Odour & Grease Control

Tank Assembly

All our tanks must be placed underground. The following steps must be carried out for this purpose:

1. Excavation

  • Dig a hole large enough to contain the tank, preventing it from coming into contact with the excavation walls.
  • Stabilize the excavation bottom

2. Installation

A layer of sand 20 cm thick should be laid on the bottom, after removing any elements that may penetrate the collection or make a concrete base if the ground is not strong enough or stable. The device should be installed at the bottom of the excavation and leveled exactly. Centre it in relation to the excavation. Note the direction of the foundation, take into account the direction of wastewater flow. The inlet and outlet are marked with arrows on the unit.

Connect the inlet and outlet tightly with pipes of the correct diameter. If necessary, install manholes on the ground. For this purpose, use our polyethylene extension or steel adapter for a cast iron manhole.
Use sand or sandy material for backfilling the tank. Covering should be carried out symmetrically in successive layers compacted by pouring.

Fill with clean water during backfilling to balance the pressure. The backfill should be finished with soil, free of stones and sharp objects. Maximum filling height above the device: max. 50 cm.


Generally, there are different types of installations (the main cases are described below). The description provided is for information purposes only.
Depending on soil testing and specific cases, we advise you to contact a specialized design office.

Movement of vehicles or installation of the tank at a depth of more than 50 cm

It is forbidden to drive vehicles, parking and storing heavy loads on the tank; otherwise, it is necessary to use a plate ensuring distribution of forces. Its thickness and reinforcement depend on the load. This panel protrudes beyond the edges of the trench and rests on a load-bearing, intact natural ground.
After stabilizing the backfill, reinforced concrete slab should be set, adjusting the hatches so that the surfaces of the holes are at least exposed without contacting the walls or the upper part of the tank. As a result, to limit the stress to which the tank is subjected, the plate must absolutely rest on a stabilized surface around the tank. At least 5 cm of free space should be left between the tank and the relief plate.
Note: backfilling should be made using stabilized sand, dosed as 200 kg of dry cement / m3 of sand.


If there is a ground water table, lower the ground water level and use the anchor kit to secure the tank to the concrete base as shown below. Fasten the threaded rod through the chemical anchor in the concrete bases or attach the steel cable to the reinforcement of the concrete base. A PVC drainage well with a diameter of 315 mm should be installed in the embankment as close to the tank as possible to visualize the level of the ground water table.
During maintenance operations, especially emptying, the groundwater level can be lowered by pumping it into the drainage well.


Build a retaining wall to protect the tank against lateral pressure.


Before being put into service, the hydrocarbon separator must be filled with clean water up to the line indicating the water level.