figure 1: the 5 cu m septic tank.

Continuing on in our series of articles with the theme “prevention of failures during service of structural plastic products” and in particular, underground tanks and chambers, in this article we appraise some of the common test methods applied to these products.

During the Nordic ARM conference held in Horsens, Denmark in February 2011, Martin and David, directors of Rota Design Limited, presented a case study involving the failure of a 5 cubic metre underground rotationally moulded PE septic tank. The tank didn’t fail, it imploded within hours of installation and many more followed. We presented the analysis of 100 projects taken a random from our files, which had been undertaken during recent years, and that alarmed us so much, it inspired us to write this series of articles.