SINGAPORE - Two local contractors have been heavily fined for silty water discharge and inadequate earth control measures.

Chye Joo Construction and The Builders (Hup Huat) were fined $30,300 and $14,400 respectively this month, the PUB said on Thursday (May 23).

The offences, committed between October and December last year, were uncovered during the PUB's regular site inspections and after public feedback.

The agency said the contractors have since tightened their earth control measures, and silty water is no longer flowing into drains.

Earth control measures are implemented at construction sites to safeguard Singapore's water resources by ensuring that silt is not washed from exposed earth into the waterways after rain.

Chye Joo Construction built undersized silty water treatment plants and holding ponds at two work sites in Jalan Gali Batu and Jurong Road, which were up to six times and 22 times undersized respectively. This caused silty water to overflow into the roadside drains and waterways.

At the Jalan Gali Batu worksite, the water contained a concentration of suspended solids that was almost 400 times higher than the permitted limit. The company also allowed silty water to overflow onto the footpath and into the roadside drains along Mandai Road.

In another worksite at North Buona Vista Drive, it allowed silt to build up within a treatment plant, causing it to overload and discharge silty water into a nearby drain.

Other offences include failure to install a perimeter drain to channel surface runoff to a holding pond

As for The Builders (Hup Huat), it did not build a large enough silty water treatment plant in its Fernvale Street work site.

Cut-off drains were not constructed to contain silty water within its Fernvale Street and Tampines Ave 5 worksites. There was also no CCTV system to monitor the quality of the water before it was discharged into the drains.

Said the PUB: "All contractors are required to plan and implement earth control measures at construction sites to contain and remove the silt from the water before discharging it into the public drains. If not, silt will build up in waterways, adversely affecting their effectiveness in channelling stormwater flow."

Currently, there are about 1,000 construction sites islandwide that involve earthworks.

The PUB conducts site checks every two weeks or once every two months - depending on the stage of construction work and the size of earthworks - to ensure that they comply with earth control measures.

The agency has taken 100 contractors to task each year in the last three years for failing to comply with earth control measures.

The public can report sightings of silty discharge or pollution in drains and canals to the PUB's 24-hour Call Centre at 1800-CALL-PUB (1800-2255-782), together with details of the location, as well as photos and videos.