ASEAN countries are undergoing rapid urbanisation leading to an increase in demand for clean water. However, depleting levels of groundwater and changing climate is compounding the water scarcity issue in the Southeast Asian region. The conventional approaches to meet water demand through reliance on rainfall and river run-off are not enough to ensure round-the-clock water supply. Therefore, desalinated water is turning out to be a sustainable alternative for clean water supply. At present, countries like Singapore, Thailand, the Philippines and Vietnam have developed a number of desalination plants. Others like Cambodia, Laos, Brunei and Myanmar are yet to fully explore the potential of reverse osmosis (RO) technology. However, as the demand of water is projected to grow, threefold additional capacity of desalinated water is required. To this end, two desalination plants are coming up in Singapore, a green desalination plant is being developed in Vietnam and in Malaysia a desalination plant is planned to be set up in Johor state. But challenges such as the high cost involved in installation, higher consumption of energy resulting in greater carbon emissions and discharge of brine in the desalination procedure are the key barriers to its greater adoption. In light of these issues, small-scale desalination plants would be the key alternative that can help bridge the water demand-supply gap in the region.
Existing plants
The Public Utility Board, Singapore, introduced desalination plants as an alternative source of fresh water supply in 2005 when two desalination plants – one at SingSpring with 30 million gallons per day (mgd) capacity and the other at Tuaspring with 40 mgd capacity – were commenced. The two plants helped PUB meet up to 25 per cent of the water needs. In the last few years, water supply demand in the country has increased rapidly and according to PUB estimates, the daily water consumption is expected to almost double to 3.6 million cubic metres per day (cu m/day) by 2060. As part of its long-term water supply strategy, the PUB introduced desalinated water as Singapore’s fourth National Tap. Also, to create additional supply, the government expanded the current desalination capacity by developing new plants. One such plant has been developed in Tuas and was operationalised in July 2018. With the capacity to produce 30 mgd of drinking water, the third desalination plant can serve around 200,000 households daily. It was developed by HSL Constructor, on a public-private partnership basis (PPP), at a cost of SGD 217 million. With its completion, the desalination capacity of the country has increased from 100 mgd to 130 mgd.
Jakarta, the capital of Indonesia, also took similar measures to deal with water crisis. The Water Resource Agency of Jakarta undertook construction of three desalination plants in the region in 2018. These clean water units are located on the islands of Payung, Kelapa Dua and Pramuka. All the three plants use RO technology to desalinate water. As of February 2019, Jakarta administration has finished the construction of all the three plants and is testing the water quality and production capacity of the same. Once commercial supply commences, about 520 houses on Panggang Island, 274 on Pramuka Island, 111 on Kelapa Dua Island and 49 on Payung Island will receive clean water from these plants.
The Phuket Provincial Water Supply (PPWS) in Thailand also developed a desalination plant in the region. The plant is capable of producing up to 12,000 cu m/day of potable water. It is also based on RO technology to process clean water that is supplied to the Kata-Karon region.
In the Philippines, Mactan Rock Industries, Inc. (MRII) in partnership with Pilipinas Water Resources, Inc., developed the biggest desalination plant in Southern Philippines at the South Road Properties, to supply at least 22,000 cu m/day of potable water for industries.
Upcoming capacity additions
As ASEAN countries are endowed with a vast coastline, desalinated water deems to be the key pillar for sustained water supply. To tap the same, countries are planning to develop more desalination plants in the region. For instance, the PUB, Singapore, is developing two more desalination plants in the country to meet the projected demand. While one plant is being developed at Keppel Marina East, the other or the fifth desalination plant is being constructed in Jurong Island.
The plant at Jurong Island, worth $282.28 million, is being developed on a PPP basis and aims to meet up to 30 per cent of the water demand of the city. To execute the same, a consortium of Tuas Power Limited and Singapore Technologies Marine Limited was selected as the concessionaire on September 27, 2017. Later, a concession company called TP-STM Water Resources Pte. Limited was formed for its implementation.
To process clean water, ultrafiltration technology, which is a pretreatment technique that uses a low pressure membrane, is being used. In February 2019, the contract to supply Memcor’s low pressure membrane system was awarded to Evoqua. The system incorporates pre-engineered low pressure membrane modules with pre-assembled arrays to minimise the time and cost of installation. Through these membranes, the plant will produce 36 mgd (136,000 cu m/day) of clean water. Spanning a 9,700 square foot area, the plant will be the first compact ultrafiltration plant in the region.
The PUB is also engaged in developing another desalination plant called the Fourth Desalination Plant at Keppel Marina East. The unique feature about the plant is that it has dual-mode desalination facility that uses RO technology to treat both seawater and freshwater from the Marina reservoir depending on wet or dry weather conditions. To develop the plant, the contract was awarded to Keppel Infrastructure Holdings Pte Limited, while RO membranes are being procured from the Nitto Denko Corporation. The contract for procuring membranes was awarded in June 2018.
This dual-mode desalination feature helps reduce energy usage when freshwater is available in abundance. It will have capacity to process 30 mgd of seawater and freshwater of the Marina reservoir to generate 137,000 million cu m/day of clean water. Besides housing the plant, the facility will also feature a green public recreational space, including a 215,278 square foot open green rooftop and rainwater harvesting structure for irrigating plants.
Both the plants are likely to be completed by 2020 and are expected to meet the projected demand for 2060. Besides, the water agency is exploring the potential of building a fifth plant on Jurong Island to double the desalination capacity by 2030, and triple it by 2060.
Malaysia too is planning to develop a desalination plant in Johor state on a PPP basis. To develop the same, Forest City in Johor has been selected as the proposed site.
In Vietnam, Belgium’s Asian Infrastructure Engineering and Investment Company (AIEI) and France’s SCE have formed a joint venture (JV) to construct a green water desalination plant in Ninh Thuan. This green desalination plant will be powered through wind energy as against conventional electricity. Through this green initiative a lot of energy will be saved in desalination. As per plans, the JV will develop pilot desalination plants in Ninh Thuan, Binh Thuan, Soc Trang, Ca Mau, Kien Giang, and Ben Tre to provide water for irrigation of around 40 hectares of rice cultivation area per day. The capacity of each system is estimated at 400 cu m/day.
Opportunities and key barriers
The Southeast Asian region offers immense opportunities for developers and contractors to create their footprint in the desalination market. Significant industrial development in the ASEAN countries such as Vietnam, Malaysia, Thailand, Indonesia and the Philippines is also considered to provide ample opportunities for the desalination market expansion by 2025. At the same time, some countries are yet to explore the potential of desalination technology which highlights the fact the market is still in the nascent stages.
At the same time, a number of challenges need to be addressed by both the government as well as the companies to make the Southeast Asian countries rely heavily on desalinated water. At present, a desalination plant requires a huge investment and consumes a lot of energy in order to desalinate water. But for developing countries in the Southeast Asia, cost structure has to be taken into account to increase its adoption. A major portion of the cost is attributable to membranes used for filtration for which cheaper substitutes can be developed. Also, a higher energy consumption for desalination correlates to a higher carbon emission count which is already a pressing issue for ASEAN economies. To this end, green desalination plants that depend on renewable energy sources, like the one developed at Jakarta, can be a viable option.
Another critical issue is brine, the primary by-product of desalination that contains chemicals and suspended particles. The by-product is discharged into the waterbody disturbing the ecosystem as it is high in salt content that reduces oxygen levels. According to experts, the brine can be recycled to generate new economic value instead of carelessly dumping the same into the sea. Minerals such as salt, chlorine and calcium that are present in brine can be recovered for reuse elsewhere. Lastly, it should be scientifically treated so as to safely discharge it into the ocean.
