The Maine Drug Enforcement Agency on Tuesday arrested a couple in the Knox County town of Washington on methamphetamine charges.

It was the 21st meth lab-related incident responded to by MDEA this year, the agency said.

Dustin Carpenter, 25, who recently moved to Washington from Alabama, was charged with aggravated trafficking in methamphetamine, a Class A felony, the MDEA said in a news release. Gina Glidden, 27, also of Washington, was charged with trafficking in methamphetamine, a Class B felony, and violation of conditional release.

The couple were living in the basement of the home of Glidden’s grandmother, according to the MDEA.

MDEA Cmdr. Scott J. Pelletier said that for the past two months agents had been investigating the manufacture of methamphetamine by Carpenter and Glidden, who had bought pseudoephedrine, solvents, lithium and other items essential to the manufacturing process.

On Tuesday afternoon agents searched the residence at 92 Crystal Lake Road. The search revealed evidence of methamphetamine manufacturing but no active labs were present, according to the MDEA.

Carpenter and Glidden were arrested and taken to the Knox County Jail in Rockland. Carpenter’s charge was aggravated because of a prior conviction for methamphetamine manufacturing in Alabama. Bail was set at $10,000 cash.

Glidden, who was out on bail for a pending heroin possession charge in Lincoln County, was denied bail. She is due to appear in court on Wednesday.

Glidden’s grandmother and two others who were at the home Tuesday were not charged and were not a part of the investigation, the MDEA said.