Key to more sustainable water management

I THANK S. Piarapakaran for his very timely letter “Time to adopt new ways to treat wastewater” ( The Star, March 22).

The recognition of treated wastewater (particularly sewage) effluent as a national resource is key to more sustainable water management. Beneficial use of water resources is not just for drinking but also industry, agriculture, recreation and many others. Water and wastewater management must be viewed in the natural water cycle context.

Malaysians are blessed with abundant water, unlike many other countries. Besides surface water in rivers and lakes, we also have largely untapped ground water reserves. This has led to a complacent attitude among people as well as policy makers. We use huge amounts of water on a per capita basis. This must be curbed through a range of strategies such as addressing waste, reducing non-revenue water (NRW), encouraging reuse, education and awareness, incentives and disincentives, and including a tariff strategy. Using clean drinking water for non-potable purposes such as industry or even watering golf courses is a hugely wasteful practice.

Policy must provide an enabling environment for suitable strategies to encourage practices which are aligned to the national agenda. Planning of water and sewerage infrastructure, tariffs and management must all aim for conservation and low water, energy and carbon footprints.

In India, water usage by industries is already being limited by regulation, forcing them to look for reuse/ recycle alternatives. Many sewage treatment plants recover effluent for reuse. From the process, they also recover energy sufficient for a large portion of their in-plant needs.

In many countries in Africa and in India, the sanitation sector sees human waste as a potential resource and sets recovery of these materials as a major objective.

In Melbourne, Australia, centralised sewerage systems treat and make available good quality effluent. But the treatment plants are located far from where the water is needed. As a result, “sewer mining” has been introduced where consumers are allowed to tap sewage from sewers and treat it locally for reuse.

In many developing countries, the preference for water-borne centralised sewerages is being re-examined. The traditional concept of mix-convey-separate-treat is highly water- and energy-intensive. Decentralised and on-site sewerage management concepts, and even source separation, are being considered appropriate in specific situations. Technologies for these are being developed and deployed successfully in many parts of the world.

In Malaysia, too, we should set policy aspirations which aim for sustainability in the long run, strategising water and sewerage management in an integrated manner, considering not only the water cycle but also the water/ energy/ food nexus. Strategies must be contextualised so that each area can plan based on its specific needs, thereby avoiding wasteful practices. For example, on-site or decentralised sewerage management systems may be more appropriate for sparse rural or semi urban areas.

The time is right for a national sewerage policy that’s aligned to national aspirations and should set the stage for a transformation of the whole water sector to a more sustainable model.