The cause of a blaze at a tip near Bristol has been revealed as a battery or electrical item in the non-recyclable waste area.
Residents were advised to close their windows and doors because of a plume of smoke when fire broke out at Mangotsfield Sort It recycling centre on May 17.
Avon Fire & Rescue Service has now confirmed to South Gloucestershire Council that the cause was accidental.
In a weekly email newsletter to residents, the local authority said: “Following the fire on May 17, most of the internal repairs were quickly carried out and the centre reopened just a few days later on May 20.
“We have been advised that the fire was caused by a battery or electrical item in the non-recyclable waste area.”
It said 75 per cent of waste placed in the non-recyclable area could be recycled from home.
“To help people recycle more at the Sort It centres, we will re-introduce our open bag policy in July,” the council said.
“Tables will be available to open bags of mixed waste and sort recyclable items.
“Sorting waste before arriving will also allow more waste to be recycled and help prevent fire.
“In good news for the Mangotsfield Sort It centre, planning approval has been granted for a slip road at the site to prevent queuing on the local roads at busy times.
“Work is expected to start this autumn and access to the recycling centre will be maintained wherever possible to minimise disruption.”
Ten fire crews from Kingswood, Hicks Gate, Temple, Yate, Portishead, Southmead, Pill and Avonmouth were sent to the scene last month.
They used two jets, two high-pressure hose reels and multiple thermal imaging cameras to extinguish the blaze, and 12 firefighters wore breathing apparatus.
The service drone was also used to assess the severity of the flames, while positive pressure ventilation fans were used to clear smoke logging from the building in Carsons Road.