The venue’s two existing grease traps had reached the end of their life. They needed a single high-capacity replacement, new trade waste drainage, and full pipe replacement and all within a confined site that was still in operation. The work also involved new trade waste drainage and replacement sewer and stormwater pipes. All three systems needed connections near the driveway, beside an existing building.
Citi Industries replaced the traps and completed the related drainage work. The crew also dealt with buried services and restricted access.
Challenges
The Narrow Passage to the Driveway
Inside the venue, trade waste drainage ran near the toilets and bar. Outside, the new line followed a narrow space between containers and the main building before reaching the driveway.
Existing sewer and stormwater drains occupied the same section. However, the job called for both systems to be replaced with new PVC. Workers had to route the trade waste pipe around the two lines being replaced.
Containers and the building restricted access on either side of the passage. Its limited width affected how much room workers had for cutting, digging and positioning pipes.
Working Beneath Existing Concrete
The replacement tank and new drains sat below surfaces already covered in concrete. Cutting without checking first could damage the services buried underneath. The crew scanned for buried services before cutting.
Barricades kept pedestrians away from the work zone during cutting and excavation. The team needed to keep nearby walking routes separated while the ground remained open.
Solutions
Scanned, Cut and Removed the Old Traps
Workers scanned the concrete for buried services before cutting the areas needed for underground access. They lifted the affected sections and exposed the existing grease traps.
The crew decommissioned and removed both old units. Concrete waste went to an appropriate council facility, while the team cleared excess spoil from the site.
Installed the 2,000-Litre Trap and Trade Waste Connection
The team installed one 2,000-litre below-ground grease trap near the driveway. Because vehicles would pass over the installation, Class D lids were fitted to handle the load.
The City of Gold Coast required a separate manhole for grease traps deeper than 350 mm. Workers built one beside the tank for access to the buried equipment.
With the tank in place, the crew connected the new trade waste pipe to its inlet.
Replaced Sewer and Stormwater Pipework
Along the wall beside the main building, workers reran the sewer lines in new PVC towards the driveway.
The crew replaced the in-ground stormwater pipes with new PVC and installed a surcharge pit in the driveway. AS/NZS 3500 plumbing standards covered the drainage work. The Plumbing and Drainage Act 2018 and City of Gold Coast trade waste guidelines also applied.
Installed the 100 mm Grease Trap Vent
Workers installed one 100 mm vent for the replacement grease trap. The pipe ran along the wall and up the existing kitchen ventilation ducting route.
Added Backflow Protection and Washdown Water
Workers installed a 15 mm reduced pressure zone device, known as an RPZD. This backflow valve helps prevent contaminated water flowing backwards into the drinking water supply.
The team also fitted a new hose tap within five metres of the grease trap. That gave maintenance crews a nearby water point for washdown during cleaning.
Reinstated Concrete and Cleared the Site
Once the underground equipment and pipework were installed, the crew reinstated concrete across the affected areas.
Workers removed remaining spoil and cleaned the site.
Final Outcome
The venue finished with one 2,000-litre trap replacing its two old units.
For grease trap design, supply and installation on the Gold Coast, get in touch with our team. We also offer trade wastewater management services for connected drainage. Call 1300 002 484 to discuss your project.
1300 002 484
