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Wastewater Surveillance Programme

The National Environment Agency (NEA) operates a wastewater surveillance programme for tracking and early warning of infectious disease transmission, in partnership with the Communicable Diseases Agency (CDA) and supported by the National Water Agency PUB. Initiated in February 2020 to monitor COVID-19 transmission, the sampling network now covers more than 500 sites across Singapore. Data from the network supports situational awareness, risk communications and public health measures.

 Why Wastewater Surveillance?

Individuals infected with certain pathogens shed the pathogen’s genetic material in bodily discharges such as urine, stool, and sputum, which enter wastewater in sewage systems. The genetic material in wastewater can then be detected and analysed in NEA’s testing laboratories.  

Wastewater surveillance is non-intrusive and has the potential to capture data from a community, including mildly symptomatic or asymptomatic individuals who may not seek medical care. This complements clinical surveillance to provide a more complete assessment of community-level disease trends.

Pathogens Under Surveillance  

Pathogens are selected for monitoring in wastewater based on factors such as public health significance and technical feasibility. Examples of pathogens under surveillance include:

We track SARS-CoV-2 virus levels and variants circulating in the community. Analysis has demonstrated strong correlation between wastewater viral loads and reported COVID-19 cases. The data provides early indicators of infection trends and helps identify emerging variants of concern.

Related studies:

Since mid-2023, the programme has expanded to include Zika virus surveillance in wastewater as part of an integrated approach to vector-borne disease monitoring, complementing case and mosquito surveillance. This enables early detection of potential transmission and supports targeted public health responses. For more information on Zika, visit NEA’s Zika webpage.

Related publication(s):

 

Equipment and Installations

The programme uses wastewater autosamplers strategically deployed across Singapore's sewage network. These autosamplers collect wastewater at regular intervals, ensuring consistent data quality and coverage. Sampling sites are carefully selected based on catchment characteristics and operational requirements.

Autosampler used for wastewater sampling

Wastewater Autosampler

You may notice our equipment installations in your neighbourhood, pictured below. To ensure public safety and equipment security, autosamplers are deployed within a housing, with some long-term deployment sites also featuring protective hoarding structures.

Setup of NEA Wastewater Surveillance Programme at a selected site
Setup with Safety Cones and Safety BarsSetup with Hoarding
Setup with Safety Cones and Safety BarsSetup with Hoarding

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