proctor, 42, of Oxford.

Renaud and Dumont are related, and the mobile home is owned by a relative, according to Steve McCausland, spokesman for the Maine Department of Public Safety.

Agents closed a portion of Cressey Road for several hours Thursday while they worked at the property, which includes a house trailer, out-buildings and surrounding woods.

Investigators with the Maine Drug Enforcement Agency were at the scene along with Monmouth police and fire departments and the Maine Department of Environmental Protection.

McCausland said the lab team collected a large amount of evidence in extreme heat. The work required officers to don heavy, chemical protective gear because of the type of chemicals involved in making meth.

“The processing of the scene was halted on more than one occasion to allow volatile compounds to be vented,” McCausland said.

The evidence seized from the home, a vehicle and surrounding woods was being taken to the state Health and Environmental Testing Lab for analysis.

“Hazardous materials, beyond what is needed for testing, were turned over to DEP for disposal,” McCausland said.

Authorities didn’t specify what was taken from the home.

The agency said this is the 10th methamphetamine lab investigated in Maine this year. Locally, a methamphetamine-producing operation was discovered by state drug agents April 26 in Augusta, according to MDEA data.

Darrell Crandall, division commander for the drug enforcement agency, said earlier that the road was closed and people were urged to stay back during the several hours’ search.

The three men arrested were taken to Kennebec County Jail.

Bail for Dumont and Proctor was set at $2,500 each, and Renaud’s bail was set at $5,000. They are expected to make initial court appearances today.

Betty Adams — 621-5631

badams@centralmaine.com