Singaporean contractor Avenue Engineering Pte Ltd has been found guilty of flouting Earth Control Measures (ECM) regulations under the Sewerage and Drainage Act (SDA) and was fined $10,000 on 9 February 2021.
On 10 October 2020, silty water was discharged into a public drain from an ECM machine at Avenue Engineering’s construction site located at Tampines Avenue 12. This was captured by the Silt Imagery Detection System (SIDS) – a system that uses image analytic technology to detect silt discharge and sends automatic alerts to contractors upon detection.
Investigations by National Water Agency PUB revealed that the contractor had failed to ensure proper functioning of its ECM machine that treats silty water and did not take prompt action to stop the discharge immediately upon receiving notification from the SIDS. As a result, silty water was discharged into the public drain for two hours.
Since 2017, Avenue Engineering has committed a total of eight offences under the SDA, with six offences in 2018 alone. This amounted to almost $62,000 in fines for the company. Repeat offenders will face punitive measures such as tightened screening of their ECM plans and more frequent inspection of their sites. Heavier penalties of up to $50,000 could also be imposed on subsequent ECM offences.
Ensuring adequate ECM for construction sites
Silty water is generated when rainwater runoff mixes with exposed earth materials and soil at construction sites. Under PUB’s Code of Practice on Surface Water Drainage, contractors are required to plan and implement ECM at construction sites to contain and treat silty water (i.e. remove silt from the water) before discharging it into the public drains. Otherwise, silt will build up in the waterways, which will affect the waterways’ effectiveness in channelling stormwater flow, and aesthetics of the environment.
The ECM plan must be submitted to PUB for approval before construction work commences. Upon approval, contractors must monitor the silty water treatment process and stop silty water discharge from entering any public drain immediately upon detection.
“PUB reminds all contractors to implement proper earth control measures at their construction worksites to prevent silty runoff and keep our waterways free-flowing. We take a serious view of construction works that affect our public drainage system as silty discharge may result in the accumulation of sediment and affect drainage capacity, which could lead to flash floods in the event of heavy rainfall,” said Mr Yeo Keng Soon, PUB’s Director of Catchment and Waterways.
Currently, there are about 1,100 sites around the island involving earthworks and PUB conducts regular checks at these sites for compliance with ECM requirements. Depending on the stage of construction work and the size of earthworks, checks can range from fortnightly to once every two months. In the last three years, PUB has taken enforcement action against about 100 contractors each year for failing to comply with ECM requirements.