SPAN chairman Charles Santiago said reclaimed water would particularly benefit industries, with the Bayan Baru and Jelutong sewage treatment plants located near factories.
In an interview with FMT, he said Sungai Muda, from where 80% of Penang’s water is drawn, was quickly depleting, with its water level having declined sharply to merely 7% of its previous level.
“Penang has to start looking inward for sources of water, and tap into what you have in excess,” Santiago said, adding that it would be cheaper to treat wastewater than to process it from rivers.
A study by SPAN found that Penang would be able to reclaim 200 million litres (MLD) of water per day out of wastewater from the island alone. Currently, Penang produces 1,126 MLD of water from its nine treatment plants across the state.
Santiago said treating wastewater was already a practice globally, and that such reclaimed water is already being used in the agricultural and construction sectors here.
He said some developing countries have also mandated using only wastewater to run industries, with India already requiring factories to use 50% reclaimed water.
“The state should be gearing up for reclaimed water in the next five years.
“The state government should mandate that those in the construction, manufacturing and agricultural sectors use only reclaimed water. It is the preferred international standard today,” he said.
Santiago said a pilot programme in Selangor saw a rubber glove factory benefiting from reclaimed water, receiving a steady supply of two million litres daily.
He said the Bayan Baru Indah Water treatment plant, located next to the Free Industrial Zone, is able to produce 50 MLD, while the Jelutong plant not far away could produce triple that amount.
He said water recycling plants could be easily constructed next to these Indah Water plants.
Look into off-river storage for dry spells
The SPAN chief said Penang should also look into off-river storage, such as ponds, lakes and former mining ponds, to overcome water shortages during dry periods.
He said these storages can come from nearby rivers, rainfall runoffs or other local water sources.
Santiago cited Selangor’s Hybrid Off River Augmentation System (Horas), which is able to store up to 3,000 MLD of stormwater and underground water to later be treated for potable water.
Nonetheless, he said, Penang must increase efforts to conserve water, with the state consuming 305 litres per capita per day, compared to the national average of 237 litres per capita daily.
He said newer projects should be required to install water saving devices in washrooms, while a water saving audit should be carried out throughout the state.