Indah Water Konsortium Sdn Bhd (IWK) need to obtain the approval of the government to review its sewerage tariff rates due to its rising cost of operation.

Deputy Energy, Green Technology and Water Minister Datuk Seri Mahdzir Khalid said with the rising cost of operations, IWK was now depending on government subsidy to maintain the tariff rates.

"Moreover, the tariff rates have not been reviewed for 20 years. Nonetheless if IWK felt it needed to review the tariff rates, it need to get the approval of the government first," he told reporters after visiting the IWK Bunus Regional Sewage Treatment Plant here Thursday.

He said public knowledge and awareness on the role of IWK was still low, especially on the sewerage tariff payment rate imposed on consumers.

"IWK need to step up its awareness and information programmes on sewerage services and explain the tariff rates to the people through the mass media," he added.

He also opened the Indah Water Konsortium Sdn Bhd's Centre of Excellence for Research and Innovation (ICERIW) which was set up to carry out studies on improving the process, continuous monitoring and to support research initiatives with public institutions of higher learning.

Meanwhile, IWK chief executive officer Datuk Abdul Kadir Mohd Din said the establishment of ICERIW would reduce the dependence of IWK on external or commercial laboratories, as the centre was equipped to analyse the required parameters.

"Earlier tests were contracted to external laboratories but with ICERIW, monitoring tests and analysis will be carried in-house," he said.