At the same time, the movement of people to towns and cities leads to an increase in construction of new residential buildings and commercial and industrial facilities, which requires an increase in capacity of the water supply network and, therefore, reconstruction of water supply systems. In 2014, the amount of used water treated corresponded to water used by 1.7 million persons. However, this number is theoretical since industrial wastewater is also included, but not measured, as is also water coming from various sources due to the deteriorated state of network.