HAY RIVER - Volunteer firefighters - assisted by water bombers, a helicopter and heavy equipment - fought for many hours to put out a persistent fire that ignited at the Hay River dump.

Hay River Fire Chief Trent Atwell said he suspects the fire – which broke out at midday on May 31 and burned until 7 a.m. the next morning – was caused by spontaneous combustion.

Crews battle a fire at the Hay River dump in a multi-pronged attack, including GNWT water bombers, the Hay River Fire Department and heavy equipment from private contractors. - Paul Bickford/NNSL photo

While admitting it was speculation on his part, Atwell said the fire may have originated in a bag of leaves.

As leaves decompose, heat builds up and sometimes can ignite.

Whatever the cause, the fire was difficult to put out.

Atwell described the fire as "stubborn," noting it was in the domestic garbage section of the dump.

"It took a lot of water and a lot of energy," said the fire chief, who was not in Hay River at the time of the fire, but was briefed on what happened.

The firefighters, assisted by heavy equipment from local contractors, had to dig into layers of compacted trash as the fire burned deeper.

Atwell said the fire covered about one or two acres of the dump, but it was kept out of a section containing discarded construction material.

Atwell said there have been fires at the dump before, but not one as stubborn for about 15 years.

Between 12 and 18 firefighters were battling the blaze at any one time, he said.

The Department of Environment and Natural Resources (ENR) also responded with two CL-215 water bombers from Fort Smith and a plane to guide them, along with a Hay River-based helicopter with a water bucket.

Richard Olsen, manager of forests with ENR in Fort Smith, said the water bombers responded at the request of the Hay River Fire Department.

It was the first action for ENR water bombers this year.

"They've been doing some practicing, but it's not the same as being on a fire," Olsen said.

While the firefighting efforts were underway, Highway 5 was intermittently closed by the RCMP over the course of six hours.

The closures were out of safety concerns as the helicopter repeatedly flew low over the road to pick up water from a pond just of the highway.

Atwell said firefighters wanted to make sure the fire did not spread outside the dump, which is located about five kilometres from downtown Hay River.

The volunteer firefighters worked hard in battling the blaze, he said. "They gave it their all."

It is yet to be determined how much the fire will cost the Town of Hay River.

Atwell said there will be invoices from private contractors for the use of their equipment.

Olsen said no decision has been made by ENR on whether Hay River will be billed for the water bombers' time, noting that will be determined by senior management of the department.