OTTAWA — The cost for a new Canadian special forces base planned for the Trenton area has more than tripled and is now estimated to be more than $1 billion.

Chief of Defence Staff Gen. Jon Vance has been warned that the project to move the Joint Task Force 2 commando unit from Ottawa to Canadian Forces Base Trenton is facing major risk in “cost and scope,” according to documents obtained by the Ottawa Citizen through the Access to Information law.

The unit had planned to leave its Dwyer Hill facility in Ottawa after 2019 for a new installation at CFB Trenton. Whether or not that happens is now unclear.

The previous Conservative government had authorized $346 million for building of the new JTF2 site and the move of the unit.

But special forces have significantly added capabilities to the proposed site, expanding it beyond its original scope, which has driven costs up to about $1.2 billion.

Concern has been building inside National Defence headquarters about the growing cost of the facility.

The Liberal government is in the midst of a defence review, which is expected to shift money to top military priorities and new initiatives. There is concern that if the costly JTF2 base proceeds, then funding will be drawn away from the army, navy or air force, a government source said.

The project continues to refine the scope to meet minimum operational requirements within budget constraints.

Department of National Defence spokesman Evan Koronewski said the project, which is in the design phase with architectural and engineering studies underway, has yet to receive further direction from government. “The project continues to refine the scope to meet minimum operational requirements within budget constraints,” he said in an email. “Once the design is substantially complete, the department will seek further direction from Treasury Board on the implementation plan.”

“This decision is not anticipated until late summer 2017,” added Koronewski. “Unfortunately, there are no other updates available at this time.”

Rick Norlock, the former Conservative MP for Northumberland–Quinte West, also hinted at the cost issues last year while he was still in government. “It’s now hugely more expensive than originally” planned, Norlock told CJBQ, a Belleville radio station.

Last year DND spokeswoman Ashley Lemire noted the initial cost estimate for the special forces base was done in 2006.

The military has been talking about the need for a new base for JTF2 since 2005. Among the options considered was an expansion of the existing Ottawa site or moving the unit to CFB Petawawa.

In 2008, the Conservative government announced JTF2 would be relocated to CFB Trenton, but in 2014, DND officials said the unit would remain at its Ottawa location at least until 2019.

Last year the Citizen reported that DND was looking for a one-year extension. It wanted to spend $17 million to hire a contractor to provide maintenance and support services for JTF2 at Dwyer Hill from 2017 to 2020.

In a controversial move, the Conservative government in 2012 expropriated a 90-hectare farm, near the Trenton base, that was owned by Frank Meyers. The farm had been in the Meyers family for more than 200 years and a bid to stop the expropriation failed.

The military took over the property, tore down barns, and built a berm and some access roads. Little else has been done with the land.

Meyers’ supporters have asked the Liberal government to return the property but it has declined to do so.

Once JTF2 vacates its Dwyer Hill installation, the site will be offered up within DND and then to other federal departments. After that it could be offered to provincial and municipal governments. “If there is no interest at these levels, the property will be sold on the open market through an open and fair process,” a DND spokeswoman has said.