We at Trisoplast love a project that requires us to implement smart solutions to achieve the best possible result, and it’s even better if we are able to protect the environment at the same time. The C2 depot in Rijnmond was just such a project.

Dangerous situation

In the 1990s, hazardous chemical waste was disposed of in a huge concrete basin of 300 x 50 x 11 metres. This class of chemical waste, which includes products containing heavy metals such as used batteries, could not be incinerated or recycled. The C2 depot is operated by Rijnmond Waste Management. The basin is surrounded by a containment dike constructed of incinerator bottom ash. A giant movable roof was constructed above the basin to prevent rainwater getting into the waste. The roof was only shifted to a new section after the waste it was protecting had been covered with a temporary liner. This system proved to be sub-optimal and in fact very dangerous; in the late 1990s, some employees who had been working in the basin fell ill, and in 2002 the waste actually caught fire. This was enough reason to cease disposing waste here in 2005, and the remaining space in the basin was filled with bottom ash.

Win-win

The slopes of the containment dike around the basin were originally sealed with a layer of sand and bentonite. This layer had been corroded by the bottom ash in the dike and no longer met the impermeability requirements. So in 2002, Trisoplast laid a new liner on the containment dike, on top of the now-obsolete sand-bentonite layer. We conceived an innovative win-win solution that benefited both the customer and the environment. We did this by mixing a part of the existing sand-bentonite mixture with bentonite-polymer powder, which resulted in an extremely tough new sealing layer, without needing to bring in a lot of new sand.
To make the basin completely safe following its somewhat turbulent history, in 2011, some years after the basin had been decommissioned, it was decided to seal the top of the basin for the long term with a Trisoplast liner as well.