WE have long depended solely on rivers for our water needs. But after our rivers became parched earlier this year, there is now a buzz in the water industry about the “five taps”.
These taps are new sources of water worth exploring, namely groundwater, rooftop rainwater, stormwater, sewage wastewater and sea water. Malaysian Water Association deputy president V. Subramaniam says 98.5% of our raw water is drawn from rivers.
“With our abundant rainfall, some 3,000mm a day, it is logical and easiest to use surface water. The problem is the uneven rainfall distribution and deteriorating water quality due to pollution of rivers. Based on recent experiences of drastically changed rainfall patterns, we now need to also consider alternative sources of water to build water security.”
He says the extent to which we should consider these alternatives depend on whether we can reduce our water demand and water losses (non-revenue water or NRW).
Malaysians are high water users; each person consumed 212 litres a day in 2012. Penangites used the most water, at 285 litres each. In comparison, Singaporeans used only 156 litres each, while the British, 153 litres.
The national NRW in 2012 was 36.4%, with 73% of that being physical water losses (through burst pipes, leaks in distribution pipes as well as leaks and overflows in service reservoirs). The rest is water thefts and under-reading of water meters. (Singapore records an NRW of only 5%).
“The water that is leaked amounted to 4,000 million litres a day, which is enough for the use of Selangor, Kuala Lumpur and Putrajaya,” says Subramaniam, who has 40 years’ experience in the drinking water industry.
He adds that curbing the leakages is not a simple matter of replacing old pipes as leaks can occur even in newly developed areas due to poor construction practices.
Subramaniam says treated wastewater (from sewage effluent) will be more suited to localised use such as within an industrial estate, and on-site application.
For stormwater, we will have to develop the infrastructure to collect, store and treat it for use. Groundwater is a feasible water source but we have to choose suitable sites and not over-extract, to prevent the possibility of land subsidence or salt water intrusion.
“There has to be legislation to protect recharge areas (for the underground aquifers). If you clear the forest or pollute the recharge area, then groundwater will not be replenished. If there is too much agriculture and industries in the recharge areas, chemicals can possibly pollute the water table.”
Ultimately, decisions on tapping new water sources lie with the Federal and state governments. There are many things to consider, such as costs, infrastructure development, consumer acceptability and sustainable exploitation.
Policy measures to consider are realistic water tariffs, penalties or surcharge for excessive water use, water-use restrictions when needed, integrated management of water resources and river basins and environmental controls.
Subramaniam says the approach should be conjunctive use, that is, co-ordinated management of surface water and groundwater supplies to maximise the yield of overall water resources.
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