As a Thessaloniki prosecutor yesterday launched an investigation into the collapse of the public water supply in Greece’s second largest city, experts told Kathimerini that the local water board had known for at least four years that the main pipe serving the city was dangerously corroded. The pipe, which carries water to the northern port city from Aravissos, some 75 kilometers (46 miles) to the west, broke in two places on Tuesday afternoon, halting the water supply to large areas of Thessaloniki. The local water board (EYATH) said it would have repaired the damage by late yesterday, although parts of the city – whose population exceeds 1 million – were not expected to have water until tomorrow. Prosecutor Panayiotis Ioannidis ordered a preliminary investigation, instructing judicial officials to establish whether charges should be brought against EYATH officials. But experts told Kathimerini yesterday that EYATH had been officially notified as early as 2000 that the Aravissos pipe was badly corroded at the point where it ruptured on Tuesday, in the industrial area of Sindos some 13 kilometers west of the city center. According to Professor Georgios Penelis, head of Thessaloniki University’s Reinforced Concrete Laboratory, corrosion of the Aravissos pipe started some 12 years after its construction in 1975. The 1,500-meter stretch of the pipe that goes under Sindos was gradually eaten away at points by industrial waste from neighboring factories and pesticides used by local farmers, Penelis said. «We looked into the possibility of the damage having been caused by excessive use of chlorine in the water, but concluded that external factors were to blame, mainly pesticides and industrial waste,» he said. This resulted in a series of smaller or larger ruptures, the worst of which was in 1995, when the problem was about as acute as it is now. EYATH officials asked the laboratory to prepare a study on the situation, which recommended that the entire Sindos stretch of the pipe should be replaced. However, EYATH rejected that proposal as too costly. In 2000, laboratory experts tabled an alternative proposal, which called for the pipe’s corroded metal reinforcement rods to be replaced with more resistant materials. According to Penelis, EYATH totally ignored the study.