The impact of the state of drinking water supply networks on the quality of water intended for consumption

ანოტაცია

The suitability of drinking water for drinking depends not only on the source and purification system, but also on the quality of the water supply facilities. In fact, the quality of drinking water is significantly deteriorating due to the dilapidated state and lack of maintenance of drinking water supply networks. Most of the drinking water supply networks in different cities are aging. Despite the efforts made by the company responsible for the purification and distribution of water to make the water suitable for drinking, the water in consumers' taps is often colored, has an unpleasant taste and settles after collection. As a result, people are concerned about the suitability of tap water for drinking, and some turn to alternative sources of drinking water of unknown quality. In order to determine the factors responsible for the deterioration of the color and taste of water, as well as the most affected areas of the network, diagnostics of the network equipment were carried out. Water samples taken from the network were analyzed for color and turbidity. Diagnostics showed that most of the equipment (suction cups, valves, drains and fire hydrants) are outdated and irregularly maintained. The analyses show that water is more colored in cast iron and PVC pipes than in asbestos-cement pipes. The color values ​​in the network vary from 0 to 27 UVC for asbestos-cement pipes, from 15 to 56 UCV for ductile iron pipes and from 11 to 102 UCV for PVC pipes. On the other hand, the turbidity values ​​vary from 8.02 to 3.32 NTU for ductile iron pipes, from 8.51 to 16.98 NTU for asbestos-cement pipes and from 0.9 to 6.98 NTU for PVC pipes. Old cast iron pipes release iron ions when in contact with water, which deteriorates their color. Old cast iron pipes release iron ions into the water, which deteriorates its color. High color values ​​observed near drains are believed to be due to irregular network maintenance. In fact, after network maintenance, a decrease in turbidity of 2% to 73% is observed, while for color, this figure varies from 5% to 72%. In short, network aging and irregular maintenance contribute significantly to the deterioration of water quality.