Construction of Changi Newater factory to start in 2024 after environmental impact study

SINGAPORE - Construction of an additional Newater factory at Changi’s used water reclamation plant will begin in 2024 following the completion of an environmental impact assessment. It had concluded that discharge from the new factory would not affect the marine environment.

This factory will join two existing ones at the Changi Water Reclamation Plant (WRP) and will cater to the growing demand for water, ensuring that Singapore’s water production is climate-resilient. It is expected to be completed in 2026.

Plans to build the factory were announced in 2020, but its construction could not be carried out until the environmental impact assessment of its development and operations was completed.

Singapore currently has five Newater factories – two in Changi, and one each in Bedok, Ulu Pandan and Kranji.

The new factory will replace the ageing 20-year-old one in Bedok, which national water agency PUB plans to decommission to free up space for other needs. 

To produce Newater, treated used water is purified by reverse osmosis. Ultraviolet light is used to remove any remaining viruses or bacteria in the water.

The new Newater factory will receive treated used water from Changi WRP and produce up to 50 million gallons of Newater per day, said PUB. This is equivalent to what the two existing factories at Changi produce a day, and is more than twice the capacity of the Bedok factory, which produces 18 million gallons of water per day.

Newater is mainly supplied to wafer fabrication plants, industrial estates and commercial buildings. By 2065, two-thirds of Singapore’s water demand is expected to come from non-domestic sectors.

The new factory will use more efficient treatment methods that will increase the recovery rate of Newater from the current 75 per cent to 90 per cent. This means that only 10 per cent of the water will be discarded.

The rejected water will be blended with that from the other two Newater factories and excess treated effluent from Changi WRP, before being discharged into the sea.

The additional discharge would have no impact on the marine environment or biodiversity, said the environmental impact assessment report commissioned by PUB.

But the additional discharge will have a raised phosphate level, said the report, which was done by environmental consultant DHI.

This raised level is projected to be low, and will be diluted quickly and dispersed by the strong currents in the area of the discharge, said PUB.

Increased phosphate and nitrogen levels in seawater could increase the risk of algae blooms, which could starve the seawater of oxygen, killing marine species such as fish.

In most marine environments, including Singapore’s, such blooms are predominantly driven by nitrogen levels rather than phosphorus. Hence, DHI concluded that no additional mitigation measures are required.  

Since the Changi WRP started operations in 2008, six water-quality monitoring points have been set up around the plant. Data has shown there is no adverse impact of the WRP and the two existing Newater factories on water quality.

Two more water-quality monitoring stations will be set up with the construction of the third Newater facility at the plant. PUB is also looking into ways to further reduce phosphate levels in the discarded water.

Asked whether reclamation works conducted around the vicinity of the Changi WRP could affect tidal currents in the area and increase the risks of algae blooms, a PUB spokesman said the consultant found that the risk was not significant.

Land reclamation, which changes the coastline and may affect currents, is

being done at Changi Bay.

The future development of Long Island, a reclaimed island on the south-east coast from Marina to Changi, would also involve reclamation works.

The DHI report recommended that PUB continues to monitor and conduct research on emerging pollutants and how these may affect marine life, as these were not studied under the scope of the environmental impact assessment due to the lack of available data.

The report also noted that there is uncertainty over the specific compounds found in the discarded water from the reverse osmosis process.

It recommended that PUB commissions a research study to screen for high-risk pollutants, whether the concentrations fluctuate over time and how to remove them.

Emeritus Professor Ng Wun Jern of the School of Civil and Environmental Engineering at Nanyang Technological University (NTU) said emerging pollutants can include compounds in pharmaceuticals, pesticides, personal products and various industrial chemicals.

He stressed that the water treatment process would be able to remove most of the pollutants, but there could be “very low residual concentrations” of such pollutants.

One example of an emerging pollutant could be dipropylene-glycol, which is used in fragrances, or 6PPD, an industrial chemical used in the manufacture of rubber tyres.

In the United States, tyre fragments washed into urban waterways have caused the death of fish. When asked, Prof Ng said this usually happens in freshwater ecosystems, not marine ones.

“The impact of pollutants can differ depending on the nature of the receiving waters,” he noted.

“I personally do feel that emerging pollutants should not be addressed at the end of the pipe (when they are being discharged), but in their use and as they enter the used water treatment facilities,” said Prof Ng.

Professor Shane Snyder, director of NTU’s Nanyang Environment and Water Research Institute, said he is glad the environmental impact assessment report placed a focus on the impact of emerging contaminants on marine life.

The Singapore coast is a habitat for marine creatures like the critically endangered hawksbill turtle, which nests along the beaches, he said.

“It will be vital to utilise modern analytical and bioanalytical tools that PUB has championed to continue proactive monitoring of our unique and diverse coastal waters,” he added.

Correction note: An earlier version of the story stated that reclamation works are ongoing. This is inaccurate, as reclamation works have not started. We are sorry for the error.