Helensville Primary - Blk 14, Site: Drainage Remediation

⁠⁠⁠Field Drainage

• CCTV investigation and hydro jetting has been carried out to map out the school’s entire stormwater and wastewater network. Further work is required to address the drainage issue the school is experiencing on the playing field.
• Engage with a drainlayer to scope the works required.
• Excavate and install lateral drains.
• Include gravel bands.
• Dispose of soil
• Expose, remove and install modern approved subsoil drainage systems to replace the older style subsoil drain.
•  Install Verti drain.
• Seed playing fields with grass seed.
• Apply fertiliser

Kowhai Block

CCTV investigation and hydro jetting has been carried out to map out the school’s entire stormwater and wastewater network. Further work is required to address the drainage issue the school is experiencing around Kowhai Block.

As per CCTV investigation, the stormwater drain suffers from a broken pipe and major cracks. within, causing blockages (cesspit 23 towards track line 4)

- Cut and remove the hard surface.

- Excavate down to locate marks.

- Cut and remove the affected sections by approximately 8-meters.

- Replace the removed section with a new PVC pipe.

- Backfill.

- Reinstate with plain concrete / hot mix asphalt.

- Upon completion, we will remove spoil.

Cesspit 15 towards 25

- Establishment.

- Hydro jetting the pipe clean.

- Cut and remove hard surfaces.

- Excavating down to defective earthenware joint displacement, cracks and root ingress.

- Expose and remove the defective earthenware root intrusion section.

Install x1 150mm 13-meters of CIPP Liners to seal the cracks, root intrusion and joint displacement section.

- Backfill with Hardfill and compact.

- Reinstatement of hard surface as required.

- Upon completion, remove spoil.

- Post-construction CCTV.

- Disestablishment