The plastic seepage screen was selected on the basis of its flexibility in applications. Due to the light weight and interlocking system, the seepage screen can easily be inserted in the soil. To avoid damage caused by seepage in the municipality of Woerden, a depth of 7.5 metres and a length of 165 metres was sufficient. However, depths up to twelve metres are possible as well. Apart from the ease of insertion, the municipality of Woerden also selected plastic due to its environmentally friendly characteristics. The seepage screen is made from one hundred percent recyclable plastic, which can be recycled up to six times. As such it complies with the cradle-to-cradle principle. Moreover, the screen is virtually maintenance-free and has a very long lifespan of a minimum of fifty years. This long lifespan is related to the fact that no corrosion will occur, as with steel dam walls, and the screens are rot-proof and rodent free.
As such the plastic seepage screen, contrary to hardwood and steel, fully complies with the sustainable procurement policy of municipalities and authorities. After all, sustainability during all phases of the procurement process of municipalities and authorities is of increasing importance. This is emphasised by the new national procurement law, which stipulates guidelines related to the MEAT-specifications (Most Economically Advantageous Tender). Here, not only the price is important, but the quality of the construction is taken into consideration as well. Reduction of nuisance.To ensure that residents would be hindered as little as possible by the insertion, a preliminary test was successfully conducted whilst inserting the seepage screen without a vibration process. By drilling first, the seepage screen can simply be pushed into the soil, without damaging the seepage screen. Because no vibrations occur with this installation technique, no damage to walls or window frames will be incurred by the surrounding houses.
Moreover, Profextru developed a method to guarantee the watertight properties of the seepage screen. Jointly with Van Schie and an external agency extensive tests have been completed. The external agency will be conducting a permanent leak detection test. This makes the plastic seepage screen a sustainable alternative to bentonite walls.