The fire started at Quercia Limited's site off Dawson Lane, near Buckshaw Village, at around 12.15am on Wednesday (July 13).
By 1pm that day, 15 fire engines were battling the flames, with crews expected to remain at the scene for the rest of the day.
Incident commander Mal Dewhurst said: “We estimate approximately 6,000 sq m of surface area of the landfill is affected by the fire.
Driver caught 'snoring merrily away' on the M6 near Bamber Bridge with full-beam headlights and engine running
Lanes reopen after car crash on M6 brings Preston motorway traffic to a halt with severe delays expected
M6, M61 and M55 delays in Preston due to Blackpool Air Show and Lake District holiday traffic
Lancashire residents left without water on one of the hottest weekends this summer should expect supplies to return this evening
Two Preston men arrested after serious assault near Harris Museum
“There are areas that we know it has gone deep-seated.”
Two Stingers from Blackburn and Skelmersdale, two high volume pumps from Burnley, the BA Unit from Preston and the foam pod from Leyland also remained.
Incident Commander John Rossen said LFRS were “likely to be in attendance for a number of days.”
Footage shared by Lancashire Fire and Rescue Service’s drone team showed the extent of the fire.
“This is the situation this evening at the incident in Chorley as the sun sets,” a spokesman for LFRS said.
“We will be working throughout the night.
“Please do not fly drones near the scene.”
Nearby residents were urged to keep doors and windows closed due to the large amount of smoke being produced by the fire.
Dawson Lane was also closed in both directions as emergency services battled the flames, with motorists advised to find alternative routes.
Crews worked alongside specialists from the Environment Agency as well as local authorities to help bring the fire to a safe conclusion.