This research activity demonstrates that materials used in water distribution systems are part of the overall treatment process that affect the water quality which consumers drink at their tap. The interaction between water and the infrastructure used for its supply are fundamental in producing safety drinking water. Subtle reactions between water and different materials used for its transport can affect the finale quality delivered to consumers. The study, developed in the period June 2009 – June 2011, in a project regarding safety of drinking water distribution systems in some municipalities from Romania, demonstrated that materials used in drinking water domestic installations have a major contribution in the deterioration of water quality supplied by local distribution operators. In some locations, in first draw samples collected in the morning from kitchen cold taps were detected high quantity of Cu, Fe, Ni and Pb correlated with materials used in internal distribution system (Cu pipes, Pb pipes, PVC pipes, branch pipes, cast iron and unprotected steel pipes, Ni-Cr plated taps). The main causes are the process of water stagnation and the lack of maintenance of the internal distribution materials. For samples were collected with fully flushed procedure, the quality of drinking water was better, the number of non-compliance samples decreased with 50%. The customers were advised that, it be not recommended to use the first draw water for cooking and drinking purpose. Recommendations in cases of exceeding the limit values of metals in drinking water were either flushing water for more than five minutes and then use water for household consumption or replacement of pipes and fittings in both, local or domestic distribution systems.

Aluminum salts are widely used across Romania in surface water treatment as coagulants. It is well-known that the efficiency of these coagulants has a complex dependency on the nature of the raw water, being affected by temperature, pH, and suspended solids. The objective of this case study was to compare the coagulation-flocculation efficiency process of raw water from the Bega River, at low temperature and turbidity, taking into account the use of alternative coagulating agents such as alum, poly aluminum chloride (PAC), and their mixing in 1:1 ratio. The raw water samples were treated using "Jar test" procedure, comparable with the current plant conditions at Timisoara Waterworks and taking into account possible operational improvements. For the mixture method applied in which was combined alum and PAC in 1:1 mixing ratio were achieved lower concentrations in aluminum residual, TOC, and turbidity.

The aim of the study was to identify the risk prevalence of relevant metals in in-building installation systems in Timisoara City. In the study were collected more than 250 tap water samples in order to get an overview of the overall current contamination level of drinking water at the point of consumption. In the monitoring program were included three water plants, fifteen points from the control program of the company, thirty-three tap waters (first draw and fully flushed sampling procedure) and thirty-two tap water samples (random daytime sampling). The quality of drinking water produced by AQUATIM Company was in accordance with the European Directive 98/83/EC requirements. In samples collected from customer’s tap the percent of non-compliance samples was around 50% in first draw, 10% in fully flushed and 25% in random daytime samples. The domestic distribution systems have an important influence to the quality of drinking water delivered by the AQUATIM Company.