NEA traces green water in Yishun canal to ink-contaminated wash water

SINGAPORE: The National Environment Agency (NEA) has attributed the discolouration of water in a Yishun canal to wash water contaminated with water-based ink.

The incident was first noticed on 16 August and again on 23 August, when residents reported green-coloured water pooling in a canal along Yishun Close. NEA confirmed that the water has since returned to normal and said it continues to monitor the area closely.

In a statement issued on 27 August, the agency said it was investigating the source of the discharge and considering appropriate enforcement measures.

Investigation and enforcement actions

Under Singapore’s Environmental Protection and Management (Trade Effluent) Regulations, it is an offence to discharge pollutants into any watercourse without written approval.

Those found guilty of such offences may face fines of up to S$20,000 for a first conviction. Repeat offenders may be fined up to S$50,000 or jailed for up to three months.

NEA said it is working to determine the exact source of the contaminated wash water and to identify whether it originated from industrial, commercial, or residential premises nearby.

“We take a serious view of such illegal discharges, which can harm aquatic ecosystems and affect water quality,” the agency said.

Residents raise concerns

Nee Soon GRC Member of Parliament Jackson Lam said on 26 August that residents had alerted him to the unusual green tint in the canal water.

He contacted NEA to verify the cause and shared photographs of the discoloured canal in a Facebook post that evening.

The images showed a stretch of the canal with bright green water, contrasting sharply with the surrounding concrete banks and vegetation.

“The matter has been escalated to the relevant authorities, and NEA is looking into it,” Mr Lam wrote.

Previous cases of water discolouration

The Yishun incident follows several cases of unusual water discolouration across Singapore in recent years.

In March 2025, a canal in Tengah turned brown when accumulated silt was stirred up by heavy rain during a monsoon surge.

A year earlier, in 2024, water in a canal near Newton turned bright blue, prompting public concern. At the time, national water agency PUB clarified that there were no abnormalities detected downstream in the Bukit Timah Canal or in Marina Reservoir.

Such incidents, while visually striking, are typically isolated and temporary. However, authorities stress that unauthorised discharges remain a concern due to potential environmental harm.

Ongoing monitoring and public advisories

NEA said its officers will continue to monitor the Yishun site to ensure no recurrence of contamination.

The agency also reminded members of the public and nearby businesses not to dispose of any chemical or paint residues into open drains or water channels.

“Proper waste disposal and responsible management of industrial effluents are essential to maintaining clean waterways,” NEA said.

Residents who observe any unusual water discolouration or discharge are encouraged to report it immediately via the myENV mobile app or the NEA hotline.