The Electricity Generating Authority of Thailand (Egat)'s initial inspection found that landslides at Mae Moh lignite mine in Lampang's Mae Moh district was caused by water infiltration.
The landslides occurred at about 9 am on March 18 at the mine's dump site. The soil blocked about one kilomtre section of a road inside the mine which has also been used by the locals.
The landslides had damaged many electricity poles, but did not disrupt electricity services in the areas.
Opas Jariyaphum, head of Mae Moh Mine's planning and management, said after inspecting the site yesterday (March 19) that the landslide happened at the mine's soil dumping zone.
Soil dug out from the mine over the past 20 years had been piled up in the area which is now about 300 metres high, he said.
On March 18, the soil slid down from the third layer of the pile at about 100 metres high and blocked the road, Mr Opas said.
He said authorities believed that accumulated rainfall infiltration caused landslides.
Villagers there were advised to use a detour instead for safety, he said.
But villagers at Tambon Ban Dong said the road is a key route to the district office and the detour is 6 kilometres longer.
Several soil conveyors were also affected by the landslides while the whole area has been cordoned off for safety reasons.
Source: Thai Public Broadcasting Service (ThaiPBS)