PUEBLO, COLO. -- Some of the first steps towards removing a stockpile in Pueblo of ammunition containing mustard gas are underway.

The Pueblo Chemical Depot (PCD) contains more than 2,500 tons of mustard agent.

In the late nineties the U.S. signed a treaty agreeing to dispose of all chemical munitions, but because the ones at the PCD contain mustard gas, it's a complex process.

Mustard gas was used in World War I as chemical warfare.

"Mustard is a blistering agent. It is a delayed reaction and it was designed to incapacitate people, not kill. It was not designed as a lethal toxic chemical munition, it was designed to injure people," Lisabeth Wachutka, an ammunition inspector, said.

Wachutka said mustard gas actually isn't even a gas, but a liquid agent.

"The term was gas, so it became a popular term that everybody just used gas to understand it, but these are liquid-filled agents," she said.

Health officials have also determined that mustard gas can potentially cause cancer.

"So we have to be very very careful in what we do and how we handle it," Wachutka said.

The PCD has nearly 800,000 rounds of ammunition that needs to be destroyed, but because of the danger involved officials want to get the process right before they start on the real thing.

Thursday the last of the ATE (ACWA Test Equipment) rounds arrived at the depot to be stored until crews can use them to practice the destruction process.

"These are rounds that were specifically designed by the Army to be used in the demil facilities to be used for practice for the robotics and for the people to handle them, so we don't have to handle the real chemical rounds or rounds that have explosives in them," Wachutka said.

The rounds look and feel exactly like the rounds containing mustard agent. The only difference is their color.

Wachutka said it's important for the people to become comfortable around the munitions before working with "live" rounds.

"You have to be able to understand your requirements and trust the equipment, trust the procedures, and so the more you train with them and the more you practice with them, the better you become in being able to handle this type of equipment," Wachutka said.

Wachutka added it's not only beneficial to the human workers, but also for the machines.

"It also allows us to test our equipment, to make sure all the settings are correct, all the specifications are correct," she said. "So if a machine has to be set for one inch or x number of millimeters we know that that's the exact setting, so when a piece of robotic comes along and picks something up we know that it's perfectly done, because we've used these rounds and these rounds were made to the specification of a real round."

A new plant has been built at the PCD where the mustard agent will be removed.

Officials said the ammunition will be brought into the plant, disassembled and the mustard agent drained.

The agent will then be neutralized and then broken down by microbes.

"The people of Colorado said that we do not, for lack of a better term, like incineration," Wachutka said. "We want you to come up with an alternate technology which was ACWA (Assembled Chemical Weapons Alternatives), and they designed a method to dispose of the munitions that was not incineration, it's a washout."

The plant is currently undergoing systemization and is scheduled to begin operation in January 2015, allowing a lot of time to perfect the system.

"We have safety meetings all the time to discuss how the operation is gonna flow, we make sure that everybody is aware of what's going on so they understand the procedures and understand what their job is, and then we also have a very high level and high tech monitoring, so we know that we're perfectly safe when we're working with these munitions," Wachutka said.

Wachutka said she's excited to be a part of a process that's making the world safer.

"I've worked in the ammunition field for 31 years now, and this is something that's really neat," she said. "It's really fascinating for me and my career to be able to see a first-of-its-kind facility, which is what our disposal plant is. And then to be able to see this possibly hazardous material be destroyed and to be destroyed safely and securely and to be part of it is quite an honor."