Underground containers

Although they differ considerably in construction from other solutions, they formally belong to the same department as other waste containers. Underground containers are a system solution used in modern residential estates and urban spaces where aesthetics are a priority: most of the structure is concealed below ground, with only a small insertion column visible on the surface. This is the preferred solution for developers and managers of prestigious residential schemes, where conventional bin stores would spoil the look of the surroundings.

Installing an underground system involves a higher initial cost than above-ground containers because of the foundation works, but in the long term it reduces maintenance costs and improves the appearance of the surroundings.

The market offers single-chamber systems, dedicated to a single waste stream, as well as banks of several chambers placed side by side, providing full segregation at a single point. The underground structure is usually made of galvanised steel or precast concrete. Both solutions are designed to ensure watertightness, resistance to ground pressure and resistance to moisture over many years of service without the need for structural intervention.

Installation involves excavating to the appropriate depth, setting the tank on a prepared foundation and connecting a drainage system that prevents rainwater from accumulating inside the chamber. Emptying is carried out by a specialist vehicle equipped with a hook crane, which lifts out the inner container without the need to dig up the entire installation. The collection cycle must be agreed in advance with the waste collection operator for the area.

Concealing most of the capacity below ground brings measurable hygiene benefits: it limits access to the waste by rodents and birds, reduces unpleasant odours on hot days and protects the contents from direct sunlight, which slows the decomposition of bio-waste. For residents, it also means less noise when depositing waste compared with metal above-ground containers.

Underground systems increasingly appear in the documentation of new development projects as early as the site layout design stage, as they allow the waste collection point to be planned without reserving a separate, visible area for a bin store. The collection point can then form part of a footpath or car park, practically unnoticeable to passers-by.

The insertion column visible on the surface is usually designed in vandal-resistant material, most often stainless steel or powder-coated galvanised steel, with a mechanism limiting the amount of waste deposited at one time. This prevents the upper part of the installation from being clogged with large cardboard boxes or bags, which would otherwise block access for other residents using the same point during the day.