In the Netherlands the drinking water distribution network contributes to about 120.000 km underground pipelines. In the 1950’s to the 1970’s the network expanded rapidly due to the expansion of urbanized areas and connecting rural areas. With an estimated average life time of around 70 years many of these pipes are expected to be in need of replacement in the next decades.
Traditionally pipes are replaced by using open trenches. However, in the light of the increase in replacements this may change. To ensure current service levels, replacement techniques will have to be balanced for relevant elements such as effectiveness, nuisance for the environment and costs. Dutch drinking water companies want to know when to use which technique, but currently have too few experiences with trenchless techniques to allow for a detailed analysis. Experiences are usually limited to a few kilometers or locations that are not representative for larger parts of the network. In addition, each company evaluates projects differently and relevant aspects such as environmental impact or nuisance were difficult to quantify, making it difficult to compare experiences.
Therefore, a project was carried out which included a pilot and evaluation program of innovative trenchless technologies, with pilots for innovative CIPP, close-fit and pipe-pulling technologies. The evaluation method was specifically designed to quantify aspects as costs, environmental impact and nuisance. All pilots were thus evaluated according to the same standards, for the first time allowing for comparison of results. The evaluation results were used to assess applicability of the different techniques in the drinking water network.
The evaluation method is generally applicable to replacement projects. Combining results from drinking water, gas and sewer networks, internationally, using this evaluation method enhances the use of innovations from different sectors into another and help the choice when to use which technique.