Cabramatta is a busy and bustling community located in south-west Sydney. This multicultural area is abundant with packed restaurants, local retail and commercial businesses. The streets are filled with vehicles and pedestrians in almost every direction. The task of completing emergency sewer rehabilitation within the heart of Cabramatta was always going to be a major challenge.
On arrival at Hughes Street, the Insituform team walked inside a commercial arcade and into a law firm where they found a newly installed floor with a maintenance hole (MH) lid inside the office room floor. They then walked down to an underground car park, and to their surprise, found the bottom of the MH, and both the 150 mm and 300 mm ductile iron pipes hanging off the ceiling of the top level of the double storey car park. There was a gaping hole in the wall where it was evident raw sewage was flowing behind it with residue marks penetrating through the bricks. The Insituform crew knew they had to react quickly or this could result in a significant environmental issue.
Initial CCTV footage revealed cracks and an open joint allowing sewage to escape from the 300 mm pipe. The MH was also leaking and urgently required sealing. In addition, the 150 mm pipe had a dead-end on it, which was found to be inside the next building over newly laid tiles inside a renovated kitchen. Fortunately, this line was found to be in good condition, narrowly avoiding a further major community relations challenge.
Due to the high flows and location of the MH inside the law firm office, night work was required for the lining activities. To make the job even more challenging, Insituform also had to get access to a buried MH to line from busy Arthur Street.Article continues below…
Community consultation, access, and flow control were the main challenges of this emergency job. To overcome these challenges, Insituform organised a consultation meeting with the legal firm, building manager, civil crew, traffic controllers, and client representative. All parties discussed concerns surrounding access time frames, noise, sewer odour, and security impacts.
An agreed two-day plan was put in place to:
- Crack open the MH lid inside the law firm at 7 am on Tuesday before the office opened up for business
- Excavate and raise the buried MH in the road on Tuesday
- Line the sewer pipe on Tuesday night between 7 pm to 5 am
- Restore and seal MHs on Wednesday morning.
The lawyers agreed to provide Insituform access into the building at 7 pm for lining activities and lock up the office at completion of night work.
However, on the night of lining, the work almost didn’t go ahead, when the crew turned up to site at 7 pm to find the law firm locked up with no one in attendance. After several unsuccessful attempts to contact the tenant, Insituform’s team expected the worst – the crew would have to pack up site and postpone the works.
And then, the unexpected happened. At 11 pm, the legal firm contacted Insituform advising that a representative was on his way to the office to unlock the door – a major relief for the crew! The race against the clock then began. Despite the rain and access delay at the start, works could immediately proceed as planned. Insituform lined the 300 mm pipe using their iPlus Infusion CIPP tight-fit method. Final CCTV showed that the newly rehabilitated 300 mm pipe was completely renewed and sealed. Similarly, the leaking MH was also rectified as part of the works to completely address the issues on the site.
Thank goodness for trenchless solutions!