MOORHEAD, Minn.-A steady stream of hefty drug seizures during traffic stops during the past nine months has been a bonanza for area law enforcement agencies. However, success in that arena brings big challenges in others.

The latest bust was May 30 on Interstate 94 near West Fargo, when 100 pounds of marijuana was confiscated after a trooper pulled a driver over for an equipment violation.

"We're getting better at it," said Lt. Troy Hischer of the North Dakota Highway Patrol.

More than a half-ton of marijuana and 30 pounds of meth were nabbed along I-94 in North Dakota between Fargo and Jamestown, and more than 500 pounds of marijuana were confiscated in Minnesota during stops in Otter Tail County and near Alexandria during the past nine months.

The trend has officers figuring out where to store and how to dispose of the large volume of drugs after the criminal cases they're tied to are wrapped up.

Although several law enforcement agencies, including the Fargo Police Department, did not want to provide details about their drug handling for security reasons, Moorhead Police recently demonstrated their process.

The drug purge

From evidence storage to destruction by fire, the system follows strict protocol. Lt. Mike Detloff said they can't just drop off the haul at an incinerator and leave.

"With the rules of evidence, we have to watch it go in and catch fire," he said.

Moorhead Police recently conducted their annual audit and evidence "purge," getting rid of items no longer needed for a criminal case. Evidence can only be disposed of when there's a conviction or dismissal of a case, and the 90-day appeals period has passed.

All confiscated drugs, guns and cash must have two-factor security in storage.

"They have to be in a locked room, in a locked room," Detloff said.

He and evidence technician Laura Hilgers took out each piece of sealed evidence, and with information provided by the officer who investigated the case, marked it to be kept or destroyed.

With plenty of drug cases still pending in Moorhead, this year's purge was thin - three boxes of marijuana aimed for disposal.

"Probably the least amount we've ever taken," Detloff said.

A fourth box containing opioids and cocaine will be taken later to the 3M incinerator in Cottage Grove, Minn., the only facility in the state approved to dispose of all narcotics.

Detloff and Hilgers brought the marijuana to Prairie Lakes Municipal Solid Waste Authority in Perham, Minn., one of a few incinerators in the state that can destroy household pharmaceuticals and plant-based drugs, including marijuana, hashish and khat.

Scorching heat

At the Perham incinerator, the boxes of marijuana were weighed and then hauled up several flights of stairs to the belly of the plant.

It's a massive, putrid garbage pit, with a large mechanical claw lurking above, and the heat from the nearby incinerator is intense.

Maintenance manager Scott Monson said the facility burns 140 tons of solid waste every day and is mostly known for generating steam to power a couple of large businesses in Perham. However, its two combustion units, heated to about 1,850 degrees Fahrenheit, are also a means for quick disposal of illicit drugs.

"I would say it's the perfect way to get rid of it. I mean, it's gone," Monson said.

Detloff watched as the boxes of pot he tossed into the hopper fell to the garbage pit below, and the mechanical claw piled more garbage on top, all destined for the scorching heat.

"I'm satisfied that it's unrecoverable at this point," he said, referring to the rules of evidence that require him to ensure the drugs are gone, for good.

Juggling storage, disposal

Detloff said the amount of drugs Moorhead Police have incinerated varies. In 2013, they delivered 41 pounds for disposal, followed by 104 pounds, 83 pounds, 28 pounds and 54 pounds in subsequent years.

The annual cost is usually around $250, he said.

As drug seizures grow in size and number, law officers will continue to juggle the storage and disposal aspects.

The granddaddy of recent busts-475 pounds of pot-happened in January near Jamestown, and Stutsman County Sheriff Chad Kaiser gives some credit for the bust to a recently acquired K-9.

"We never got those amounts before, usually just drugs for personal use," he said.

His department is expanding its holding areas for drugs. Hischer said the Highway Patrol has evidence lockers in eight locations across the state.

"We don't want to end up with a thousand pounds. We don't have room," he said.