Limited site access can determine how a grease trap installation needs to be completed. A commercial food service business in Acacia Ridge needed a new below ground trap, yet the only route to the tank ran through a tight pedestrian path. Several existing underground services ran beneath the walkway and needed to remain undisturbed.
So the operator engaged Citi Industries to install the grease trap and fit out the kitchen. The real test was getting the pipework in by hand, without striking a single live line.
Project Overview
This grease trap installation combined external groundworks with a full internal kitchen fit-out. The external works centred on a 1000-litre below ground trap, while the internal works brought water and waste to every fixture. Because a narrow walkway blocked machine access, much of the digging happened by hand.
The team also had to work carefully around several existing underground services. Each existing line had to be located and worked around as the new pipework went in.
Key scope items included:
- A 1000-litre below ground grease trap with a Class D vehicular traffic lid
- Concrete scanning, cutting, removal, and replacement across the groundworks
- Trade waste drainage installed as per the hydraulic plan
- Vents to atmosphere for both the tank and the new trade waste line
- A new trade waste line inside the tenancy connecting all fixtures
- Hand excavation through the narrow walkway around multiple existing services
- One RPZD backflow valve on the closest hosetap and one bucket trap in the kitchen
- A full internal fit-out with a new 80-litre Vulcan electric hot water unit
Challenges
A commercial kitchen cannot open until its trade waste system is compliant and connected. In line with Urban Utilities trade waste guidelines, that means a sized grease trap and correctly run drainage. The main challenge was physical access. The team needed to find a safe way to reach the tank position.Â
The walkway was too narrow for an excavator, so the crew had to dig by hand. Hand excavation was slower, yet it gave the control that a congested site demanded. As a result, the team could feel their way around each buried line rather than risk a machine strike.Â
Multiple services ran beneath the path and the team had to work safely around each one. Scanning the ground first mapped where they sat, which guided each careful dig.
Key constraints on this project:
- A narrow walkway ruled out machinery and forced hand excavation
- Multiple existing services ran through the only route to the tank
- Each buried line had to be located and worked around, not disturbed
- Concrete scanning preceded every cut to confirm what lay below
- Pedestrian traffic meant barricading stayed up across the works
Pedestrian traffic meant barricading stayed up across the works
Solutions
Citi Industries planned each stage around the site’s restricted access and existing underground services. Each stage below reflected the tight, service-heavy conditions.
Scanning and Hand Excavation
To begin, the crew scanned the concrete and the ground to map every buried service. With those lines marked, they cut the concrete and dug the walkway section by hand. Hand digging lets the team expose each existing service gently and keep it intact.
This patient approach is central to our grease trap design and installation work on congested sites. Using machinery or rushing the excavation would have increased the risk of damaging existing services.
Setting the Below Ground Trap
Next, the team installed the 1000-litre trap with its Class D lid. A grease trap is a buried chamber that captures fats and oils before they reach the sewer. The Class D lid handled vehicle loads, which suited the trafficked location.
Once the tank was seated, the crew reinstated the concrete over the groundworks. Our below ground grease traps range covers this common tenancy size.
Trade Waste Drainage, Venting and Bucket Trap
The team then installed the trade waste drainage connecting the kitchen fixtures to the grease trap. The crew ran the trade waste line through the walkway and into the tenancy, connecting each fixture per the plan. Both the tank and the trade waste line were vented to the atmosphere.
Proper venting is a requirement under Queensland regulated plumbing work requirements. The team also fitted a bucket trap in the kitchen, catching solids at floor level before they reached the drainage.
Backflow Protection and Internal Fit-out
Finally, the team completed the internal works and protected the water supply. They fitted an RPZD valve on the closest hosetap, blocking any backflow into the mains. The crew then roughed in cold and hot water, ran the sanitary plumbing, and connected the basin, wash sink, cleaners sink, and tapware.
To finish, they mounted a new 80-litre single-element Vulcan hot water unit in the cleaners room. That unit now serves the commercial kitchen with a reliable hot supply.Â
Final Outcome
Despite the restricted access, the team completed the pipework and delivered a compliant commercial kitchen. Citi Industries completed the Acacia Ridge installation in December 2025 without damaging a single existing service. As a result, the kitchen discharges legally and the fixtures all draw a proper water supply.
- A 1000-litre below ground trap installed via careful hand excavation
- Every existing service located, negotiated, and left intact
- Trade waste drainage and venting completed to the hydraulic plan
- RPZD valve, bucket trap, and an 80-litre hot water unit all commissioned
The completed system meets current trade waste and plumbing requirements and is ready for inspection. The reinstated walkway looks as it did before the dig began.
Final Thoughts
A tight, service-heavy site does not have to mean a compromised install. The right method, in this case patient hand excavation, protects what is already in the ground. However, that outcome depends on scanning first and digging with care.
Citi Industries assesses site access and existing services before excavation begins. This approach reduces the risk of service strikes, damage and unnecessary repair work on congested sites. The team locates every service, works around it, and still delivers a compliant kitchen.
If your site is tight, buried in services, or hard to reach, the team can plan the safe route in. Book a site assessment and we will map the services and the works before anyone digs.
Call Citi Industries on 1300 002 484 to discuss your project.
1300 002 484
