Requirements specification

Requirements specification from public clients

The supply and installation of a system of watertight containers that can be assembled as modules into one or more interconnected watertight basins.

The size should ideally be manageable for individuals during installation. The aim is achieve a size of 700 mm x 700 mm x 615 mm and a maximum weight of 21 kg per unit.

Containers fit different pipe dimensions

The tanks must be joinable and watertight at the connection point where the pipe holes are no smaller than DN 500 mm. The basins must be able to undergo a pressure test at a maximum pressure of 0.15 bar, which must be verified by engineering calculations.

The tanks should be able to connect to different pipe dimensions from DN 110 mm up to a maximum size of DN 500 mm pipes directly into the basin.

After installation, it must be possible to replace individual containers without removing and reinstalling the entire basin. A repair unit is required to replace defective tanks.

One should be able to access the utility lines beneath the basins in case damage occurs to them.

The basins must be able to withstand a static pressure load of at least 100 kN per m2 when installed 40 cm
below ground level and must be able to be installed in at least a class DK T3 roadway.

The maximum deflection at the centre of the container’s surface when buried 40 cm in the roadway (10 cm asphalt and 30 cm stable) is 2 mm, and this must be documented.

It must be possible to clean the basins via a minimum pipe hole of DN 500 mm in all basins and the water
flow must be unobstructed throughout the entire 500mm diameter of the pipe hole.

For inspection purposes, the basins should be able to accommodate 500 mm and 425 mm diameter pipes
from the top of the basins.

The basins must themselves be waterproof and may not rely on external membranes to become watertight.

The basins should be able to accommodate a sand
fill layer or 2/5 gravel on the sides with a minimum
thickness of 20 cm and a 0-32 stabilised gravel layer

on top of the basins along with a 5-cm protective layer of stone-free material.

Stackable containers

The tanks must be able to be built around utility lines and still form an integrated basin without the use of pipes.

The tanks should be stackable to a height of 1,845 m (2,46 contact UWR) with the same pressure on the surface of at least 100 kN/m2 and where the top layer is located 40 cm below ground level. There should not be any limit to the width and length that the tanks can accommodate. The tanks should be set up as connected vessels, where the height can be divided into several independent basins.

The basins must be temperature independent and oil resistant as well as having a lifespan of more than 75 years. Documentation from a recognised independent GTS institute is expected.

There must be CO2 accounting for the modular basin, and it needs to be possible to describe how many tonnes of CO2 are recorded per m3 of installation.

Basins must be able to be installed to existing piping systems where all joints are oil resistant without any
presence of EPDM rubber.

Basins must be buoyant up to a width of 5.3 metres and a height of 1.845 metres. The buoyancy protection must be partially integrated into the basin with the excavation taking up no more than 15% of the basin width.

The tanks must be able to accommodate various accessories that can be integrated into the basins. The road runoff water should be able to be purified from, for example, PAH and heavy metals. It must be possible to insert, replace or access different cleaning filters from the inspection pipes into the basins.

Ideally, the tanks will be locally produced or with evidence of Danish labour where apprentices with Danish citizenship are part of the manufacturer’s setup.