NEW WESTMINSTER, B.C. -- Fire crews in New Westminster are still battling the stubborn blaze in Pier Park on the city’s waterfront that's been burning since Sunday evening.

The fire is under control but continues to smoulder beneath the decking of the pier and New Westminster Fire Rescue Service says it’s necessary to rip the aging structure apart piece by piece.

“We’re starting to remove the decking of the pier and that’s the only way that we’re going to be confident that the fire’s extinguished,” said asst. deputy Chief Curtis Bremner.

The wooden portion of the pier is made up of wood soaked in creosote which has sent dangerous fumes wafting throughout the city since the fire began Sunday evening.

In a statement to CTV News, Environment and Climate Change Canada says there are major concerns about lasting environmental impacts to the water as well.

“The Government of Canada is very concerned about the situation in New Westminster and any potential impact it could have on the Fraser River and any of the iconic species that inhabit it.”

Mayor Jonathan Cote says fire crews are working with federal and provincial agencies and the Canadian Coast Guard to limit the environmental impact as much as possible.

“Our fire services department, along with all the crews working on the site have actually set up a containment boom to limit any damage that might be going through to the Fraser River,” he said.

Adding to the distress New Westminster residents feel about losing an iconic location in the city, police say arson is suspected in this fire, and have announced an arrest with charges pending.

“Because it’s an ongoing investigation, we can’t release any details about the specific individual but we are still seeking people to come forward and speak to us if they have any information about the fire,” said Sgt. Sanjay Kumar.

On Wednesday, crews dismantled the beloved W-sculpture — a piece of public art made from repurposed shipping containers that graced the river since 2015.

“We’re quite upset. Especially the loss of the W. The W’s our home,” said New Westminster resident Kendra Stogrin. “It was devastating. It was depressing. I cried.”

Taking the pier apart is slow tedious work and it’s not clear yet how long it will have to continue before firefighters can be certain they’ve completely extinguished the blaze.