Replacement of AC mains: Combining several sources of information on the condition

The water distribution network in the Netherlands consists for 29% of asbestos cement (AC) mains. Water companies expect that in the coming decades an increased number of AC mains will reach the end of life, resulting in a strong increase of the volume of mains to be replaced and consequently a significant increase of investments. As data on the condition of AC mains is scarce, combining information from different sources is the most efficient way to move forward. In this paper the characteristics of AC mains in the Netherlands and the most important factors affecting the condition are described. A description of the most important sources of information for the condition of AC mains, combined with research results, are given. The information sources are burst registration, phenolphthalein tests, non-destructive inspection and expert knowledge. Combining information on the condition of AC mains effectively, provides the most important input for software models that support water companies in making effective decisions on mains replacement.