A drug bust used to mean that Minnesota law enforcement would either stockpile the illegal booty in crowded property rooms or spend thousands of dollars to escort it out of state to be destroyed.

Now, Minnesota agencies can dispose of the confiscated drugs for free at the 3M incinerator in Cottage Grove.

The incinerator at 3M Cottage Grove is the only facility in the state that is approved to dispose of not only prescription drugs but all narcotics.

"I think all of the sheriffs were waiting for something like this to come along to help us in disposing of these illegal drugs because it is a problem and they do take up a lot of space," said Kent Wilkening, president of the Minnesota Sheriffs' Association and sheriff for Nobles County. "We just don't like having this kind of stuff sitting around."

Last year, 3M was given approval to burn hazardous waste from outside sources including law enforcement agencies. After a three-year battle with local residents, some of whom were worried that there could be adverse environmental effects, the citizens' advisory board of the Minnesota Pollution Control Agency (MPCA) reissued air and hazardous-waste permits to allow 3M to burn solvents from outside sources.

The drugs from law enforcement agencies are estimated to amount to less than 1/100th of 1 percent of the total volume of material destroyed at the incinerator.

The Minnesota Department of Public Safety's Office of Justice Programs and the MPCA worked with 3M on the initiative, said Brian Marquart, statewide gang and drug coordinator at the department.

"Law enforcement needs a safe and effective way to get rid of controlled substances that have either been purchased or seized during investigations. … Law enforcement can't just keep stockpiling this," Marquart said.

Some agencies have paid up to $2,000 for a drum to be escorted out of state for incineration.

Besides paying for the barrels to store them in, using the 3M incinerator is free for agencies, Marquart said.

Wilkening's office has ordered 10 five-gallon containers to begin to move drugs that were being kept in the property room. Getting rid of the drugs frees up space and makes audits easier as well as hedges the temptation of somebody stealing the drugs, he said.

In February, a Washington County deputy was charged with stealing prescription drugs from the sheriff's office drug takeback bin. The deputy resigned the night he was caught after being seen in videotape opening the bin and removing bottles of medications.

The closest other facility that could destroy all types of drugs is in Sauget, Ill., said Brandon Finke, a pollution control specialist at the MPCA.

There are five other municipal solid waste incinerators in Minnesota that can destroy household pharmaceuticals and plant-based drugs like marijuana but not other narcotics, which can be hazardous if simply burned and released into the air, Finke said.

The 3M incinerator destroys 99.9999 percent of combustible waste.

"This is the best destruction of these chemicals that we can achieve in Minnesota," Finke said.

Law enforcement has to fill barrels of each separate type of material off-site and accompany them sealed to the 3M facility. Under the watch of video surveillance, the barrel is first destroyed in a kiln that ranges in temperature from 1,800 to 2,000 degrees Fahrenheit.

It then enters a secondary chamber in which combustible gases are destroyed before water is used to cool down the air and then a subcooler is used to further reduce the temperature. Scrubbers remove particles from the air and a precipitator cleans the air again electrostatically before the clean air exits through the exhaust stack.

3M conducted its first test run in May by disposing of four 30-gallon drums containing drugs turned over by the Minnesota Bureau of Criminal Apprehension.

"It is a win-win for the community and for 3M because we have the incinerator and we're pleased to offer this service to the community, to the tax payers, to the state," said Vickie Batroot, the site director at 3M Cottage Grove.

Nicole Norfleet • 612-673-4495

Twitter: @stribnorfleet