Singapore to upgrade coastal monitoring sensors to measure radioactivity, waves
Chin Hui Shan Straits Times 27 Mar 2025
SINGAPORE – Singapore’s coastal monitoring network, which has been keeping tabs on water quality around the country for over 10 years, will be upgraded to include sensors that can measure radioactivity as well as wave parameters, The Straits Times has learnt.
The current Neptune system monitors the waters around Singapore so that the authorities can respond more quickly to water pollution incidents, including oil spills, and other environmental risks like algae blooms.
In response to queries from ST, the National Environment Agency (NEA) said it is “timely to review and expand the monitoring capabilities” to measure not only the key physical, chemical and biological water quality parameters, but also other parameters such as radioactivity and hydrology.
Fully implemented in August 2014, the current system comprises a network of eight buoy-based monitoring stations located along the Strait of Singapore and Strait of Johor. It is now in its 11th year of operation.
Besides monitoring for pollution, the system is put in place for long-term water quality trend analysis and early warning for potential changes in water quality.
Each buoy functions as an on-site chemistry laboratory, continuously testing water quality and transmitting real-time results wirelessly to NEA.
It monitors a range of water quality, meteorological and hydrological parameters, such as the amount of dissolved oxygen, wind direction and water current speed.
But with the upgrade, the new sensors will monitor significant wave height and wave period – which is the time taken for one wave cycle to be completed – to support studies on the potential impact of climate change on local wave conditions, said NEA.
The upgraded system will also have new radiological sensors that monitor the radiation level in the water. This will complement existing air and water radiation monitoring stations deployed across Singapore.
The buoys will be slightly redesigned to accommodate the additional sensors and enhanced functionalities.
To improve operational efficiency, the buoys will be installed with an automated smart flushing system custom-designed by NEA to reduce biofouling on its sensors. Biofouling refers to the unwanted accumulation of micro-organisms, plants, algae or small animals on submerged surfaces.
The flushing system will lengthen the lifespan of the buoys and improve the quality and availability of data, said NEA.
Another enhancement is the use of a three-point mooring system for each buoy to reduce drifting radius during low tides.
The buoys will also be fitted with guard rails to better prevent seawater from seeping into the sensors and electrical housing compartments.
Data from the upgraded system will complement the Marine Environment Sensing Network (MESN), a multi-institution project that aims to set up three research buoys to monitor the marine environment, said Dr Jani Tanzil, facility director of St John’s Island National Marine Laboratory (SJINML).
MESN can deliver information on the condition of Singapore’s seawater, including temperature, salinity, acidity level and nutrients.
For example, data collected in 2024 alerted researchers to the mass coral bleaching incident during the marine heatwave.
While both systems support real-time monitoring of Singapore’s waters, Dr Tanzil said MESN focuses on data relevant to marine climate change science and is more targeted, with only three locations, as compared with NEA’s Neptune network, which has eight buoys.
“NEA’s network serves the very important purpose of making sure that our water quality standards around Singapore are met and will undoubtedly become even more key when it comes to monitoring for things like oil spills,” she said.
Besides cross-checking and filling gaps for data, she hopes the upgraded system will also complement MESN’s data in understanding the health of Singapore’s marine ecosystems.
NEA said: “While both systems are independent of each other, there is cross-sharing of knowledge and experience between NEA and SJINML on the use of water sensor technology, buoy designs and observations on water quality trends.”
According to Dr Tanzil, MESN currently deploys two buoys – off St John’s Island and Raffles Lighthouse – and plans to install the third one near Pulau Ubin in April.
With NEA’s upgraded system complementing the existing radiation monitoring sensors in Singapore, the agency can gain a complete picture of the background radiation and detect any abnormality from airborne or waterborne radioactive elements, said Dr Victor Nian, founding co-chairman of independent think-tank Centre for Strategic Energy and Resources.
“This is a timely implementation in view of the potential nuclear power projects in neighbouring countries,” said Dr Nian.
Five of the 10 Asean countries – Vietnam, Indonesia, Philippines, Malaysia and Thailand – are either studying the feasibility of advanced nuclear technology to meet their growing energy needs, or already have plans to build new reactors in the coming decades.
On the importance of renewing water monitoring sensors, Dr Tanzil said that as technology advances, more sophisticated monitoring tools are being developed that are more accurate, efficient and cost-effective, and require less maintenance.
She also emphasised the need to ensure that the sensors developed are suitable for Singapore’s coastal and dynamic waters. Sensors developed and tested in temperate or clearer water regions may not perform as well as predicted in the waters here.
Dr Tanzil added that renewing sensors will support long-term monitoring efforts, providing a clearer and more comprehensive picture of Singapore’s marine ecosystem in the years to come, while safeguarding the shared seas.