Metering the quality of water supply and sewage network maintenance services

In most European countries as well as in Finland the responsibility for arranging water supply and sewerage services is by law vested in municipalities, including water and sewage network maintenance. This does not, however, mean that municipalities have to produce maintenance-related services completely by themselves. Outsourcing of these services to another service provider, public or private, may provide new innovations and improve productivity also in network maintenance. The water and sewer networks constitute an enormous mass of public property which operation is vital for communities' everyday life. In Finland, as in many other countries, the renovation need of water networks is increasing rapidly. If a maintenance contract is concluded with a service provider, the quality of maintenance services' must be measured somehow to make sure that the public property value and technical properties do not deteriorate during the maintenance contract period. In addition, the Finnish purchase law for special industries like water services requires a buyer to treat service providers as equal and not to discriminate them when tendering. This often calls for different kinds of qualitative and quantitative indicators. The metering of maintenance service quality is difficult in all industrial sectors. Special challenges in water and sewer networks are caused by the fact that the object being maintained is mainly buried underground, thus out of sight. An additional challenge is caused by the slow progress of network deterioration; the maintenance activities carried out or those being neglected do not necessarily cause any significant changes in network performance in the short run. In the worst case a deteriorated network may cause problems and interruptions in water services even if the maintenance partner has carried out all the investments and renovation activities that have been agreed among the contracting parties. Traditional key figures that are monitored from the networks, like leakage rate in water and sewer systems and number of leakages and blockages, do not provide a solid basis for maintenance service quality assessment. The leakage rate in sewer system is highly depending on the e.g. rainfall and water system leakage rate can be affected by a part of the network that is not on the service provider's responsibility. Therefore some additional means of service quality metering must be considered