AUSTIN (KXAN) — The Fayette County Sheriff’s Office said it seized an estimated $100 million worth of fentanyl Friday on Interstate 10.

Fayette County Sheriff Keith Korenek said the county’s narcotics canine unit, Sgt. Randy Thumann and K9 Kolt, pulled over a Jeep SUV on I-10 for a traffic violation.

Once the deputy was given permission to search the vehicle, he saw what appeared to be an aftermarket compartment built into the vehicle.

The compartment was described by the sheriff’s office as “well-constructed and operated on electric motors,” and once Thumann was able to open it, he found five bricks of the drug fentanyl inside.

Each brick weighed three pounds, for a total of 15 pounds of the drug. A nationwide law enforcement task force called the Fentanyl Working Group says 2.2 pounds (1 kilogram) of the drug can be used to make 1 million pills with a street value of $20 million.

Korenek said Briana Tenorio, 18, and Jonathan Gonzalez, 20, both of Houston, were arrested and charged with felony drug possession. According to jail records, both were booked into Fayette County Jail but were released on bond.