Background

Full replacement of the Public Waste Collection System (PWCS)

After two decades of continuous operation, the PWCS at Blocks 296A–E and 297A–D CCK Ave 2 showed signs of aging. Greenwave undertook the reconstruction of the Pneumatic Waste Conveyance System (PWCS) at CCK Ave 2 which was HDB’s first estate to implement the PWCS.

  • The original PWCS system required a full rebuild to restore reliability and efficiency.

  • Reconstruction had to be carried out under full occupancy and near sensitive sites, demanding careful engineering and logistical planning.

Implementation Approach

Greenwave Solutions Pte Ltd was appointed to design and execute the upgrade, leveraging its specialization in environmental engineering.

The project scope covered full replacement of the vacuum pipe network, disposal chute interfaces, and central bin station equipment within the estate.

Despite the works being carried out during the COVID-19 period, the team met all safety protocols and even leveraged some lull periods to accelerate progress.

The rebuilding contract began in November 2019 with a 27-month timeline. By October 2021, the new PWCS was completed and commissioned — four months ahead of schedule.

The project team coordinated closely with the Town Council, HDB officers, and the nearby primary school to schedule works and communicate with residents.

Daily progress was managed to maintain site cleanliness and safety, exemplifying Greenwave’s commitment to stakeholder engagement and minimal inconvenience.

Importantly, the new system’s design also introduced improved features such as sturdier piping with proper supports and modern control systems, bringing this 1990s-era pilot site up to par with today’s PWCS technology.

Greenwave modernised Singapore’s first public housing PWCS estate with virtually no disturbance to residents’ daily lives.

In summary

Highlights

Live Environment, Zero Disruption.

  • Works carried out in occupied estate without relocating residents

  • Precautions for noise, dust, and student safety near primary school

Optimised for Space and Aesthetic Constraints.

  • Installed new high-durability pipes with concrete haunching for stability and longevity

  • Used “daily trench” method: excavate and install pipe sections during the work day, then cover the trench with steel plates every evening to restore the lane

  • Main PWCS trunk under fire engine access road, posing significant challenge

Maintaining Waste Services During Valve Replacement

  • One of the most complex tasks was the replacement of the system’s main discharge valve and lead-in pipes while residents continued using their rubbish chutes normally.

  • Greenwave engineered a temporary bypass and timed cut-over to minimise shutdown of refuse disposal

In summary

Highlights

Live Environment, Zero Disruption.

  • Works carried out in occupied estate without relocating residents

  • Precautions for noise, dust, and student safety near primary school

Upgrading Underground Pipelines

  • Installed new high-durability pipes with concrete haunching for stability and longevity

  • Main PWCS trunk under fire engine access road, posing significant challenge

  • Used “daily trench” method: excavate and install pipe sections during the work day, then cover the trench with steel plates every evening to restore the lane

Maintaining Waste Services During Valve Replacement

  • One of the most complex tasks was the replacement of the system’s main discharge valve and lead-in pipes while residents continued using their rubbish chutes normally.

  • Greenwave engineered a temporary bypass and timed cut-over to minimise shutdown of refuse disposal

Expertise in complex PWCS Projects

The success at Choa Chu Kang showcases Greenwave’s expertise in handling multifaceted projects. Greenwave is a leading specialist in pneumatic waste conveyance system with track records spanning new estate constructions and rebuilding, refurbish or retrofit in existing estates.