ABSTRACT
The quantity and quality of water delivered and used by households is an important aspect of
domestic water supplies, influencing hygiene and thus public health (Howard and Bartram,
2003). Fresh, clean water is commonly taken for granted as a basic commodity in most
European countries. Typically, the primary goal of public water supply organizations, e.g. in the
Netherlands, Ireland, or Sweden, is to achieve consumer satisfaction through high service levels.
Service level is indicated by the amount of downtime (lack of water) experienced by customers.
Downtime in water supply can occur due to several foreseen (e.g. scheduled maintenance work)
or unforeseen reasons due to disruptions (e.g. quality issues, but usually pipe breakages).
Organizations use proactive planning to try to avoid unforeseen disruptions by employing
redundant resources (additional pipelines, pumps, water sources, employees, etc.). This prevents
disturbances from reaching the final customer. In addition, maintenance activities are used to
detect possible weaknesses in the system in advance. Yet not all events can be proactively
planned for. A variety of restrictions hinder the ability of the water supply organization to
engage in proactive maintenance activities to try to avoid unforeseeable disruptions, e.g. the
relative inaccessibility of the distribution network due to its underground location.