Tuas Desalination Plant opens, another milestone in Singapore’s water quest

CHEN LIN Today Online 29 Jun 18;

SINGAPORE — Singapore's first desalination plant owned and operated by the Government officially opened on Thursday (June 28).

The Tuas Desalination Plant is the Republic's third and has a capacity of 30 million gallons per day (mgd).

Singapore’s water sustainability came under the spotlight earlier this week when Malaysian Prime Minister Mahathir Mohamad revived a dispute with Singapore over the terms agreed in a 1962 pact.

At the opening ceremony, Minister for the Environment and Water Resources Masagos Zulkifli reiterated that this latest milestone in Singapore's water story "did not come easy". He did not make any reference to Dr Mahathir’s latest remarks.

Mr Masagos said: "Gradually but surely, we will continue to build up the capacity of our desalination and NEWater capacities, so that by 2060, NEWater and desalination can supply a combined 85 per cent of our water needs then."

Desalination, where membranes remove salts and minerals from seawater to produce drinking water, now meets up to 30 per cent of Singapore's water demand.

Singapore currently has five desalination plants, including two still in the works.

The Tuas Desalination Plant is the third in Singapore. Hyflux clinched contracts for the first two desalination plants, SingSpring and Tuaspring, while an upcoming fourth plant will be owned and operated by Keppel Infrastructure Holdings. The fifth desalination plant will be built by a Tuas Power-Singapore Technologies Marine consortium.

The opening of the Tuas plant also comes after Hyflux’s financial woes came to light last month. The homegrown water treatment firm’s troubles were partly attributed to the losses it incurred on the Tuaspring project, which it has been trying in vain to sell off.

Nevertheless, the Government had made the decision in 2015 to own and operate the Tuas Desalination Plant.

"PUB found that there is a need for us to build that competency in water desalination treatment. And at the same time, having our own plant gives us a platform to implement new ideas, new research and development (R&D) projects," said Mr Bernard Koh, national water agency PUB's director of water supply (plants).

PUB chief executive Ng Joo Hee said the plant could serve as a "real-world testbed" for technologies that could halve the energy needed for desalination, which is currently 3.5kWh per cubic metre.

Indeed, Mr Masagos pointed out: "Desalination is an especially energy-intensive water source and if we continue with business-as-usual, Singapore's desalination energy usage in 2060 will be four times that of today."

Adding that Singapore does not wish to become energy-reliant in its quest to overcome water scarcity, Mr Masagos said PUB is exploring new technologies and the use of cleaner energy to make the desalination process more energy-efficient.

One example he cited was an experiment with electrochemical desalination technology, which has the potential the halve the current energy use in desalination through the use of reverse osmosis, that is being conducted at the plant.

And the development of such low-energy desalination technologies need to be accelerated, he added, making PUB's continual work with its R&D partners critical.

The Tuas Desalination Plant is a "strategic infrastructural asset" that will boost Singapore's desalination capacity from the current 100 mgd to 130 mgd, PUB said in its media release.

Occupying about 3.5 hectares, the plant is one of the most compact in the world and is able to meet the water demand of about 200,000 households.

Construction by HSL Constructor began in November 2015, and the plant began its testing and commissioning at the beginning of this year.

Mr Koh said equipment was stacked "to a certain extent". The plant's compactness could, however, pose challenges during maintenance work, as there is less space between the pipes and equipment, and workers would have limited space to carry out their work.

The new plant is the first that uses advanced pretreatment technology – a combination of dissolved air floatation and ultrafiltration.

Together, they reduce the deposits of impurities on reverse osmosis membranes. The membranes can last for a month before they need to be cleaned, about one to two weeks longer than with the conventional system.

SingSpring plant, which was built in 2005, has only the dissolved air floatation system, while TuaSpring, built in 2013, has only the ultrafiltration system.

In dissolved air floatation, chemicals are introduced into seawater to gather impurities into bigger particles. Fine air bubbles are then injected into the particles, which float and are removed.

During ultrafiltration, seawater passes through semi-permeable membranes that remove impurities, microorganisms and bacteria.

"From SingSpring and TuaSpring, we learned that pretreatment is very important and we combined (the two systems) as the pre-treatment," said Mr Koh.

Advanced pretreatment technology makes the plant more robust — should there be deterioration of seawater quality due to a minor oil spill or algae bloom, the dissolved air floatation system can help to reduce algae count. This helps to preserve the ultrafiltration membranes, which subsequently helps to preserve the membranes used for reverse osmosis.

The Tuas Desalination Plant cost S$217 million, an amount that includes maintenance costs for the first 24 months.

It is also the first desalination plant that will have solar panels on more than half of its roof surface. To be installed by the end of this year, the panels will cover more than 7,000 sq m and meet less than 1 per cent of the plant's needs, which is also equivalent to powering more than 300 four-room flats for a year.

Asked about the environmental impact of the plant, the PUB said an assessment was done. Seawater quality is monitored "very closely" and the brine is released into the open sea.

The fourth and fifth desalination plants in Marina East and Jurong Island are expected to be completed in 2020.


Singapore opens its third desalination plant in Tuas
Lianne Chia and Vanessa Lim Channel NewsAsia 28 Jun 18;

SINGAPORE: Singapore on Thursday (Jun 28) opened its third desalination plant, boosting the country’s desalination capacity from 100 to 130 million gallons a day (mgd).

The Tuas Desalination Plant, which can produce 30 million gallons of drinking water a day, will help to meet up to 30 per cent of Singapore’s current water demand.

Spanning just 3.5ha - the size of three rugby fields - Tuas Desalination Plant is the country’s smallest plant to date.

Despite its size, the plant can produce the same amount of drinking water as SingSpring Desalination Plant, Singapore’s first such plant.

SingSpring occupies 6.3ha, nearly double the footprint of Tuas Desalination Plant.

Both plants can produce up to 30mgd of drinking water, which is enough to supply to 200,000 households.

The first to be owned and operated by PUB, the Tuas plant will also be used to test new energy-saving technologies.

The plant is also the first in Singapore to adopt an advanced pre-treatment technology, which combines two existing filtration methods – dissolved air floatation and ultrafiltration.

This will help to reduce membrane fouling when treating seawater of varying water quality, as well as to prolong the lifespan of a membrane.

To reduce the plant's carbon footprint, a 1.2MWp solar photovoltaic (PV) system will be installed on more than half of the plant’s roof surface by the end of the year.

Covering more than 7,000 sq m, the solar PV system will be able to generate 1.4 million kWh of clean energy a year, which will be used to power the plant’s administrative building.

With Singapore’s water demand projected to double from the current 430mgd by 2060, two more desalination plants are in the pipeline.

Slated to be completed in 2020, Marina East Desalination Plant and a fifth desalination plant at Jurong Island will bring the total daily water production in Singapore to 190mgd in two years’ time.

INVESTMENTS IN WATER NETWORK "HEAVY BUT NECESSARY": MASAGOS

Speaking at the opening of the plant, Minister for Environment and Water Resources Masagos Zulkifli pointed out the need for Singapore to continually expand and enhance its water supply network.

He cited examples of cities like Cape Town in South Africa and Sao Paulo in Brazil. In Sao Paulo, a severe drought had caused the stock level of its main reservoir fall below 4 per cent, and its 21 million inhabitants had at one point less than 20 days of water.

“We are laying more pipes to reach the population and industries in new growth nodes while maintaining and renewing existing water infrastructure,” said Mr Masagos.

He added that all these are “heavy, but necessary investments”, and take time. These investments must also be made ahead of time and demand, so Singaporeans will not face the same problems as Sao Paulo and Cape Town, the minister said.

“This is made possible by right-pricing water to reflect the long-run marginal cost of producing our next drop of water, which is likely to come from NEWater and desalinated water.”

Source: CNA/ad(cy)


Singapore opens third desalination plant in Tuas
Jose Hong Straits Times 28 Jun 18;

SINGAPORE - Singapore's third desalination plant officially opened on Thursday (June 28), helping the Republic to further overcome its water challenges.

The $217 million Tuas Desalination Plant can produce up to 30 million gallons a day (mgd) of drinking water, the amount used by around 200,000 households daily.

With the new plant, 30 per cent of Singapore's water needs can now be met by desalination, up from 25 per cent. The new facility adds to SingSpring Desalination Plant, which also can produce 30mgd of drinking water, and Tuaspring Desalination Plant, whose capacity is 70mgd.

At the plant's opening on Thursday morning, Minister for the Environment and Water Resources Masagos Zulkifli said water is an existential issue for Singapore.

"Desalination, like Newater, is a weather-resilient water source. It helps us better cope with the threat of climate change," he said, referring to the high-grade reclaimed water known as Newater. Singapore also relies on water from local catchment and imported water.

The new plant is the first owned and operated by national water agency PUB, with SingSpring and Tuaspring both run by Hyflux. The water treatment facilities operator has been in the news recently for its financial woes and is seeking to sell the loss-making Tuaspring plant.

In response to media queries, PUB water supply (plants) director Bernard Koh said: "PUB's decision to run this plant on our own was not triggered by any lapses or inefficiencies experienced by the private sector."

Instead, he said the move allows PUB to build up its water treatment skills, and implement its own research and development projects.

Singapore's latest desalination plant is at 3.5ha, the smallest of the country's desalination facilities. It will remain so even after the next two desalination plants are built in Marina East and Jurong Island by 2020.

Yet in terms of the amount of water purified for its size, Tuas Desalination Plant is the most space efficient desalination plant in the world, said a PUB spokesman.

It is also the first to use solar power and the most technologically advanced.

More than 7,000 sq m of the new plant's roof will be covered by a photovoltaic system, and when online, the solar panels can generate 1.4 million kilowatt-hours of energy a year, enough to power more than 300 four-room flats in the same period. However, in a sign of how much electricity is needed for desalination, this is enough only to run the plant's administrative building - less than 1 per cent of the total facility's needs.

Tuas Desalination Plant is also the most technologically advanced.

By combining two methods used separately in Singspring and Tuaspring, the lifespan of its reverse osmosis membranes - where the final stage of purification occurs - increases from as little as two weeks to one month.

The opening of Tuas Desalination Plant comes after Malaysian Prime Minister Mahathir Mohamad earlier this week criticised the water supply deal between Singapore and Malaysia.

When asked if his comments meant that Singapore's quest for water self-sufficiency has become more pressing, the Lee Kuan Yew School of Public Policy's Cecilia Tortajada noted that the new desalination plant was planned years ago.

The senior research fellow from the school's Institute of Water Policy added that PUB has always taken a long-term view of Singapore's quest to become self-reliant in water.

She said: "The urgency to become water self-sufficient is not new and has always been a priority for Singapore… Johor is a very important source of water, but so are Newater, desalination, and local catchments, and PUB has been working on all of them."