PUB team to study use of groundwater

The Straits Times AsiaOne 25 Mar 14;

SINGAPORE - Singapore has ramped up efforts to study extracting its underground water for use.

National water agency PUB has formed a team of international experts to advise it, and will dig its first exploratory monitoring wells in the next few months.

It is interested in the subterranean Jurong rock formation in western Singapore, which could hold water-bearing layers of rock called aquifers.

Even if Singapore is unable to extract substantial water from them regularly, such aquifers could act as "water banks" for drought periods, said PUB chief technology officer Harry Seah.

While there is "no timeline" for when this water could contribute to Singapore's supply, the exploratory efforts will help to prepare the country, he said.

"We are building up our expertise in the field... and if groundwater does become feasible, we will have a ready team to manage the groundwater resource," he said.

The PUB plans to install 20 to 30 monitoring wells in western Singapore and then monitor the flow of water through them for six to 12 months.

These wells will be about 5cm wide and 10m to 20m deep. Their locations are being worked out, but likely options include green verges alongside roads and other public areas.

The answers sought include where rainwater goes after it seeps into the ground.

"For example, we want to know how much of it goes vertically down into aquifers, and how much horizontal movement there is instead," said Mr Seah.

This information will be useful when Singapore looks into how much water is available, how much of it can be extracted safely and the rate of extraction that would allow rainfall here to naturally replace the removed water.

To speed up the study process, PUB has asked six experts around the world for help. They include: Lord Ronald Oxburgh, a noted geologist and geophysicist; Professor Ken Howard, president of the International Association of Hydrogeologists and an expert in urban groundwater management; and Mr Roy Herndon, chief hydrogeologist at the Orange County Water District in California, which has been extracting groundwater for decades.

Although he played down suggestions by reporters that underground water could be Singapore's fifth tap - after imports from Malaysia, used water and treated seawater and rainwater - Mr Seah said that there is always urgency for the PUB to explore new ideas.

The PUB studied underground water in eastern Singapore's old alluvium geology in the 1990s, but the data from the technology and method used then did not give the agency "adequate confidence" that extracting the water would be sustainable or safe.

"As Singapore progresses, the water demand will keep growing," he said. "If we continue with business as usual, the energy needed will grow much faster as we ramp up desalination and Newater (used water) to meet demand. It's not sustainable."

While the PUB has embarked on research to reduce the energy needed for water treatment, "groundwater is freshwater", said Mr Seah.

"If we have abundant rainwater, we can inject some into the ground, increase our storage... extract the water to meet our demand and give us more buffer for drought."

PUB to monitor groundwater in western, southern Singapore
Monica Kotwani Channel NewsAsia 25 Mar 14;

ORANGE COUNTY, California: Singapore's national water agency, PUB, will embark on a second stage of collecting groundwater data in western and southern Singapore.

This is part of a feasibility study into extracting groundwater, or possibly using porous rocks as underground reservoirs.

PUB said this while visiting this year's Lee Kuan Yew Water Prize winners, the Orange County Water District, which has been tapping and studying its groundwater resource for decades.

In California, PUB is studying how Orange County Water District has been managing its groundwater since the 1930s.

Over the next few months, PUB will drill between 20 and 30 wells at various parts of a 200-million-year-old area in Singapore known as the Jurong Formation.

The monitoring wells measure about five centimetres wide, and will be drilled to different depths of between 10 and 20 metres.

Each well will have narrow openings at different levels to collect information such as whether water flows vertically or horizontally, as well as water quality -- whether it is fresh or brackish water.

The idea is to study the feasibility of extracting groundwater as another water source, or using the porous rock underground as storage space for water collected on the surface.

Harry Seah, chief technology officer at PUB, said: "We are a very small, tiny island and we are densely populated, and water demand will grow over time. And we need to develop ways and means to increase the amount of water that can come out of 710 sq km of land.

“So if I can't go horizontally, I must go vertically. That's why this groundwater thing is a study that we are looking into, in a way, to address whether I can increase storage within the 710 sq kilometres. So imagine you have a multi-layered storage, and it's nature's -- it's free. And it’s the same concept that they are doing here in Orange County.”

Compared with Orange County, which has been working with groundwater for decades, Singapore's own journey with groundwater is still at its infancy. PUB said this is where an international panel with its expertise comes in.

PUB said the panel will guide them on the conduct of the study, and look into concerns such as land subsidence due to over-pumping of groundwater, and seawater intrusion.

The panel is made up of six experts, including the Water District's chief hydro-geologist Roy Herndon.

Mr Herndon said: "Given that Singapore is an island and if the data indicate that there are some significant groundwater resources that may be developed in the future, in the long run, seawater intrusion I believe would be something that will be a key part of Singapore's groundwater understanding."

Orange County injects half the used water it recycles underground to prevent seawater from contaminating its groundwater.

The other half is transported to basins, where it seeps into the ground to be extracted after some time.

- CNA/gn

PUB forms team to study groundwater use
Feng Zengkun The Straits Times AsiaOne 27 Mar 14;

ORANGE COUNTY, California - Singapore has ramped up efforts to study whether and how the country's underground water can be extracted for use.

National water agency PUB has formed a team of international experts to advise it, and will dig its first exploratory monitoring wells in the next few months.

It is interested in the subterranean Jurong rock formation in western Singapore, which could hold water-bearing layers of rock called aquifers.

Even if Singapore is unable to extract substantial water from them regularly, such aquifers could act as "water banks" for drought periods, said PUB chief technology officer Harry Seah.

While there is no timeline for when this water could contribute to Singapore's supply, the exploratory efforts will help to prepare the country, he said.

"We are building up our expertise in the field... and if groundwater does become feasible, we will have a ready team to manage the groundwater resource."

The PUB plans to install 20 to 30 monitoring wells in western Singapore and monitor the flow of water through them for six to 12 months. These wells will be about 5cm wide and 10m to 20m deep. Their locations are being worked out, but likely options include green verges alongside roads and other public areas.

Among other things, they will help find out where rainwater goes after it seeps into the ground.

"For example, we want to know how much of it goes vertically down into aquifers, and how much horizontal movement there is instead," said Mr Seah.

This information will be useful when Singapore looks into how much water is available, how much of it can be safely extracted, and how fast it can be extracted such that rainfall can naturally replace the removed water.

To speed up the learning process, PUB has asked six experts around the world for help. They include: Lord Ronald Oxburgh, a noted geologist and geophysicist; Professor Ken Howard, president of the International Association of Hydrogeologists and an expert in urban groundwater management; and Mr Roy Herndon, chief hydrogeologist at the Orange County Water District in California, which has been extracting groundwater for decades.

Although he played down suggestions by reporters that underground water could be Singapore's fifth tap - after imports from Malaysia, recycled used water and treated seawater and rainwater - Mr Seah added that there is always urgency for the PUB to explore new ideas.

The PUB studied underground water in eastern Singapore in the 1990s, but the data from the technology used then did not give the agency "adequate confidence" that extracting the water would be sustainable or safe.

"As Singapore progresses, the water demand will keep growing. If we continue with business as usual, the energy needed will grow much faster as we ramp up desalination and Newater to meet demand. It's not sustainable," said Mr Seah.

While the PUB has embarked on research to reduce the energy needed for water treatment, "groundwater is freshwater", he added. "If we have abundant rainwater, we can inject some into the ground, increase our storage... extract the water to meet our demand and give us more buffer for drought."

LKY Water Prize winner to help S"pore extract groundwater
Feng Zengkun The Straits Times AsiaOne 27 Mar 14;

SINGAPORE will have the benefit of learning from the best if it wants to extract underground water to add to its supply.

The Orange County Water District (OCWD) in California was awarded the Lee Kuan Yew Water Prize last month for its pioneering work in groundwater management and water re-use.

The district manages a large underground basin that supplies about 70 per cent of water for 2.4 million people in arid southern California.

The OCWD's chief hydrogeologist Roy Herndon, who oversees the basin's water quality among other things, is one of six experts the PUB has tapped to help Singapore on its own groundwater journey.

He said that since Singapore is an island, it will have to study how to prevent seawater intrusion, where the seawater contaminates the underground water. Orange County uses hydraulic barriers.

Parts of California have experienced land subsidence, where extracting groundwater caused the ground to compress and sink.

"In Orange County, that has not been a problem," said Mr Herndon. "We minimised the risk by not allowing groundwater levels to go too low in the basin."

The Lee Kuan Yew Water Prize award ceremony and banquet will be held on June 2, during the Singapore International Water Week from June 1 to 5.

The OCWD will receive $300,000, a certificate and a gold medallion.