A comprehensive investigation by the Department of Environment (DoE) Saturday over the Sungai Semantan pollution issue in Pahang revealed the water quality had returned to normal.

Natural Resources and Environment Minister Datuk Seri Wan Junaidi Tuanku Jaafar said he directed DoE to conduct an investigation after complaints that raw water channelled to Selangor from the intake point at the river was polluted.

"The investigation found the condition of the water had returned to normal, namely, the water was clear and without odour," he said in a statement Sunday.

On Oct 7, DoE in Temerloh, Pahang had received information from the Air Pahang Regulatory Body (BDKSAP) regarding the problem of smelly water at the Sungai Langat Water Treatment Plant in Selangor.

Wan Junaidi said follow-up formation received by BDKSAP at 11pm the same day said that the quality of water at Sungai Semantan was good and was odourless.

"But DoE was informed once again on Oct 8 that the smelly water was detected at the intake point of the river," he said.

He said DoE had investigated a premises in the Bentong Industrial Area in Pahang and found the factory had complied with regulations under the department.

Wan Junaidi said the factory was also carrying out maintenance work on its effluent treatment plant to boost its capability and the investigation was continued on other premises.

"During inspections on effluence processing systems, it was found that the effluences released into the river were clear and without any smell," he said adding that the problem was also not detected at a rubber-related premises.

He said inspection on premises in the Bentong, Pahang area also did not find any effluent which smelled especially of solvent, the probable cause of the pollutions in the river.

Wan Junaidi said DoE would act firmly if any factory flouted the Environment Quality Act 1974. -- Bernama