The federal government-funded RM2.1 million “bio-drain and wetlands” system, touted to be Asia’s first, was designed by a group of researchers from Universiti Sains Malaysia (USM).

It took about a year to build.

The river’s Water Quality Index improved from Class IV or V to Class II during a test run over the past few weeks.

Class I is the best quality, while Class V is the worst.

In explaining the workings of the system, project coordinator Assoc Prof Nik Fuad Nik Abdullah of USM said the river water would first be channeled to a “bio-drain”.

A water pump sucks out water from the river into the bio-drain, which is a deep concrete tank measuring about the size of a badminton court.

In the tank, there are rotating brushes similar to those at automated car washes.

These polystyrene brushes contain dirt eating bacteria. After the water has been cleaned, another pump sends out the treated water to a mini “wetlands” about 15 metres away.

At the wetlands, the water is run through six types of greens that remove ammonia, nitrate, phosphorous and suspended solids.

The end product, which is clean Class II water, will be released back into the river.

Nik said there was virtually no need for maintenance of the system, except to trim the wetlands once in a while.

“As for the pumps, they have a long service life and will require periodic checks,” Nik said.

Meanwhile, state executive councillor Chow Kon Yeow said he was confident the filtration system would work in the long run to maintain the cleanliness of the river.

“The Sungai Satu was heavily polluted due to dumping of rubbish, water waste from restaurants and homes along the river.

“With this system, we hope to fix the problem. We are happy that the federal and state governments had cooperated to ensure this project’s success,” he told reporters during a site visit here today.