He said regular monitoring by the environment department had shown persistently poor water quality.

“This is likely due to the discharge of untreated pig farm waste, as there is no operational sewage treatment plant in the area.

“We have also conducted an odour pollution study at Kampung Selamat in Tasek Gelugor, with monitoring carried out at 13 locations in the area,” he said.

Nik Nazmi said the department had shared its findings with the relevant agencies in Penang, such as the veterinary services department and the Seberang Perai City Council.

He said while all inspected industrial premises in the area comply with the Environmental Quality Act 1974, the disposal of pig farm waste does not fall under the environment department’s jurisdiction.

He was responding to Siti Mastura Muhammad (PN-Kepala Batas), who raised concerns over the disposal of pig farm sewage into the river.

The Penang government said last November it had stepped up enforcement to curb pollution from pig farms, pushing them to convert from open farm systems to closed systems to improve waste management.

According to a written reply to a PN assemblyman in Penang, 117 farms have adopted the system as of 2024, with Kampung Valdor now sending waste to a biogas facility instead of discharging into rivers.

In Seberang Perai Utara, where Tasek Gelugor is located, farms are required to install solid waste separators and maintain sewage ponds treated with beneficial bacteria and fungi to break down waste, reduce odour and improve water and soil quality.

A total of 50 farms were penalised as of November, mainly in Seberang Perai Utara (33) and Seberang Perai Selatan (15).

Farms exceeding the 50ppm biochemical oxygen demand (BOD) limit face fines of at least RM5,000. A total of 519 compound notices have been issued since 2022.

BOD measures how much oxygen is needed to break down waste in water, with higher readings indicating more pollution and less oxygen for aquatic life.