Officials inspect 200-litre tanks containing toxic chemicals in Kanchanaburi's Tha Muang district.

Yongyuth Tiyapairat said during a field trip yesterday to inspect the dumping site that the case was much more serious than he had initially thought. Trees in the area were dead, their leaves burnt from the acid fallout of toxic chemicals.

"I didn't think it was this bad. This is worse than the ore-processing plant that dumped lead into a natural waterway," he said referring to the case of Lower Kliti Village, which had its only water source contaminated with lead.

More than 150 tanks of 200-litre containers of hydrochloric acid, and another 150 tanks of used solvent, were illegally piled up on private land, owned by local people, a few days ago. Though provincial authorities and the Tha Muang Tambon Administration Organisation (TAO), which oversees the area, had already asked police to charge the owner of the land, Yongyuth said he would ask the environmental police to join the investigation.

The environmental police (formerly known as forest police) come under the Royal Thai Police, and are in charge of all cases relating to exploiting natural resources and polluting the environment.

He said once the police discover the real owner of the chemical substances, the ministry would then file another case against them.

Adisak Thongkaimook, deputy director of the Pollution Control Department, said the department would not clean up the site since it must be left untouched to be further used as evidence in the police investigation. However, he insisted that his department can contain the spread of the toxic pollution to other areas. According to Adisak, the hazardous substances are waste from a factory, but he could not yet specify what kind of factory it is.

 "I believe the owner of the land should know the origin of the substances. It is unbelievable that large amounts of toxic waste were dumped on his land without his knowledge,' he said.